WO2018198185A1 - Rotating electrical machine management device and rotating electrical machine management method - Google Patents

Abstract

The present invention performs simpler and more reliable management of the dissipation of heat resulting from the adhesion of dust or the like to the surface of a rotating electrical machine casing. Provided is a rotating electrical machine management device comprising a control unit that includes: an input means for inputting an actual temperature detected from a rotating electrical machine casing; a calculation means for finding an estimated temperature of the rotating electrical machine casing with a heat dissipation value from the surface of the rotating electrical machine casing being taken into account; a means for correcting the heat dissipation value such that a deviation of the estimated temperature relative to the actual temperature becomes equal; and a notification means for outputting a notification signal when a correction amount of the heat dissipation value or a correction rate thereof exceeds a predetermined value.

Description

Rotating electrical machine management apparatus and rotating electrical machine management method

The present invention relates to a rotating electrical machine management apparatus and a rotating electrical machine management method, and more particularly, to a rotating electrical machine management apparatus and a rotating electrical machine management method for managing a heat dissipation impediment such as dirt attached to the rotating electrical machine.

In general industries, general-purpose induction motors (inductive motors) driven by inverters and permanent magnet brushless DC motors are used for speed control applications as power sources such as fan pump air conditioners and transport machines in various production plants. ing. Permanent magnet AC servo motors and vector control for rapid acceleration / deceleration and positioning control that make use of excellent servo performance for speed, torque, and position control applications in semiconductor, electronic component manufacturing and assembly machines, forging machines, etc. An induction motor dedicated to inverter drive is used.

As an example of the use of motors, in the forging machine field, automobile bodies and the like are die-cut from plate materials, and drawing is performed with a press machine. However, AC servo motors with excellent low-speed and high-torque characteristics are used as drive motors. In an example of a press machine using an AC servo motor, it is possible to repeat the rapid acceleration, deceleration and vertical movement of the slide. With the die drawing, the machining speed is reduced to a sudden low speed just before the material from the high speed operation of the slide. The drawing process prevents seizure due to mold temperature rise, improves the dimensional accuracy of the inner diameter of the molded product, makes it possible to temporarily stop the slide during pressurization and operate the hydraulic system, etc. Molding that has been difficult with conventional press machines can now be performed easily.

In order to meet these required performances, AC servo motors have been designed with induction-type motors that have elongated rotor shapes and low inertia, and are dedicated to vector control motors with speed and position sensors. Further, in a permanent magnet motor, a rare earth (eg, neodymium (Nd)) of a high performance permanent magnet is used for the rotor, and the motor is placed in an environment where the motor becomes hot during operation. For this reason, in order to further improve the heat resistance of the permanent magnet, dysprosium (Dy) is used as a part of the additive to cope with high response due to low inertia. And the maximum efficiency of AC servo motors for servo press machines was designed exclusively for the low-speed, high-torque range that is used most frequently.

In addition, servo press machines are required to increase the rotational speed, and it is also required to store rotational energy in the high-speed range during no-load operation, and to use this energy to drill holes in steel materials in the next operation. It became so. As for the load in the press machine, a constant continuous load is not applied, repeated load use that repeatedly repeats acceleration, deceleration, pushing and holding or servo lock with variable speed, or repeated repeated load continuously Is use.

General-purpose induction motors (induction motors), permanent magnet brushless DC motors, permanent magnet AC servo motors, and vector control inverter drive induction motors are incorporated into machines such as press machines and injection molding machines at general factories. Driven. The environment installed in a general factory is rare in an air-conditioned clean room or the like, and many are buildings where outside air enters the factory when the entrance door of the factory is opened. For this reason, the air cleanliness is not controlled and the room pressure is not a positive pressure that is greater than the outside air pressure, so the surrounding air where the AC motor is installed contains a lot of floating dust that has flowed in from outside air. It is out.

On the other hand, in a drive device (an inverter, a brushless DC controller, an AC servo amplifier, or a vector control inverter) that drives an AC motor, a technology in which a motor overload protection function is built in is known.

As an example, Patent Document 1 discloses that when a temperature detection unit is disposed between an inner surface of a motor and a stator winding, and it is detected that the temperature near the stator winding is equal to or higher than a predetermined value, Discontinuing energization of the battery is disclosed.

Patent Document 2 detects the internal temperature and environmental temperature of a servo amplifier or motor, calculates the temperature difference between them, and calculates the theoretical value of the temperature rise of the servo amplifier or motor from the amount of heat generated by the heat generating part. A technique for diagnosing the cooling capacity of a means is disclosed. Patent Document 2 further discloses a technique for displaying the cleaning time and replacement time of the cooling fan.

Patent Document 3 discloses a technology for performing motor overload protection by subtracting the output power of the motor from the input power of the motor and further subtracting the heat dissipation loss from this value to estimate the motor winding temperature.

Dust is a granular substance floating in the air, and is generally called dust. Dust is fine particles formed by crushing solids such as earth and sand, rocks, metal, plants, sawdust, and straw scraps. Cotton dust may also be floating in the air in factories that produce clothing, towels, futons, curtains and carpets. At the metal processing site, cutting, grinding and precision processing of metal materials are performed from a processing line by a machine tool, metal powder and chips are discharged, and oil mist and oil smoke are scattered. Dust, cotton dust, metal powder, discharge of chips, oil mist, and oily smoke may be floating in factories that produce products obtained by cutting and polishing raw materials, and factories related to clothing. The production lines of these factories have AC motors in various machines for the purpose of processing materials that are processed directly into products, or materials that are not final products but indirectly required. The electrical equipment built in is installed.

Some of these machines have a large number of small to large capacity motors built-in, and dust, cotton dust, metal powder, solid chips, oil mist, and smoke splashes are floating in the air. It adheres to and accumulates on the motor housing for a long time.

Normally, after the start time of the factory, employees are all in the room and the line equipment is in operation, so the motor temperature rises, and dust brought in from the outside and dust generated in the line drifts or discharges in the room. As a result, the indoor temperature also rises. In the evening, after work hours, the number of employees will be reduced and the equipment will be shut down, so that dust will slowly and slowly accumulate on the motor housing. In addition, the temperature of the motor decreases and the room temperature gradually decreases. When the room temperature decreases, the water vapor that cannot be present in the indoor air condenses on the dust accumulated on the motor. Condensation is formed on the dust accumulated on each day, and the condensed water vapor evaporates at the start of operation, and the cycle continues to dust accumulation. In addition, since the humidity is always high during the rainy season, a larger amount of dew will form.

Japanese Patent Laid-Open No. 10-174276 JP 2006-221512 A JP-A-11-089083

Factory equipment is inspected on a daily basis or at regular intervals, but it may be difficult to inspect depending on the installation location in the factory or the installation location in the machine. In addition, when the equipment is sold and transferred overseas, the maintenance contract may not be made and may be left to the seller. If the environment where the machine is installed at the relocation site is other than an air-conditioned clean room, and if the climate in Japan is significantly different from the climate of the relocation site, the periodic inspection contents created in Japan may not be satisfied. If proper inspection is not performed, dust adhesion on the surface of the motor housing may stick to the surface of the housing. In this state, the heat dissipation efficiency of the motor is remarkably reduced, and the motor may be burned out even under a rated load.

In the above-mentioned Patent Document 1, dust adhesion detection on the motor casing surface is not performed. For this reason, dust abnormality detection and alarm output cannot be performed, and the time for cleaning cannot be notified from the inverter. However, since the stator winding temperature is directly detected, it is possible to protect the motor from burning. This document 1 describes that a temperature detection sensor and a speed detection processing circuit unit are mounted on a printed wiring board, and the printed wiring board is disposed between a motor inner end face and a stator winding. The temperature sensor and electronic components on the printed wiring board change from the normal temperature to the maximum allowable temperature according to the heat resistance class of the stator winding. There are problems with the reliability of the solder connection part and the reliability of the printed wiring board itself and the electronic components. Further, a current in which switching noise of the PWM output waveform is superimposed flows from the inverter to the stator winding, and noise countermeasures are indispensable for the printed wiring board. If the printed wiring board is covered and shielded with an iron plate to reduce the influence of noise, the temperature of the stator winding escapes to the motor housing through the iron plate, so that heat is not accurately transmitted to the temperature sensor, resulting in a temperature error. For this reason, the temperature sensor faithfully conveys the temperature of the winding, and the electronic components are required to have a heat insulation effect while shielding external noise. There are challenges that must be addressed.

Patent Document 2 detects the internal temperature and environmental temperature of the motor and calculates the temperature difference between them. The amount of heat generated by the motor detects the motor drive current from the characteristics of the motor drive current i versus the amount of heat Q shown in FIG. It is shown that the calorific value is calculated. However, since the amount of heat generated by the motor is not determined only by current, it is difficult to cope with heat generated by factors other than current. Non-Patent Document 1 is disclosed for motor loss. Page 44 shows four types of motor loss: mechanical loss, iron loss, copper loss, and stray load loss. FIG. 3 shows the relationship between the motor loss and the load factor, and it is described that the iron loss and the copper loss are dominant in the motor loss. In FIG. 3, the mechanical loss and the iron loss are constant with respect to the increase of the load factor, and are not affected by the fluctuation of the load factor. Further, it is described that copper loss and stray load loss increase with an increase in load factor, and copper loss includes primary copper loss and secondary copper loss due to motor winding resistance. Even in permanent magnet AC servo motors and brushless DC motors, where the motor load factor is proportional to the motor current, the temperature rise of the motor is related to the motor loss, but the iron loss and mechanical loss are related to the motor current. It doesn't matter. As for the adhesion of dust to the surface of the motor housing, the adhered dust hinders heat radiation from the motor surface, so that even if the load is light, the amount of accumulated heat increases and the motor temperature rises. However, since the motor current does not increase the load factor, the generated loss does not increase. Therefore, the motor drive current i versus the heat generation amount Q disclosed in FIG. There is a problem that dust adhesion is not considered.

Patent Document 3 discloses that motor overload protection is performed by subtracting the motor output power from the motor input power, further subtracting the heat dissipation loss from this value, and estimating the motor winding temperature. Normally, the temperature rise of the motor generates heat because there is a loss in the motor. Document 3 shows that the calculation of the heat generation amount of the motor is not based on the total loss but on the loss obtained by subtracting the heat dissipation amount from the total loss. As a result, the estimated temperature is not accurate because the motor loss is not calculated by the total loss. Moreover, the adhesion of dust to the motor housing surface is not considered. For this reason, since the above-mentioned content is not considered in the motor temperature estimation calculation, there is a problem that the risk of motor burnout remains.
There is a demand for a technique for more easily and surely managing heat dissipation due to dust adhering to the surface of a rotating electrical machine casing.

In order to solve the above problems, for example, the configuration described in the claims is applied. That is, an input means for the actual temperature detected from the rotating electrical machine casing, a calculating means for obtaining an estimated temperature of the rotating electrical machine casing in consideration of a heat radiation value from the surface of the rotating electrical machine casing, and the estimated temperature relative to the actual temperature A rotating electrical machine management comprising a control unit having means for correcting the heat dissipation value so that the deviations are equal and a notification means for outputting a notification signal when the correction amount or correction ratio of the heat dissipation value exceeds a predetermined value Device.

Further, the control method of the rotating electrical machine by the control device, wherein the control device includes a housing temperature of the rotating electrical machine detected from a temperature detection device and a housing estimated temperature of the rotating electrical machine obtained by calculation. Calculate the deviation, calculate the heat dissipation value of the rotating electrical machine casing where the deviation is equal, and notify the outside when the ratio between the heat dissipation value as the initial value and the heat dissipation value obtained by the calculation is greater than or equal to a predetermined value This is a method for managing a rotating electrical machine that outputs a signal.

ADVANTAGE OF THE INVENTION According to this invention, the deterioration of the heat dissipation resulting from dust adhesion etc. to a rotary electric machine housing | casing can be managed simply and reliably.
Further problems, configurations and effects of the present invention will become more apparent from the following description.

It is a figure which shows typically the loss of the motor at the time of the power running of the motor power converter device by one Embodiment to which this invention is applied. It is a figure which shows typically the loss of the motor at the time of regeneration of the motor power converter device by this embodiment. It is a figure which shows typically the loss of the motor at the time of regeneration of the motor power converter device when using the DC power supply by this embodiment. It is a figure explaining the case where repetitive load is used in this embodiment from the rotational speed and torque of a press machine motor. It is a figure explaining the kind of loss which occurs in each part of the motor by this embodiment. It is a block diagram which shows typically the structure of the motor temperature diagnostic apparatus by Example 1. FIG. FIG. 7 is a block diagram schematically showing an example in which the input power detection portion has another configuration in the configuration of FIG. 6. It is a figure which shows typically an example of the dust adhesion characteristic to the motor housing | casing by Example 1, and the transition of a dust excessive warning and an overload detection output signal. It is a figure which shows typically an example of the excessive dust amount warning from the motor temperature diagnostic apparatus by Example 1 to a monitor panel. It is a figure which shows typically the followable | trackability of the motor effective surface area at the time of the auto tuning by Example 1. FIG. FIG. 6 is a diagram schematically illustrating reading / writing of dust amount data in a memory by a hardware circuit when power is turned on / off according to the first embodiment. FIG. 11 according to the first embodiment shows a time chart of power on / off. It is a figure which shows typically followability when the motor effective surface area by Example 1 is reset to the initial value. It is a block diagram which shows typically the structure combined with the overload protection circuit of another system in the motor temperature diagnostic apparatus by Example 2. FIG. FIG. 10 is a block diagram schematically illustrating a configuration in which a motor with a forced air cooling fan is combined with a rotating electrical machine in the motor temperature diagnosis apparatus according to the third embodiment. It is a motor temperature diagnostic apparatus by Example 3, and is a figure which illustrates typically the heat dissipation characteristic of a motor housing | casing.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

First, the relational expression of the motor temperature related to this embodiment will be described. Regardless of induction motors or permanent magnet motors, AC motors serve to convert electrical energy into work energy. However, not all of the input power Pin input to the AC motor is useful as work energy, and part of it is consumed as a loss inside the motor, and part of the heat becomes sound. Electric power useful for work is output power Pout, which gives torque Tf and rotational speed Nf to a load connected to the motor. Inputs and outputs are expressed in units of W (watts).

Suppose that the input Pin (W) and the output Pout (W), the relational expression of the motor efficiency η and the loss Ploss (W) can be expressed by (Equation 1) and (Equation 2).

In the present embodiment, the physical quantity that is the basis of the heat quantity of the motor is not the motor current but the total loss quantity Ploss of the motor. It is necessary to devise to calculate the total loss amount by accumulating individual losses, but the total loss can be obtained even if the breakdown of the loss is not known. That is, as shown in (Expression 2), the total loss Ploss of the motor is obtained by subtracting the output power Pout from the input power Pin of the motor.

In the motor loss, iron loss is classified into hysteresis loss and eddy current loss, and it was mentioned earlier that the loss does not change even if the motor current increases. As for hysteresis loss and eddy current loss, Steinmetz's empirical formula has been conventionally known. Hysteresis loss Ph has the following relationship (Equation 3), and eddy current loss Pec has the following relationship (Equation 4). Become.

The hysteresis loss is proportional to the frequency (motor rotation speed), and the eddy current loss is proportional to the square of the frequency (motor rotation speed), so it becomes particularly large at high speed. Further, in a motor power converter in which a motor is driven with a PWM (Pulse Width Modulation) waveform, the carrier frequency is given by a ripple current including a high frequency component of several k to several tens of kHz. The current including the high-frequency ripple becomes a magnetic flux with ripple in the iron core or permanent magnet of the motor, and causes iron loss which is hysteresis loss or eddy current loss. The iron loss is obtained by a magnetic field analysis simulation because a magnetic circuit is formed by the material of the permanent magnet of the rotor, the plate thickness, and the cross-sectional hole shape in the stator or rotor core or permanent magnet motor.

The motor output power Pout can be obtained by (Equation 5). Here, the rotational speed Nf and the torque Tf of the motor are controlled by an AC servo amplifier, a DCBL controller, an inverter, a vector control inverter, etc. (hereinafter sometimes referred to as “motor power converter”) that drive the motor. And can be easily calculated in the motor power converter. A technique is also known in which an inverter uses sensorless vector control to perform high-accuracy speed control by estimating the rotational speed of the motor and suppressing the load fluctuation rate even if the motor does not have a speed sensor such as an encoder. The motor output power Pout can also be calculated using the estimated rotational speed Nf of the motor that is internally processing the sensorless vector control inverter.

Next, the motor input power Pin is expressed by (Equation 6). Similarly to the above, the motor input power Pin is an output of these motor power conversion devices, and is an amount controlled by itself, which can be easily calculated.

As another method, the instantaneous value product of each phase voltage and phase current applied to the motor is calculated, and the sum of the phase powers of the U, V, and W phases of the motor can be obtained by (Equation 7). it can.

Here, when each instantaneous value phase voltage is represented by Vu, Vv, and Vw, the phase voltage effective value is represented by Vrms, the angular frequency of the power source is represented by ω, and the time is represented by t, more specifically, (Equation 8-1) to (Equation 8-3) and (Equation 9-1) to (Equation 9-3) are substituted and calculated, and the input power Pin of the motor can be obtained by (Equation 10).

Also, if each instantaneous phase current is Iu, Iv, Iw, the effective phase current value is Irms, and the phase angle is φ

The total loss Ploss of the motor obtained in the above (Equation 2) is calculated as Pin-Pout as (Motor input power)-(Motor output power) as an amount that changes to the conventional motor current. If the total heat quantity of the motor is Q1 (J), the total loss Ploss can be integrated over time and expressed as (Equation 11).

In addition, a normal motor is composed of various parts, and each material is different. Therefore, the measurement of the specific heat c1 between the motor electrical part and the housing is not performed by the cooling fan, but the measurement location of the motor temperature is determined, and a constant loss is caused in the motor stator winding while maintaining heat insulation with respect to the surroundings. Ploss (amount of heat) is given, and the temperature rise ΔTc1 of the motor housing is measured and calculated by (Equation 12). The equivalent specific heat of the motor is the equivalent specific heat because the motor is made of various materials, and the temperature rise value changes when the measurement location is changed, so the specific specific heat in the sense of specific heat at that location is specified. It expresses as

When the equivalent specific heat c1 of the motor is obtained by (Equation 12), the total amount of heat Q1 generated from the inside of the motor winding (including the core and the like) is accumulated in the motor housing by (Equation 11), and the motor housing ( The temperature rise Tc1 of the heat storage unit is obtained by (Equation 13).

The temperature rise Tc2 (K) of the stator winding of the motor is expressed as follows: the amount of heat of the stator is Q2 (J), the mass of the stator is m2 (kg), and the equivalent specific heat of the stator winding is c2 (J / kg · K). Then, (Formula 14) is obtained.

Next, the temperature rise Tc3 (K) of the rotor cage conductor of the induction motor is such that the amount of heat of the rotor is Q3 (J), the mass of the rotor m3 (kg), and the equivalent specific heat c3 of the rotor cage conductor ( J / kg · K), it is as shown in (Equation 15).

Further, the temperature increase of the permanent magnet of the rotor of the permanent magnet type motor is expressed as the same symbol as Tc3 (K), the amount of heat of the rotor is Q3 (J), the mass of the rotor m3 (kg), the permanent magnet of the rotor Assuming that the equivalent specific heat c3 (J / kg · K) is given, the temperature rise value is expressed as the same equation as (Equation 15).

Similarly, the temperature rise Tc4 (K) of the bearing of the motor is expressed as follows, assuming that the heat quantity of the bearings and others is Q4 (J), the mass of the bearings and other parts m4 (kg), and the equivalent specific heat c4 (J / kg · K) of the bearings. 16).

Here, most of the motor loss is diffused (propagated) to each part of the motor as heat. For example, it is conducted through a solid metal such as an installation jig, and is radiated into the atmosphere by natural or forced convection from cooling fins on the motor surface. Alternatively, a part of the sound is emitted as a sound. In either case, heat transfer is expressed by (Equation 17).

In addition, there is a thermal resistance Rth (° C./W) as a mathematical formula for calculating a temperature rise value with a cooling fin or the like. This thermal resistance gives the loss value (W) in the steady state, and it can be calculated that the temperature rise value in the saturated state becomes (K), but the load applied to the motor is real time. When changing, there is a possibility that an excessive temperature cannot be obtained even if the loss value (W) that changes instantaneously is multiplied by the thermal resistance.

Therefore, in this embodiment, the motor is expressed by a thermal transfer function, the temperature rise value of the motor housing is calculated by (Equation 13), and the temperature rise value of the motor housing takes the difference from the ambient temperature. The amount of heat released per unit time from the motor is calculated from (Equation 17) from the temperature difference of the motor housing. From these, the current total loss value of the motor is calculated from the difference between the total loss Ploss generated from the motor and the heat dissipation amount Qf per unit time radiated from the motor, and the motor is fixed from this total loss current value. The temperature increase value of the stator winding is calculated from (Equation 14), the temperature increase value of the motor rotor is calculated from (Equation 15), and the temperature increase value of the bearing portion that supports the rotor by the motor stator is 16), the temperature rise value of each part is compared with a threshold value for determining an overload, and when any part detects an overload first, it outputs it as an overload of the motor.
The above is the relational expression of the motor temperature related to the present embodiment. Hereinafter, each exemplary embodiment will be described in detail with reference to the drawings.

FIG. 1 schematically shows motor loss during powering of the motor power converter. Reference numeral 1 denotes a motor, which rectifies the power supplied from the AC power source 2 by the full-wave rectifying converter 5 of the forward converter 4 with a power regeneration function, smoothes it by the smoothing capacitor 8, and converts it to a DC power source.

Next, this DC power is converted back to AC by the reverse converter 9 to supply power to the motor 1. In addition, in the reverse converter 9, the switching element 10 and the flywheel diode 11 are connected in antiparallel, and one arm connected in series on the upper side (P side) and lower side (N side) has an n-arm structure, that is, an n-phase component. Is done. In FIG. 2, three phases for three arms are shown. The switching element 10 performs PWM (Pulse Width Moduiation) control by switching of the power circuit. The motor 1 applies a rotational speed Nf and torque Tf to the motor output shaft as power to drive the machine.

Here, the width of the arrow of the motor 1 shown in the figure schematically shows the magnitude of the electric power. In the power running state, the motor 1 obtains the input power Pin and outputs the motor output Pout. Therefore, the magnitude relationship is input power Pin> output power Pout, and the reduced amount is loss Ploss. Most of the loss Ploss is generated by the motor. During the power running operation, the power regeneration converter 6 of the forward converter 4 with the power regeneration function is in a resting state.

FIG. 2 schematically shows motor loss during regeneration of the motor power converter. FIG. 2 shows, for example, the case where the motor is an elevator motor that performs four-quadrant operation. The elevator motor moves up and down in the vertical direction, and when it is lowered, the motor torque is output in the upward direction while suppressing the vehicle cage from falling in the direction of gravity, and the speed moves smoothly in the downward direction. Become. In the regenerative operation, the motor output shaft is rotated from the outside as the vehicle cage descends due to gravity. Therefore, the motor is in a power generation state, and the generated (regenerated) energy passes from the motor 1 through the inverse converter 9 and charges the smoothing capacitor 8 with the generated (regenerated) energy. The forward converter 4 with a power regeneration function is a power regeneration converter 6 that regenerates the power generation (regeneration) energy accumulated in the smoothing capacitor 8 to the AC power source 2 through the regeneration AC reactor 7.

At this time, when the relationship between the motor input power Pin and the output power Pout is viewed in terms of energy flow, the power from the load (machine) side passes through the motor, and the power source of the reverse converter 9, the smoothing capacitor 8, and the forward converter 4 with the power regeneration function. It is regenerated to the AC power source 2 through the regenerative converter 6 and the regenerative AC reactor 7. At this time, the directions of the arrows of Pin 1 and Pout of the motor 1 are opposite to those in FIG. 2, and the width of the arrow (degree of power) is the largest at the motor output Pout, the input power Pin is small, and the magnitude relationship. Is (absolute value of input power Pin) <(absolute value of output power Pout), and the smaller amount is loss Ploss. Most of the loss Ploss is generated by the motor. During the regenerative operation, the full-wave rectifying converter 5 of the forward converter 4 with the power regeneration function is in a resting state.

1 and 2, the input power Pin and the output power Pout are handled in a four-quadrant operation, so the power running state in FIG. 1 is defined as a positive direction. Therefore, in FIG. 2, which is in the regenerative state, the input power Pin and the output power Pout are negative values.

Here, it is verified whether or not the direction of the motor loss shown in FIG. In FIG. 2, since the input power Pin and the output power Pout are negative values (absolute value of the input power Pin) <(absolute value of the output power Pout), the absolute value of Pout is large. When Pin is expressed as (−small) and Pout as (−large), (Expression 2) Ploss = Pin−Pout = (− small) − (− large) = (− small + large)> 0, and Ploss is positive. Value. Therefore, it can be seen that the direction of Ploss in FIG. 2 is the same as that in FIG.

Fig. 3 schematically shows motor loss during regeneration of a motor power converter using a DC power source. In FIG. 2 and FIG. 3, a DC power source is obtained through a forward converter for conversion by an AC converter, and then converted into AC again by an inverse converter. However, the forward converter 4 with a power regeneration function is not required for supply by a DC power source (for example, a battery).

Since FIG. 3 shows a regenerative state, the generated (regenerated) energy passes from the motor 1 through the inverse converter 9 and charges the smoothing capacitor 8 with the generated (regenerated) energy. For this reason, the motor 1 and the inverter 9 are the same as those in FIG. The difference from FIG. 2 is that the power supply is a direct current, and this direct current charges the smoothing capacitor 8 with power generation (regeneration) energy, and at the same time, directly regenerates and charges the direct current power supply 3. The positive and negative polarities and magnitudes of the absolute values of the input power Pin and the output power Pout are the same as in FIG. The description of the motor loss during power running is omitted here because the forward converter 4 with the power regeneration function in FIG. 1 is a direct current output and is the same as the description of the inverse converter 9 in FIG.

FIG. 4 is a diagram illustrating an example of using a repetitive load from the rotational speed and torque of a press machine motor. In this example, it is assumed that the press machine has a structure in which the rotational movement of the motor is changed to a reciprocating movement by a crank mechanism, and performs thin plate drawing at the bottom dead center by moving the slide up and down. In FIG. 4, the upper side shows the motor rotation speed. The slide of the press machine is driven forward from the top dead center, stopped just before the thin plate material before the bottom dead center to prevent seizing of the mold, held down, and then lowered again to press and draw. I do. After sufficient pressing, the motor operates in the same forward direction, the slide rises, returns to top dead center, and the 1/2 cycle is completed. The lower side of FIG. 4 shows the torque of the motor. The motor accelerates in the power running direction when it descends 1, operates at a constant speed, with regenerative torque when decelerated to a stop, and the pushing throttle is in power running. When the slide returns to the top dead center, the motor accelerates in the forward direction, operates at a constant speed with power running, and stops at a regenerative operation when decelerating.

When this operation is repeated, the motor moves down the slide in the reverse direction, stops just before the thin plate material before the bottom dead center to prevent seizure of the mold, holds the position, then lowers again to perform the drawing process. Do. After fully pressing, the motor operates in the same reverse rotation direction, the slide moves up and returns to top dead center, and the remaining half cycle is completed. The motor can rotate once in the forward operation, return once in the reverse operation, and the slide can be drawn twice.

¡When this operation is performed at high speed, the slide starts to rotate forward from the middle point between the top dead center and the bottom dead center, is drawn at the bottom dead center, and stops after driving at the opposite middle point. Return starts with reverse rotation, draws at the bottom dead center, and returns to the original intermediate point with reverse rotation. This operation is called a pendulum operation because the fulcrum of the crankshaft is fixed to a freewheel that performs a circular motion, and the fulcrum moves like a pendulum of a watch. When the rotation angle of the fulcrum is smaller than 180 °, the tact time is reduced, the load factor of the motor is increased, and the continuous load is used in the direction of overload, so that sufficient overload protection is required.

FIG. 5 shows the types of losses that occur in each part of the motor. The loss generated for each part of the induction motor and the permanent magnet motor is roughly classified into a fixed loss and a load loss. Fixed loss includes iron loss and mechanical loss that are not related to the size of the load, and load loss includes copper loss and stray load loss that increase or decrease depending on the load size. The copper loss shown in FIG. 5 occurs in the primary winding and the secondary winding, and occurs as (current square) × (winding resistance). Copper loss occurs in the stator windings of induction and permanent magnet motors and the squirrel-cage conductors or bar conductors of induction motors. The stray load loss is a loss caused by an eddy current flowing in a metal part other than the conductor and the iron core due to the flow of the load current. The stray load loss is generated in the motor housing and the cover and is difficult to measure and measure. Iron loss includes hysteresis loss and eddy current loss, which are related to the increase in frequency (motor rotation speed) and maximum magnetic flux density, and occur in the stator and rotor iron cores and permanent magnet motor permanent magnets. (Expression 3) (Expression 4) Further, in an inverter, a controller, and a servo amplifier driven with a PWM waveform, iron loss due to a high frequency carrier frequency given to the motor occurs in the iron core and permanent magnet. The mechanical loss includes a friction loss generated between the shaft and the bearing and a wind loss caused by friction of the rotor with surrounding air. When the motor is cooled by another cooling fan, the power consumption of the fan is also added to the mechanical loss. These losses are divided into an induction motor and a permanent magnet motor in FIG. 6. The parts are the iron core and windings for the stator, the iron core for the rotor, the cage conductor (induction motor), and the permanent. In addition to magnets (permanent magnet motors), other than stators / rotors, they are classified into bearings and fans. There are four types of losses: copper loss (primary and secondary), stray load loss, iron loss, and mechanical loss. The parts to be marked are indicated by circles.
Based on the above, embodiments will be described below.

FIG. 6 schematically shows the configuration of the motor temperature diagnostic apparatus 76 according to the first embodiment to which the present invention is applied. The motor temperature diagnosis device 76 is connected to the motor 1a and the motor power conversion device 74 via a communication line, and changes the measured temperature of the motor 1a and the predicted temperature obtained by calculation by inputting and outputting various signals. Is detected. The motor temperature diagnostic device 76 has a function of detecting this change as a change in the heat dissipation state of the motor 1a. In the present embodiment, this change is regarded as the degree of adhesion of dust or the like on the surface of the housing of the motor 1a and output externally.

The motor 1a is, for example, a natural air-cooled fully-closed rotating electric machine, such as an induction motor or a permanent magnet motor. In this embodiment, a three-phase motor is illustrated, but a multi-phase motor other than the three-phase motor may be used. An encoder 14 is provided on the non-load side, and outputs the position and speed signal of the output shaft to the motor power converter 74 in the case of a permanent magnet motor. The motor 1a is electrically connected to the motor power converter 74, and power is supplied from the PWM circuit 25 of the motor power converter 74 via the power lines U, V, and W. The main circuit configuration of the PWM circuit 25 includes the forward converter 4 with the power regeneration function and the inverse converter 9 shown in FIGS. The PWM circuit 25 is connected to the AC main circuit power source 2 or the DC power source 3 shown in FIGS.

The motor 1 a includes a motor housing temperature detector 71 (for example, a temperature sensor) on the surface of the housing, and the motor housing temperature detector 71 transmits the motor housing temperature to the motor temperature diagnostic device 76. The motor housing temperature is received by the dust amount detection circuit 72 of the motor temperature diagnostic device 76. The motor temperature diagnosis device 76 receives the ambient temperature Ta of the motor 1a via the motor ambient temperature detector 52 (for example, a temperature sensor). The ambient temperature Ta is taken into the motor housing block 75 of the motor temperature diagnostic device 76.

The motor current is detected by the U-phase current detector CTu12 and the W-phase current detector CTw13 arranged on the output side of the PWM circuit 25, and the signal is sent to the position / speed / current control logic circuit 70. The position / speed / current control logic circuit 70 detects the position / speed / current control of the motor 1a from the encoder 14, the magnetic pole position signal in the case of a permanent magnet motor, and the U-phase current detector CTu12. And, the current detected by the W-phase current detector CTw13 is subjected to vector control with a sensor by a feedback signal, and the motor current is controlled by the load (for example, positioning of the workpiece and increase / decrease in speed) connected to the output shaft of the motor 1a. While trying to run.

Next, the total loss Ploss signal output from the position / velocity / current control logic circuit 70 to the motor housing block 75 is the input power Pin−output power of (Equation 2) inside the position / speed / current control logic circuit 70. It is given by calculating Pout. The motor output power Pout can be obtained by (Equation 5). Here, the rotational speed Nf and the torque Tf of the motor 1a are amounts controlled by the motor power converter 74 that drives the motor, and can be calculated in the motor power converter 74. Further, the motor input power Pin is expressed by (Equation 6) and is an amount controlled by itself, and can be obtained by calculation with the motor power converter 74.

The motor housing block 75 to which the total loss Ploss signal is input will be described. The motor housing block 75 includes a stator, a rotor, and a bearing portion, and shows a block of the entire motor including the motor housing and the electric portion. Here, the total loss Ploss (input power Pin−output power Pout) of the motor is given and passed through the subtractor 20 and input to the transfer function of the motor heat storage unit 42-1: 1 / (m1 · c1 · s). The total amount of heat Q1 is calculated, for example, as shown in (Equation 11), and the motor housing estimated temperature increase value Tc1 (K) is calculated as shown, for example, in (Equation 13). The motor ambient temperature Ta (° C.) is added to this value, and the motor casing estimated temperature Tc1 (° C.) is output to the overload determination circuit 43-1 and the subtracter 20.

The estimated motor housing temperature Tc1 (° C.) is subtracted from the ambient temperature Ta (° C.) by the subtracter 20, and the equation (17) is calculated from the transfer function of the motor heat radiation unit 40: α · (kf × A). Then, the heat radiation amount Qf (J / s) per unit time is output. Here, kf represents a forced cooling coefficient. In FIG. 1, since the motor 1a is a natural air cooling type fully closed motor, it is given by kf = 1. The output of the motor heat radiating unit 40 is subtracted by the subtracter 20 from the total loss Ploss, and the amount of heat radiated Qf per unit time is subtracted to constitute negative feedback feedback. Here, Ploss-Qf is referred to as a total loss current value Pe. The total loss current value Pe is input to the transfer function of the motor heat storage unit 42-1: 1 / (m1 · c1 · s), and the total heat quantity Q1 of the motor is calculated as shown in (Equation 11), for example, ( As shown by the equation (13), the motor housing temperature rise value Tc1 (K) is calculated, and thereafter this is repeatedly calculated.

The total loss current value Pe branches from the motor housing block 75 to the overload detection unit 73, and multiplies the loss ratio of the specific part of the motor to the total loss Pe (loss of specific part / total loss Pe). When the temperature rises above the overload threshold, the overload detection output OL-2 is output and the motor is overloaded to stop power supply to the motor. Can be done. As a result, the motor can be protected from burning and the like.

The overload detection unit 73 includes an entire housing including a motor electrical unit, a stator side winding on the stator side, a permanent magnet on the rotor side (in the case of a permanent magnet type motor), or a secondary winding (induction type). In the case of a motor) and an overload calculation unit including a plurality of parts including a bearing. Each calculation unit performs overload detection of each part in comparison with a threshold value that secures an appropriate temperature margin according to different materials and heat resistance classes. The overload detection signal for each of these parts is logically summed, and when one of them generates the overload detection signal first, this is used as an overload detection signal for the motor, and an overload detection output OL-2 is output. By stopping the power supply to the motor by overloading the motor, the motor can be protected from burning. Which part is overloaded depends on the condition of the applied load, for example, constant load use or the most severe repeated load use condition, and therefore, it is always different for each type of loss occurring in each part described in FIG. Determination is made in the overload detection unit 73 by calculation.

By the way, if dust adheres to the surface of the motor casing, the heat dissipation efficiency from the motor is reduced. In such a case, even if the load is light, the temperature rise of the motor becomes large and the motor may be burned out. The total amount of heat stored in the motor is stored in the motor heat storage unit 42-1, and is radiated from the motor heat dissipation unit 40. The integrated value of the total loss current value Pe, which is the difference, is the total amount of heat at that time, and is established by the balance between the heat storage unit 42-1 and the heat radiating unit 40. In the case of natural cooling, the heat radiation amount Qf of the motor heat radiation portion 40 is given, for example, as shown in (Equation 17), and is represented by the product of the heat transfer coefficient α and the surface area A of the motor, and there is no adhesion of dust or the like. In this case, the motor surface area A0 is stored in the memory as a parameter at the time of shipment from the manufacturer. The present embodiment is characterized in that the motor temperature is managed in consideration of the fact that the motor surface area changes substantially on the heat dissipation surface due to adhesion of dust or the like. That is, when dust or the like adheres to the surface of the motor housing, the motor surface area apparently decreases, and this is treated as a variable as the motor effective surface area A.

Here, the motor temperature diagnosis device 76 determines how much the amount of dust and the like adhering to the motor housing is reduced by the current motor effective surface area ratio Ar = A / A0 with respect to the initial value (A0) without dust or the like. The amount of dust adhering to the motor housing is calculated numerically depending on whether or not Such calculation is performed by the dust amount detection circuit 72.

The dust amount detection circuit 72 takes in the motor casing detection temperature Tc1f from the motor casing temperature detector 71. On the other hand, the dust amount detection circuit 72 takes in the motor housing estimated temperature Tc1 from the motor housing block 75, and the subtracter 20 calculates the difference Tc1f-Tc1. Thereafter, the deviation signal Te obtained by the calculation is amplified by the amplification circuit or proportional integration circuit 67, the polarity is inverted by the inversion circuit 77, and the signal is sent to the motor effective surface area calculation circuit 68.

Here, at the start of operation, an initial value A0 is set for the motor effective surface area A. However, if dust is actually attached to the surface of the motor housing, the heat dissipation efficiency is reduced. The case detection temperature Tc1f has a higher temperature rise value than when there is no dust. On the other hand, since the motor effective surface area is the initial value A0 (there is no dust), the heat dissipation efficiency does not decrease in the calculation in the motor casing block 75, so the estimated motor casing temperature Tc1 is The temperature at the time of absence is maintained, and the deviation Te is positive (Tc1f−Tc1> 0). The deviation Te is amplified by the amplifying circuit or the proportional integration circuit 67 and the polarity is inverted by the inverting circuit 77. Therefore, the motor effective surface area calculating circuit 68 operates to reduce (correct) the value of the motor surface area A0 that is set to the initial value. To do. The output of the motor effective surface area calculation circuit 68 constantly updates the variable parameter of the motor effective surface area A of the transfer function 40 of the motor heat radiation part of the motor housing block 75.

The above operation operates to reduce the effective surface area of the motor when dust adheres to the surface of the motor casing, so that the estimated motor casing temperature Tc1 is brought closer to the actual motor casing detection temperature Tc1f. When the deviation Te becomes zero, the motor effective surface area calculation circuit 68 stops the increase / decrease operation of the motor effective surface area, so that the motor effective surface area has settled in the tuning completed state. Here, the effective surface area A of the motor is treated as a variable parameter for dust adhering to the motor housing surface, and it is related to the amount of heat dissipation in the balance of the total motor heat Q1 = (heat storage)-(heat dissipation). Increase or decrease the effective surface area of the motor.

Further, the output of the motor effective surface area calculation circuit 68 is compared with a predetermined dust amount threshold value by the warning determination circuit 69, and when the set dust amount threshold value is exceeded, the operation of the motor is continued and the dust excessive warning output WN is output. It is like that.

When dust adheres to the surface of the motor casing, the motor effective surface area is reduced, the estimated motor casing temperature Tc1 is brought close to the actual motor casing detection temperature Tc1f, and the deviation Te is zero while following the dust accumulation amount. Continue to maintain. Since this operation is performed by a negative feedback automatic control system, the amount of dust on the motor housing is automatically tuned as the motor effective surface area.

In addition, when the motor housing detection temperature Tc1f of the dust amount detection circuit 72 and the motor housing estimated temperature Tc1 do not match, the actual motor housing temperature and the estimated temperature of the motor housing block 75 which is a computational model are calculated. Is in a disjoint state, and the actual total heat quantity of the motor is not reflected in the calculation model. In this state, the overload detection by the motor housing block 75 and the overload detection performed by the overload detection unit 73 cannot perform normal operations.

Note that the dust amount detection circuit 72, the motor housing block 75, and the overload detection portion 73 in the motor temperature diagnosis device 76 described above are realized by the cooperation of the CPU and software.

FIG. 7 schematically shows an example in which the input power detection portion is implemented with another configuration. In the description of FIG. 6, the total loss Ploss signal output to the motor housing block 75 by the position / velocity / current control logic circuit 70 is given by calculating the input power Pin−the output power Pout. Was calculated as shown in (Equation 6), for example. In contrast, the modification shown in FIG. 6 detects the phase voltages Vu, Vv, Vw from the motor terminal voltage, and the motor current detects Iuf, Iwf from the U-phase, W-phase current detectors CTu12, CTw13. Arithmetic is performed. FIG. 7 schematically shows the flow of Pin calculation processing. The phase current Ivf is configured to be Ivf = − (Iuf + Iwf) from the three-phase current Iuf + Ivf + Iwf = 0. The CPU of the position / velocity / current control logic circuit 70 calculates (Equation 8-1) by calculating the instantaneous value product of the phase voltage and phase current for each of the U, V, and W phases. The product operation of the phase voltage of (Equation 8-3) and the phase current of (Equation 9-1) to (Equation 9-3) is performed. The CPU can obtain “three-phase input power Pin” by adding the input power amounts of the U phase, V phase, and W phase of each phase.

FIG. 8 schematically shows an example of dust adhesion characteristics to the motor casing, and an excessive dust warning and overload detection output signal. In FIG. 8, the X axis represents time t, the Y axis (upper left axis) represents the motor effective surface area ratio Ar (= A / A0), and the Y axis (upper right axis) represents the rate of decrease in the motor effective surface area ratio (= Ar -1). When the scale on the left side of the Y axis is 1.0, 0.8, 0.6..., The right side of the Y axis is 0, −0.2, −0.4. When the dust begins to adhere to the motor housing, the motor surface area is still visible, so the motor effective surface area slowly decreases. When the range in which the motor surface area can be visually checked becomes, for example, about half, the decreasing slope of the motor effective surface area becomes steep. If the entire motor is covered more than a certain level, the rate of decrease will saturate even if it accumulates more. The motor temperature diagnosis device 76 outputs an excessive dust warning signal WN and an OL-1 signal and an OL-2 signal that are overload detection output signals.

Further, when the motor effective surface area is in the tuning state, that is, when the deviation Te between the motor housing estimated temperature Tc1 and the motor housing detection temperature Tc1f is within a certain value, the motor temperature diagnosis device 76 completes the motor effective surface area tuning. The MA signal indicating the above is output. The timings of these output signals are shown in FIG. The excessive dust warning signal WN is a warning signal, and the operation of the motor continues. With this warning signal, a warning is displayed to the operator or driver who operates this machine that dust is attached to the motor casing.

The OL-1 signal, which is an overload detection output signal, accurately grasps the total heat quantity of the motor, and is output when the motor casing temperature exceeds the first threshold value that causes an overload.

Further, the OL-2 signal that is an overload detection output signal is sent to the overload detection part 73 when, for example, if the part is a stator winding, the stator winding exceeds a second threshold value at which the stator winding is overloaded. Output. The overload detection output signals OL-1 and OL-2 protect the motor from burning by stopping the power to the motor because the motor part is overloaded.

The MA signal indicating whether the motor effective surface area is in the tuning state can be monitored by the operation and the monitor panel (display device) as shown in FIG. The amount of dust adhering to the motor housing is plotted with the ratio of the current motor effective surface area to the initial motor effective surface area as time passes, and is displayed on the monitor screen together with the dust amount threshold. Similarly, an excessive dust warning output (WN) and overload detection outputs (OL-1) and (OL-2) can be confirmed. In FIG. 8, the individual operations of the overload detection outputs (OL-1) and (OL-2) are such that (OL-1) is turned on first and (OL-2) is turned on later. This shows that the power supply to the motor is stopped first (OL-1). In FIG. 1, the (OL-1) and (OL-2) outputs have been described as individual outputs. However, the (OL-1) and (OL-2) outputs are logically ORed in the motor temperature diagnosis device 76. The overload output of the motor may be set when it is turned on first. The monitor screen displayed on the operation and monitor panel also displays the individual (OL-1) and (OL-2) operations, so the driver etc. Can be confirmed. Since the motor effective surface area tuning completion MA signal is also monitored, the tuning state can be confirmed in the same manner.

FIG. 9 schematically shows a notification of an excessive dust amount warning as an example of an external notification output to be displayed on the monitor panel from the motor temperature diagnostic device. When dust adheres to the motor housing and an excessive dust warning is output, a warning is displayed on the external operation and monitor panel 92 through the connection cable 93 from the motor temperature diagnosis device 76, and the operator or mobile machine operating the machine It is necessary to immediately notify the warning state to the driver who drives the vehicle (for example, a traveling carriage or a construction machine). The reason for outputting the warning is that the motor stops suddenly in the overload protection trip that performs the overload protection operation with the highest priority, but the motor suddenly stops in the same way as the line device, etc. to which the motor is applied. There is a risk of sudden deceleration and damage to line products. Also, when stopping at a high speed on a downhill with an automobile, the regenerative brake is generally operated while driving the motor, decelerated to a safe speed, and then braked at a safe place to stop. When the protective trip occurs, the regenerative brake is not applied and the brakes are relied only on, and the brakes may burn out. In order to prevent these, an alarm can be output, leading to a switching operation such as a stop preparation or a stop preparation operation until the vehicle is decelerated to a safe speed.

FIG. 9 shows an example of display on the screen of the external operation and monitor panel 92 when a warning is output. “Warning” and other display examples are not limited to those described. As shown in the figure, “Warning” and “Motor cleaning Execute immediately! ”,“ Excessive dust on the motor ”or“ Deterioration of motor cooling capacity ”, etc. The operator who operates the machine or the driver who operates the moving machine is clearly indicated or blinking the frame, buzzer, sound Furthermore, various modes such as adding a warning by vibration or the like can be taken.

FIG. 10 is a diagram for explaining the followability of the motor effective surface area during auto-tuning. The dust amount detection circuit 72 operates so as to numerically reduce the motor effective surface area when dust adheres to the surface of the motor housing, and the deviation Te signal is brought close to the estimated motor housing temperature Tc1f to the actual motor housing detection temperature Tc1f. It becomes zero. Since this operation is always performed by automatic control, auto tuning is performed. FIG. 10 shows that during operation of the motor, when dust or the like adheres to the motor casing and the motor effective surface area ratio Ar (= A / A0) reaches about 0.85, the operator stops the operation, The example which implemented the cleaning which removes the dust adhering to a housing | casing is shown. FIG. 10 is an example in which the motor is restarted after cleaning, and the data update history of the motor effective surface area ratio Ar is shown in the time chart before and after cleaning. Since the motor effective surface area A that has been auto-tuned before cleaning remains as it is, the motor effective surface area ratio Ar (= A / A0) is 0.85. Adhesion has been removed and Ar = 1.0. The machine is restarted in this state, and auto-tuning of the motor effective surface area is executed.

In this figure, it rose slowly during the time tr from the restart and recovered to Ar = 1.0. At this time, the motor effective surface area tuning completion MA signal is not completed until the time tr. On the contrary, the motor effective surface area data is auto-tuned to the initial value A0 over the time tr. The reason for this is that the adhesion of dust to the motor casing is usually as fast as several months and as long as half a year. The integration time of the amplifier circuit or the proportional integration circuit 67 is set to a long time, and the proportional gain is also a small value. On the other hand, if the integration time is short and the proportional gain is large, the overshoot becomes large, resulting in an oscillation system or an unstable system. For this reason, if it adjusts to a stable system, even if it changes suddenly, it will become slow followability.

FIG. 11 is a diagram for explaining the reading / writing of the dust amount data to the memory by the hardware circuit when the power is turned on / off. The quantification of the amount of dust attached to the motor housing is expressed by a reduction in the motor effective surface area ratio relative to the initial value. The effective surface area of the motor is treated as a variable because data is updated every time dust accumulates and adheres. For example, the final value of the motor effective surface area A is stored in the non-volatile memory immediately before the control power is turned off at the end of the day's work, and after the control power is turned on the next day, the motor effective surface area A is stored from the non-volatile memory. Read data and start operation. The initial motor effective surface area A0 free from dust is stored in the ROM memory. FIG. 11 shows a configuration circuit of the motor effective surface area calculation circuit 68. A signal obtained by amplifying or proportionally integrating the deviation signal Te by the amplifier circuit or proportional integration circuit 67 is input to the motor effective surface area calculation circuit 68 through the inverting circuit 77. There are two types of memories. The initial motor effective surface area A0 is stored in the ROM 94, and the motor effective surface area A updated every time is stored in the nonvolatile memory 95.

Reference numeral 96 denotes an arithmetic work area. 88 switches SW1 are turned on at the rising edge of the logic power supply, data is read from the non-volatile memory 95, and 89 switches SW2 are turned on immediately before the logic power supply is turned off. The effective motor surface area A thus written is written into the nonvolatile memory 95. When the initial motor effective surface area A0 is forcibly reset, the switch SW3 of 90 is turned on and the initial motor effective surface area A0 is read from the ROM 94. An A0 reset external input is given from the outside to the position / velocity / current control logic circuit 70 and from the position / velocity / current control logic circuit 70 to the motor effective surface area calculation circuit 68 as an A0 reset signal, which will be described later. In FIG. 13, after the dust adhering to the motor casing is cleaned, the motor effective surface area is reset to the initial value (forced) and used when restarting.

FIG. 12 is a diagram for explaining the state of FIG. 11 when the power is turned on / off with a time chart. The logic power supply of the motor temperature diagnosis device 76 is supplied from the position / speed / current control logic circuit 70. The switch SW1 of 88 reads the motor effective surface area A from the nonvolatile memory 95 at the rising edge of the logic power supply, and the switch SW2 of 89 switches the motor effective surface area A updated at the falling edge of the logic power supply to the nonvolatile memory 95. Written. Further, when the A0 reset external input is turned on from the outside, the switch SW3 of the ROM 94 to 90 is turned on at the rising edge of the A0 reset signal, and is reset to the initial motor effective surface area A0.

FIG. 13 is a diagram for explaining the followability when the motor effective surface area is reset to the initial value. In FIG. 10, after cleaning the dust adhering to the motor housing, the motor effective surface area was restarted without being reset to the initial value, and the data of the motor effective surface area was executed by auto tuning. It was. Here, after cleaning the dust adhering to the motor housing, the motor effective surface area is reset to the initial value, and the motor effective surface area of the ROM 94 is forced to the initial value A0 by the A0 reset signal by the A0 reset external input described in FIG. It is the time chart which reset and restarted. The figure shows that during the time tr period after cleaning, the MA output of motor effective surface area tuning completion is not turned off and the operation is started in the tuning state.

The above is the first embodiment. According to the first embodiment, when correcting the deviation between the measured value of the surface of the motor casing detected by the temperature sensor and the estimated value of the surface of the motor casing based on various parameters given in advance, The effective surface area of the motor is given as a variable, and the degree of separation between the initial value variable (initial motor effective surface area) and the current variable based on actual measurement (current motor effective surface area) is the heat dissipation of the actual motor surface (contamination condition). ) And can be managed as a decline.

Further, according to the first embodiment, the heat dissipation (dirt, etc.) on the surface of the motor casing can be achieved with a simple configuration in which an input from a temperature sensor installed on the casing surface is compared with a predetermined calculation parameter. Management can be performed, and the state of the motor surface can be managed easily and reliably even in an installation environment where visual inspection or the like is difficult. There is also an advantage that the amount of sensors installed can be deleted.

Next, Example 2 will be described. The second embodiment is mainly different from the first embodiment in that the configuration of the overload protection circuit is different.
FIG. 14 schematically shows a configuration in which an overload protection circuit of a system different from that shown in FIG. The difference from FIG. 6 is that the signal output from the position / speed / current control logic circuit 70 of the motor power converter 74 to the overload detection portion 73 is the current I. The motor's total loss Ploss signal is required to accurately perform motor overload protection, but motor power that uses overload protection that operates early using simple overload protection based on motor current detection There is a conversion device. A configuration in the case where dust excessive warning output is performed when dust adheres to the housing of a motor operated by these devices is shown.

The current of the motor 1a is detected by the U-phase current detector CTu12 and the W-phase current detector CTw13 of the motor power converter 74, and the current signal I from the position / speed / current control logic circuit 70 is detected as an overload detection part 73. Can be sent to. Further, since the dust amount detection circuit 72 and the motor housing block 75 are incorporated, if the motor housing temperature detector 71 is attached to the surface of the motor housing, an excessive dust warning can be output. Since the signal output from the position / speed / current control logic circuit 70 of the motor power conversion device 74 to the overload detection portion 73 is the same as that of FIG.

Example 3 will be described. The third embodiment is mainly different from the first and second embodiments in that the motor includes a forced air cooling fan, and the heat dissipation of the motor is managed in consideration of the cooling performance by the fan and ON / OFF of the fan.

FIG. 15 schematically shows the configuration of the motor temperature diagnosis apparatus of the third embodiment. The difference from FIG. 6 and the like is that 1b is a fully-closed motor with a forced air cooling fan. A forced air cooling fan 16 is attached to the opposite side of the load, covered with an end cover 15, and air is blown from the intake port to the output shaft side. Is taken into account. The power supply for the forced air cooling fan 16 is supplied from the position / speed / current control logic circuit 70 of the motor power converter 74 through the fan current detection circuit 17. Further, when the forced air cooling fan 16 is rotating by the switch SW4 having the forced cooling coefficient kf calculated by the transfer function 40 of the motor heat radiation portion of the motor housing block 75 in the motor temperature diagnosis device 76, the SW4 is It is off and is calculated with the value according to (2) of FIG. On the other hand, when the forced air cooling fan 16 is stopped, SW4 is on, and the calculation is performed with a value of kf = 1 shown in (1) of FIG.

One reason for this is that in the event of an emergency, for example, when the forced air cooling fan 16 stops due to a failure while driving at a high speed on a downhill of an automobile, the dust amount detection circuit 72 and the motor housing block are subject to restrictions on short-time use. While operating the motor temperature diagnostic device 76 including 75, the alarm output due to dust adhesion and the overload protection operation are enabled, the vehicle is decelerated to a safe speed, and it can be operated until it is stopped by braking the safe place. . The other is that the forced air cooling fan 16 is actively stopped during light load, and a motor temperature diagnosis device 76 including a dust amount detection circuit 72 and a motor housing block 75 is provided to prevent wind noise from the forced air cooling fan 16. The operation is to enable the alarm output due to dust adhesion and the overload protection operation while operating. The fan current detection circuit 17 detects that the fan current has become zero when the winding of the forced air cooling fan 16 is broken due to the end of its life, and passes through the position / speed / current control logic circuit 70 to detect the motor temperature. This is sent to the CPU 53 of the diagnostic device 76 to switch the SW4.

If the forced air cooling fan 16 stops due to a failure in an emergency, the CPU in the motor power conversion device 74 or the motor temperature diagnosis device 76 detects that the forced air cooling fan 16 has stopped due to a failure, and switches 91 SW4 is turned on. In order to prevent wind noise from the forced air cooling fan 16, the switch SW4 91 in the motor temperature diagnosis device 76 is turned on / off in accordance with the operation of turning on / off the forced air cooling fan 16.

Referring to FIG. 16, a method for accurately measuring the total heat radiation per unit time from the motor from the test data will be described. The total heat dissipation is per unit time due to heat conduction from the cooling fins around the motor frame per unit time and heat conduction from the other mounting base (surface plate) that contacts the foot mounting part where the motor is installed. If the motor is a flange type or the motor is a flange type, the amount of heat per unit time by heat conduction to the mating mounting base that contacts the flange surface is a unit that is the total amount (total value), although it is difficult to measure each individual amount of heat It is a measurement of total heat dissipation per hour. The motor may be natural cooling or forced cooling.

When measuring the heat dissipation characteristics of the motor housing, check the motor installation conditions, etc., and measure the temperature rise test by combining the drive device (motor power converter) and the motor. A temperature rise test is performed by changing the motor speed and load factor to change the motor housing temperature shown on the x-axis in FIG. 16 and the ambient temperature difference Tθ1 to Tθ3. In a state where the rise is saturated and settled at a constant temperature), the total loss Ploss applied to the motor is equal to the total heat radiation amount Qf from the motor per unit time. From this, the total heat radiation amount Qf per unit time from the motor can be accurately obtained by measuring the total loss amount Ploss applied to the motor when the motor is in a thermal equilibrium state. Therefore, the data shown in FIG. 16 is collected for each motor output, and the motor housing temperature and the ambient temperature difference value Tθ (K) are obtained if both data are obtained, whether the motor is forced air cooling or natural cooling. Can be calculated by the heat radiation amount Qf per unit time.

In a fully enclosed motor with a forced air cooling fan, when the effect of the forced air cooling fan is replaced with natural air cooling based on the motor surface area A from (Equation 17), how many times the surface area of the motor surface area A is. Multiply by the forced cooling coefficient kf and express by (kf × A). In the heat dissipation characteristic diagram of the motor housing in FIG. 16, when the motor housing temperature and the ambient temperature difference Tθ are, for example, Tθ2, the heat dissipation amount Qf per unit time is Qf2 (0) with natural cooling kf = 1 in (1). When the wind speed V (m / s) of (2), the magnification of how many times the heat release amount of Qf2 is the forced cooling coefficient kf. However, during natural cooling and forced cooling, the temperature difference Tθ is not constant and does not become a constant value, and may saturate from a certain value. In this case, kf is stored in memory in the form of a graph. Become. The above data is stored in the memory, and the heat dissipation per short time is calculated from the table by referring to the table based on the difference between the motor housing temperature and the ambient temperature.

As mentioned above, although the form for implementing this invention was demonstrated variously, this invention is not limited to these, A various structure etc. can be taken in the range which does not deviate from the meaning.

DESCRIPTION OF SYMBOLS 1 ... Motor, 1a ... Natural air cooling type fully closed motor, 1b ... Fully closed motor with a forced air cooling fan, 2 ... AC main circuit power supply, 3 ... DC power supply, 4 ... -Forward converter with power regeneration function, 5 ... Converter for full wave rectification, 6 ... Converter for power regeneration, 7 ... AC reactor for regeneration, 8 ... Smoothing capacitor, 9 ... Reverse conversion , 10 ... switching element, 11 ... flywheel diode, 12 ... U-phase current detector CTu, 13 ... W-phase current detector CTw, 14 ... encoder, 15 ... end Cover: 16 ... Forced air cooling fan, 17 ... Fan current detection circuit, 19 ... Adder, 20 ... Subtractor, 25 ... PWM circuit, 40 ... Transfer function of motor heat radiation part , 42-1 ... transfer function of the motor heat storage unit, 43-1・ Motor casing overload determination circuit 45... Filter circuit, 46... Inverting circuit, 47... Multiplication operator, 48. , 53... CPU, 67... Amplification circuit or proportional integration circuit, 68... Motor effective surface area calculation circuit, 69... Warning judgment circuit, 70... Position / speed / current control logic circuit, 71 ... Motor housing temperature detector, 72 ... Dust amount detection circuit 73 ... Overload detection part, 74 ... Motor power converter, 75 ... Motor housing block, 76 ... Motor temperature diagnosis device, 77... Inverting circuit, 88... Switch SW 1, 89... Switch SW 2, 90. ... Connection cable Le, 94 ... ROM, 95 ... nonvolatile memory, 96 ... operation work Elijah

Claims (13)

Means for inputting the actual temperature detected from the rotating electrical machine housing;
A calculation means for obtaining an estimated temperature of the rotating electrical machine housing in consideration of a heat radiation value from the surface of the rotating electrical machine housing;
Means for correcting the heat dissipation value so that the deviation of the estimated temperature from the actual temperature is equal;
A rotating electrical machine management apparatus comprising a control unit having a notification unit that outputs a notification signal when a correction amount or a correction ratio of the heat dissipation value exceeds a predetermined value. The rotating electrical machine management device according to claim 1,
The rotating electrical machine management apparatus, wherein the calculating means obtains the estimated temperature in consideration of a heat radiation value from an equivalent specific heat corresponding to a mass of the rotating electrical machine that occupies a total accumulated loss of the rotating electrical machine for a predetermined time. The rotating electrical machine management device according to claim 2,
The rotating electrical machine management apparatus in which the calculating means sets the difference between the input power and the output power of the rotating electrical machine as the total loss. The rotating electrical machine management device according to claim 1,
The external notification means is
A rotating electrical machine sensing device that outputs, as the notification signal, a signal that causes a display device connected so as to be communicable to display that the heat dissipation of the surface of the rotating electrical machine casing is reduced. The rotating electrical machine management device according to claim 4,
The display indicating that the heat dissipation performance is reduced includes at least one of a degree of contamination on the surface of the rotating electrical machine casing and a cleaning warning on the surface of the rotating electrical machine casing. The rotating electrical machine management device according to claim 1,
The external notification means is
The rotating electrical machine management apparatus which outputs further the signal which displays the temporal transition of the correction amount or correction | amendment ratio of the said heat dissipation value on the display apparatus connected so that communication was possible. The rotating electrical machine management device according to claim 1,
The rotating electrical machine management apparatus, wherein the calculating means calculates the heat radiation value further considering cooling by a fan device that cools the rotating electrical machine. The rotating electrical machine management device according to claim 7,
The rotating electrical machine management device, wherein the calculating means calculates the heat radiation value in consideration of cooling by the fan device according to operation / stop of the fan device that cools the rotating electrical machine. The rotating electrical machine management device according to claim 1,
The rotating electrical machine management apparatus, wherein the control unit further has a function of changing a power frequency supplied to the rotating electrical machine. The rotating electrical machine management device according to claim 1,
The rotating electrical machine management apparatus, wherein the control unit further has a function of changing a voltage supplied to the rotating electrical machine. The rotating electrical machine management device according to claim 1,
A rotating electrical machine management apparatus, wherein the rotating electrical machine is an electric motor or a generator. A method of managing a rotating electrical machine by a control device,
The control device is
Calculate the deviation between the casing temperature of the rotating electrical machine detected from the temperature detection device and the casing estimated temperature of the rotating electrical machine obtained by calculation,
Calculate the heat dissipation value of the rotating electrical machine casing where the deviation becomes equal,
A method of managing a rotating electrical machine that outputs a notification signal to the outside when a ratio between a heat dissipation value as an initial value and a heat dissipation value obtained by the calculation is equal to or greater than a predetermined value. A method for managing a rotating electrical machine according to claim 12,
The control device is
The total loss, which is the difference between the input power and output power of the rotating electrical machine, is integrated over time to obtain the total heat of all the motors, and the total heat is divided by the product of the mass of the rotating electrical machine and the equivalent specific heat. A method for managing a rotating electrical machine that obtains the estimated temperature of the housing of the electrical machine.

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