Motor drive device, air conditioner, motor drive method, and motor drive program

Abstract

To provide a motor drive device capable of suppressing possibility that a changeover switch is damaged when a motor is driven, and suppressing possibility that the motor drive device fails, an air conditioner, a motor drive method, and a motor drive program.SOLUTION: A motor drive device 20 includes: a drive circuit 23 that is provided corresponding to a plurality of motors 22 and selectively drives the motor; a changeover switch 25 that is disposed between a power supply 24 and the plurality of motors and switches the motor connected to the power supply; and a controller 21 that selects the motor to be controlled among the plurality of motors, outputs a switching control signal for connecting the motor to be controlled and the power supply to the changeover switch, and outputs a drive control signal for driving the motor to be controlled relative to the drive circuit, and the changeover switch is configured to allow a current to flow in both directions.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a motor drive device, an air conditioner, a motor drive method, and a motor drive program.

Background Art

[0002] As an example of the configuration of a motor drive device, there is a configuration in which a plurality of motors to be driven are controlled by a smaller number of drive circuits than the number of motors. By adopting such a configuration, it is possible to suppress an increase in the number of component elements mounted on the motor drive device and the number of ports of the controller required for motor control, and to suppress an increase in the cost of motor control. For example, Patent Document 1 discloses a circuit that uses a single drive circuit for driving a motor and switches the motors to be driven using a plurality of transistors.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the circuit configuration disclosed in Patent Document 1, the transistors may be damaged by the reverse current and overvoltage generated when the motor to be driven operates. In the worst case, the transistors may fail and the motor drive device may no longer be able to operate.

[0005] In view of such circumstances, the present disclosure has been made, and an object thereof is to provide a motor drive device, an air conditioner, a motor drive method, and a motor drive program that suppress the possibility of damage to a switching switch during motor drive and suppress the possibility of failure of the motor drive device.

Means for Solving the Problems

[0006] In order to solve the above problems, the motor drive device, air conditioner, motor drive method, and motor drive program of the present disclosure employ the following means. The motor drive device of the present disclosure is provided corresponding to a plurality of motors, and includes a drive circuit that selectively drives the motors, a changeover switch disposed between a power source and the plurality of motors and connected to the power source for switching the motors connected to the power source, and a controller that selects a motor to be a control target among the plurality of motors, outputs a changeover control signal for connecting the motor to be the control target and the power source to the changeover switch, and outputs a drive control signal for driving the motor to be the control target to the drive circuit. The changeover switch is configured to be able to conduct current in both directions.

[0007] The air conditioner of the present disclosure includes a refrigerant circuit having a compressor that compresses a refrigerant, a condenser that condenses the compressed refrigerant, an expansion valve that expands the condensed refrigerant, and an evaporator that evaporates the expanded refrigerant, and a plurality of motors controlled by the above motor drive device.

[0008] The motor drive method of the present disclosure includes a step of selectively driving the motors using a drive circuit provided corresponding to the plurality of motors, a step of switching the motors connected to the power source using a changeover switch disposed between the power source and the plurality of motors and configured to be able to conduct current in both directions, and a step of selecting a motor to be a control target among the plurality of motors, outputting a changeover control signal for connecting the motor to be the control target and the power source to the changeover switch, and outputting a drive control signal for driving the motor to be the control target to the drive circuit.

[0009] The motor drive program of the present disclosure uses a drive circuit provided corresponding to a plurality of motors to alternately drive the motors, and a switching switch that is arranged between the power supply and the plurality of motors and is configured to be able to conduct current in both directions, and uses the switching switch to switch the motor connected to the power supply, selects a motor to be controlled from among the plurality of motors, outputs a switching control signal for connecting the motor to be controlled and the power supply to the switching switch, and outputs a drive control signal for driving the motor to be controlled to the drive circuit, and causes a computer to execute the processes.

Advantages of the Invention

[0010] According to the present disclosure, it is possible to suppress the possibility that the switching switch is damaged during the driving of the motor, and to suppress the possibility that the motor drive device fails.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0012] Hereinafter, an embodiment of a motor drive device, an air conditioner, a motor drive method, and a motor drive program according to the present disclosure will be described with reference to the drawings. In the following description, when there are a plurality of similar components, if the similar components are to be individually distinguished, any one of a to d is appended to the end of the reference numeral, and if the similar components are not to be individually distinguished, the description of the alphabets a to d is omitted.

[0013] FIG. 1 is a schematic diagram showing a part of the configuration of the air conditioner 1 in the present disclosure. As shown in FIG. 1, the air conditioner 1 includes an HVAC ECU (Heating, Ventilation and Air Conditioning Electric Control Unit) (motor drive device) 20 that controls a damper motor 22 described later. The air conditioner 1 also includes a plurality of damper motors 22, a blower motor 31, and various sensors 32.

[0014] The air conditioner 1 also includes a refrigerant circuit having a compressor (not shown) that compresses the refrigerant, a condenser (not shown) that condenses the compressed refrigerant, an expansion valve (not shown) that expands the condensed refrigerant, and an evaporator (not shown) that evaporates the expanded refrigerant, and a plurality of damper motors 22 controlled by the HVAC ECU 20. Here, the refrigerant evaporated by the evaporator becomes gaseous and returns to the compressor again. The air conditioner 1 adjusts the temperature of the space to be air-conditioned by using the refrigerant circuit in which the refrigerant circulates. Regarding other configurations of the air conditioner 1, known ones can be applied and will not be described in detail here.

[0015] The HVAC ECU 20 includes a CPU (controller) 21, a drive circuit 23, and a changeover switch 25, and is connected via cables to a blower motor 31, various sensors 32, a plurality of damper motors 22, etc. The HVAC ECU 20 receives the detected amounts of various sensors and controls the operations of various actuators in accordance with the operating conditions of the air conditioner. Specifically, the HVAC ECU 20 adjusts heating and cooling according to the room temperature and the outside air temperature, and controls the damper motor 22 to maintain an appropriate temperature, humidity, or air quality. Details of the control of the damper motor 22 by the HVAC ECU 20 will be described later.

[0016] The damper motor 22 adjusts the flow of air in the air conditioner and supplies air whose temperature has been adjusted by heating or cooling to a specific space or direction. Further, the damper motor 22 may have a function of switching between taking in fresh air from the outside and circulating the air in the air-conditioned space.

[0017] FIG. 2 is a diagram showing an example of the hardware configuration of the HVAC ECU 20 in the present disclosure. As shown in FIG. 2, the HVAC ECU 20 is a computer, and includes, for example, a CPU (Central Processing Unit) 21, a main memory 212, a secondary storage (memory) 213, a communication interface 214, etc. Further, the HVAC ECU 20 may include an input device 215 for receiving an input from a user, a display 216, etc. Further, the HVAC ECU 20 may include a drive circuit 23 and a changeover switch 25. These components are connected via, for example, a bus 218.

[0018] The main memory 212 is composed of, for example, a writable memory such as a cache memory and a RAM (Random Access Memory), and is used as a work area for reading the execution program of the CPU 21, writing processing data by the execution program, etc. The secondary storage device 213 is a non-transitory computer readable storage medium. Examples of the secondary storage device 213 include magnetic disks such as HDD (Hard Disk Drive), magneto-optical disks, CD-ROM, DVD-ROM, semiconductor memories such as SSD (Solid State Drive), and the like.

[0019] FIG. 3 is a diagram showing the HVAC ECU 20' including a plurality of drive circuits 23' in a circuit example. The HVAC ECU 20' includes a CPU 21' and a drive circuit 23'. The drive circuit 23' includes a plurality of drive switches 231a' to 231d'. Similarly, the drive circuit 23'' includes a plurality of drive switches 231a'' to 231d''. The drive switches 231a' to 231h' are, for example, transistors. The CPU 21' outputs a switching control signal (for example, a PWM signal) to each of the drive switches 231a' to 231h' in order to selectively drive the damper motors 22a', 22b'. The on / off states of the drive switches 231a' to 231h' are switched according to the control switching signal, and by switching the on / off states of the drive switches 231a' to 231h', it is switched which damper motor 22a', 22b' is supplied with power from the power supply 24'. Further, the CPU 21' controls the damper motor 22' to be driven by switching the on / off states of the drive switches 231a' to 231h'. Note that a known method may be appropriately used for the method of generating the switching control signal output by the CPU 21', and it will not be described in detail here.

[0020] FIG. 4 is a diagram illustrating the relationship between the on / off states of the drive switches 231a' to 231d' in a circuit example and the direction of current flow in the damper motor 22a'. For simplicity of explanation, in FIG. 4, the illustration of the drive switches 231a'' to 231d'' and the damper motor 22b' is omitted, but they are controlled in the same manner. For example, when the CPU 21´ outputs a switching control signal to turn on the drive switches 231a´ and 231c´ and turn off the drive switches 231b´ and 231d´, the current flowing from the power supply 24´ flows through the motor coils of the damper motor 22a´ to the drive switches 231a´ and 231c´ that are in the on state (black arrows in Fig. 4). Conversely, when the CPU 21´ outputs a switching control signal to turn on the drive switches 231b´ and 231d´ and turn off the drive switches 231a´ and 231c´, the current flowing from the power supply 24´ flows through the motor coils of the damper motor 22a´ to the drive switches 231b´ and 231d´ that are in the on state (white arrows in Fig. 4).

[0021] The CPU 21´ controls the drive of the damper motor 22a´ by switching the on / off states of the drive switches 231a´ to 231d´ according to the operation of the air conditioner. For example, regarding the timing of switching each drive switch, the CPU 21´ may provide a phase difference for each of the drive switches 231a´ to 231d´. For example, it may be switched so that the pair of two drive switches 231a´ and 231c´ and the pair of two drive switches 231b´ and 231d´ are alternately turned on every half cycle. Also, based on the timing of turning on the drive switch 231a´, the timing of turning on each of the drive switches 231b´ to 231d´ may be shifted by 1 / 4 cycle each.

[0022] In the examples of Figs. 3 and 4, in this way, corresponding to the increase in the number of damper motors 22´, the number of drive circuits 23´ to be provided increases, so a circuit area for providing the drive circuit 23´ is required. Also, when the number of drive circuits 23´ increases, the CPU 21´ requires a CPU port for each drive circuit 23´. That is, when the number of damper motors 22 that are the control targets increases, the required number of CPU ports of the CPU 21´ increases proportionally. When the required number of ports of the CPU 21´ increases, there is a possibility that the CPU ports are insufficient, and ultimately there is a need to change the CPU. Furthermore, the wiring between the components of the air conditioner 1 becomes complicated, and there is also a possibility that the board design becomes difficult. In view of such circumstances, the inventors considered a configuration of the HVAC ECU that does not increase the number of drive circuits even when controlling a plurality of damper motors.

[0023] [First Embodiment] (Configuration of HVAC ECU) Hereinafter, the first embodiment of the present disclosure will be described with reference to FIG. 5. FIG. 5 is a diagram showing the circuit configuration of the HVAC ECU 20 in the first embodiment of the present disclosure. Further, the HVAC ECU 20 in the first embodiment of the present disclosure is different from the HVAC ECU 20' illustrated in FIGS. 3 and 4 in that a plurality of damper motors 22 can be driven and controlled by one drive circuit 23 by switching the connection between the power supply 24 and the damper motor 22 to be controlled using the changeover switch 25.

[0024] The CPU 21 selects the damper motor 22 to be controlled among the plurality of damper motors 22, outputs a switching control signal for connecting the damper motor 22 to be controlled and the power supply 24 to the changeover switch 25, and outputs a drive control signal for driving the damper motor 22 to be controlled to the drive circuit 23.

[0025] The switching control signal output by the CPU 21 is, for example, a voltage signal. The voltage signal is, for example, a binary voltage signal of H / L. The CPU 21 switches the connection state of each switch element 251 provided in the changeover switch 25 by outputting a voltage signal of either H / L to each switch element 251. Each switch element turns on when an H voltage signal is output and turns off when an L voltage signal is output. Note that the switching control signal is not limited to a voltage signal and may be any control signal that can switch the connection state of the switch element 251.

[0026] The drive control signal output by the CPU 21 is, for example, a PWM signal. The PWM signal can be switched on / off at high speed and is a signal that operates at a high frequency. Also, the CPU 21 controls the power of the damper motor 22 that is the control target by changing the duty cycle of each PWM signal output to each drive switch 231. Note that the drive control signal is not limited to the PWM signal, and any control signal that can switch the connection state of the drive switch 231 may be used.

[0027] The drive circuit 23 is provided corresponding to a plurality of damper motors 22 (22a, 22b) and drives the damper motors 22 alternately. Also, the drive circuit 23 includes a plurality of drive switches 231a to 231d and a plurality of protection elements 26a to 26d for ESD countermeasures corresponding to each drive switch. The drive switches 231a to 231d are, for example, transistors. Note that the drive switches 231a to 231d are not limited to transistors, and any element that functions as a switching element may be used. Details of the protection element 26 will be described later. Also, each of the plurality of drive switches 231a to 231d is connected corresponding to the plus side or minus side motor coil of each phase of the A phase and B phase of the damper motor 22 that is the control target, and the damper motor 22 is controlled by controlling the on / off of each of the drive switches 231a to 231d. For example, the drive switch 231a is connected to the plus side motor coil of the A phase of the damper motor 22, the drive switch 231b is connected to the minus side motor coil of the A phase of the damper motor 22, the drive switch 231c is connected to the plus side motor coil of the B phase of the damper motor 22, and the drive switch 231d is connected to the minus side motor coil of the B phase of the damper motor 22.

[0028] In this embodiment, each drive switch 231a to 231d included in the drive circuit 23 and each motor coil of the damper motors 22a and 22b are connected outside the HVAC ECU 20. Thus, by connecting the drive circuit 23 and the motor coils of each phase of the damper motor 22 outside the HVAC ECU 20, the number of input lines to the HVAC ECU 20 can be reduced, and the connector of the HVAC ECU 20 can be miniaturized.

[0029] The changeover switch 25 is arranged between the power supply 24 and the plurality of damper motors 22, and switches the damper motor 22 connected to the power supply 24. Further, the changeover switch 25 is configured to be able to conduct current in both directions. Also, for example, the changeover switch 25 includes a plurality of switch elements 251a and 251b. Depending on the changeover control signal output by the CPU 21, either one of the switch elements 251a and 251b is turned on. Thereby, corresponding to the turned-on switch element 251, the connection state is switched so that the damper motor 22 to be controlled and the power supply 24 are electrically connected.

[0030] Also, the switch elements 251a and 251b included in the changeover switch 25 are, for example, semiconductor switches that can conduct current in both directions, and may be solid-state relays. Further, the switch elements 251a and 251b may be mechanical switches that conduct by physically contacting each other. Thus, by using switch elements configured to be able to conduct current in both directions, the possibility of the changeover switch 25 being damaged by reverse current or overvoltage generated during driving of the damper motor 22 can be suppressed, and the possibility of the HVAC ECU 20 malfunctioning can be suppressed. Note that the switch elements 251a and 251b are not limited to this example, and any switch elements configured to be able to conduct current in both directions may be used.

[0031] Each of the plurality of protection elements 26a to 26d is connected between the damper motor 22 and each of the drive switches 231a to 231d. The protection element 26 is, for example, a Zener diode. The Zener diode has the property of making the reverse bias voltage a stable Zener voltage. For this reason, the Zener diode can suppress the elements included in the HVAC ECU 20 from being damaged due to electrostatic discharge (ESD: Electrostatic Discharge) or overvoltage generated in the HVAC ECU 20.

[0032] (Regarding the operation of the HVAC ECU) The HVAC ECU 20 drives and controls each damper motor in accordance with the operating conditions of the air conditioner 1. Specifically, the CPU 21 included in the HVAC ECU 20 outputs a drive control signal to the drive circuit 23 and outputs a switching control signal to the changeover switch 25. When only the damper motor 22a among the plurality of damper motors 22 is driven and controlled, the CPU 21 selects the damper motor 22a among the plurality of damper motors 22 as a control target and outputs a switching control signal for connecting the control target damper motor 22a and the power supply 24 to the changeover switch 25. The changeover switch 25 turns on the switch element 251a and turns off the switch element 251b based on the switching control signal output from the CPU 21. As a result, the current supplied from the power supply 24 is supplied to the motor coils of each phase of the damper motor 22a in accordance with the control state of the drive circuit 23.

[0033] In addition, the CPU 21 turns on the drive switches 231a and 231c and turns off the drive switches 231b and 231d. In this case, the current flowing through the damper motor 22a flows from the power supply 24 through the switch element 251a to the motor coils on the plus side of the A phase and the plus side of the B phase of the damper motor 22a, respectively. Then, the current flowing through the motor coil on the plus side of the A phase of the damper motor 22a passes through the drive switch 231a and flows to the ground, and the current flowing through the motor coil on the plus side of the B phase of the damper motor 22a passes through the drive switch 231c and flows to the ground.

[0034] Here, a protection element 26a, which is a Zener diode, is connected between the motor coil on the plus side of phase A of the damper motor 22a and the drive switch 231a. This suppresses the possibility that the elements included in the HVAC ECU 20 are damaged by electrostatic discharge (ESD) or overvoltage generated in the HVAC ECU 20. Similarly, a protection element 26c, which is a Zener diode, is connected between the motor coil on the plus side of phase B of the damper motor 22a and the drive switch 231c.

[0035] Furthermore, after a predetermined time has elapsed, the CPU 21 turns on the drive switches 231b and 231d and outputs a drive control signal to the drive circuit 23 to turn off the drive switches 231a and 231c. In this case, the current flowing through the damper motor 22a flows from the power supply 24 through the switch element 251a to the motor coils on the minus side of phase A and the minus side of phase B of the damper motor 22a, respectively. Then, the current flowing through the motor coil on the minus side of phase A of the damper motor 22a passes through the drive switch 231b and flows to the ground, and the current flowing through the motor coil on the plus side of phase B of the damper motor 22a passes through the drive switch 231c and flows to the ground.

[0036] Here, a protection element 26b, which is a Zener diode, is connected between the motor coil on the plus side of phase B of the damper motor 22a and the drive switch 231b. This suppresses the possibility that the elements included in the HVAC ECU 20 are damaged by electrostatic discharge (ESD) or overvoltage generated in the HVAC ECU 20. Similarly, a protection element 26d, which is a Zener diode, is connected between the motor coil on the minus side of phase B of the damper motor 22a and the drive switch 231d.

[0037] In this way, by the CPU 21 outputting different drive control signals to the drive circuit 23 at every elapse of a predetermined time, the on / off states of the drive switches 231a to 231d are switched, and the damper motor 22a can be driven and controlled to rotate in either the clockwise (CW) or counterclockwise (CCW) direction.

[0038] Also, when switching the damper motor 22 to be controlled from the damper motor 22a to the damper motor 22b in response to the operating conditions of the air conditioner, the CPU 21 outputs a switching control signal for connecting the damper motor 22b to be controlled and the power supply 24 to the switching switch 25. Based on the switching control signal output from the CPU 21, the switching switch 25 turns off the switch element 251a and turns on the switch element 251b. Thereby, the current supplied from the power supply 24 is supplied to the motor coils of each phase of the damper motor 22b corresponding to the control state of the drive circuit 23.

[0039] Even when the damper motor 22b is the object to be controlled, the CPU 21 can drive and control the damper motor 22a to rotate in either the clockwise (CW) or counterclockwise (CCW) direction by switching the on / off states of the drive switches 231a to 231d at every elapse of a predetermined time, similar to the case when the damper motor 22a is the object to be controlled. Also, the CPU 21 may appropriately switch which of the damper motors 22a and 22b is the object to be controlled in response to the operating conditions of the air conditioner.

[0040] Note that in the example of this embodiment, the number of the damper motors 22a and 22b and the switch elements 251a and 251b is two each, but it is not limited thereto, and the number of the damper motors and the switch elements may be four. Also, the number of the damper motors and the switch elements may be any number, and in this case as well, the plurality of damper motors are driven by a common drive circuit.

[0041] In this way, regardless of whether either of the damper motors 22a and 22b is the control target, the damper motor 22 can be controlled while commonly using the drive circuit 23. As a result, corresponding to an increase in the number of damper motors 22, it is not necessary to provide the drive circuit 23, and the configuration and wiring of the HVAC ECU 20 can be simplified. For example, when adding one motor to the HVAC ECU 20 of the present disclosure, control can be achieved simply by adding one switching element of the changeover switch 25 and one CPU port of the CPU 21.

[0042] Also, the switching elements 251a and 251b included in the changeover switch 25 are, for example, semiconductor switches capable of passing current in both directions, and may be, for example, solid-state relays. Further, the switching elements 251a and 251b may be mechanical switches that conduct by physically contacting each other. Thereby, the possibility of the changeover switch 25 being damaged by reverse current or overvoltage generated during driving of the damper motor 22 can be suppressed, and the possibility of the HVAC ECU 20 malfunctioning can be suppressed.

[0043] Also, protection elements 26a to 26d for ESD countermeasures are connected between the motor coils corresponding to each phase of the damper motors 22a and 22b and the drive switches 231a to 231d. Thereby, it is possible to suppress the elements included in the HVAC ECU 20 from being damaged by static electricity. Further, since it is a configuration in which a plurality of motors can be driven and controlled by one drive circuit, the number of protection elements does not increase corresponding to an increase in the drive circuit. Thereby, an increase in cost and an increase in the board area of the HVAC ECU 20 can be suppressed. Also, even if the number of damper motors 22 increases, an increase in the number of wirings can be suppressed. Thereby, the resistance to noise generated during operation of the HVAC ECU 20 can be improved.

[0044] Also, from the viewpoint of thermal design, the drive circuit corresponds to a heat source. Therefore, the thermal design can be simplified by suppressing an increase in the number of drive circuits that are heat sources.

[0045] Also, each drive switch 231a to 231d included in the drive circuit 23 and each motor coil of the damper motors 22a and 22b are connected outside the HVAC ECU 20. In this way, by connecting the drive circuit 23 and the motor coils of each phase of the damper motor 22 outside the HVAC ECU 20, the number of input lines to the HVAC ECU 20 can be reduced, and the connector of the HVAC ECU 20 can be miniaturized.

[0046] 〔Modification of the First Embodiment〕 Hereinafter, a modification of the first embodiment of the present disclosure will be described with reference to FIG. 6. FIG. 6 is a diagram showing the circuit configuration of the HVAC ECU 20 and the damper motor 22 in a modification of the first embodiment of the present disclosure. This modification is different from the first embodiment in that each drive switch 231a to 231d included in the drive circuit 23 and each motor coil of the damper motors 22a and 22b are connected inside the HVAC ECU 20. Regarding the configuration and operation of the HVAC ECU 20, since they are the same as those in the first embodiment, the description will be omitted.

[0047] In this modification, each drive switch 231a to 231d included in the drive circuit 23 and each motor coil of the damper motors 22a and 22b are connected inside the HVAC ECU 20. In this way, by connecting the drive circuit 23 and the motor coils of each phase of the damper motor 22 inside the HVAC ECU 20, the number of wirings outside the HVAC ECU 20 can be reduced, and the noise resistance is improved. As a result, the electromagnetic compatibility (EMC) is reduced, and it is possible to suppress the occurrence of malfunction in the entire system.

[0048] 〈Supplementary Matters〉 As described above, the present disclosure has been explained using embodiments. However, the technical scope of the present disclosure is not limited to the scope described in the above embodiments. Various changes or improvements can be made to the above embodiments without departing from the gist of the present disclosure, and the forms with such changes or improvements are also included in the technical scope of the present disclosure. Further, the above embodiments may be combined as appropriate. For example, in the above embodiment, the HVAC ECU was described as an example of the motor drive device. However, the present disclosure is not limited to this example, and a motor driver corresponding to the types and usage environments of a plurality of motors to be driven may be appropriately used instead of the HVAC ECU. Further, in the above embodiment, the CPU was described as an example of the controller. However, the present disclosure is not limited to this example, and an FPGA or an ASIC may be used.

[0049] The motor drive device, air conditioner, motor drive method, and motor drive program described in the above embodiments are understood as follows, for example. The motor drive device (20) according to the first aspect of the present disclosure is provided corresponding to a plurality of motors, and includes a drive circuit (23) that selectively drives the motors, and a changeover switch (25) that is disposed between a power source and the plurality of motors and switches the motors connected to the power source. The controller (21) selects a motor to be controlled among the plurality of motors, outputs a changeover control signal for connecting the motor to be controlled and the power source to the changeover switch, and outputs a drive control signal for driving the motor to be controlled to the drive circuit. The changeover switch is configured to be able to conduct current in both directions.

[0050] According to the motor drive device of the present disclosure, since the controller outputs control signals to the drive circuit and the switching switch respectively, it is possible to switch which of the plurality of motors to supply power to, so there is no need to provide a drive circuit corresponding to the number of motors, and the configuration and wiring of the motor drive device can be simplified. Further, unlike a switching element such as a transistor, the switching switch is, for example, a mechanical switch or a solid state relay, and a switch capable of flowing current in both directions is used. Thereby, the possibility that the switching switch is damaged by the reverse current generated when the motor is driven can be suppressed, and the possibility that the motor drive device fails can be suppressed. Further, when one motor is added to the motor drive device of the present disclosure, control can be achieved simply by adding one element of the switching switch and one port of the CPU port of the drive driver.

[0051] In the motor drive device according to the second aspect of the present disclosure, in the first aspect, the drive circuit includes a plurality of drive switches (231a to 231d) and a plurality of protection elements (26a to 26d) for ESD countermeasures corresponding to each of the drive switches, and each of the plurality of protection elements is connected between the motor and each of the drive switches.

[0052] According to the motor drive device of the present disclosure, by connecting a protection element (for example, a Zener diode) for ESD (Electrostatic Discharge) countermeasures connected between the motor and each drive switch, it is possible to suppress damage to the elements included in the motor drive device due to static electricity. Further, since it is a configuration using drive circuits corresponding to a plurality of motors, the number of protection elements does not increase in response to an increase in the drive circuit. Thereby, an increase in the cost of the motor drive device and an increase in the size of the motor drive device can be suppressed. Further, since the number of wirings provided in the motor drive device can be reduced, the resistance to noise generated during the operation of the motor drive device can be improved.

[0053] In the motor drive device according to the third aspect of the present disclosure, in the first aspect or the second aspect, the drive circuit and the wiring of each phase of the motor are connected outside the motor drive device.

[0054] According to the motor drive device of the present disclosure, the number of internal wirings of the motor drive device can be reduced, the number of input lines to the motor drive device can be reduced, and the connector of the motor drive device can be miniaturized.

[0055] In the motor drive device according to the fourth aspect of the present disclosure, in the first aspect or the second aspect, the drive circuit and the wiring of each phase of the motor are connected inside the motor drive device.

[0056] According to the motor drive device of the present disclosure, the number of external wirings of the motor drive device can be reduced, and the noise resistance is improved. Thereby, it is possible to suppress a decrease in electromagnetic compatibility (EMC) performance and the occurrence of malfunction in the entire system.

[0057] The air conditioner according to the fifth aspect of the present disclosure includes a compressor, a condenser, an evaporator, and a motor controlled by the motor drive device according to any one of the first aspect to the fourth aspect.

[0058] The motor drive method according to the sixth aspect of the present disclosure includes a step of selectively driving the motor using a drive circuit (23) provided corresponding to a plurality of motors, and a switching switch (25) disposed between a power source and the plurality of motors and configured to be able to flow current in both directions. A step of switching the motor connected to the power source, a step of selecting a motor to be controlled among the plurality of motors, outputting a switching control signal for connecting the motor to be controlled and the power source to the switching switch, and outputting a drive control signal for driving the motor to be controlled to the drive circuit.

[0059] The motor drive program according to the seventh aspect of the present disclosure uses a drive circuit (23) provided corresponding to a plurality of motors to alternately drive the motors, and is disposed between a power supply and the plurality of motors and configured to be able to conduct current in both directions. A switching process for switching the motor connected to the power supply using a switching switch (25), selecting a motor to be controlled from among the plurality of motors, outputting a switching control signal for connecting the motor to be controlled and the power supply to the switching switch, and outputting a drive control signal for driving the motor to be controlled to the drive circuit. The computer is caused to execute the process.

Explanation of Signs

[0060] 1 Air conditioner 20,20´ HVACECU 21,21´ CPU 22,22a,22b,22a´,22b´ Damper motor 23,23´,23´´ Drive circuit 231,231a~231d,231a´~231d´,231a´´~231d´´ Drive switch 24,24´ Power supply 25 Switching switch 251,251a,251b Switching element 26,26a~26d Protection element 31 Blower motor 32 Sensor 212 Main storage device 213 Secondary storage device 214 Communication I / F 215 Input device 216 Display 218 Bus

Claims

1. A drive circuit provided corresponding to a plurality of motors and selectively driving the motors; A changeover switch disposed between a power source and the plurality of motors and switching the motors connected to the power source; A controller that selects a motor to be controlled from among the plurality of motors, outputs a changeover control signal for connecting the motor to be controlled and the power source to the changeover switch, and outputs a drive control signal for driving the motor to be controlled to the drive circuit; Comprising: A motor drive device in which the changeover switch is configured to be able to conduct current in both directions.

2. The drive circuit includes a plurality of drive switches and a plurality of protection elements for ESD countermeasures corresponding to each of the drive switches; The motor drive device according to claim 1, wherein each of the plurality of protection elements is connected between the motor and each of the drive switches.

3. The motor drive device according to claim 1, wherein the drive circuit and the wiring of each phase of the motor are connected outside the motor drive device.

4. The motor drive device according to claim 1, wherein the drive circuit and the wiring of each phase of the motor are connected inside the motor drive device.

5. A refrigerant circuit having a compressor for compressing a refrigerant, a condenser for condensing the compressed refrigerant, an expansion valve for expanding the condensed refrigerant, and an evaporator for evaporating the expanded refrigerant; A plurality of motors controlled by the motor drive device according to claim 1; An air conditioner comprising:

6. A step of selectively driving the motor using a drive circuit provided corresponding to a plurality of motors; A step of switching the motor connected to the power source using a changeover switch disposed between the power source and the plurality of motors and configured to be able to conduct current in both directions; A step of selecting a motor to be controlled from among the plurality of motors, outputting a changeover control signal for connecting the motor to be controlled and the power source to the changeover switch, and outputting a drive control signal for driving the motor to be controlled to the drive circuit; A motor drive method comprising:

7. A process of selectively driving the motor using a drive circuit provided corresponding to a plurality of motors; Using a switching switch that is arranged between the power supply and the plurality of motors and is configured to be able to conduct current in both directions, a process of switching the motor connected to the power supply, selecting a motor to be controlled among the plurality of motors, outputting a switching control signal for connecting the motor to be controlled and the power supply to the switching switch, and outputting a drive control signal for driving the motor to be controlled to the drive circuit, A motor drive program for causing a computer to execute.

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