KR20180108476A - Electric compressor - Google Patents

Abstract

An electric compressor (10) comprises: an electric motor (13); an inverter (31); a filter unit (60); and a control apparatus (55). The inverter (31) is configured to convert DC power supplied from a power storage device (B1) into AC power and supply the AC power after conversion to the electric motor (13). The filter unit (60) is connected to an input side of the inverter (31). The control apparatus (55) is configured to determine a connection state between the power storage device (B1) and the electric compressor (10) based on a change in resonance frequency in a circuit including the filter unit (60).

Description

[0001] ELECTRIC COMPRESSOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor, and more particularly to an electric compressor configured to be connected to a power storage device of a vehicle.

Japanese Patent Publication No. 5953240 discloses an electric compressor used in an automotive air conditioner or the like. This electric compressor is connected to the power storage device of the vehicle. This electric compressor includes a compression section for compressing a refrigerant, a motor for driving the compression section, an inverter for supplying AC power to the motor, and a control device for controlling the inverter. A smoothing capacitor is connected to the input side of the inverter. In this electric compressor, the control device controls the inverter so as to supply a predetermined current to the motor, and controls the connection state of the electric compressor and the power storage device based on the change in voltage of the smoothing capacitor when a predetermined current is supplied to the motor .

There is a possibility that the voltage of the storage device of the vehicle suddenly changes according to the running state of the vehicle. In the technique disclosed in Patent Document 1, when the voltage of the power storage device is suddenly changed due to the change of the traveling state of the vehicle, the voltage of the smoothing capacitor changes. For example, the electric compressor (electric compressor) There is a possibility that an erroneous determination that the connection between the electric compressor and the power storage device is released is made.

The present invention has been made to solve such a problem, and an object thereof is to provide an electric compressor capable of judging the connection state with the power storage device with high precision.

An electric compressor according to the present invention is configured to be connected to a power storage device of a secondary battery. An electric compressor includes a compression section, an electric motor, an inverter, a filter section, and a control device. The compression section is configured to compress the refrigerant. The electric motor is configured to drive the compression unit. The inverter is configured to convert DC power supplied from the power storage device into AC power and supply the AC power after conversion to the electric motor. The filter section is connected to the input side of the inverter. The control device is configured to determine the connection state of the power storage device and the motor-driven compressor based on a change in the resonance frequency in the circuit including the filter portion.

The inductance and the capacitance in the circuit are changed depending on whether or not the motor-driven compressor is connected to the power storage device. In other words, the resonance frequency of the circuit is changed depending on whether or not the motor-driven compressor is connected to the power storage device. According to this electric compressor, since the connection state between the power storage device and the electric compressor is determined based on the change in the resonance frequency in the above circuit, the connection state of the power storage device and the electric compressor can be determined with good accuracy.

These and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

1 is a diagram showing a configuration of a vehicle air conditioning apparatus.
2 is a circuit diagram showing another circuit connected to the inverter unit and the inverter unit.
3 is a diagram showing the relationship between the inverter unit and the vehicle-side system in the first comparative example.
4 is a diagram showing the relationship between the inverter unit and the vehicle-side system in the second comparative example.
5 is a diagram for explaining a method of determining the connection state between the motor-driven compressor and the vehicle-side system.
Fig. 6 is a flowchart showing a procedure for determining the connection state between the motor-driven compressor and the vehicle-side system.

Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or equivalent portions are denoted by the same reference numerals, and description thereof will not be repeated.

[Embodiment 1]

(Configuration of vehicle air conditioner)

1 is a diagram showing a configuration of a vehicle air conditioning system 100 to which an electric compressor 10 according to the first embodiment is applied. Referring to Fig. 1, the vehicle air conditioning system 100 is mounted on a vehicle, and is configured to perform cooling and heating in a vehicle interior. The vehicle air conditioning system 100 includes an electric compressor 10, an external cooling circuit 101, and an air conditioning ECU 102.

The external cooling circuit 101 is configured to supply the refrigerant to the electric compressor 10. The external cooling circuit 101 includes, for example, a heat exchanger and an expansion valve. The electric compressor (10) is configured to compress the refrigerant supplied from the external cooling circuit (101). That is, in the vehicle air conditioner 100, the refrigerant is compressed by the electric compressor 10, and the external cooling circuit 101 performs heat exchange and expansion of the refrigerant. As a result, cooling and heating in the passenger compartment is carried out.

The air conditioner ECU 102 has a CPU (Central Processing Unit) and a memory (not shown) built therein. Based on information stored in the memory and information from each sensor (not shown), each control unit . The air conditioning ECU 102 is capable of recognizing, for example, the temperature set by the user in relation to the air conditioning in the vehicle room and the temperature in the current vehicle room. The air conditioning ECU 102 transmits various commands such as ON / OFF commands to the motor-driven compressor 10 based on these parameters, for example.

The motor-driven compressor 10 includes a housing 11, a compression section 12, an electric motor 13, and an inverter unit 30. The motor-driven compressor 10 is connectable to the vehicle-side system 200 via the cable 150 and configured to receive the supply of DC power from the vehicle-side system 200. The relationship between the motor-driven compressor 10 and the vehicle-side system 200 will be described later in detail.

The housing 11 is substantially cylindrical and accommodates the compression section 12 and the electric motor 13 therein. The housing 11 is formed with a suction port 11a through which the refrigerant is sucked from the external cooling circuit 101 and a discharge port 11b through which the refrigerant is discharged.

The compression section 12 compresses the refrigerant sucked from the suction port 11a in the compression chamber and discharges the compressed refrigerant from the discharge port 11b. The compression section 12 may be of any type, such as a scroll type, a piston type, and a vane type.

The electric motor 13 is configured to drive the compression section 12. The electric motor 13 includes, for example, a rotary shaft 21, a rotor 22, and a stator 23. The rotary shaft 21 is cylindrical and is rotatably supported with respect to the housing 11. The rotor 22 has a cylindrical shape and is fixed to the rotating shaft 21. The stator 23 is fixed to the housing 11. The rotor 22 and the stator 23 are opposed to each other in the radial direction of the rotating shaft 21. The stator 23 includes a cylindrical stator core 24 and a coil 25. The coil 25 is formed by winding around the teeth of the stator core 24. [

The inverter unit (30) includes an inverter (31) and a case (32).

The inverter 31 is a drive circuit for driving the electric motor 13. [ The inverter 31 is connected to the coil 25 of the electric motor 13 through a connector (not shown) or the like. The inverter 31 is configured to convert the DC power supplied from the vehicle-side system 200 (power storage device B1 (described later)) into AC power and supply the AC power after conversion to the electric motor 13 .

The inverter 31 includes a circuit board 51, a power semiconductor 52, various circuits (for example, an oscillating portion 53, a control device 55, a filter portion 60 and a resonance detecting portion 61) . Various circuits will be described later in detail. The power semiconductor 52 and various circuits are mounted on the circuit board 51 together with the wiring patterns and are electrically connected.

The case 32 includes a plate-shaped base member 41 and a cylindrical cover member 42 having a bottom. The cover member 42 is attached to the base member 41. The base member 41 and the cover member 42 are fixed to the housing 11 by means of bolts 43. A connector 54 is formed on the outer surface of the case 32 and the circuit board 51 and the connector 54 are electrically connected.

The connector 54 is configured such that the cable 150 is connected. DC power is supplied from the vehicle side system 200 (power storage device B1) to the inverter 31 through the connector 54 and the cable 150. [

(Circuit configuration of motor compressor)

Fig. 2 is a circuit diagram showing another circuit connected to the inverter unit 30 and the inverter unit 30. Fig. 2, the motor-driven compressor 10 is connectable to the vehicle-side system 200 via a cable 150. The motor- The vehicle-side system 200 includes the power storage device B1.

The power storage device B1 is a power storage element configured to be chargeable / dischargeable and has a capacitance component. The power storage device B1 includes, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery or a lead acid battery, or a battery element such as a capacitor. The power storage device B1 is configured to supply DC power to the motor-driven compressor 10 in a state where the vehicle-side system 200 is connected to the motor-

The cable 150 includes a connector not shown, and the connector is configured to be connectable to the connector 54 (Fig. 1) of the motor-driven compressor 10. The cable 150 has an inductance component. In the figure, L1 represents the inductance component of the cable 150. [

The electric compressor (10) includes an electric motor (13) and an inverter unit (30). The electric motor 13 is a so-called three-phase motor. The coil 25 of the electric motor 13 includes a U-phase coil 25U, a V-phase coil 25V, and a W-phase coil 25W. The coil 25U, the coil 25V and the coil 25W are Y-connected, for example.

As described above, the inverter unit 30 includes the inverter 31, and the inverter 31 includes the power semiconductor 52, the filter unit 60, the oscillating unit 53, the resonance detecting unit 61 , And a control device 55. [

The filter unit 60 is connected to the input side of the inverter unit 30. The filter portion 60 includes, for example, a coil L2 and a capacitor C1 in the case of an LC filter. The coil L2 is connected to the positive electrode line PL1. The capacitor C1 is connected between a pair of power lines (hereinafter, simply referred to as a " power line pair ") composed of a positive line PL1 and a negative line NL1. The capacitor C1 also functions as a smoothing capacitor. For example, when the filter portion 60 is a C filter, the filter portion 60 is composed of only the capacitor C1, but also in this case, the inductance L2 due to the wiring exists.

The inverter 31 is a so-called three-phase inverter. The inverter 31 includes switching elements TU1 and TU2 connected in series between the power line pairs, switching elements TV1 and TV2 connected in series between the power line pairs, And switching elements TW1 and TW2. Each of the switching elements TU1, TU2, TV1, TV2, TW1 and TW2 (hereinafter also referred to as "switching elements TU1-TW2") is constituted by, for example, an IGBT (Insulated Gate Bipolar Transistor). Diodes DU1, DU2, DV1, DV2, DW1 and DW2 are respectively connected in anti-parallel to the switching elements TU1-TW2. A node N1 between the switching element TU1 and the switching element TU2 is connected to the coil 25U. A node N2 between the switching elements TV1 and TV2 is connected to the coil 25V. The node N3 between the switching element TW1 and the switching element TW2 is connected to the coil 25W.

The oscillating unit 53 is configured to oscillate at a predetermined frequency (predetermined frequency). The oscillation portion 53 is constituted by, for example, an LC oscillation circuit, and is connected between power line pairs. The oscillating unit 53 is configured to output a signal of a predetermined frequency using, for example, an unillustrated auxiliary battery as a power source. The oscillation section 53 includes, for example, a switching element, a drive circuit of the switching element, and a controller, and the drive circuit controls the drive circuit so that the controller switches the on / . That is, the oscillation unit 53 may be configured to oscillate at a predetermined frequency.

The resonance detecting unit 61 is configured to detect at least one of a current and a voltage generated due to the oscillation of the oscillating unit 53. For example, when the resonance detecting section 61 detects a current, the resonance detecting section 61 is constituted by a current sensor for detecting the output current of the oscillating section 53. On the other hand, when the resonance detecting unit 61 detects the voltage, the resonance detecting unit 61 is constituted by a voltage sensor that detects the output voltage of the oscillating unit 53. [ The resonance detecting section 61 outputs the detection result to the control device 55. [

The control device 55 incorporates a CPU and a memory (not shown), and controls the inverter 31 based on information stored in the memory and information from each sensor. The control device 55 drives the electric motor 13 by turning on / off the switching elements TU1-TW2, for example.

The control device 55 has a function of determining whether or not the cable 150 (vehicle-side system 200) is connected to the connector 54 (the motor-driven compressor 10). The control device 55 determines the connection state between the motor-driven compressor 10 and the vehicle-side system 200 based on the detection result of the resonance detecting portion 61. Next, a method of determining the connection state between the motor-driven compressor 10 and the vehicle-side system 200 (power storage device B1) will be described in detail.

[Connection determination of power storage device]

First, a method of determining the connection state between the motor-driven compressor (inverter unit) and the vehicle-side system (power storage device) in the plurality of comparative examples will be described. Next, a method of determining the connection state between the motor-driven compressor 10 and the vehicle-side system 200 (power storage device B1) in the first embodiment will be described.

3 is a diagram showing the relationship between the inverter unit 30X and the vehicle-side system 200X in the first comparative example. Referring to Fig. 3, the inverter unit 30X and the vehicle-side system 200X are connected via a cable 150X. The vehicle-side system 200X includes a disconnection detecting unit 210X. In a state where the connector 151X is connected to the inverter unit 30X, the circuit including the disconnection detecting unit 210X is brought into a short state. On the other hand, when the connector 151X is not connected to the inverter unit 30X, the circuit including the disconnection detecting unit 210X is in the open state. The disconnection detecting unit 210X can determine the connection state of the connector 151X and the inverter unit 30X based on whether or not a current flows in a circuit including the disconnection detecting unit 210X.

In the first comparative example, in order to determine the connection state between the connector 151X and the inverter unit 30X, it is necessary to form the single wire detecting unit 210X in the vehicle side system 200X. In this case, the vehicle-side system 200X becomes larger. The cable 150X needs to include a high-voltage power line for supplying DC power from the vehicle-side system 200X to the inverter unit 30X and a low-voltage power line connected to the single-wire detecting unit 210X. In this case, the connectors of the cable 150X and the cable 150X become larger.

Fig. 4 is a diagram showing the relationship between the inverter unit 30Y and the vehicle-side system 200Y in the second comparative example. Referring to Fig. 4, the inverter unit 30Y and the vehicle-side system 200Y are connected via a cable 150Y. The inverter unit 30Y includes a break detection unit 31Y. In a state in which the connector 151Y is connected to the inverter unit 30Y, the circuit including the disconnection detecting unit 31Y is brought into a short state. On the other hand, when the connector 151Y is not connected to the inverter unit 30Y, the circuit including the disconnection detecting unit 31Y is in an open state. The disconnection detecting section 31Y can determine the connection state of the connector 151Y and the inverter unit 30Y based on whether or not a current flows in a circuit including the disconnection detecting section 31Y, for example.

In the second comparative example, it is necessary to form the single wire detecting unit 31Y in the inverter unit 30Y in order to determine the connection state of the connector 151Y and the inverter unit 30Y. In this case, the inverter unit 30Y is enlarged. Similarly to the first comparative example, the cable 150Y has a high-voltage power line for supplying DC power from the vehicle-side system 200Y to the inverter unit 30Y and a low-voltage power line connected to the single- It is necessary to include a power line. In this case, the connectors of the cable 150Y and the cable 150Y become larger.

As a third comparative example, the following method is also conceivable. 2, for example, in the motor-driven compressor 10, the control device 55 controls the inverter 31 so that a predetermined current is supplied to the electric motor 13, Side system 200 on the basis of the change in the voltage of the capacitor C1 when a predetermined current is supplied to the vehicle-side system 100 and the vehicle- Specifically, in this case, when the voltage of the capacitor C1 is lowered by a predetermined value or more, it is determined that the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released, and the voltage of the capacitor C1 It is determined that the connection between the motor-driven compressor 10 and the vehicle-side system 200 is continued.

However, the voltage of the capacitor C1 may change rapidly depending on the running state of the vehicle. When the voltage of the capacitor C1 is lowered by a predetermined value or more due to a change in the traveling state of the vehicle, the electric compressor 10 is operated, for example, even though the electric compressor 10 and the vehicle- There is a possibility that the connection between the vehicle-side system 200 and the vehicle-side system 200 is judged to be disconnected.

As described above, the first to third comparative examples each have a problem. In the electric compressor 10 according to the first embodiment, these problems are solved. That is, in the first embodiment, the electric compressor 10, the vehicle-side system 200, the cable 150 and the like are not enlarged more than necessary and the voltage change of the capacitor C1 according to the traveling state of the vehicle It is possible to determine the connection state between the motor-driven compressor 10 and the vehicle-side system 200 without greatly influencing the vehicle-side system 200. A method of determining the connection state between the motor-driven compressor 10 and the vehicle-side system 200 in the first embodiment will be described below.

The inductance and the capacitance of the circuit (closed circuit) including the filter portion 60 are changed depending on whether the motor-driven compressor 10 is connected to the vehicle-side system 200 or not. This is because the vehicle-side system 200 has, for example, a capacitance component or an inductance component L1 of the power storage device B1. That is, depending on whether or not the motor-driven compressor 10 is connected to the vehicle-side system 200, the resonance frequency of the circuit including the filter unit 60 is changed.

In the motor-driven compressor 10 according to the first embodiment, therefore, the control device 55 controls the vehicle-side system 200 based on the change in the resonance frequency in the circuit including the filter unit 60 Device B1) and the motor-driven compressor 10 are determined. Therefore, with the motor-driven compressor 10, the connection state between the motor-driven compressor 10 and the vehicle-side system 200 can be determined with good accuracy.

More specifically, in the first embodiment, the resonance frequency of the circuit including the filter section 60 in the state in which the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released Respectively. The oscillating portion 53 is configured to oscillate at a resonance frequency that is calculated in advance (a resonance frequency in a state where the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released).

In this case, when the motor-driven compressor 10 is connected to the vehicle-side system 200, since the resonance does not occur, the amplitude of the output signal (output current) of the oscillation portion 53 is small. On the other hand, when the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released, resonance occurs, so that the amplitude of the output signal (output current) of the oscillating unit 53 becomes large. When the amplitude of the output signal of the oscillation section 53 becomes equal to or larger than a predetermined value (that is, the resonance frequency of the circuit including the filter section 60 is higher than the resonance frequency of the motor- 200 is disconnected), it is determined that the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released.

5 is a diagram for explaining a method for determining the connection state between the motor-driven compressor 10 and the vehicle-side system 200 according to the first embodiment. 5, the horizontal axis represents the oscillation frequency of the oscillation section 53, and the vertical axis represents the detection result (the amplitude of the output signal of the oscillation section 53) of the resonance detection section 61.

The relationship between the oscillation frequency and the amplitude represented by the solid line indicates the relationship between the oscillation frequency and the amplitude in a state where the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released. The frequency f1 is the resonance frequency of the circuit including the filter unit 60 in a state where the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released.

The relationship between the oscillation frequency and the amplitude represented by the dotted line shows the relationship between the oscillation frequency and the amplitude in a state where the motor-driven compressor 10 and the vehicle-side system 200 are connected. The frequency f2 is the resonance frequency of the circuit including the filter unit 60 in a state where the motor-driven compressor 10 and the vehicle-side system 200 are connected.

As described above, the oscillating unit 53 oscillates at the frequency f1. Referring to the relationship between the oscillation frequency and the amplitude represented by the dotted line, when the connection between the motor-driven compressor 10 and the vehicle-side system 200 continues, the amplitude of the signal detected by the resonance detecting unit 61 becomes A1 . On the other hand, when the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released, the amplitude of the signal detected by the resonance detecting unit 61 is A2 .

The control device 55 determines that the connection between the motor-driven compressor 10 and the vehicle-side system 200 is continued when the amplitude of the signal detected by the resonance detecting portion 61 is less than the predetermined value Th1. On the other hand, when the amplitude of the signal detected by the resonance detecting section 61 is equal to or larger than the predetermined value Th1, the control device 55 determines that the connection between the motor- do. By using such a method, the connection state between the motor-driven compressor 10 and the vehicle-side system 200 is determined with good accuracy.

According to the motor-driven compressor 10, since the oscillating portion 53 oscillates at the resonance frequency in the state where the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released, Resonance can be prevented from occurring in a normal state in which the vehicle-side system 200 is connected.

[Connection determination process of power storage device]

Fig. 6 is a flowchart showing a procedure for determining the connection state of the electric compressor 10 and the vehicle-side system 200 (power storage device B1). The processing shown in this flowchart is repeatedly executed during the system operation of the vehicle on which the electric compressor 10 is mounted. During operation of the vehicle system, the oscillating portion 53 oscillates at a resonance frequency in a state in which the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released.

Referring to Fig. 6, the control device 55 determines whether the amplitude of the detection signal detected by the resonance detection unit 61 is equal to or greater than a predetermined value (step S100). If it is determined that the amplitude of the detection signal is equal to or larger than the predetermined value (YES in step S100), the control device 55 releases the connection between the vehicle-side system 200 (power storage device B1) and the motor- (Step S110). On the other hand, when it is determined that the amplitude of the detection signal is less than the predetermined value (NO in step S100), the control device 55 determines that the connection between the vehicle-side system 200 (power storage device B1) and the motor- (Step S120).

As described above, in the motor-driven compressor 10 according to the first embodiment, the control device 55 controls the vehicle-side system 200 based on the change in the resonance frequency in the circuit including the filter unit 60, (Power storage device B1) and the motor-driven compressor 10 is determined. Therefore, with the motor-driven compressor 10, the connection state between the motor-driven compressor 10 and the vehicle-side system 200 can be determined with good accuracy.

[Embodiment 2]

In the first embodiment, the oscillating unit 53 oscillates at the resonance frequency of the circuit including the filter unit 60 in a state in which the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released Respectively. In the second embodiment, the oscillating unit 53A is configured to oscillate while changing the frequency within a predetermined range. Hereinafter, a description will be given centering on a part different from the first embodiment.

Referring again to Fig. 2, the electric compressor 10A according to the second embodiment includes an inverter unit 30A. The inverter unit 30A includes an oscillating portion 53A.

The oscillating portion 53A is configured to oscillate while changing the frequency within a predetermined range. The oscillation portion 53A includes, for example, a switching element, a drive circuit of the switching element, and a controller. For example, in the oscillation section 53A, the controller controls the drive circuit such that the drive frequency of the switching element continuously changes within a predetermined range. The reason why the oscillation frequency of the oscillation portion 53A is continuously changed will be described below.

The resonance frequency of the circuit including the filter portion 60 may deviate from the theoretical value due to, for example, the temperature or the manufacturing variation of each element. The amplitude of the signal detected by the resonance detecting unit 61 is not equal to or greater than the predetermined value although the connection between the motor-driven compressor 10A and the vehicle-side system 200 is released, for example, A situation may arise in which the disconnection between the motor-driven compressor 10A and the vehicle-side system 200 can not be detected with good accuracy.

In the second embodiment, the oscillating portion 53A is configured to include the resonance frequency of the circuit including the filter portion 60 in a state in which the connection between the motor-driven compressor 10A and the vehicle- Oscillates while changing the frequency within the range. The range for changing the frequency (hereinafter also referred to as the "predetermined range") is predetermined in consideration of the degree of deviation of the resonance frequency from the theoretical value due to the temperature and the manufacturing variation of each element. In the motor-driven compressor 10A according to the second embodiment, even if the resonance frequency of the circuit including the filter section 60 deviates somewhat from the theoretical value because the oscillation section 53A oscillates while changing the frequency, The controller 55 can detect the cancellation of the connection between the motor-driven compressor 10A and the vehicle-side system 200 with a good accuracy as far as it is within the predetermined range.

Further, the control device 55 executes the same processing as the processing shown in the flowchart of Fig. When the amplitude of the detection signal of the resonance detection unit 61 becomes equal to or larger than a predetermined value in a state where the oscillation unit 53A is oscillating while changing the frequency, the control unit 55 controls the motor-driven compressor 10A and the vehicle- ) (Power storage device B1) is released.

As described above, in the motor-driven compressor 10A according to the second embodiment, the oscillating portion 53A is configured to oscillate while changing the frequency within a predetermined range, and the control device 55 includes the resonance detecting portion 61 Side system 200 based on a change in the amplitude of the detection signal of the motor-driven compressor 10A. Even if the resonance frequency is slightly changed due to factors other than the change in the connection state of the vehicle-side system 200 (power storage device B1) and the motor-driven compressor 10A, the motor- ) And the electric compressor 10A can be judged with good accuracy.

[Other Embodiments]

In the first embodiment, the oscillation section 53 oscillates at the resonance frequency of the circuit including the filter section 60 in a state in which the connection between the motor-driven compressor 10 and the vehicle-side system 200 is released Respectively. However, the oscillation frequency of the oscillation portion 53 is not limited to this. The oscillation frequency of the oscillation portion 53 may be the resonance frequency of the circuit including the filter portion 60 in a state where the motor-driven compressor 10 and the vehicle-side system 200 are connected, for example. In this case, since the resonance occurs when the motor-driven compressor 10 and the vehicle-side system 200 are connected, the control device 55 determines that the amplitude of the detection signal of the resonance detection unit 61 is less than the predetermined value , It is determined that the connection between the motor-driven compressor (10) and the vehicle-side system (200) is released. As described above, the oscillation frequency of the oscillation section can be different from that of the second embodiment.

In the first embodiment, the power storage device B1 is not limited to a general battery, but may be a device having a large capacity condenser. For example, the power storage device B1 may be a drive inverter or the like.

While the embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are by no means intended to be limiting in all respects. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims (5)

An electric compressor configured to be connected to a power storage device of a vehicle,
A compression unit configured to compress the refrigerant;
An electric motor configured to drive the compression unit,
An inverter configured to convert DC power supplied from the power storage device into AC power and supply the AC power after conversion to the electric motor;
A filter unit connected to an input side of the inverter,
And a control device configured to determine a connection state between the power storage device and the motor-driven compressor based on a change in a resonance frequency in a circuit including the filter portion. The method according to claim 1,
Further comprising an oscillation unit connected to the circuit and configured to oscillate at a predetermined frequency,
Wherein the control device is configured to determine the connection state based on a change in amplitude of a signal caused by an oscillation of the oscillation portion. 3. The method of claim 2,
The oscillating portion is configured to oscillate at a resonance frequency of the circuit in a state in which the connection between the power storage device and the motor compressor is released,
Wherein the control device is configured to determine that the connection between the power storage device and the motor-operated compressor is released when the amplitude reaches a predetermined value or more. The method according to claim 1,
Further comprising an oscillation unit connected to the circuit and configured to oscillate while changing a frequency within a predetermined range,
Wherein the control device is configured to determine the connection state based on a change in amplitude of a signal caused by an oscillation of the oscillation portion. 5. The method of claim 4,
Wherein the oscillating portion is configured to oscillate while changing a frequency within a range including a resonance frequency of the circuit in a state in which the connection between the power storage device and the motor-
Wherein the control device is configured to determine that the connection between the power storage device and the motor-operated compressor is released when the amplitude reaches a predetermined value or more.

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