US20200032805A1

US20200032805A1 - Apparatus for controlling compressor, control system for compressor and method for controlling compressor

Info

Publication number: US20200032805A1
Application number: US16/523,472
Authority: US
Inventors: Namsik Yim; Junyoung Lim; Taekyoung Kim; Sanghoon NAM
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2018-07-27
Filing date: 2019-07-26
Publication date: 2020-01-30
Also published as: KR20200012609A

Abstract

The present disclosure relates to a compressor control apparatus, a compressor control system, and a compressor control method for controlling the switching operation of a plurality of switching modules according to a preset control criterion to discharge residual charge remaining in an electrolytic capacitor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2018-0088123, filed on Jul. 27, 2018, the contents of which is incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a compressor control apparatus for controlling a motor of a compressor, a compressor control system, and a compressor control method.

2. Description of the Conventional Art

The technology underlying the present disclosure relates to a control apparatus (inverter) for controlling an electric compressor.
In an electric vehicle using an electric compressor, it is required to discharge residual charge remaining in the electric compressor in order to prevent electric shock on a human body due to high voltage when an accident or other emergency occurs.
In case of discharging residual charge in the control of the electric compressor controlling an inverter in the related art, a high voltage drawn into the electric compressor is cut off by a high voltage distribution unit (HPDU), however, in order to remove charge remaining in an electrolytic capacitor when the power of the electric motor is cut off by the HPDU, a power device is separately configured in a PCB to discharge the residual charge of the electrolytic capacitor. In other words, a separate discharge element for discharging the residual charge is provided, and when such a discharge element is provided, the cost of manufacturing and design increases, and design constraints also increase since the amount of space used increases. Even though the power device is pursued to be miniaturized, it has been required to minimize or eliminate the power device due to the characteristics of the inverter for an electric compressor having a large space limitation. In addition, due to the safety problem, the discharge of the residual charge must be performed in a state where the power supply is cut off. However, due to the above structural/design limitations, the discharge control itself may not be performed safely and accurately.
In other words, in the related art, in order to remove the residual charge remaining in the electrolytic capacitor when the power of the electric compressor is cut off, a power device is separately configured in a PCB to discharge the residual charge of the electrolytic capacitor. The provision of such a discharge element has structural/economic limitations, and has caused a problem that the safety/accuracy/reliability of the discharge control cannot be guaranteed.

SUMMARY OF THE INVENTION

An aspect of the present disclosure is to overcome the limitations of the related art as described above.
In other words, the present disclosure provides a compressor control apparatus, a compressor control system, and a compressor control method capable of overcoming the limitations of the related art as described above.
Specifically, the present disclosure provides a compressor control apparatus, a compressor control system, and a compressor control method capable of discharging residual charge stored in a control apparatus for controlling a compressor after the operation of the compressor is stopped.
In addition, the present disclosure provides a compressor control apparatus, a compressor control system, and a compressor control method capable of appropriately and safely discharging the residual charge.
In order to solve the foregoing problems, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may have technical features in which the switching operation of a plurality of switching modules is controlled according to a preset control criterion to discharge residual charge remaining in an electrolytic capacitor.
Specifically, a discharge path may be formed through the switching operation of the plurality of switching modules, thereby discharging the residual charge through the discharge path.
In other words, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may form a discharge path between the electrolytic capacitor and the motor through the plurality of switching modules so as to discharge the residual charge through the formed discharge path as a solution.
Through the foregoing solution, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may discharge the residual charge through the discharge path so as to discharge the residual charge safely and appropriately without any additional discharge element, thereby solving the above-described problems.
The above technical features may be embodied in a compressor control apparatus, a compressor control system, and a compressor control method for controlling the operation of a compressor through an inverter unit that applies operating power to the motor through the switching operation of a plurality of switching modules, and the present disclosure may provide a compressor control apparatus, a compressor control system, and a compressor control method using the foregoing technical features as a solution to the problems.
In order to solve the foregoing problems with the above technical features, a compressor control apparatus according to an embodiment of the present disclosure may include a cutoff unit configured to interrupt power received from an external power source, an input unit configured to input power from the external power source through the cutoff unit, an inverter unit configured to convert the input power to operating power for operating a motor of a compressor through a plurality of switching modules to output the operating power to the motor, and a control unit configured to control the inverter unit to control the conversion and output of the operating power, wherein when the operation of the motor is stopped, the control unit controls the switching operation of the plurality of switching modules according to a preset control criterion to discharge residual charge stored in the input unit.
Furthermore, in order to solve the foregoing problems with the above technical features, a compressor control system according to an embodiment of the present disclosure may include a motor driven compressor, and a control apparatus comprising a plurality of switching modules configured to convert power input from an external power source to operating power for operating the motor to output the operating power to the motor so as to control the switching operation of the plurality of switching modules to control the operation of the motor, wherein the control apparatus controls the switching operation of two or more specific switching modules among the plurality of switching modules after the operation of the motor is stopped to discharge residual charge stored in the control apparatus.
Moreover, in order to solve the foregoing problems with the above technical features, there is provided a method of controlling a compressor control apparatus including a cutoff unit configured to interrupt power received from an external power source, an input unit configured to input power from the external power source through the cutoff unit, an inverter unit configured to convert the input power to operating power for operating a motor of a compressor through a plurality of switching modules to output the operating power to the motor, and a control unit configured to control the inverter unit so as to control the conversion and output of the operating power, and the method may include cutting off power input from the external power source, determining a discharge condition based on an operation state of the motor, controlling the plurality of switching modules according to a preset control criterion to perform the discharge control of residual charge stored in the input unit, and stopping the discharge control.
The compressor control apparatus, the compressor control system, and the compressor control method according to the present disclosure as described above may be applied to and implemented on a compressor control apparatus provided in a compressor, for instance, an inverter apparatus for controlling a motor of a compressor, a compressor including the same, or a control method for the compressor. However, technologies disclosed herein are not limited thereto, and may also be applicable to all compressor control apparatuses, compressors, compressor control systems, and compressor control methods to which the technical concept of the present disclosure is applicable.
A compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may form a discharge path through the switching operation of a plurality of switching modules, thereby having an effect of discharging the residual charge through the discharge path.
In other words, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may discharge the residual charge through the discharge path, thereby having an effect of safely and appropriately discharging the residual charge without any additional discharge element.
Furthermore, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may safely and appropriately discharge the residual charge thereby having an effect preventing the internal burnout of a compressor and a control apparatus that controls the compressor due to the residual charge.
Moreover, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may discharge residual charge according to an input state of external power source, an operation state of a motor, and a discharge state of the residual charge, thereby having an effect of accurately performing the discharge of residual charge, and reducing loss due to an unnecessary switching operation.
As a result, a compressor control apparatus, a compressor control system, and a compressor control method according to the present disclosure may reliably and accurately discharge residual charge without any additional discharge element, thereby having an effect of improving the limitations of the related art as well as increasing stability, accuracy, ease of use, utility, usefulness and reliability of electric compressor control using an inverter.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:

FIG. 1 is a configuration view showing a configuration of a compressor control apparatus according to the present disclosure.

FIG. 2 is a configuration view showing a specific circuit configuration of a compressor control apparatus according to the present disclosure.

FIG. 3 is a circuit configuration view showing current flow according to discharge control of a compressor control apparatus according to the present disclosure.

FIG. 4 is a graph showing a result of discharge control of a compressor control apparatus according to the present disclosure.

FIG. 5 is a flowchart showing a control process of a compressor control system according to the present disclosure.

FIG. 6 is a flowchart showing a flow of a compressor control apparatus according to the present disclosure.

FIG. 7 is a flowchart showing a specific flow of a compressor control apparatus according to the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention disclosed herein may be applicable to a compressor control apparatus, a compressor control system, a compressor control method, and a compressor to which such a technology is applied. However, the invention disclosed in this specification is not limited thereto, but may also applicable to all existing compressor control apparatuses, compressor control systems, compressors and compressor control methods, motor control apparatuses, motor operating apparatuses, inverter apparatuses of controlling a motor, control methods of a motor control apparatus, control methods of an inverter apparatus, control elements of controlling a motor control apparatus and control methods thereof, control apparatuses of controlling an inverter apparatus, and control methods thereof, and the like, and more particularly, may be usefully applicable to a compressor control apparatus, a compressor control system, and a compressor control method of controlling an electric compressor.
It should be noted that technological terms used herein are merely used to describe a specific embodiment, but not to limit the concept of technologies disclosed herein. Furthermore, unless particularly defined otherwise, technological terms used herein should be construed as a meaning that is generally understood by those having ordinary skill in the art disclosed herein, and should not be construed too broadly or too narrowly. Furthermore, if technological terms used herein are wrong terms unable to correctly express the concept of technologies disclosed herein, then they should be replaced by technological terms that are properly understood by those skilled in the art. In addition, general terms used in the present specification should be construed based on the definition of dictionary, or the context, and should not be construed too broadly or too narrowly.
Furthermore, a singular representation used in the present specification may include a plural representation as far as it represents a definitely different meaning from the context. In the present specification, the terms “comprising” and “including” should not be construed to necessarily include all of the elements or steps disclosed herein, and should be construed not to include some of the elements or steps thereof, or should be construed to further include additional elements or steps.
In describing technologies disclosed herein, moreover, the detailed description will be omitted when specific description for publicly known technologies to which the invention pertains is judged to obscure the gist of the present invention. In addition, it should be noted that the accompanying drawings are merely illustrated to easily explain the technological concept disclosed herein, and therefore, they should not be construed to limit the technological concept by the accompanying drawings.
First, a compressor control apparatus (hereinafter, referred to as a control apparatus) according to the present disclosure will be described.
The control apparatus denotes a control apparatus for controlling the operation of the compressor.
The control apparatus may be a control apparatus for supplying operating power to the motor of the compressor and controlling the operation of the compressor.
The control apparatus may be an apparatus for controlling the driving of the compressor to control the operation of the compressor.
The control apparatus may be an apparatus for controlling the motor using an inverter method.
In other words, the control apparatus may be an inverter that controls the driving of the compressor, or an apparatus including the inverter.
The control apparatus may control the operation of the motor by controlling the switching operation of the inverter and controlling the operating power applied to the motor.
The control apparatus may control the operating power through the control of the switching operation to control the operation of the motor, thereby controlling the operation of the compressor.
As illustrated in FIG. 1, a control apparatus 100 includes a cutoff unit 10 for interrupting power input from an external power source 1, an input unit 20 for receiving power from the external power source 1 through the cutoff unit 10, an inverter unit 30 for converting the received power into operating power for operating a motor 200 of a compressor (C) through a plurality of switching modules to output the operating power to the motor 200, and a control unit 40 for controlling the inverter unit 30 to control the conversion and output of the operating power.
The control apparatus 100 controls the switching operation of the plurality of switching modules included in the inverter unit 30 by the control unit 40 to control the conversion and output of the operating power converted through the switching operation, thereby controlling the operation of the motor 200.
In the control apparatus 100 including the cutoff unit 10, the input unit 20, the inverter unit 30 and the control unit 40 as described above, the control device 40 controls the switching operation of the plurality of switching modules according to a preset control criterion to discharge residual charge stored in the input unit 20 when the operation of the motor 200 is stopped.
In other words, when the operation of the motor 200 is stopped, the control apparatus 100 may control the switching operation of the plurality of switching modules according to the control criterion, thereby discharging the residual charge stored and remained in the input unit 200 during the operation of the motor 200.
The specific configuration of the control apparatus 100 may be as shown in FIG. 2.
The cutoff unit 10 may be a high voltage power distribution unit (HPDU) for distributing high voltage power.
The cutoff unit 10 is closed at normal times, and open when sensing a high voltage above a predetermined reference level to cut off power input from the external power source 1.
For example, when an accident occurs in the external power source 1 to generate a high voltage above predetermined reference level, it is detected to open, thereby cutting off power input from the external power source 1 to the control apparatus 100.
When a high voltage above the predetermined reference level is induced from the external power source 1 or a high voltage above the predetermined reference level is generated in the control apparatus 100, the cutoff unit 10 is open to separate the control apparatus 100 from the external power source 1.
The cutoff unit 10 may be controlled by the control unit 40 or a control element at an outside of the control apparatus 100.
The input unit 20 may receive direct current (DC) power or alternating current (AC) power from the external power source 1 through the cutoff unit 10.
When power input to the input unit 10 is the DC power, the external power source 1 may be a battery for storing the DC power or a power supply element for supplying the DC power.
When power input to the input unit 10 is the AC power, the external power source 1 may be power conversion element for converting the DC power to the AC power or a power supply element for supplying the AC power.
The input power may preferably be the DC power.
The input unit 20 may include a smoothing capacitor for smoothing the input power.
The smoothing capacitor may be a DC link capacitor that reduces the ripple of the input power to smooth it in the form of DC power.
The smoothing capacitor may be an electrolytic capacitor.
The input unit 20 may store and smooth the DC power input from the external power source 1 through the cutoff unit 10 in the smoothing capacitor formed of the electrolytic capacitor.
The input unit 20 is connected to the inverter unit 30 to transfer the DC power smoothed through the smoothing capacitor to the inverter unit 30.
The inverter unit 30 is connected to the motor 200 to convert the DC power received through the input unit 20 to the operating power and output it to the motor 200.
Here, the motor 200 may be a three-phase motor that drives the compressor (C), and the operating power may be in the form of three-phase AC power.
The inverter unit 30 may convert the DC power into the operating power in the form of the AC power and output it to the motor 200.
The inverter unit 30 may convert the DC power into three-phase AC power through the switching operation of the plurality of switching modules 31 to 36.
The plurality of switching modules 31 to 36 may be preferably insulated gate bipolar transistor (IGBT) modules.
The switching operation of the plurality of switching modules 31 to 36 may be controlled by the control unit 40.
The plurality of switching modules 31 to 36 may receive a control signal for the switching operation from the control unit 40 to perform a switching operation and convert the DC power to the AC power according to the control signal.
The plurality of switching modules 31 to 36 may include three pairs of switching modules 31-34, 32-35, 33-36, in which two switching modules are connected in series, as shown in FIG. 2.
The plurality of switching modules 31 to 36 including the three pairs of switching modules 31-34, 32-35, 33-36 may include first through third upper arm switching modules 30 a (31 to 33) connected to an anode end of the input unit 20, and first through third lower arm switching modules 30 b (34 to 36) connected in series to the upper arm switching modules 30 a (31 to 33), respectively, and connected to a cathode end of the input unit 20.
Here, each of the three pairs of switching modules 31-34, 32-35, 33-36 may constitute each phase of the three-phase power output to the motor 200.
For instance, the first pair 31-34 may be a U-phase, the second pair 32-35 may be a V-phase, and the third pair 33-36 may be a W-phase.
The plurality of switching modules 31 to 36 in which the upper arm switching module 30 a (31 to 33) and the lower arm switching module 30 b (34 to 36) connected to each other in pairs, respectively, may be controlled by the control unit 40 to output the operating power to the motor 200.
In other words, the inverter unit 30 including the plurality of switching modules (31 to 36) may be controlled by the control unit 40.
In the inverter unit 30, the switching operation is controlled by the control unit 40 to control and the operation of the motor 200.
The inverter unit 30 may control the operating power output to the motor 200 and applied to the motor 200 through the control of the switching operation to control the operation speed of the motor 200.
Here, the operation speed may denote a rotation speed of the motor 200.
The operation speed may also be replaced with an operation frequency at which the motor 200 operates or the number of revolutions of the motor 200 associated with the operation speed.
Hereinafter, for convenience of explanation, the embodiment will be described around the operation speed, but the implementation of the present disclosure may be implemented in a manner of replacing the operation speed with the operation frequency or the rotation speed.
The control unit 40 for controlling the switching operation to control the operation of the motor 200 may detect the voltage and current of the motor 200, and measure the operation speed of the motor 200 based on the detected motor voltage and the motor current to control the switching operation according to the measured operation speed.
The control unit 40 may detect the motor voltage and the motor current applied to the motor 200 according to the switching operation, and measure the operation speed based on the motor voltage and the motor current.
The control unit 40 may generate a control signal for controlling the switching operation according to the operation speed, and apply the control signal to the inverter 30 to control the switching operation.
The control unit 40 may determine at least one of a command voltage for the motor voltage, a command current for the motor current, a speed command for the operation speed, and a frequency command for the switching frequency according to the operation speed, and generate the control signal according to the determination result.
In other words, the control unit 40 may determine at least one the command voltage, the command current, the speed command, the speed command, and the frequency command based on at least one of the detection result of detecting the motor voltage and the motor current, and the measurement result of measuring the operation speed, and generate the control signal according to the determination result, thereby controlling at least one of the motor voltage, the motor current, the operation speed, and the switching frequency.
As described above, the control unit 40 may control at least one of the motor voltage, the motor current, the operation speed and the switching frequency through the control of the switching operation, thereby controlling the operation of the motor 200.
The control unit 40 may include a first control unit 41 for controlling the cutoff unit 10 and a second control unit 42 for controlling the inverter unit 30.
When the control unit 40 includes the first control unit 41 and the second control unit 42 as described above, the first control unit 41 may generate a control command for the control of the inverter unit 30 to transfer it to the second control unit 42, and the second control unit 42 may generate the control signal according to the control command received from the first control unit 41.
As described above, the control unit 40 that controls the switching operation of the inverter unit 30 to control the conversion and output of the operating power controls the switching operation of the plurality of switching modules 31 to 36 according the control criterion to discharge the residual charge stored in the input unit 20 when the operation of the motor 200 is stopped.
In other words, the control unit 40 controls the switching operation of the plurality of switching modules 31 to 36 to discharge the residual charge remaining in the input unit 20 when the operation of the motor 200 is stopped.
The control unit 40 may determine whether or not the operation of the motor 200 is stopped while the cutoff unit 10 is open, and controls the switching operation to discharge the residual charge when the operation of the motor is stopped.
In other words, only when the operation of the motor 200 is stopped in a state where the cutoff unit 10 is open and power input to the input unit 20 from the external power source 1 is cut off, the control unit 40 may control the switching operation to discharge the residual charge.
As described above, the switching operation may be controlled to discharge the residual charge in a state where the cutoff unit 10 is open, and the operation of the motor 200 is stopped, thereby preventing the residual charge from being discharged toward the external power source 1 and allowing power to be input from the external power source 1 to the input unit 20 to prevent the power from being stored in the input unit 20 in which the residual charge is being discharged.
In the control unit 40 that controls the switching operation to discharge the residual charge in a state where the cutoff unit 10 is open and the operation of the motor 200 is stopped as described above, the first control unit 41 may transfer information on the cutoff state of the cutoff unit 10 and the switching operation control to the second control unit 42 while the cutoff unit 10 is controlled to be open, and the second control unit 42 may control the switching operation based on the cutoff state and information on the switching operation control received from the first control unit 41.
In other words, the second control unit 42 may determine whether the operation of the motor 200 is stopped to control the switching operation only when the information on the cutoff state of the cutoff unit 10 is received from the first control unit 41.
The control unit 40 may control the switching operation to discharge the residual charge when the operation of the motor 200 is stopped for more than a preset standby time period.
In other words, the control unit 40 may control the switching operation to discharge the residual charge when the operation stop of the motor 200 has passed the standby time.
The standby time may be a period of time for which charge remaining in the motor 200 is discharged immediately after the operation of the motor 200 is stopped.
In other words, when the operation of the motor 200 is stopped for more than the standby time, the control unit 40 may determine that charge remaining in the motor 200 is discharged after the operation of the motor 200 is stopped so as to control the switching operation to discharge the residual charge.
The standby time may be a period of time for which the operation of the motor 200 is completely stopped.
For instance, it may be a period of time from the start of stopping the operation speed of the motor 200 to a time point when the operation speed is zero.
As described above, the control unit 40 may control the switching operation to discharge the residual charge after the operation of the motor 200 is completely stopped and charge remaining in the motor 200 is discharged, thereby safely and accurately discharging the residual charge remaining in the input unit 20.
The control unit 40 for discharging residual charge after the cutoff unit 10 is open, and the operation of the motor 200 is completely stopped and the charge remaining in the motor 200 is discharged, may control the switching operation according to the control criterion to discharge the residual charge.
The control criterion may be a criterion for controlling two or more of the plurality of switching modules 31 to 36.
In other words, the control unit 40 may control switching operations of two or more of the plurality of switching modules 31 to 36 when the switching operation is controlled to discharge the residual charge.
The control criterion may be a criterion for controlling the switching operation of two or more switching modules among the plurality of switching modules 31 to 36 to form a discharge path between the input unit 20 and the motor 200.
In other words, the control unit 40 may control the switching operation of two or more of the plurality of switching modules 31 to 36 according to the control criterion to form the discharge path through which the residual charge is discharged.
The control unit 40 that controls the switching operation according to the control criterion may control the switching operation of any one upper arm switching module in the switching modules 30 a connected to an anode end of the input unit 20, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b connected to a cathode end of the input unit 20 among the plurality of switching modules 31 to 36 to discharge the residual charge.
A specific example of controlling the switching operation according to the control criterion will be described below with reference to FIG. 3.
According to a specific control example of the control unit 40, as illustrated in FIG. 3, it may be possible to control the switching operation of any one upper arm switching module connected to an anode end of the input unit 20 among the plurality of switching modules 31 to 36, and one or more lower arm switching modules other than the switching module connected to the upper arm switching module among the switching modules 30 b connected to a cathode end of the input unit 20.
In other words, in this case, the control unit 40 may control the first upper arm switching module 31 among the upper arm switching modules 30 a, and the second lower arm switching module 35 and the third lower arm switching module 36 excluding the first lower arm switching module 34 connected to the first upper arm switching module 31 among the lower arm switching modules 30 b.
At this time, the control unit 40 may control the switching operation to turn on the first upper switching module 31, the second lower arm switching modules 35 and the third lower arm switching module 36.
Furthermore, the control unit 40 may control the switching operation of the second upper arm switching module 32 among the upper arm switching modules 30 a, the first lower arm switching module 34 and the third lower arm switching module 36 excluding the second lower arm switching module 35 connected to the second upper arm switching module 32 among the lower arm switching modules 30 b, and may also control the switching operation of the third upper arm switching module 33 among the upper arm switching modules 30 a, the first lower arm switching module 34 and the third lower arm switching module 35 excluding the third lower arm switching module 36 connected to the third upper arm switching module 33 among the lower arm switching modules 30 b.
The control unit 40 that controls the switching operation may control the switching operation of the upper arm switching module 30 a and the lower arm switching module 30 b to form the discharge path between the input unit 20 and the motor 200 through the upper arm switching modules 30 a and the lower arm switching modules 30 a, thereby discharging the residual charge through the formed discharge path.
In other words, the control unit 40 that controls the switching operation may control the switching operation of any one upper arm switching module in the switching modules 30 a connected to an anode end of the input unit 20, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b connected to a cathode end of the input unit 20.
Describing the operation with reference to an example illustrated in FIG. 3, the control unit 40 may control the switching operation of the first upper arm switching module 31 in the upper arm switching modules 30 a, and the second lower arm switching module 35 and the third lower arm switching module 36 excluding the first lower arm switching module 34 connected to the upper arm switching module 31 in the lower arm switching modules 30 b to be turned on to form the discharge path connected through [an anode end of the input unit 20—the first upper arm switching module 31—the motor 200—the second lower arm switching module 35 and the third lower arm switching module 36—a cathode end of the input unit 200], thereby discharging the residual charge stored in the input unit 20 through a loop of [the anode end of the input unit 20—the first upper arm switching module 31—the motor 200—the second lower arm switching module 35 and the third lower arm switching module 36—the cathode end of the input unit 200].
In other words, the control unit 40 may form the discharge path between the control apparatus 100 and the motor 200 through the turn-on control of at least two switching modules among the plurality of switching modules 31 to 36, thereby discharging the residual charge through the discharge path.
As described above, the control unit 40 may control the switching modules among the plurality of switching modules 31 to 36 to be turned on according to the control criterion to form the discharge path between the control apparatus 100 and the motor 200, thereby discharging the residual charge in the control apparatus 100 and the motor 200 without any additional discharging element.
In this manner, the control unit 40 that controls the switching operation according to the control criterion, may control the switching operation for a preset discharge time period to discharge the residual charge.
The discharge time period may be a period of time for which the residual charge is discharged through the discharge path.
In other words, the control unit 40 may control the switching operation to discharge the residual charge for the discharge time period.
The discharge time period may be one second, for example.
As described above, the discharge control result of the control unit 40 for controlling the discharge of the residual charge may be as shown in FIG. 4.
As illustrated in FIG. 4, when the cutoff unit 10 is open and the operation of the motor 200 is stopped (t1), the control unit 40 may start the discharge control of the residual charge, and control the turn-on of at least two switching modules among the plurality of switching modules 31 to 36 for the discharge time period (t3−t2) after the operation stop of the motor 200 has passed the standby time (t2) such that the residual charge flows through the discharge path formed through the switching operation in a direction of the motor 200 for the discharge time period (motor current), thereby discharging the residual charge through the discharge path for the discharge time period.
After the residual charge is completely discharged for the discharge time period (t3), the control unit 40 may stop the discharge control to prevent the unnecessary switching operation of the plurality of switching modules 31 to 36.
In other words, when the discharge time period (t3) has passed to end the discharge of the residual charge, the control unit 40 may stop the control of the switching operation to prevent the loss and burnout of the plurality of switching modules 31 to 36 according to the switching operation.
Hereinafter, a compressor control system (hereinafter, referred to as a control system) according to the present disclosure will be described, and its redundant described above in the control apparatus 100 will be omitted as much as possible.
The control system denotes a system for controlling the operation of the compressor.
The control system may be a control system for supplying operating power to the motor of the compressor to control the operation of the compressor.
The control system may be a control system that controls the motor in an inverter manner.
The control system may control the switching operation of the inverter to control operating power applied to the motor, thereby controlling the operation of the motor.
The control system may control the operating power through the control of the switching operation to control the operation of the compressor, thereby controlling the driving of the compressor.
The control system may control the driving of the compressor including the control apparatus 100 described above.
As illustrated in FIG. 2, the control system includes a control apparatus 100 including a compressor (C) operated by a motor 200, and a plurality of switching modules 31 to 36 for converting power input from an external power source 1 to operating power for operating the motor 200 to output the converted power to the motor 200 so as to control the switching operation of the plurality of switching modules 31 to 36 to control the operation of the motor 200.
Here, the control apparatus 100 may be the control apparatus 100 described above.
In the control system, after the operation of the motor 200 is stopped, the control apparatus 100 controls the switching operation of at least two specific switching modules among the plurality of switching modules 31 to 36 to discharge residual charge stored in the control apparatus 100.
In other words, the control system controls the switching operation to discharge the residual charge when the operation of the motor 200 is stopped.
As illustrated in FIG. 2, the control apparatus 100 may include a cutoff unit 10 for interrupting power input from the external power source 1, an input unit 20 for receiving power from the external power source 1 through the cutoff unit 10, an inverter unit 30 for converting the received power into the operating power through the plurality of switching modules 31 to 36 to output the operating power to the motor 200, and a control unit 40 for controlling the inverter unit 30 to control the conversion and output of the operating power.
The control apparatus 100 may also be a control element having a configuration different from that of the control apparatus 100 described above.
The control apparatus 100 for controlling the switching operation to control the operation of the motor 200 may detect the voltage and current of the motor 200, and measure the operation speed of the motor 200 based on the detected motor voltage and the motor current to control the switching operation according to the measured operation speed.
The control apparatus 100 may detect the motor voltage and the motor current applied to the motor 200 according to the switching operation, and measure the operation speed based on the motor voltage and the motor current.
The control apparatus 100 may generate a control signal for controlling the switching operation according to the operation speed, and apply the control signal to the inverter unit 30 to control the switching operation.
The control apparatus 100 may determine at least one of a command voltage for the motor voltage, a command current for the motor current, a speed command for the operation speed, and a frequency command for the switching frequency according to the operation speed, and generate the control signal according to the determination result.
In other words, the control apparatus 100 may determine at least one the command voltage, the command current, the speed command, the speed command, and the frequency command based on at least one of the detection result of detecting the motor voltage and the motor current, and the measurement result of measuring the operation speed, and generate the control signal according to the determination result, thereby controlling at least one of the motor voltage, the motor current, the operation speed, and the switching frequency.
As described above, the control apparatus 100 may control at least one of the motor voltage, the motor current, the operation speed and the switching frequency through the control of the switching operation, thereby controlling the operation of the motor 200.
As described above, the control apparatus 100 that controls the switching operation of the inverter unit 30 to control the conversion and output of the operating power controls the switching operation of the plurality of switching modules 31 to 36 according the control criterion to discharge the residual charge when the operation of the motor 200 is stopped.
Here, the residual charge may be charge in which power stored in the input unit 20 remains.
In other words, the control apparatus 100 controls the switching operation of the plurality of switching modules 31 to 36 to discharge the residual charge remaining in the input unit 20 after the operation of the motor 200 is stopped.
The control apparatus 100 may include the cutoff unit 10, which is closed at normal times, and open when sensing a high voltage above a predetermined reference level to cut off power input from the external power source 1, thereby controlling the switching operation to discharge the residual charge while the cutoff unit 10 is open.
In other words, only when the operation of the motor 200 is stopped in a state where the cutoff unit 10 is open and power input to the input unit 20 from the external power source 1 is cut off, the control apparatus 100 may control the switching operation to discharge the residual charge.
The control apparatus 100 may stop the operation of the motor 200, and control the switching operation to discharge the residual charge after a preset standby time has passed.
In other words, the control apparatus 100 may control the switching operation to discharge the residual charge when the operation of the motor 200 is stopped for more than the standby time.
The control apparatus 100 may control the switching operation according to the control criterion to discharge the residual charge.
The control criterion may be a criterion for controlling two or more of the plurality of switching modules 31 to 36.
In other words, the control apparatus 100 may control switching operations of two or more of the plurality of switching modules 31 to 36 when the switching operation is controlled to discharge the residual charge.
The control criterion may be a criterion for controlling the switching operation of two or more switching modules among the plurality of switching modules 31 to 36 to form a discharge path between the input unit 20 and the motor 200.
In other words, the control apparatus 100 may control the switching operation of two or more of the plurality of switching modules 31 to 36 according to the control criterion to form the discharge path through which the residual charge is discharged.
The control unit 100 may control the switching operation of any one upper arm switching module in the switching modules 30 a disposed at one side of the plurality of switching modules 31 to 36, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b disposed at the other side thereof to discharge the residual charge.
The control apparatus 100 may control the switching operation of any one upper arm switching module in the switching modules 30 a connected to an anode end of the input unit 20, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b connected to a cathode end of the input unit 20 among the plurality of switching modules 31 to 36 to discharge the residual charge.
As illustrated in FIG. 3, the control apparatus 100 may be possible to control the switching operation of any one upper arm switching module connected to an anode end of the input unit 20 among the plurality of switching modules 31 to 36, and one or more lower arm switching modules other than the switching module connected to the upper arm switching module among the switching modules 30 b connected to a cathode end of the input unit 20.
At this time, the control apparatus 100 may control the switching operation to turn on the first upper switching module 31, the second lower arm switching modules 35, and the third lower arm switching module 36.
The control apparatus 100 that controls the switching operation may control the switching operation of the upper arm switching module 30 a and the lower arm switching module 30 b to form the discharge path between the input unit 20 and the motor 200 through the upper arm switching modules 30 a and the lower arm switching modules 30 a, thereby discharging the residual charge through the formed discharge path.
In other words, the control apparatus 100 that controls the switching operation may control the switching operation of any one upper arm switching module in the switching modules 30 a connected to an anode end of the input unit 20, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b connected to a cathode end of the input unit 20.
In this manner, the control apparatus 100 that controls the switching operation according to the control criterion, may control the switching operation for a preset discharge time period to discharge the residual charge.
The discharge time period may be a period of time for which the residual charge is discharged through the discharge path.
In other words, the control apparatus 100 may control the switching operation to discharge the residual charge for the discharge time period.
The control process of the control system of controlling the switching operation to discharge the residual charge as described above may be carried out in a sequence as shown in FIG. 5.
The control system may control the operation of the motor 200 by the control apparatus 100 in a control process as shown in FIG. 5.
Here, the control process as shown in FIG. 5 may be carried out by the control unit 40 of the control apparatus 100, and may be applicable to the foregoing embodiment of the control unit 40 of the control apparatus 100.
As illustrated in FIG. 5, the control apparatus 100 may open (P1) the cutoff unit 10 to prepare (P2) discharge control for discharging the residual charge while cutting off power from being received from the external power source 1.
Here, the preparation (P2) for discharge control may be a process of allowing the first control unit 41 that controls the opening of the cutoff unit 10 to transfer the cutoff state information of the cutoff unit 10 and a command for the execution of the discharge control to the second control unit 42 that controls the switching operation of the plurality of switching modules 31 to 36 so as to allow the second control unit 42 to prepare the switching operation.
Then, the control apparatus 100 may stop the operation of the motor 200 (P3), and then determine whether or not the operation stop time of the motor 200 has passed the standby time period (P4), thereby controlling the switching operation in accordance with the control criterion when the motor stops for more than the standby time period.
Here, when the operation of the motor 200 is not stopped or the standby time has not passed after the operation of the motor 200 is stopped, the preparation process of the discharge control (P2) may be repeated.
The control apparatus 100 may control the switching operation for the discharge time period to discharge the residual charge for the discharge time period after starting the discharge of the residual charge (P5) so as to stop the control of the switching operation after the discharge time period has passed (P6), thereby stopping the discharge of the residual charge (P7).
The control system for controlling the switching operation to discharge the residual charge as described above may also control the switching operation in a process other than the control process as shown in FIG. 5.
Hereinafter, a compressor control method (hereinafter, referred to as a control method) according to the present disclosure will be described, and its redundant described above in the control apparatus 100 and the control system will be omitted as much as possible.
The control method may be a control method for controlling a compressor.
The control method may be a control method of a control apparatus for controlling the compressor.
The control method may be a control method of the control apparatus 100 or the control system.
As illustrated in FIG. 2, the control method is a compressor control method of the compressor control apparatus 100 including a cutoff unit 10 for interrupting power input from an external power source 1, an input unit 20 for receiving power from the external power source 1 through the cutoff unit 10, an inverter unit 30 for converting the received power into operating power for operating a motor 200 of a compressor (C) through a plurality of switching modules 31 to 36 to output the operating power to the motor 200, and a control unit 40 for controlling the inverter unit 30 to control the conversion and output of the operating power, and as illustrated in FIG. 6, the control method includes cutting off power received from the external power source 1 (S10), determining a discharge condition based on the operation state of the motor 200 (S20), controlling the plurality of switching modules 31 to 36 based on a preset control criterion to perform the discharge control of the residual charge stored in the input unit 20 (S30), and stopping the discharge control (S40).
The control method as shown in FIG. 6 may be carried out in a sequence as shown in FIG. 7.
In the step (S10) of cutting off input power, the cutoff unit 10 may be operated to be open so as to cut off power input from the external power source 1.
The step (S20) of determining a discharge condition may determine the discharge condition after the cutoff unit 10 is open in the step S10 of cutting off the input power.
The discharge condition may be a condition for performing the discharge control of the residual charge.
The discharge condition may be a condition for whether or not the operation of the motor 200 is stopped or an operation stop time period.
In other words, the step (S20) of determining the discharge condition (S20) may determine whether or not the operation is stopped or the operation stop time period.
The step (S20) of determining the discharge condition may include determining whether or not the operation is stopped (S21) and determining the operation stop time period (S22).
The step (S21) of determining whether or not the operation is stopped may determine whether or not the operation of the motor 200 is stopped.
The step (S21) of determining whether or not the operation is stopped may determine whether or not the operation speed of the motor 200 is zero to determine whether or not the operation is stopped.
The step (S22) of determining the operation stop time period may compare a time period for which the operation of the motor 200 is stopped with the standby time period when it is determined that the operation of the motor 200 is stopped in the step (S21) of determining whether or not the operation is stopped to determine whether or not the operation stop time period has passed the standby time period.
The step (S22) of determining the operation stop time period may determine that the operation of the motor 200 is completely stopped when the operation stop time period of the motor 200 has passed the standby time period.
The step (S30) of performing the discharge control may control the switching operation of the plurality of switching modules 31 to 36 to discharge the residual charge when the operation stop time period of the motor 200 has passed the standby time period in the step (S20) of determining the discharge condition.
The step (S30) of performing the discharge control may control the switching operation of any one upper arm switching module connected to an anode end of the input unit 20 among the plurality of switching modules 31 to 36, and one or more lower arm switching modules other than the switching module connected to the upper arm switching module among the switching modules 30 b connected to a cathode end of the input unit 20.
The step (S30) of performing the discharge control may control the switching operation of the upper arm switching module 30 a and the lower arm switching module 30 b to form the discharge path between the input unit 20 and the motor 200 through the upper arm switching modules 30 a and the lower arm switching modules 30 a, thereby discharging the residual charge through the formed discharge path.
The step S30 of performing the discharging control for discharging the residual charge as described above may include controlling the switching operation of the plurality of switching modules 31 to 36 according to the control criterion (S31) and maintaining the control of the switching operation for a preset discharge time period (S32).
The step (S31) of controlling the switching operation may control the switching operation of any one upper arm switching module in the switching modules 30 a connected to an anode end of the input unit 20, and one or more lower arm switching modules excluding a switching module connected to the upper arm switching module in the switching modules 30 b connected to a cathode end of the input unit 20 as described above.
The step (S32) of maintaining the discharge time period may perform the step (S31) of controlling the switching operation for the discharge time period.
The step (S40) of stopping the discharge control may stop the discharge control after the execution of the step (S30) of performing the discharge control.
Though a specific embodiment according to the present disclosure has been described above, it will be apparent to those skilled in this art that various modification may be made without departing from the scope of the present invention. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.
Although the present disclosure has been described with respect to specific embodiments and drawings, the present disclosure is not limited to those embodiments, and it will be apparent to those skilled in the art that various changes and modifications can be made from the description disclosed herein. Consequently, the concept of the present disclosure should be construed in accordance with the appended claims, and all the same and equivalent changes will fall into the scope of the present disclosure.

Claims

What is claimed is:

1. A compressor control apparatus, comprising:

a cutoff unit configured to interrupt power input from an external power source;

an input unit configured to receive the power input from the external power source through the cutoff unit;

an inverter unit configured to convert an input power supplied from the input unit to an operating power for operating a motor of a compressor, the inverter unit comprising a plurality of switching modules configured to perform a switching operation to control an output of the operating power to the motor; and

a control unit configured to, by controlling the inverter unit, control a conversion of the input power to the operating power and the output of the operating power,

wherein the control unit is configured to, based on an operation of the motor being stopped, control the switching operation of the plurality of switching modules according to a preset control criterion to thereby discharge a residual charge stored in the input unit.

2. The compressor control apparatus of claim 1, wherein the cutoff unit is configured to:

maintain a closed state to transmit the power input from the external power source to the input unit, and

change to an open state to cut off the power input from the external power source based on sensing a high voltage that is greater than a predetermined reference level.

3. The compressor control apparatus of claim 1, wherein the plurality of switching modules comprise three pairs of switching modules, each pair of switching modules comprising two switching modules connected to each other electrically in series.

4. The compressor control apparatus of claim 1, wherein the plurality of switching modules comprise:

a first upper arm switching module, a second upper arm switching module, and a third upper arm switching module that are connected to an anode end of the input unit; and

a first lower arm switching module, a second lower arm switching module, and a third lower arm switching module that are connected to a cathode end of the input unit,

wherein the first upper arm switching module and the first lower arm switching module are connected to each other electrically in series,

wherein the second upper arm switching module and the second lower arm switching module are connected to each other electrically in series, and

wherein the third upper arm switching module and the third lower arm switching module are connected to each other electrically in series.

5. The compressor control apparatus of claim 1, wherein the control unit is configured to:

determine whether or not the operation of the motor is stopped based on the cutoff unit being opened to cut off the power input from the external power source; and

based on a determination that the operation of the motor is stopped, control the switching operation to discharge the residual charge.

6. The compressor control apparatus of claim 1, wherein the control unit is configured to:

control the switching operation to discharge the residual charge based on the operation of the motor being stopped for a duration greater than a preset standby time period.

7. The compressor control apparatus of claim 2, wherein the preset control criterion comprises an operation of at least two of the plurality of switching modules to control the switching operation.

8. The compressor control apparatus of claim 1, wherein the plurality of switching modules comprise a plurality of upper arm switching modules connected to an anode end of the input unit and a plurality of lower arm switching modules connected to a cathode end of the input unit, and

wherein the control unit is configured to:

control the switching operation of one of the plurality of upper arm switching modules and one or more of the plurality of lower arm switching modules other than one lower arm switching module connected to the one of the plurality of upper arm switching modules to thereby discharge the residual charge.

9. The compressor control apparatus of claim 8, wherein the control unit is configured to:

control the switching operation of the one of the plurality of upper arm switching modules and the one or more of the plurality of lower arm switching modules to define a discharge path between the input unit and the motor through the one of the plurality of upper arm switching modules and the one or more of the plurality of lower arm switching modules to thereby discharge the residual charge through the defined discharge path.

10. The compressor control apparatus of claim 1, wherein the control unit is configured to control the switching operation for a preset discharge time period to discharge the residual charge.

11. A compressor control system, comprising:

a motor configured to drive a compressor; and

a control apparatus comprising a plurality of switching modules configured to convert a power input from an external power source to an operating power for operating the motor, the control apparatus being configured to output the operating power to the motor to control operation of the motor based on controlling a switching operation of the plurality of switching modules,

wherein the control apparatus is configured to, based on an operation of the motor being stopped, control the switching operation of two or more of the plurality of switching modules to thereby discharge a residual charge stored in the control apparatus.

12. The compressor control system of claim 11, wherein the control apparatus is configured to:

maintain a closed state to transmit the power input from the external power source to the motor;

change to an open state to interrupt the power input from the external power source based on sensing a high voltage that is greater than a predetermined reference level; and

in the open state, control the switching operation to discharge the residual charge.

13. The compressor control system of claim 11, wherein the control apparatus is configured to:

stop the operation of the motor; and

control the switching operation to discharge the residual charge based on an elapse of a preset standby time period after stopping the operation of the motor.

14. The compressor control system of claim 11, wherein the plurality of switching modules comprise a plurality of upper arm switching modules disposed at a first side of the plurality of switching modules and a plurality of lower arm switching modules disposed at a second side of the plurality of switching modules, and

wherein the control apparatus is configured to:

control the switching operation of one of the plurality of upper arm switching modules and one or more of the plurality of lower arm switching modules other than one lower switching module connected to the one of the plurality of upper arm switching modules to thereby discharge the residual charge.

15. The compressor control system of claim 14, wherein the control apparatus is configured to:

control the switching operation of the one of the plurality of upper arm switching modules and the one or more of the plurality of lower arm switching modules to define a discharge path between the control apparatus and the motor through the one of the plurality of upper arm switching modules and the one or more of the plurality of lower arm switching modules to thereby discharge the residual charge through the defined discharge path.

16. The compressor control system of claim 11, wherein the control apparatus is configured to control the switching operation for a preset discharge time period to discharge the residual charge.

17. A method of controlling a compressor control apparatus that includes a cutoff unit configured to interrupt power input from an external power source, an input unit configured to receive the power input from the external power source through the cutoff unit, an inverter unit that is configured to convert an input power supplied from the input unit to an operating power for operating a motor of a compressor, the inverter unit including a plurality of switching modules configured to perform a switching operation to control an output of the operating power to the motor, and a control unit configured to, by controlling the inverter unit, control a conversion from the input power to the operating power and the output of the operating power, the method comprising:

cutting off the power input from the external power source;

determining a discharge condition based on an operation of the motor;

based on the discharge condition, performing a discharge control of a residual charge stored in the input unit by controlling the plurality of switching modules according to a preset control criterion; and

stopping the discharge control.

18. The method of claim 17, wherein the discharge condition comprises whether or not the operation of the motor is stopped or an operation stop time period for which the operation of the motor has been stopped.

19. The method of claim 17, wherein the plurality of switching modules comprise a plurality of upper arm switching modules connected to an anode end of the input unit and a plurality of lower arm switching modules connected to a cathode end of the input unit, and

wherein performing the discharge control comprises:

controlling the switching operation of one of the plurality of upper arm switching modules and one or more of the plurality of lower arm switching modules other than one lower arm switching module connected to the one of the plurality of upper arm switching modules.

20. The method of claim 17, wherein performing the discharge control comprises performing the discharge control for a preset discharge time period.