JP5417740B2 - Inverter device - Google Patents

Description

  The present invention relates to an inverter device that allows a controller to identify a cause of a stop.

  The circuit and operation of an inverter device that has been conventionally performed will be described below. FIG. 4 shows an electrical circuit diagram of a conventional inverter device 120 and its periphery. Prior to operation, the magnet rotor 5 constituting the sensorless DC brushless motor 11 (hereinafter referred to as a motor) is positioned. Positioning is performed by outputting a direct current from the inverter device 120 to the stator winding 4 constituting the motor 11.

During operation, the control circuit 107 controls the switching element 2 (IGBT, FET, transistor, etc.) constituting the inverter circuit, so that the DC voltage from the battery 1 is switched by PWM modulation and is sinusoidal. Is output to the stator winding 4 constituting the motor 11. Thereby, the motor 11 is driven. The diode 3 serves as a circulation route for the current flowing through the stator winding 4. The detected current value of the current detector 106 is sent to the control circuit 107, used for power consumption calculation, switching element 2 protection, and the like, and further used for position estimation of the magnet rotor 5. The control circuit power supply 8 steps down the DC voltage from the battery 1 for the control circuit. The temperature sensor 80 that detects the temperature of the switching element 2 is installed on a heat sink for heat dissipation of the switching element 2. When the temperature detected by the temperature sensor 80 is high, protection such as reducing or stopping the output of the inverter circuit is performed (see, for example, Patent Document 1). The control circuit 107 performs data transmission / reception via a communication line 12 with a controller (not shown) that commands the operation rotational speed.
JP-A-8-48140 (Page 7, Figure 1, Page 8, Figure 4)

  As described above, in the inverter device, when the temperature of the heat sink for the switching element of the inverter circuit is high, protection such as reducing or stopping the output of the inverter circuit is performed. The output reduction / stop state of the inverter circuit is transmitted from the control circuit to the controller via the communication line. Therefore, the controller can grasp the state of the inverter device.

  On the other hand, some control circuit power supplies stop output for their own protection when the temperature rises. When the temperature of the control circuit power supply rises, the control circuit can take measures such as reducing the output of the inverter circuit, and can transmit this to the controller. However, if the control circuit power supply stops outputting, the control circuit will not operate and cannot be transmitted to the controller. Therefore, the controller cannot grasp the state of the inverter device (stop due to failure, stop due to switching element temperature protection, stop due to control circuit power supply temperature protection: these cause categories).

  The present invention solves such a conventional problem, and an object of the present invention is to provide an inverter device in which a controller can identify a cause of a stop.

  In order to solve the above problems, an inverter device of the present invention includes an inverter circuit connected to a DC power supply, a control circuit that outputs an alternating current of a frequency commanded by the controller from the inverter circuit to the motor, and a voltage for the control circuit Control circuit power supply that outputs to the control circuit, and a temperature detector that detects the temperature of the control circuit power supply, the control circuit power supply has a temperature protection function that stops the output at a predetermined temperature, When the temperature detected by the temperature detector rises and approaches a predetermined temperature, it is transmitted to the controller that the temperature of the control circuit power supply has approached the predetermined temperature.

  Thereby, before the temperature of the control circuit power supply reaches the predetermined temperature and the control circuit does not operate, the control circuit transmits to the controller that the temperature of the control circuit power supply has approached the predetermined temperature. Therefore, when the control circuit power supply stops outputting, the control circuit becomes inoperative, and transmission to the controller becomes impossible, the controller can determine that the inverter device has been stopped due to the temperature protection of the control circuit power supply. Therefore, the controller can specify the cause of the inverter device stop.

  In the inverter device of the present invention, the controller can specify the cause of the inverter device stop.

  An inverter device according to a first aspect of the present invention is an inverter circuit connected to a DC power source, a control circuit for outputting an AC current of a frequency commanded by the controller from the inverter circuit to the motor, and a voltage for the control circuit to be output to the control circuit. A control circuit power supply and a temperature detector for detecting the temperature of the control circuit power supply are provided. The control circuit power supply has a temperature protection function for stopping output at a predetermined temperature. When the temperature rises and approaches a predetermined temperature, the controller notifies the controller that the temperature of the control circuit power supply has approached the predetermined temperature.

  Thereby, before the temperature of the control circuit power supply reaches the predetermined temperature and the control circuit does not operate, the control circuit transmits to the controller that the temperature of the control circuit power supply has approached the predetermined temperature. Therefore, when the control circuit power supply stops outputting, the control circuit becomes inoperative, and transmission to the controller becomes impossible, the controller can determine that the inverter device has been stopped due to the temperature protection of the control circuit power supply. Therefore, the controller can specify the cause of the inverter device stop.

  According to a second invention, in the inverter device of the first invention, the inverter device is mounted on an electric compressor and drives a motor of the electric compressor. Since the inverter device is mounted on the electric compressor, it receives heat from the electric compressor. Therefore, the present inverter device is useful because the controller can specify the stop of the control circuit due to the temperature rise.

  A third invention is an inverter device according to the first or second invention, which is mounted on a vehicle. An inverter device mounted on a vehicle has a severe temperature environment. Therefore, the present inverter device is useful because the controller can specify the stop of the control circuit due to the temperature rise.

  A fourth invention is an inverter device according to the third invention, which is mounted on an engine. The inverter device mounted on the engine receives heat from the engine. Therefore, the present inverter device is useful because the controller can specify the stop of the control circuit due to the temperature rise.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment.

(Embodiment 1)
FIG. 1 shows an inverter device 20 according to Embodiment 1 of the present invention and an electric circuit around it. Prior to operation, the magnet rotor 5 constituting the motor 11 is positioned. The positioning is performed by outputting a direct current from the inverter device 20 to the stator winding 4 constituting the motor 11.

  The operation will be described below. The control circuit 7 calculates the induced voltage of the stator winding 4 by the magnet rotor 5 constituting the motor 11 and estimates the position of the magnet rotor 5. And based on this position estimation, the driving | operation rotation speed command received from the controller 50 via the communication line 12, etc., the switching element 2 which comprises the inverter circuit 10 is controlled, and the DC voltage from the battery 1 is switched by PWM modulation. As a result, a sinusoidal alternating current is output to the stator winding 4 of the motor 11. The control circuit 7 is connected to the upper arm switching elements U, V, W and the lower arm switching elements X, Y, Z by a connection line 18 via a drive circuit or the like, and controls each switching element. The control circuit power supply 8 steps down the DC voltage from the battery 1 and supplies it to the control circuit 7. The detected current value of the shunt resistor 6 as a current detector is sent to the control circuit 7, used for power consumption calculation, protection of the switching element 2, etc., and further used for position estimation of the magnet rotor 5.

  Next, the cause specification of the stop of the inverter device 20 by the controller 50 will be described below. The temperature sensor 80 that detects the temperature of the switching element 2 is installed on a heat sink (not shown) for heat dissipation of the switching element 2. When the temperature detected by the temperature sensor 80 is high, protection such as reducing or stopping the output of the inverter circuit 10 is performed. For example, when the temperature detected by the temperature sensor 80 reaches 80 ° C., the control circuit 7 reduces the output of the inverter circuit 10. Still, when the temperature reaches 100 ° C., the control circuit 7 stops the output of the inverter circuit 10. Then, the control circuit 7 transmits, via the communication line 12, the temperature detected by the temperature sensor 80, the output being reduced, or the output being stopped, to the controller 50 that commands the operating rotational speed. Thereby, the controller 50 can determine that the inverter device 20 is in a state where the output is being reduced or the output is being stopped due to the temperature protection of the switching element 2.

  A temperature sensor 9 for detecting the temperature of the control circuit power supply 8 is installed in the vicinity of the control circuit power supply 8. When the temperature detected by the temperature sensor 9 is high, protection such as reducing the output of the inverter circuit 10 is performed. For example, when the temperature detected by the temperature sensor 9 reaches 80 ° C., the control circuit 7 reduces the output of the inverter circuit 10. Then, the control circuit 7 transmits, via the communication line 12, the temperature detected by the temperature sensor 9 or the output being reduced to the controller 50 that commands the operating rotational speed. Thus, the controller 50 can determine that the inverter device 20 is in a state where the output of the control circuit power supply 8 is being reduced due to temperature protection.

  Still, when the temperature detected by the temperature sensor 9 rises and approaches 100 ° C. and reaches 98 ° C., the control circuit 7 notifies the controller 50 that the detected temperature of the temperature sensor 9 has approached the predetermined temperature 100 ° C. 12 to transmit. As a result, the controller 50 determines that the inverter device 20 stops output due to its own temperature protection of the control circuit power supply 8. When the temperature detected by the temperature sensor 9 reaches 100 ° C., the control circuit power supply 8 stops output for its own protection. Here, since the operation of the control circuit 7 is stopped, communication with the controller 50 is interrupted. Therefore, the controller 50 determines that the inverter device 20 has stopped output due to the temperature protection of the control circuit power supply 8 itself. On the other hand, the fact that the temperature detected by the temperature sensor 9 has approached the predetermined temperature of 100 ° C. is not transmitted from the control circuit 7 to the controller 50 via the communication line 12, and communication between the control circuit 7 and the controller 50 is interrupted. In the case of failure, it is determined as a failure.

  As described above, the controller 50 can grasp the output stop state due to the temperature protection of the switching element 2 and the output stop state due to the temperature protection of the control circuit power supply 8 itself. Further, the stop state due to overcurrent or the like can be grasped from the detected current value of the shunt resistor 6. The other stop state is determined as a stop state due to a failure. Therefore, the controller 50 can specify the cause of the stop of the inverter device 20. If the control circuit power supply 8 and the temperature sensor 9 are surface-mounted on a printed circuit board, the relative positional relationship between the control circuit power supply 8 and the temperature sensor 9 can be fixed and the temperature can be easily detected.

  In the above embodiment, the control circuit power supply 8 steps down the DC voltage from the battery 1 and supplies it to the control circuit 7. However, the control circuit power supply 8 is not limited to the DC voltage from the battery 1 and may be the voltage of another power supply. The shunt resistor 6 may be provided on the plus side of the power supply line. Further, it may be provided on the negative side of the lower arm switching element and the power supply line. The current detector is not limited to the shunt resistor but may be a current detector using a Hall element. It may be provided between the inverter circuit 10 and the motor 11 to directly detect the motor current.

(Embodiment 2)
FIG. 2 is a diagram in which the inverter device 20 is attached in close contact with the right side of the electric compressor 40. The compression mechanism 28, the motor 11, and the like are installed in the metal casing 32. The refrigerant is sucked from the suction port 33 and compressed by the compression mechanism 28 (scroll in this example) being driven by the motor 11. The compressed refrigerant cools the motor 11 when passing through the motor 11 and is discharged from the discharge port 34.

  The inverter device 20 uses a case 30 so as to be attached to the electric compressor 40. The inverter circuit unit 10 serving as a heat source is cooled by the low-pressure refrigerant through the low-pressure pipe 38. A terminal 39 connected to the stator winding 4 of the motor 11 inside the electric compressor 40 is connected to the output section of the inverter circuit section 10. A connection line 36 fixed to the inverter device 20 by the holding unit 35 includes a communication line 12 for a power line to the battery 1 and an air conditioner controller (not shown) that transmits a rotation speed signal.

  Since the inverter device 20 is mounted on the electric compressor 40, the inverter device 20 receives heat from the compression mechanism portion 28 of the electric compressor 40. Therefore, the present inverter device 20 is useful because the air conditioner controller can specify that the control circuit 7 is stopped due to a temperature rise.

  In the above embodiment, the compression mechanism of the electric compressor is a scroll. However, the present invention is not limited to this. Moreover, although the compressed refrigerant showed about the high voltage | pressure type which cools a motor, a low voltage | pressure type may be sufficient.

(Embodiment 3)
FIG. 3 shows an example in which the inverter device of the present invention is configured integrally with a compressor (Embodiment 2) and applied to an air conditioner and mounted on an engine 70 of a vehicle 60. The inverter device-integrated electric compressor 61, the outdoor heat exchanger 63, and the outdoor fan 62 are mounted in an engine room (or motor room) in front of the vehicle 60. On the other hand, an indoor fan 65, an indoor heat exchanger 67, and an air conditioner controller 64 are disposed in the vehicle compartment. Air outside the vehicle is sucked from the air introduction port 66, and the air heat-exchanged by the indoor heat exchanger 67 is blown into the vehicle interior.

  Since the inverter-unit-integrated electric compressor 61 mounted on the vehicle is outside the passenger compartment, the thermal environment is severe. In particular, the inverter device mounted on the engine directly receives heat from the engine. Therefore, the present inverter device 20 is useful because the air conditioner controller 64 can specify that the control circuit 7 is stopped due to a temperature rise.

  In each of the above embodiments, the DC power source is a battery. However, the present invention is not limited to this, and a DC power source rectified from a commercial AC power source may be used. Although the motor is a sensorless DC brushless motor, it can also be applied to a reluctance motor, an induction motor, or the like. The present invention can be applied not only to sinusoidal driving but also to a 120-degree conduction method.

  As described above, in the inverter device according to the present invention, the controller can identify the cause of the stop of the inverter device. Therefore, it can be applied to various consumer products and various industrial equipment.

The inverter apparatus which concerns on Embodiment 1 of this invention, and its surrounding electric circuit diagram Sectional drawing of the inverter apparatus integrated electric compressor which concerns on Embodiment 2 of this invention. Schematic diagram of a vehicle equipped with an inverter device according to Embodiment 3 of the present invention Conventional inverter device and peripheral electrical circuit diagram

Explanation of symbols

1 Battery 2 Switching Element 4 Stator Winding 5 Magnet Rotor 6 Shunt Resistance (Current Detector)
7 Control circuit 8 Control circuit power supply 9 Temperature sensor (for control circuit power supply)
DESCRIPTION OF SYMBOLS 10 Inverter circuit 11 Sensorless DC brushless motor 12 Communication line 20 Inverter apparatus 40 Electric compressor 50 Controller 60 Vehicle 70 Engine

Claims (4)

An inverter circuit connected to a DC power supply; a control circuit that outputs an alternating current of a frequency commanded by a controller from the inverter circuit to the motor; a control circuit power supply that outputs a voltage for the control circuit to the control circuit; In an inverter device comprising a temperature detector for detecting the temperature of the control circuit power supply, the control circuit power supply has a temperature protection function for stopping the output at a predetermined temperature, and the control circuit detects the temperature detected by the temperature detector. Rises and reaches a first temperature lower than the predetermined temperature, the output of the inverter circuit is reduced and transmitted to the controller, and the temperature further rises and the detected temperature of the power source temperature detector becomes the predetermined temperature. When approaching, the control that the temperature of the circuit power supply is close to the predetermined temperature by transmitting to the controller inverter output reduction and stop Identifiable and the inverter device that the cause is due to the overheat protection. The inverter device according to claim 1, wherein the inverter device is mounted on an electric compressor and drives a motor of the electric compressor. The inverter apparatus of Claim 1 or Claim 2 mounted in a vehicle. The inverter apparatus of Claim 3 mounted in an engine.