JP2016038595A - Power adjustment device and power adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a power balance between three phases in a stationary state.SOLUTION: A power adjustment device comprises control units 1R, 1S and 1T controlling electric heaters using R, S and T phases, respectively and an upper/lower limit value calculation function unit 2. The upper/lower limit value calculation function unit 2 includes: measurement units 21R, 21S and 21T measuring power consumption of electric heaters of R, S and T phases, respectively; a maximum/minimum power detection unit 22 detecting the maximum power and the minimum power; an upper/lower limit correction value calculation unit 23 calculating, when difference between the maximum power and the minimum power is a threshold or more, an operation amount upper limit correction value of a control loop of a phase for which the maximum power is detected on the basis of any operation amount MV_R', MV_S' or MV_T' of the control loop of the phase for which the maximum power is detected; and an upper/lower limit value output unit 24 outputting the operation amount upper limit correction value to an upper limit input unit of the control loop of the phase for which the maximum power is detected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power adjustment device and a power adjustment method for improving a power balance among three phases of three-phase alternating currents of R phase, S phase, and T phase.

  With the revision of the law caused by the global warming problem, there is a strong demand for energy usage management in factories and production lines. Since heating devices and air conditioners in factories are equipment devices that use a large amount of energy, they are often managed so that the upper limit of the amount of energy used is lower than the original maximum amount. For example, in an equipment device that uses electric power, an operation is performed in which the electric power demand management system restricts the electric power usage to within a specific amount of electric power consumption based on an instruction from the electric power demand management system.

  Especially for heating devices with multiple actuators (electric heaters), power sum suppression is required to suppress the total power supplied at the same time when starting up (when simultaneously raising the temperature of the area where multiple electric heaters are installed) Control (see Patent Document 1) has been proposed. FIG. 6 is a block diagram showing the configuration of the heating device disclosed in Patent Document 1. In FIG. The heating device is heated by a heat treatment furnace 100 for heating an object to be heated, electric heaters H1 to H4 that are a plurality of control actuators installed in the heat treatment furnace 100, and heaters H1 to H4, respectively. A plurality of temperature sensors S1 to S4 that measure the temperature PV of the control zones Z1 to Z4 in the heat treatment furnace 100, a power sum suppression control device 101 that calculates the operation amounts MV1 to MV4 output to the heaters H1 to H4, and power It is comprised from the electric power regulators 102-1 to 102-4 which supply the electric power according to operation amount MV1-MV4 output from the sum total suppression control apparatus 101 to heater H1-H4, respectively. In the heating device shown in FIG. 6, four control loops for controlling the temperature PV of the control zones Z1 to Z4 are formed.

  The power sum suppression control apparatus 101 receives information on the allocated total power PW that defines the power usage of the heaters H1 to H4 from the host PC 103, which is a computer of a power demand management system that manages power, and consumes each control loop. The power margin of each control loop is calculated from the power value, and the manipulated variable output upper limit values OH1_1 to OH1_4 of each control loop are calculated based on the ratio of the power margin of each control loop to the total power margin and the allocated total power PW. . Then, the power sum suppression control device 101 calculates the operation amounts MV1 to MV4 of each control loop by PID control calculation, and executes an upper limit process for limiting the operation amounts MV1 to MV4 to the operation amount upper limit values OH1_1 to OH1_4 or less. Thus, the manipulated variables MV1 to MV4 after the upper limit processing are output to the power adjusters 102-1 to 102-4 of the corresponding control loop. Thus, by operating the operation amount upper limit values OH1_1 to OH1_4, it is possible to suppress the total power at the time of recovery in applying a disturbance to a specified value or less.

  According to the technique disclosed in Patent Document 1, the power consumption of the actuator (electric heater) is controlled by PID control during steady state (steady state) other than when the temperature is raised during temperature control (such as a large output for suppressing disturbance). Since it becomes an arbitrary intermediate value (a value away from the upper limit determined by the operation amount upper limit value OH) determined by the operation amount MV of (feedback control), the power sum suppression control becomes an unconstrained state. That is, if the temperature control actuator is a single-phase electric heater, the balance between phases is not taken into consideration.

  Here, the interphase balance is the balance that should be maintained on the power consumption side for the R phase, S phase, and T phase of the three-phase alternating current. As shown in Patent Document 2, countermeasures at the power converter level have been proposed, but when using a plurality of single-phase electric heaters as described above, each phase is designed to be used in a balanced manner. Even if the power consumption becomes an arbitrary intermediate value, the power balance between the three phases becomes a balance that cannot be assumed in advance.

  For example, as an easy-to-understand form, a single 400 W unit is used for each of the RS phase, ST phase, and TR phase, or R phase, S phase, T phase, and neutral (hereinafter simply referred to as R phase, S phase, and T phase, respectively). Assume a three heater system to which phase electric heaters are assigned. For all three electric heaters, if the operation amount MV of PID control is the upper limit processing MV = 100% with the operation amount upper limit value OH = 100%, the R phase, the S phase, and the T phase are 400 W each. The power consumption state is reached, and the balance between phases as designed is obtained. On the other hand, when the R-phase operation amount MV = 90%, the S-phase operation amount MV = 50%, and the T-phase operation amount MV = 10%, the R-phase power consumption is 360 W, the S-phase power consumption is 200 W, The power balance between the three phases falls into an inappropriate state such that the power consumption of the T phase is 40 W.

JP 2012-048370 A JP2013-066631A

  As described above, in the conventional technique, the power balance between the three phases can fall into an inappropriate state in the steady state where the power used by the apparatus is an arbitrary intermediate value determined by the operation amount MV of PID control (feedback control). There was a problem that there was.

  The present invention has been made in order to solve the above-described problem, and in a steady state where the power used is an arbitrary intermediate value determined by the operation amount MV of PID control (feedback control), the power that improves the power balance between the three phases. An object is to provide an adjustment device and a power adjustment method. The steady state in this case also means a settling state in which the control amount PV substantially matches the set value SP.

  The power adjustment device of the present invention includes an R-phase control unit that controls an actuator that uses an R-phase of three-phase AC, an S-phase control unit that controls an actuator that uses an S-phase of three-phase AC, T-phase control means for controlling an actuator that uses the T-phase; and correction means for adjusting the power balance among the three phases; each of the R-phase control means, the S-phase control means, and the T-phase control means Is an upper limit value input means for inputting an operation amount upper limit correction value for the corresponding phase control loop, and a control operation for calculating the operation amount MV based on the deviation between the set value SP of the corresponding phase control loop and the control amount PV. Means, limit processing means for performing upper / lower limit processing for limiting the manipulated variable MV to a value that is greater than or equal to the manipulated variable lower limit value OL and less than or equal to the manipulated variable upper limit value OH, and a set value SP and control of the control loop for the corresponding phase With quantity PV Corresponds to the upper limit value replacing means for setting the manipulated variable upper limit correction value as the manipulated variable upper limit value OH of the limit processing means and the manipulated variable MV after the upper and lower limit processing when the deviation is equal to or less than the predetermined deviation allowable range δ. Manipulated variable output means for outputting to the actuator of the control loop of the phase to be inputted, and the correcting means inputs the manipulated variable MV after the upper and lower limit processing of each phase of the R phase, S phase, and T phase. A manipulated variable input means, a used power measurement estimating means for measuring or estimating the used power of each of the R-phase, S-phase, and T-phase actuators for each phase, and a use measured or estimated by the used power measurement estimating means Among the power, the maximum power detection means for detecting the maximum power and the operation amount upper limit correction value of the control loop of the phase in which the maximum power is detected are the upper and lower limit limits of the control loop in the phase in which the maximum power is detected. Based on the manipulated variable MV after the shut-off process, a correction value calculating means for calculating the maximum power to be suppressed, and an operation amount upper limit corrected value calculated by the corrected value calculating means Output means for outputting to the upper limit value input means of the control loop of the detected phase.

  Further, in one configuration example of the power adjustment apparatus of the present invention, each of the R phase control unit, the S phase control unit, and the T phase control unit further sets an operation amount lower limit correction value of a corresponding phase control loop. When the deviation between the input lower limit value input means and the set value SP of the corresponding phase control loop and the control amount PV is equal to or less than the deviation allowable range δ, the manipulated variable lower limit correction value is set as the manipulated variable of the limit processing means. Lower limit value replacement means for setting as a lower limit value OL, and the correction means further includes minimum power detection means for detecting the minimum power among the used power measured or estimated by the used power measurement estimation means, The correction value calculation means uses the operation amount lower limit correction value of the phase control loop in which the minimum power is detected based on the operation amount MV after the upper and lower limit processing of the phase control loop in which the minimum power is detected. And the output means calculates the operation amount lower limit correction value calculated by the correction value calculation means as the lower limit of the control loop of the phase where the minimum power is detected. It outputs to a value input means, It is characterized by the above-mentioned.

Further, in one configuration example of the power adjustment apparatus of the present invention, the correction unit further includes a minimum power detection unit that detects a minimum power among the used powers measured or estimated by the used power measurement estimation unit, The correction value calculating means determines whether a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold value, and calculates the operation amount upper limit correction value when the difference is equal to or greater than the threshold value. To do.
Further, in one configuration example of the power adjustment apparatus of the present invention, the correction value calculation means determines whether or not a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold, and is equal to or greater than the threshold. In this case, the operation amount upper limit correction value and the operation amount lower limit correction value are calculated.

Further, in one configuration example of the power adjustment device of the present invention, each of the R-phase control unit, the S-phase control unit, and the T-phase control unit further includes an operation amount upper limit value OH set in the limit processing unit. Is provided with a notification means for notifying the operator that the operation amount upper limit value OH is different from the normal specified value.
Further, in one configuration example of the power adjustment device of the present invention, each of the R-phase control unit, the S-phase control unit, and the T-phase control unit further includes an operation amount upper limit value OH set in the limit processing unit. Alternatively, it is provided with notifying means for notifying the operator that the operation amount upper limit value OH or the operation amount lower limit value OL is different from the normal specified value when the operation amount lower limit value OL is not the normal specified value. It is what.

  The power adjustment method of the present invention includes an R-phase control step for controlling an actuator that uses a three-phase AC R-phase, an S-phase control step for controlling an actuator that uses a three-phase AC S-phase, A T-phase control step for controlling an actuator using an alternating T-phase; and a correction step for adjusting a power balance among the three phases; the R-phase control step, the S-phase control step, and the T-phase control step Is calculated based on the deviation between the upper limit value input step for inputting the operation amount upper limit correction value of the corresponding phase control loop and the set value SP of the corresponding phase control loop and the control amount PV. A control calculation step, a limit processing step for executing an upper / lower limit process for limiting the manipulated variable MV to a value greater than or equal to the manipulated variable lower limit value OL and less than or equal to the manipulated variable upper limit value OH, An upper limit value replacing step of setting the manipulated variable upper limit correction value as the manipulated variable upper limit value OH when the deviation between the set value SP of the control loop of the phase to be controlled and the controlled variable PV is equal to or less than a predetermined deviation allowable range δ; The operation amount output step of outputting the operation amount MV after the upper / lower limit processing to the actuator of the control loop of the corresponding phase is repeatedly executed, and the correction step is performed for each phase of the R phase, the S phase, and the T phase. An operation amount input step for inputting the operation amount MV after the upper and lower limit processing, and a used power measurement estimation step for measuring or estimating the used power of each of the R-phase, S-phase, and T-phase actuators for each phase; Of the used power measured or estimated in the used power measurement estimation step, the maximum power detection step for detecting the maximum power and the operation of the control loop of the phase in which the maximum power is detected A correction value calculating step for calculating an amount upper limit correction value based on the operation amount MV after the upper and lower limit processing of the control loop of the phase in which the maximum power is detected; An output step of repeatedly giving the manipulated variable upper limit correction value calculated in the correction value calculating step to the control step of the phase in which the maximum power is detected is repeatedly executed.

  According to the present invention, in the control means for each of the R phase, the S phase, and the T phase, the operation amount upper limit correction value input from the correction means is used as the control value PV and the control amount PV of the corresponding phase control loop. Is set as the operation amount upper limit value OH of the limit processing means when the deviation is equal to or less than the predetermined deviation allowable range δ, and is calculated based on the deviation between the set value SP of the corresponding phase control loop and the control amount PV. Executes upper / lower limit processing that limits the manipulated variable MV to a value that is greater than or equal to the manipulated variable lower limit value OL and less than or equal to the manipulated variable upper limit value OH. Then, the correcting means measures or estimates the electric power used for each of the R-phase, S-phase, and T-phase actuators for each phase, detects the maximum electric power from the measured or estimated electric power used, and determines the maximum electric power. Control of detected phase The operation amount upper limit correction value for the loop is calculated based on the operation amount MV after the upper and lower limit processing of the control loop of the phase in which the maximum power is detected so that the increase in the maximum power is suppressed, and the calculated operation By outputting the amount upper limit correction value to the control means of the phase in which the maximum power is detected, in a steady state where the power used is an arbitrary intermediate value determined by the manipulated variable MV of PID control (feedback control), The power balance can be improved.

  In the present invention, in the control means for each of the R phase, S phase, and T phase, the manipulated variable lower limit correction value input from the correction means is used as the control value PV and the control value PV of the control loop for the corresponding phase. Is set as the operation amount lower limit value OL of the limit processing means when the deviation is less than the allowable deviation range δ, and the correction means detects the minimum power among the used powers measured or estimated by the used power measurement estimation means. Then, the operation amount lower limit correction value of the control loop of the phase where the minimum power is detected is controlled based on the operation amount MV after the upper and lower limit processing of the control loop of the phase where the minimum power is detected. Thus, by outputting the calculated manipulated variable lower limit correction value to the control means of the phase where the minimum power is detected, the power balance among the three phases can be further improved.

  Further, in the present invention, when the operation amount upper limit value OH set in the limit processing means is not the normal specified value, the operator is controlled with an operation amount upper limit value OH different from the normal specified value. It can be recognized that it is being performed.

  Further, in the present invention, when the operation amount upper limit value OH or the operation amount lower limit value OL set in the limit processing means is not the normal designated value, the operator notifies the operator that the operation amount is different from the normal designated value. It can be recognized that the control is performed with the upper limit value OH or the operation amount lower limit value OL.

It is a block diagram which shows the structure of the power adjustment device which concerns on embodiment of this invention. It is a block diagram of the control system which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the R phase control part, S phase control part, and T phase control part of the power regulator which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the upper / lower limit value calculation function part of the power adjustment device which concerns on embodiment of this invention. It is a figure which shows the operation example of the power adjustment device which concerns on embodiment of this invention. It is a block diagram which shows the structure of a heating apparatus provided with a some electric heater.

[Principle of Invention 1]
Since the power consumption of the control device including an actuator such as an electric heater is determined by the manipulated variable MV, if the PID control loop (the control loop that feeds back the controlled variable PV and matches the set value SP) performs strict control, The power consumption is determined uniformly only by the circumstances of PID control.

  However, the inventor has noted that in many cases, the PID control loop is accompanied by a tolerance that does not have to strictly maintain the SP = PV state. Then, the total power (or the total manipulated variable MV) is measured or estimated for each of the R phase, the S phase, and the T phase, the interphase power maximum difference is greater than or equal to the threshold value, and the deviation between the set value SP and the control amount PV. It is conceived that the maximum interphase power difference can be improved by correcting the manipulated variable upper limit value OH when the deviation is within the deviation allowable range.

  For example, in the heating control by the electric heater, when the electric power used in the R phase exceeds the threshold electric power used in the S phase, the operation amount upper limit value OH of the PID control loop by the electric heater using the R phase is set low. The amount of power used in the R phase is reduced by reducing the manipulated variable MV of the R phase PID control loop. Alternatively, if the operation amount upper limit value OH of the PID control loop by the electric heater using the S phase is corrected to the low side, the correction is restored to the high side and the operation amount MV of the S phase PID control loop is increased. By doing so, the power used in the S phase is increased. Even if the interphase balance between a plurality of PID control loops is not completely improved, the interphase balance of the entire factory is important, and therefore it is significant to contribute to the improvement of the interphase balance.

  Note that the threshold may be set to zero and the determination of whether or not it is equal to or greater than the threshold may be substantially omitted, but since the interphase balance itself is not a strict requirement, it is practical to set the threshold determination. is there.

[Principle of Invention 2]
By further correcting not only the operation amount upper limit value OH but also the operation amount lower limit value OL, the interphase balance can be easily improved.
For example, in the heating control by the electric heater, when the electric power used in the R phase exceeds the threshold electric power used in the S phase, the operation amount lower limit value OL of the PID control loop by the electric heater using the S phase is increased. The power used in the S phase is increased by increasing the manipulated variable MV of the S phase PID control loop. Alternatively, if the operation amount lower limit value OL of the PID control loop by the electric heater using the R phase is corrected to the high side, the correction is restored to the low side and the operation amount MV of the R phase PID control loop is lowered. By doing so, the electric power used in the R phase is lowered.

[Principle 3 of the invention]
In a steady state in which the power consumption of the apparatus is an arbitrary intermediate value, the manipulated variable upper limit value OH, the manipulated variable lower limit value OL, and the manipulated variable MV are in a state where the manipulated variable upper limit value OH or manipulated variable lower limit value OL is not corrected at all. The divergence from is likely to increase. In that case, if the standard correction amount in one control cycle of the operation amount upper limit value OH and the operation amount lower limit value OL is designed to be small considering the control stability, the operation amount upper limit as described above A large number of control cycles are required until the manipulated variable MV is forcibly corrected by the correction operation of the value OH and the manipulated variable lower limit value OL.

  Therefore, when the manipulated variable upper limit value OH, the manipulated variable lower limit value OL, and the manipulated variable MV deviate when the manipulated variable upper limit value OH or the manipulated variable lower limit value OL is changed, The operation amount upper limit value OH or the operation amount lower limit value OL of the PID control loop is once matched with the current value of the operation amount MV of the PID control loop, and then the operation amount upper limit value OH or the operation amount lower limit value OL is corrected. It is preferable to do so.

[Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a power adjustment device (control device) according to an embodiment of the present invention. The present embodiment is an example corresponding to Principle 1 of the invention, Principle 2 of the invention, and Principle 3 of the invention. In addition, in order to simplify the description, it is assumed that there is one R-phase, S-phase, and T-phase electric heater, and each electric heater is used as an actuator in a separate PID control loop. It is assumed that the deviation allowable range δ is a numerical value setting common to the three PID control loops.

  The power adjustment device includes an R phase control unit 1R that controls an electric heater (actuator) that uses the R phase, an S phase control unit 1S that controls an electric heater that uses the S phase, and an electric heater that uses the T phase. It comprises a T-phase control unit 1T to be controlled and an upper / lower limit value calculating function unit 2 (correction means) for adjusting the power balance between the three phases.

  The R-phase control unit 1R includes a set value SP_R input unit 10R that inputs a set value SP_R, a control amount PV_R input unit 11R that inputs a control amount PV_R, and an upper limit value OH_R ′ that inputs an operation amount upper limit correction value OH_R ′. Unit 12R, a lower limit value OL_R ′ input unit 13R for inputting an operation amount lower limit correction value OL_R ′, a PID_R control calculation unit 14R that calculates an operation amount MV_R based on a deviation between the set value SP_R and the control amount PV_R, and an operation amount A limit processing unit 15R that executes upper / lower limit processing for limiting MV_R to a value that is greater than or equal to the manipulated variable lower limit value OL_R and less than or equal to the manipulated variable upper limit value OH_R, and a confirmation deviation EH_R = SP_R-PV_R is an allowable deviation range δ (δ ≧ 0) Upper limit replacement for setting the operation amount upper limit correction value OH_R ′ as the operation amount upper limit value OH_R of the limit processing unit 15R when Unit 16R, and lower limit value replacement unit 17R that sets the manipulated variable lower limit correction value OL_R ′ as the manipulated variable lower limit value OL_R of the limit processing unit 15R when the confirmation deviation EL_R = PV_R-SP_R is equal to or less than the deviation allowable range δ, The power regulator of the electric heater using the R phase includes an operation amount MV_R ′ output unit 18R that outputs the operation amount MV_R ′ subjected to the upper and lower limit processing.

  The S-phase control unit 1S has a set value SP_S input unit 10S that inputs a set value SP_S, a control amount PV_S input unit 11S that inputs a control amount PV_S, and an upper limit value OH_S ′ that inputs an operation amount upper limit correction value OH_S ′. Unit 12S, a lower limit value OL_S ′ input unit 13S for inputting the operation amount lower limit correction value OL_S ′, a PID_S control calculation unit 14S for calculating the operation amount MV_S based on a deviation between the set value SP_S and the control amount PV_S, and an operation amount Limit processing unit 15S that executes upper / lower limit processing for limiting MV_S to a value that is greater than or equal to operation amount lower limit value OL_S and less than or equal to operation amount upper limit value OH_S, and when confirmation deviation EH_S = SP_S-PV_S is less than or equal to deviation allowable range δ Upper limit replacement unit 16S that sets the operation amount upper limit correction value OH_S ′ as the operation amount upper limit value OH_S of the limit processing unit 15S. When the confirmation deviation EL_S = PV_S−SP_S is equal to or less than the deviation allowable range δ, the lower limit value replacement unit 17S that sets the operation amount lower limit correction value OL_S ′ as the operation amount lower limit value OL_S of the limit processing unit 15S, and the S phase The power regulator of the electric heater to be used includes an operation amount MV_S ′ output unit 18S that outputs the operation amount MV_S ′ subjected to the upper and lower limit processing.

  The T-phase control unit 1T has a set value SP_T input unit 10T that inputs a set value SP_T, a control amount PV_T input unit 11T that inputs a control amount PV_T, and an upper limit value OH_T ′ that inputs an operation amount upper limit correction value OH_T ′. Unit 12T, a lower limit value OL_T ′ input unit 13T for inputting the operation amount lower limit correction value OL_T ′, a PID_T control calculation unit 14T for calculating the operation amount MV_T based on a deviation between the set value SP_T and the control amount PV_T, and an operation amount Limit processing unit 15T that performs upper / lower limit processing for limiting MV_T to a value that is greater than or equal to the operation amount lower limit value OL_T and less than or equal to the operation amount upper limit value OH_T, and when the confirmation deviation EH_T = SP_T-PV_T is less than or equal to the deviation allowable range δ Upper limit replacement unit 16T that sets operation amount upper limit correction value OH_T ′ as operation amount upper limit value OH_T of limit processing unit 15T When the confirmation deviation EL_T = PV_T−SP_T is equal to or less than the deviation allowable range δ, the lower limit value replacement unit 17T that sets the manipulated variable lower limit correction value OL_T ′ as the manipulated variable lower limit value OL_T of the limit processing unit 15T, and the T phase The power regulator of the electric heater to be used includes an operation amount MV_T ′ output unit 18T that outputs the operation amount MV_T ′ subjected to the upper and lower limit processing.

  The upper / lower limit calculation function unit 2 includes an operation amount MV_R ′ input unit 20R that inputs the operation amount MV_R ′ subjected to upper / lower limit processing, and an operation amount MV_S ′ input unit that inputs the operation amount MV_S ′ subjected to upper / lower limit processing. 20S, an operation amount MV_T ′ input unit 20T for inputting the operation amount MV_T ′ subjected to the upper and lower limit processing, a power W_R measurement unit 21R for measuring the power consumption W_R of the electric heater using the R phase, and the S phase are used. Electric power W_S measuring unit 21S for measuring the electric power W_S used for the electric heater, electric power W_T measuring unit 21T for measuring the electric power W_T used for the electric heater using the T phase, electric power W_R for the R phase, electric power used for the S phase Among the W_S and T phase used power W_T, the maximum / minimum power detector 22 for detecting the maximum power W_X and the minimum power W_Y, and the maximum / minimum power difference W_X−W_Y It is determined whether the threshold value TH is equal to or greater than the threshold value TH. If the threshold value TH is greater than or equal to the threshold value TH, the manipulated variable upper limit correction value OH_X ′ (OH_R ′, OH_S ′, OH_T) of the control loop of the phase in which the maximum power W_X is detected '), Based on the manipulated variable MV_X' (one of MV_R ', MV_S', MV_T ') of the control loop of the phase in which the maximum power W_X is detected, the increase in the maximum power W_X is suppressed. The operation amount lower limit correction value OL_Y ′ (one of OL_R ′, OL_S ′, OL_T ′) of the phase of the control loop in which the minimum power W_Y is detected is calculated as the control loop of the phase in which the minimum power W_Y is detected. Based on the manipulated variable MV_Y ′ (any one of MV_R ′, MV_S ′, and MV_T ′), the upper and lower limit correction value calculations are performed so as to suppress the decrease in the minimum power W_Y. Unit 23 and the operation amount upper limit correction value OH_X ′ are output to the upper limit value input unit (12R, 12S, or 12T) of the control loop of the phase where the maximum power W_X is detected, and the operation amount lower limit correction value OL_Y ′ is output. And an upper / lower limit value output unit 24 that outputs to the lower limit value input unit (any one of 13R, 13S, and 13T) of the control loop of the phase in which the minimum power W_Y is detected.

  The power W_R measurement unit 21R, the power W_S measurement unit 21S, and the power W_T measurement unit 21T constitute a used power measurement estimation unit. The maximum / minimum power detection unit 22 constitutes a maximum power detection unit and a minimum power detection unit, the upper / lower limit correction value calculation unit 23 constitutes a correction value calculation unit, and the upper / lower limit value output unit 24 constitutes an output unit. Yes.

  FIG. 2 is a block diagram of the control system of the present embodiment. The R-phase control unit 1R, the R-phase electric heater HR, and the R-phase control target 3R constitute an R-phase PID control loop, and the S-phase control unit 1S, the S-phase electric heater HS, and the S-phase control target 3S. And the T-phase control unit 1T, the T-phase electric heater HT, and the T-phase control target 3T constitute a T-phase PID control loop.

  When the power adjustment device of the present embodiment is applied to the heating device shown in FIG. 6, for example, the single-phase electric heaters H1, H2, and H3 become R-phase, S-phase, and T-phase electric heaters HR, HS, and HT, The control zones Z1, Z2, Z3 of the heat treatment furnace heated by the electric heaters H1, H2, H3 (HR, HS, HT) are controlled objects 3R, 3S, 3T, and the temperatures measured by the temperature sensors S1, S2, S3. Is controlled amounts PV_R, PV_S, and PV_T.

  The actual output destinations of the manipulated variables MV_R ′, MV_S ′, and MV_T ′ are the power regulators 102-1, 102-2, and 102-3, and the electric power according to the manipulated variables MV_R ′, MV_S ′, and MV_T ′ is adjusted. The electric heaters H1, H2, and H3 (HR, HS, and HT) are supplied from the units 102-1, 102-2, and 102-3. The electric heater H4 is a three-phase electric heater that does not affect the interphase balance. By designing in this way, if all the electric heater outputs are in a state other than the intermediate value, the interphase balance is maintained, and many single-phase electric heaters advantageous in cost can be employed.

Hereinafter, the operation of the power adjustment apparatus according to the present embodiment will be described in detail. FIG. 3 is a flowchart showing the operation of the R-phase control unit 1R, and FIG. 4 is a flowchart showing the operation of the upper / lower limit value calculation function unit 2.
First, the operation of the R-phase control unit 1R will be described. The set value SP_R is set by an operator of the power adjustment apparatus or the like, and is input to the PID_R control calculation unit 14R, the upper limit value replacing unit 16R, and the lower limit value replacing unit 17R via the set value SP_R input unit 10R (step in FIG. 3). S100).

  The control amount PV_R is measured by a sensor (temperature sensor S1 in the example of FIG. 6) or the like, and is input to the PID_R control calculation unit 14R, the upper limit replacement unit 16R, and the lower limit replacement unit 17R via the control amount PV_R input unit 11R. (Step S101 in FIG. 3).

  The upper limit value OH_R ′ input unit 12R outputs this operation amount when there is an output of the operation amount upper limit correction value OH_R ′ from the upper / lower limit value output unit 24 of the upper / lower limit value calculation function unit 2 (YES in step S102 in FIG. 3). The upper limit correction value OH_R ′ is received and input to the upper limit replacement unit 16R (step S103 in FIG. 3).

  The lower limit value OL_R ′ input unit 13R receives the manipulated variable when the manipulated variable lower limit correction value OL_R ′ is output from the upper / lower limit value output unit 24 of the upper / lower limit value calculation function unit 2 (YES in step S104 in FIG. 3). The lower limit correction value OL_R ′ is received and input to the lower limit replacement unit 17R (step S105 in FIG. 3).

  The upper limit replacement unit 16R sets a normal designated value (for example, OH_R = 100%) as an initial value of the operation amount upper limit value OH_R of the limit processing unit 15R when the power adjustment device is turned on or when control is started. Then, upper limit replacement unit 16R has confirmation deviation EH_R = SP_R−PV_R based on setting value SP_R and control amount PV_R equal to or smaller than predetermined deviation allowable range δ (δ ≧ 0) (YES in step S106 in FIG. 3), and When the operation amount upper limit correction value OH_R ′ is input from the upper limit value OH_R ′ input unit 12R (YES in step S107 in FIG. 3), the input operation amount upper limit correction value OH_R ′ is the normal specified value (for example, OH_R = 100). %) (YES in step S108 in FIG. 3), the manipulated variable upper limit correction value OH_R ′ is set as the manipulated variable upper limit value OH_R of the limit processing unit 15R (step S109 in FIG. 3).

  The lower limit replacement unit 17R sets a normal designated value (for example, OL_R = 0%) as an initial value of the operation amount lower limit value OL_R of the limit processing unit 15R when the power adjustment device is turned on or when control is started. Then, the lower limit replacement unit 17R has a confirmation deviation EL_R = PV_R−SP_R based on the set value SP_R and the control amount PV_R equal to or smaller than a predetermined deviation allowable range δ (δ ≧ 0) (YES in step S110 in FIG. 3). When the manipulated variable lower limit correction value OL_R ′ is input from the lower limit value OL_R ′ input unit 13R (YES in step S111 in FIG. 3), the input manipulated variable lower limit corrected value OL_R ′ is a normally specified value (for example, OL_R = 0). % (YES in step S112 in FIG. 3), this manipulated variable lower limit correction value OL_R ′ is set as the manipulated variable lower limit value OL_R of the limit processing unit 15R (step S113 in FIG. 3). However, when the manipulated variable upper limit correction value OH_R 'is input from the upper limit value OH_R' input unit 12R, the manipulated variable lower limit corrected value OL_R 'is not input, so that it can also be determined.

Next, the PID_R control calculation unit 14R calculates a manipulated variable MV_R by performing a PID control calculation like the following transfer function equation based on the deviation between the set value SP_R and the control amount PV_R (step S114 in FIG. 3). .
MV_R = (100.0 / PB_R) {1+ (1 / TI_Rs) + TD_Rs}
× (SP_R-PV_R) (1)
PB_R is a predefined proportional band, TI_R is a predefined integration time, TD_R is a predefined differential time, and s is a Laplace operator.

The limit processing unit 15R performs upper limit processing such as equation (2) on the manipulated variable MV_R calculated by the PID_R control calculation unit 14R, and simultaneously performs lower limit processing such as equation (3). The operation amount MV_R ′ subjected to limit processing is output (step S115 in FIG. 3).
IF MV_R> OH_R THEN MV_R ′ = OH_R (2)
IF MV_R <OL_R THEN MV_R ′ = OL_R (3)

  That is, when the manipulated variable MV_R is greater than or equal to the manipulated variable lower limit value OL_R and less than or equal to the manipulated variable upper limit value OH_R, the limit processing unit 15R outputs the manipulated variable MV_R as the manipulated variable MV_R ′ as it is, but the manipulated variable MV_R is the manipulated variable upper limit value. When larger than OH_R, the operation amount MV_R ′ = OH_R, and when smaller than the operation amount lower limit value OL_R, the operation amount MV_R ′ = OL_R. Thus, the upper and lower limit processing is performed to limit the operation amount MV_R to a value that is greater than or equal to the operation amount lower limit value OL_R and less than or equal to the operation amount upper limit value OH_R.

  The manipulated variable MV_R ′ output unit 18R is limited to the upper / lower limit value calculation function unit 2 and the power regulator (electric power regulator 102-1 in the example of FIG. 6) of the electric heater HR of the corresponding R-phase control loop. The operation amount MV_R ′ subjected to the upper / lower limit processing by the processing unit 15R is output (step S116 in FIG. 3).

  The R-phase control unit 1R performs the processes in steps S100 to S116 as described above for each control cycle until the control is terminated by, for example, an operator instruction (YES in step S117 in FIG. 3).

Next, the operation of the S phase control unit 1S will be described. Since the operation of the S-phase control unit 1S is the same as that of the R-phase control unit 1R, the operation will be described with reference to FIG.
The set value SP_S is set by an operator or the like, and is input to the PID_S control calculation unit 14S, the upper limit value replacing unit 16S, and the lower limit value replacing unit 17S via the set value SP_S input unit 10S (step S100).

  The control amount PV_S is measured by a sensor (temperature sensor S2 in the example of FIG. 6) or the like, and is input to the PID_S control calculation unit 14S, the upper limit replacement unit 16S, and the lower limit replacement unit 17S via the control amount PV_S input unit 11S. (Step S101).

  The upper limit value OH_S ′ input unit 12S, when there is an operation amount upper limit correction value OH_S ′ output from the upper / lower limit value output unit 24 of the upper / lower limit value calculation function unit 2 (YES in step S102), The value OH_S ′ is received and input to the upper limit replacement unit 16S (step S103).

  The lower limit value OL_S ′ input unit 13S outputs the manipulated variable lower limit correction when there is an output of the manipulated variable lower limit corrected value OL_S ′ from the upper and lower limit value output unit 24 of the upper / lower limit value calculation function unit 2 (YES in step S104). The value OL_S ′ is received and input to the lower limit replacement unit 17S (step S105).

  The upper limit replacement unit 16S sets a normal specified value (for example, OH_S = 100%) as an initial value of the operation amount upper limit value OH_S of the limit processing unit 15S when the power adjustment device is turned on or starts control. Then, upper limit replacement unit 16S has confirmation deviation EH_S = SP_S−PV_S based on setting value SP_S and control amount PV_S equal to or smaller than predetermined deviation allowable range δ (YES in step S106), and upper limit value OH_S ′ input unit 12S. When the operation amount upper limit correction value OH_S ′ is input (YES in step S107), if the input operation amount upper limit correction value OH_S ′ is less than the normal specified value (for example, OH_S = 100%) (step S108). In step S109), the operation amount upper limit correction value OH_S ′ is set as the operation amount upper limit value OH_S of the limit processing unit 15S.

  The lower limit replacement unit 17S sets a normal designated value (for example, OL_S = 0%) as an initial value of the operation amount lower limit value OL_S of the limit processing unit 15S when the power adjustment device is turned on or when control is started. Then, the lower limit replacement unit 17S has a confirmation deviation EL_S = PV_S−SP_S based on the set value SP_S and the control amount PV_S that is equal to or smaller than the predetermined deviation allowable range δ (YES in step S110), and the lower limit OL_S ′ input unit 13S. When the operation amount lower limit correction value OL_S ′ is input from (YES in step S111), if the input operation amount lower limit correction value OL_S ′ is larger than the normal specified value (for example, OL_S = 0%) (step). In S112, the manipulated variable lower limit correction value OL_S ′ is set as the manipulated variable lower limit value OL_S of the limit processing unit 15S (step S113). However, if the manipulated variable upper limit correction value OH_S 'is input from the upper limit value OH_S' input unit 12S, the manipulated variable lower limit corrected value OL_S 'is not input, so that it can also be determined.

Next, the PID_S control calculation unit 14S calculates a manipulated variable MV_S by performing a PID control calculation such as the following transfer function equation based on the deviation between the set value SP_S and the control amount PV_S (step S114).
MV_S = (100.0 / PB_S) {1+ (1 / TI_Ss) + TD_Ss}
× (SP_S-PV_S) (4)
PB_S is a predefined proportional band, TI_S is a predefined integration time, and TD_S is a predefined differential time.

The limit processing unit 15S performs an upper limit process such as Expression (5) on the operation amount MV_S calculated by the PID_S control calculation unit 14S, and simultaneously performs a lower limit process such as Expression (6). The operation amount MV_S ′ subjected to the limit process is output (step S115).
IF MV_S> OH_S THEN MV_S ′ = OH_S (5)
IF MV_S <OL_S THEN MV_S ′ = OL_S (6)

  That is, when the manipulated variable MV_S is greater than or equal to the manipulated variable lower limit value OL_S and less than or equal to the manipulated variable upper limit value OH_S, the limit processing unit 15S outputs the manipulated variable MV_S as the manipulated variable MV_S ′, but the manipulated variable MV_S is the manipulated variable upper limit value. When larger than OH_S, the operation amount MV_S ′ = OH_S, and when smaller than the operation amount lower limit OL_S, the operation amount MV_S ′ = OL_S. In this way, the upper and lower limit processing for limiting the operation amount MV_2 to a value that is greater than or equal to the operation amount lower limit value OL_S and less than or equal to the operation amount upper limit value OH_S is performed.

  The manipulated variable MV_S ′ output unit 18S is limited to the upper / lower limit value calculation function unit 2 and the power adjuster (the power adjuster 102-2 in the example of FIG. 6) of the electric heater HS of the corresponding S-phase control loop. The operation amount MV_S subjected to the upper and lower limit processing by the processing unit 15S is output (step S116).

  The S-phase control unit 1S performs the processes in steps S100 to S116 as described above for each control cycle until the control is terminated by an operator instruction (YES in step S117).

Next, the operation of the T-phase control unit 1T will be described. Since the operation of the T-phase control unit 1T is the same as that of the R-phase control unit 1R, the operation will be described with reference to FIG.
The set value SP_T is set by an operator or the like, and is input to the PID_T control calculation unit 14T, the upper limit value replacing unit 16T, and the lower limit value replacing unit 17T via the set value SP_T input unit 10T (step S100).

  The control amount PV_T is measured by a sensor (temperature sensor S3 in the example of FIG. 6) or the like, and is input to the PID_T control calculation unit 14T, the upper limit replacement unit 16T, and the lower limit replacement unit 17T via the control amount PV_T input unit 11T. (Step S101).

  The upper limit value OH_T ′ input unit 12T, when there is an output of the operation amount upper limit correction value OH_T ′ from the upper / lower limit value output unit 24 of the upper / lower limit value calculation function unit 2 (YES in step S102), The value OH_T ′ is received and input to the upper limit replacement unit 16T (step S103).

  The lower limit value OL_T ′ input unit 13T outputs the operation amount lower limit correction when there is an output of the operation amount lower limit correction value OL_T ′ from the upper and lower limit value output unit 24 of the upper and lower limit value calculation function unit 2 (YES in step S104). The value OL_T ′ is received and input to the lower limit replacement unit 17T (step S105).

  The upper limit replacement unit 16T sets a normal specified value (for example, OH_T = 100%) as an initial value of the operation amount upper limit value OH_T of the limit processing unit 15T when the power adjustment device is turned on or starts control. Then, the upper limit replacement unit 16T has a confirmation deviation EH_T = SP_T−PV_T based on the set value SP_T and the control amount PV_T that is equal to or smaller than the predetermined deviation allowable range δ (YES in step S106), and the upper limit OH_T ′ input unit 12T. When the operation amount upper limit correction value OH_T ′ is input (YES in step S107), if the input operation amount upper limit correction value OH_T ′ is less than the normal specified value (for example, OH_T = 100%) (step S108). In step S109), the manipulated variable upper limit correction value OH_T ′ is set as the manipulated variable upper limit value OH_T of the limit processing unit 15T.

  The lower limit replacement unit 17T sets a normal specified value (for example, OL_T = 0%) as an initial value of the operation amount lower limit value OL_T of the limit processing unit 15T when the power adjustment device is turned on or starts control. Then, the lower limit replacement unit 17T has a confirmation deviation EL_T = PV_T−SP_T based on the set value SP_T and the control amount PV_T that is equal to or smaller than a predetermined deviation allowable range δ (YES in step S110), and a lower limit OL_T ′ input unit 13T. When the operation amount lower limit correction value OL_T ′ is input from (YES in step S111), if the input operation amount lower limit correction value OL_T ′ is larger than the normal specified value (for example, OL_T = 0%) (step) In S112, the manipulated variable lower limit correction value OL_T ′ is set as the manipulated variable lower limit value OL_T of the limit processing unit 15T (step S113). However, when the operation amount upper limit correction value OH_T 'is input from the upper limit value OH_T' input unit 12T, the operation amount lower limit correction value OL_T 'is not input.

Next, the PID_T control calculation unit 14T calculates a manipulated variable MV_T by performing a PID control calculation like the following transfer function equation based on the deviation between the set value SP_T and the control amount PV_T (step S114).
MV_T = (100.0 / PB_T) {1+ (1 / TI_Ts) + TD_Ts}
× (SP_T-PV_T) (7)
PB_T is a predefined proportional band, TI_T is a predefined integration time, and TD_T is a predefined differential time.

The limit processing unit 15T performs an upper limit process such as Expression (8) on the operation amount MV_T calculated by the PID_T control calculation unit 14T, and simultaneously performs a lower limit process such as Expression (9). The operation amount MV_T ′ subjected to the limit process is output (step S115).
IF MV_T> OH_T THEN MV_T ′ = OH_T (8)
IF MV_T <OL_T THEN MV_T ′ = OL_T (9)

  That is, when the manipulated variable MV_T is greater than or equal to the manipulated variable lower limit value OL_T and less than or equal to the manipulated variable upper limit value OH_T, the limit processing unit 15T outputs the manipulated variable MV_T as the manipulated variable MV_T ′ as it is. When it is larger than OH_T, the operation amount MV_T ′ = OH_T, and when it is smaller than the operation amount lower limit value OL_T, the operation amount MV_T ′ = OL_T. In this way, the upper / lower limit processing for limiting the operation amount MV_T to a value that is greater than or equal to the operation amount lower limit value OL_T and less than or equal to the operation amount upper limit value OH_T is performed.

  The manipulated variable MV_T ′ output unit 18T is limited to the upper / lower limit value calculation function unit 2 and the power regulator (the power regulator 102-3 in the example of FIG. 6) of the electric heater HT of the corresponding T-phase control loop. The operation amount MV_T subjected to the upper and lower limit processing by the processing unit 15T is output (step S116).

  The T-phase control unit 1T performs the processes in steps S100 to S116 as described above for each control cycle until the control is terminated by an operator instruction (YES in step S117).

  Next, the operation of the upper / lower limit value calculation function unit 2 will be described. The manipulated variable MV_R ′ input unit 20R receives the manipulated variable MV_R ′ output from the manipulated variable MV_R ′ output unit 18R of the R-phase control unit 1R and inputs the manipulated variable MV_R ′ to the upper / lower limit correction value calculating unit 23 (step S200 in FIG. 4). . The manipulated variable MV_S ′ input unit 20S receives the manipulated variable MV_S ′ output from the manipulated variable MV_S ′ output unit 18S of the S-phase control unit 1S and inputs it to the upper / lower limit correction value calculating unit 23 (step S201 in FIG. 4). . The manipulated variable MV_T ′ input unit 20T receives the manipulated variable MV_T ′ output from the manipulated variable MV_T ′ output unit 18T of the T-phase controller 1T and inputs the manipulated variable MV_T ′ to the upper / lower limit correction value calculator 23 (step S202 in FIG. 4). .

  The power W_R measurement unit 21R measures the power consumption W_R of the electric heater HR that uses the R phase (step S203 in FIG. 4). On the other hand, the power W_S measurement unit 21S measures the power consumption W_S of the electric heater HS that uses the S phase (step S204 in FIG. 4). The power W_T measurement unit 21T measures the power consumption W_T of the electric heater HT that uses the T phase (step S205 in FIG. 4).

  The maximum / minimum power detection unit 22 detects the maximum power W_X and the minimum power W_Y among the R-phase use power W_R, the S-phase use power W_S, and the T-phase use power W_T (step S206 in FIG. 4). For example, the maximum power W_X = W_R if the W_R is the maximum of the three used powers, and the minimum power W_Y = W_T if the W_T is the minimum.

The upper / lower limit correction value calculation unit 23 determines whether or not the difference W_X−W_Y between the maximum power W_X and the minimum power W_Y is equal to or greater than a predetermined threshold TH (step S207 in FIG. 4). Then, when the difference W_X−W_Y between the maximum power W_X and the minimum power W_Y is equal to or greater than the threshold value TH (YES in step S207), the upper / lower limit correction value calculation unit 23 determines the control loop of the phase in which the maximum power W_X is detected. The manipulated variable upper limit correction value OH_X ′ (any one of OH_R ′, OH_S ′, and OH_T ′) is set to the manipulated variable MV_X ′ (MV_R ′, MV_S ′, MV_T ′) of the control loop of the phase in which the maximum power W_X is detected. ) As follows (step S208 in FIG. 4).
OH_X ′ ← MV_X′−D (10)

Further, when the difference W_X−W_Y between the maximum power W_X and the minimum power W_Y is equal to or greater than the threshold value TH (YES in step S207), the upper / lower limit correction value calculation unit 23 determines the control loop of the phase in which the minimum power W_Y is detected. The manipulated variable lower limit correction value OL_Y ′ (one of OL_R ′, OL_S ′, OL_T ′) is set to one of the manipulated variables MV_Y ′ (MV_R ′, MV_S ′, MV_T ′) of the control loop of the phase in which the minimum power W_Y is detected. ) To calculate as follows (step S209 in FIG. 4).
OL_Y ′ ← MV_Y ′ + D (11)

  That is, the upper and lower limit correction value calculation unit 23 newly calculates a value obtained by subtracting the change amount D (D is a positive value defined in advance) from the current operation amount MV_X ′ (any one of MV_R ′, MV_S ′, and MV_T ′). A value obtained by adding the change amount D to the current operation amount MV_Y ′ (one of MV_R ′, MV_S ′, and MV_T ′) is set as a new operation amount lower limit correction value OL_Y ′.

  The upper / lower limit value output unit 24 uses the operation amount upper limit correction value OH_X ′ calculated by the upper / lower limit correction value calculation unit 23 as the upper limit value input unit (12R, 12S, 12T of the control loop of the phase in which the maximum power W_X is detected. The manipulated variable lower limit correction value OL_Y ′ calculated by the upper and lower limit correction value calculation unit 23 is output to any one of the lower limit value input units (13R, 13S, 13T) of the control loop of the phase in which the minimum power W_Y is detected. (Step S210 in FIG. 4).

  The upper / lower limit value calculation function unit 2 performs the processes in steps S200 to S210 as described above for each control cycle until the control is terminated by, for example, an operator instruction (YES in step S211 in FIG. 4).

  According to the calculation and replacement procedure of the manipulated variable upper limit correction value OH_X ′ and the manipulated variable lower limit corrected value OL_Y ′, the manipulated variable upper limit of the control loop of the phase corresponding to the largest one of the powers W_R, W_S, and W_T is used. The value OH_X ′ (one of OH_R, OH_S, and OH_T) is corrected to the lower side, and the operation amount lower limit value OL_Y ′ (OL_R) of the control loop of the phase corresponding to the smallest one of the used powers W_R, W_S, and W_T , OL_S, OL_T) is corrected to the higher side.

  That is, the operation amount MV_X (one of MV_R, MV_S, MV_T) of the control loop of the phase corresponding to the largest one of the used powers W_R, W_S, W_T decreases, and the used power W_X also decreases, and the used power The manipulated variable MV_Y (one of MV_R, MV_S, MV_T) of the phase control loop corresponding to the smallest one of W_R, W_S, and W_T increases, and the used power W_Y also increases. Thereby, the electric power balance between three phases is adjusted. The present invention is applicable even when there are a plurality of R-phase, S-phase, and T-phase control loops.

  Since the change amount D is an arbitrary change amount for sequentially changing the operation amount upper limit correction value OH_X ′ and the operation amount lower limit correction value OL_Y ′, the change amount D is preferably designed to be a small positive value. By using the change amount D, the operation amount upper limit correction value OH_X ′ and the operation amount lower limit correction value OL_Y ′ are calculated as shown in the equations (10) and (11), thereby realizing the principle 3 of the invention. Processing can be realized.

  The used electric power W_R, W_S, and W_T are not limited to the measurement by the power meter, and may be estimated values based on the operation amounts MV_R, MV_S, and MV_T, for example. As a method for estimating the power consumption W_R, W_S, and W_T, for example, a technique disclosed in Japanese Unexamined Patent Application Publication No. 2009-229382 is known.

  When the manipulated variable upper limit values OH_R, OH_S, and OH_T of the limit processing units 15R, 15S, and 15T are not normally designated values, they are controlled with the manipulated variable upper limit values OH_R, OH_S, and OH_T that are different from the original values. It is preferable to output, for example, from the upper limit value replacement units 16R, 16S, and 16T, a signal for notifying the operator that the control is performed with the operation amount upper limit values OH_R, OH_S, and OH_T different from those. In this case, the upper limit replacement units 16R, 16S, and 16T serve as notification means.

  When the manipulated variable lower limit values OL_R, OL_S, OL_T of the limit processing units 15R, 15S, 15T are not normally designated values, they are controlled with the manipulated variable lower limit values OL_R, OL_S, OL_T that are different from the original values. It is preferable to output, for example, from the lower limit value replacement units 17R, 17S, and 17T, a signal for notifying the operator that the control is performed with the operation amount lower limit values OL_R, OL_S, and OL_T that are different from those. In this case, the lower limit replacement units 17R, 17S, and 17T serve as notification means.

  FIG. 5A to FIG. 5C are diagrams showing an operation example of the power adjustment apparatus of the present embodiment, and FIG. 5A shows set values SP_R, SP_S, SP_T, control amounts PV_R, PV_S, PV_T. FIG. 5B is a diagram showing changes in the manipulated variables MV_R ′, MV_S ′, and MV_T ′, and FIG. 5C is a diagram showing changes in the used powers W_R, W_S, and W_T. Here, in order to further simplify the explanation, the electric power used in the R phase gradually increases and the electric power used in the T phase while maintaining the temperature (control amount PV) constant due to the electric heater characteristics and circuit characteristics. Assumes a case where gradual decline.

  Since the used power W_R is further increased in the R phase where the used power is originally high and the used power W_T is further decreased in the T phase where the used power is originally low, the difference between the used power of the R phase and the T phase at the specific time (maximum minimum The difference in power is equal to or greater than the threshold value TH. Accordingly, the manipulated variable upper limit correction value OH_R ′ (a value lower than the normal specified value 100%) is output from the upper / lower limit value calculation function unit 2 to the R phase control unit 1R, and is output to the T phase control unit 1T. The manipulated variable lower limit correction value OL_T ′ (a value higher than the normal specified value 0%) is output.

  As a result, the operation amount upper limit value OH_R is corrected to a value lower than the normal specified value 100%, and the operation amount lower limit value OL_T is corrected to a value higher than the normal specified value 0%, which is shown in FIG. Thus, the operation amount MV_R ′ gradually decreases and the operation amount MV_T ′ gradually increases. Then, an increase in the R-phase use power W_R is suppressed, a decrease in the T-phase use power W_T is suppressed, and the difference between the R-phase and T-phase use powers (the difference between the maximum and minimum powers) is maintained near the threshold TH. Is done. That is, the power balance between the three phases is improved as compared with the case where the present embodiment is not applied.

  In the present embodiment, the operation amount upper limit correction value OH_X ′ and the operation amount lower limit correction value OL_Y ′ are calculated when the difference W_X−W_Y between the maximum power W_X and the minimum power W_Y is equal to or greater than the threshold value TH. The determination as to whether or not the difference W_X−W_Y between the maximum power W_X and the minimum power W_Y is greater than or equal to the threshold value TH is not essential. You may unconditionally implement processing of Steps S208-S210.

  In the present embodiment, the upper / lower limit correction value calculation unit 23 calculates both the operation amount upper limit correction value OH_X ′ and the operation amount lower limit correction value OL_Y ′. However, the present invention is not limited to this. Only the amount upper limit correction value OH_X ′ may be calculated. In this case, in the R phase control unit 1R, the S phase control unit 1S, and the T phase control unit 1T, the lower limit value OL_R ′ input unit 13R, the lower limit value OL_S ′ input unit 13S, the lower limit value OL_T ′ input unit 13T, and the lower limit value replacement unit 17R, 17S, and 17T are unnecessary. The upper / lower limit value output unit 24 may output only the manipulated variable upper limit correction value OH_X ′.

  Further, as described above, the present invention can be applied even when there are a plurality of R-phase, S-phase, and T-phase control loops. In this case, assuming that one electric heater is used for each control loop, a plurality of R-phase electric heaters HR, S-phase electric heaters HS, and T-phase electric heaters HT are provided. Become. The R-phase control unit 1R is provided for each R-phase control loop, and the process of FIG. 3 is performed for each R-phase control loop. Similarly, the S-phase control unit 1S is provided for each S-phase control loop, and the process of FIG. 3 is performed for each S-phase control loop. The T-phase control unit 1T is provided for each T-phase control loop, and the process of FIG. 3 is performed for each T-phase control loop.

  When there are a plurality of R-phase, S-phase, and T-phase control loops, the power W_R measurement unit 21R measures the total power W_R of power used by the plurality of electric heaters HR that use the R-phase (step S203), and the power W_S. The measuring unit 21S measures the total power W_S of the electric power used by the plurality of electric heaters HS using the S phase (step S204), and the electric power W_T measuring unit 21T calculates the electric power used by the plurality of electric heaters HT using the T phase. The total sum W_T is measured (step S205).

  When there are a plurality of R-phase, S-phase, and T-phase control loops, the manipulated variable MV_R ′ input unit 20R receives the manipulated variable MV_R ′ of each R-phase control loop (step S200) and inputs the manipulated variable MV_S ′. The unit 20S receives the operation amount MV_S ′ of each control loop of the S phase (step S201), and the operation amount MV_T ′ input unit 20T receives the operation amount MV_T ′ of each control loop of the T phase (step S202). .

  When there are a plurality of R-phase, S-phase, and T-phase control loops, the upper / lower limit correction value calculation unit 23 calculates an operation amount upper limit correction value OH_X ′ for each control loop in which the maximum power W_X is detected ( In step S208, the manipulated variable lower limit correction value OL_Y ′ may be calculated for each phase control loop in which the minimum power W_Y is detected (step S209). The upper / lower limit value output unit 24 outputs the operation amount upper limit correction value OH_X ′ calculated for each control loop by the upper / lower limit correction value calculation unit 23 to the upper limit value input unit of the corresponding control loop, and the upper / lower limit correction value calculation unit The manipulated variable lower limit correction value OL_Y ′ calculated for each control loop 23 may be output to the lower limit value input unit of the corresponding control loop (step S210).

  The power adjustment apparatus described in the present embodiment can be realized by a computer having a CPU (Central Processing Unit), a storage device, and an interface, and a program for controlling these hardware resources. The CPU executes the processing described in the present embodiment in accordance with a program stored in the storage device.

  The present invention can be applied to a technique for improving the power balance among the three phases of the three-phase alternating currents of the R phase, the S phase, and the T phase.

  1R ... R phase control unit, 1S ... S phase control unit, 1T ... T phase control unit, 2 ... upper / lower limit value calculation function unit, 10R, 10S, 10T ... set value input unit, 11R, 11S, 11T ... control amount input , 12R, 12S, 12T ... upper limit input unit, 13R, 13S, 13T ... lower limit input unit, 14R, 14S, 14T ... control calculation unit, 15R, 15S, 15T ... limit processing unit, 16R, 16S, 16T ... Upper limit replacement unit, 17R, 17S, 17T ... lower limit replacement unit, 18R, 18S, 18T ... manipulated variable output unit, 20R, 20S, 20T ... manipulated variable input unit, 21R, 21S, 21T ... power measurement unit, 22 ... Maximum / minimum power detection unit, 23... Upper / lower limit correction value calculation unit, 24... Upper / lower limit value output unit.

Claims (12)

R-phase control means for controlling an actuator that uses the three-phase AC R-phase;
S-phase control means for controlling an actuator using the S-phase of three-phase alternating current;
T-phase control means for controlling an actuator that uses T-phase of three-phase alternating current;
Correction means for adjusting the power balance between the three phases,
Each of the R phase control means, the S phase control means, and the T phase control means,
Upper limit value input means for inputting the operation amount upper limit correction value of the control loop of the corresponding phase;
Control arithmetic means for calculating the manipulated variable MV based on the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV;
Limit processing means for performing upper and lower limit processing for limiting the operation amount MV to a value not less than the operation amount lower limit value OL and not more than the operation amount upper limit value OH;
The upper limit for setting the manipulated variable upper limit correction value as the manipulated variable upper limit value OH of the limit processing means when the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV is less than or equal to the predetermined deviation allowable range δ. Value substitution means;
An operation amount output means for outputting the operation amount MV after the upper and lower limit processing to the actuator of the corresponding phase control loop,
The correcting means is
An operation amount input means for inputting an operation amount MV after the upper and lower limit processing of each phase of the R phase, the S phase, and the T phase;
Used power measurement estimating means for measuring or estimating the used power of each of the R-phase, S-phase, and T-phase actuators for each phase;
Among the used power measured or estimated by the used power measurement estimating means, the maximum power detecting means for detecting the maximum power,
Based on the manipulated variable MV after the upper and lower limit processing of the control loop of the phase in which the maximum power is detected, the upper limit of the manipulated variable MV of the phase in which the maximum power is detected is increased. Correction value calculation means for calculating to be suppressed;
An electric power adjustment apparatus comprising: an output unit that outputs an operation amount upper limit correction value calculated by the correction value calculation unit to the upper limit input unit of the control loop of the phase in which the maximum power is detected. The power adjustment device according to claim 1,
Each of the R phase control means, the S phase control means, and the T phase control means,
Furthermore, a lower limit input means for inputting a manipulated variable lower limit correction value of the corresponding phase control loop,
Lower limit value for setting the manipulated variable lower limit correction value as the manipulated variable lower limit value OL of the limit processing means when the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV is less than or equal to the deviation allowable range δ. Each with a replacement means,
The correcting means is
Furthermore, it comprises a minimum power detecting means for detecting a minimum power among the used power measured or estimated by the used power measurement estimating means,
The correction value calculating means calculates an operation amount lower limit correction value of the phase control loop in which the minimum power is detected based on an operation amount MV after the upper and lower limit processing of the phase control loop in which the minimum power is detected. , Calculating so that the decrease in the minimum power is suppressed,
The output means outputs the manipulated variable lower limit correction value calculated by the correction value calculation means to the lower limit input means of the control loop of the phase where the minimum power is detected. The power adjustment device according to claim 1,
The correcting means is
Furthermore, it comprises a minimum power detecting means for detecting a minimum power among the used power measured or estimated by the used power measurement estimating means,
The correction value calculation means determines whether or not a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold value, and calculates the operation amount upper limit correction value when the difference is equal to or greater than the threshold value. Power adjustment device. The power adjustment device according to claim 2,
The correction value calculation means determines whether or not a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold, and when the difference is equal to or greater than the threshold, the operation amount upper limit correction value and the operation amount lower limit correction. A power adjustment device characterized by calculating a value. The power adjustment device according to claim 1 or 3,
Each of the R phase control means, the S phase control means, and the T phase control means,
Furthermore, when the operation amount upper limit value OH set in the limit processing means is not a normal specified value, a notification means for notifying the operator that the operation amount upper limit value OH is different from the normal specified value is provided. The power adjustment device characterized by the above-mentioned. The power adjustment device according to claim 2 or 4,
Each of the R phase control means, the S phase control means, and the T phase control means,
Further, when the manipulated variable upper limit value OH or manipulated variable lower limit value OL set in the limit processing means is not a normal designated value, control is performed with an manipulated variable upper limit value OH or manipulated variable lower limit value OL that is different from the normal designated value. A power adjustment device comprising a notification means for notifying an operator that the An R-phase control step for controlling an actuator using the three-phase AC R-phase;
An S phase control step for controlling an actuator using the S phase of the three-phase alternating current;
A T-phase control step for controlling an actuator using a T-phase of three-phase alternating current;
A correction step for adjusting the power balance between the three phases,
Each of the R phase control step, the S phase control step, and the T phase control step includes:
An upper limit value input step for inputting an operation amount upper limit correction value of the control loop of the corresponding phase;
A control calculation step for calculating the manipulated variable MV based on the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV;
A limit processing step for executing upper / lower limit processing for limiting the operation amount MV to a value not less than the operation amount lower limit value OL and not more than the operation amount upper limit value OH;
An upper limit value replacing step of setting the manipulated variable upper limit correction value as the manipulated variable upper limit value OH when the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV is equal to or less than a predetermined deviation allowable range δ; ,
An operation amount output step for outputting the operation amount MV after the upper and lower limit processing to the actuator of the corresponding phase control loop is repeatedly executed,
The correcting step includes
An operation amount input step of inputting an operation amount MV after the upper and lower limit processing of each of the R phase, S phase, and T phase;
A used power measurement estimating step for measuring or estimating the used power of each of the R-phase, S-phase, and T-phase actuators;
Of the used power measured or estimated in this used power measurement estimation step, a maximum power detection step for detecting the maximum power;
Based on the manipulated variable MV after the upper and lower limit processing of the control loop of the phase in which the maximum power is detected, the upper limit of the manipulated variable MV of the phase in which the maximum power is detected is increased. A correction value calculation step for calculating to be suppressed;
An electric power adjustment method comprising: repeatedly performing an output step of applying an operation amount upper limit correction value calculated in the correction value calculation step to the control step of the phase in which the maximum power is detected. The power adjustment method according to claim 7, wherein
Each of the R phase control step, the S phase control step, and the T phase control step includes:
Furthermore, a lower limit input step for inputting the manipulated variable lower limit correction value of the corresponding phase control loop,
A lower limit replacement step for setting the manipulated variable lower limit correction value as the manipulated variable lower limit OL when the deviation between the set value SP of the corresponding phase control loop and the controlled variable PV is less than or equal to the deviation allowable range δ; Run each one repeatedly
The correcting step includes
Furthermore, a minimum power detection step for detecting a minimum power among the used power measured or estimated in the used power measurement estimation step,
In the correction value calculating step, the operation amount lower limit correction value of the control loop of the phase in which the minimum power is detected is based on the operation amount MV after the upper and lower limit processing of the control loop of the phase in which the minimum power is detected. And calculating so as to suppress a decrease in the minimum power,
The output step includes a step of giving the manipulated variable lower limit correction value calculated in the correction value calculation step to the control step of the phase in which the minimum power is detected. The power adjustment method according to claim 7, wherein
The correcting step includes
Furthermore, a minimum power detection step for detecting a minimum power among the used power measured or estimated in the used power measurement estimation step,
The correction value calculating step includes a step of determining whether a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold value, and calculating the operation amount upper limit correction value when the difference is equal to or greater than the threshold value. The power adjustment method characterized by the above-mentioned. The power adjustment method according to claim 8, wherein
The correction value calculating step determines whether or not a difference between the maximum power and the minimum power is equal to or greater than a predetermined threshold, and when the difference is equal to or greater than the threshold, the operation amount upper limit correction value and the operation amount lower limit correction A power adjustment method comprising a step of calculating a value. The power adjustment method according to claim 7 or 9,
Each of the R phase control step, the S phase control step, and the T phase control step includes:
The power adjustment further includes a notifying step for notifying the operator that the operation amount upper limit value OH is controlled with an operation amount upper limit value OH different from the normal specification value when the operation amount upper limit value OH is not the normal specification value. Method. The power adjustment method according to claim 8 or 10,
Each of the R phase control step, the S phase control step, and the T phase control step includes:
Further, when the manipulated variable upper limit value OH or the manipulated variable lower limit value OL is not the normal designated value, the operator is notified that the control is performed with the manipulated variable upper limit value OH or the manipulated variable lower limit value OL different from the usual designated value. The power adjustment method characterized by including the notification step to do.

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