Vehicle auxiliary control circuit

Abstract

The present invention provides a vehicle auxiliary equipment control circuit that can maintain a constant drive voltage for auxiliary equipment regardless of the voltage of the drive battery. [Solution] The electric compressor control circuit (vehicle auxiliary control circuit) has both a bidirectional AC-DC conversion circuit and a DC-DC conversion circuit, and is equipped with an on-board charger that is connected to an AC power source (external power source) to charge the vehicle's drive battery. The electric compressor (auxiliary equipment) connected in parallel between the AC power source and the on-board charger is driven by a predetermined AC voltage obtained by converting the DC voltage from the drive battery using the DC-DC conversion circuit and the AC-DC conversion circuit.

Description

Technical Field

[0001] The present invention relates to an accessory control circuit for a vehicle.

Background Art

[0002] Patent Document 1 discloses an electric compressor drive circuit that operates with a DC voltage supplied from a driving battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the electric compressor drive circuit disclosed in Patent Document 1, when the voltage of the driving battery is changed, it is necessary to change the specifications of the circuit related to the drive of the electric compressor to match the voltage of the driving battery. Therefore, it was necessary to prepare a drive circuit corresponding to the voltage of the driving battery.

[0005] An object of the present invention is to provide a vehicle accessory control circuit that can keep the drive voltage of an accessory constant regardless of the voltage of a driving battery.

Means for Solving the Problems

[0006] To achieve the above object, the vehicle accessory control circuit according to the present invention has an AC-DC conversion circuit and a DC-DC conversion circuit that can both be used bidirectionally, is connected to an external power source, and includes an in-vehicle charger that charges a driving battery of a vehicle. An accessory of the vehicle connected in parallel between the external power source and the in-vehicle charger is driven by a predetermined AC voltage obtained by converting the DC voltage from the driving battery by the DC-DC conversion circuit and the AC-DC conversion circuit.

[0007] This configuration makes it possible to provide a vehicle auxiliary equipment control device that can maintain a constant drive voltage for the auxiliary equipment regardless of the voltage of the drive battery.

[0008] Furthermore, in the vehicle auxiliary equipment control device according to the present invention, the auxiliary equipment drive circuit includes a switch circuit for operating itself.

[0009] This configuration allows auxiliary equipment to be driven at the appropriate time.

[0010] Furthermore, in the vehicle auxiliary equipment control device according to the present invention, the auxiliary equipment drive circuit drives an electric compressor mounted on the vehicle.

[0011] This configuration allows the drive voltage of the electric compressor to be kept constant, regardless of the voltage of the drive battery. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a vehicle auxiliary equipment control device that can maintain a constant drive voltage for the auxiliary equipment regardless of the voltage of the drive battery. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a circuit diagram showing an example of an electric compressor control circuit according to an embodiment. [Figure 2] Figure 2 is a circuit diagram showing an example of an electric compressor control circuit for a comparative example. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0015] (Outline configuration of the electric compressor control circuit) The schematic configuration of the electric compressor control circuit according to an embodiment of the present invention will be explained using Figure 1. Figure 1 is a circuit diagram showing an example of the electric compressor control circuit according to an embodiment.

[0016] The electric compressor control circuit 10a of this embodiment is mounted on an electrified vehicle (not shown), such as an electric vehicle, and uses the power of the vehicle's drive battery 40 to drive the motor 52 of the electric compressor 50, thereby providing air conditioning to the vehicle's interior. The electric compressor control circuit 10a may also drive the motor 52 of the electric compressor 50 to operate a heat pump cycle, thereby providing heating to the vehicle's interior. The electric compressor control circuit 10a is an example of a vehicle auxiliary control circuit in this disclosure.

[0017] The electric compressor control circuit 10a comprises an AC power supply 20, an on-board charger 30, a drive battery 40, an electric compressor 50, a charging ECU 60, and an air conditioning ECU 70.

[0018] The AC power supply 20 is located outside the vehicle and charges the drive battery 40 by being connected to the on-board charger 30 provided by the electric compressor control circuit 10a. The AC power supply 20 is an example of an external power supply in this disclosure. The AC power supply 20 can be, for example, three-phase AC or single-phase AC. In this embodiment, the AC power supply 20 will be described as being three-phase AC.

[0019] The onboard charger 30 charges the drive battery 40 with power supplied from the AC power source 20. Furthermore, the onboard charger 30 is bidirectional and can output AC power to the charging inlet side by receiving DC power from the drive battery 40. The detailed configuration of the onboard charger 30 will be described later.

[0020] The drive battery 40 is a rechargeable battery, such as a lithium-ion battery, that is mounted on the vehicle and serves as a power source for electrified vehicles such as electric vehicles. The drive battery 40 is charged by an on-board charger 30 and an AC power supply 20 connected to a charging inlet.

[0021] The electric compressor 50 circulates the heat cycle of the refrigerant used for air conditioning in the vehicle cabin. The electric compressor 50 is an example of an auxiliary machine in the present disclosure. The detailed configuration of the electric compressor 50 will be described later.

[0022] The charging ECU 60 controls the operations of the AC-DC conversion circuit 31 and the DC-DC conversion circuit 32 provided in the in-vehicle charger 30. The charging ECU 60 instructs the in-vehicle charger 30, for example, to start charging or end charging. Further, the charging ECU 60 receives an instruction from the air conditioner ECU 70 and instructs the in-vehicle charger 30 to operate in the reverse direction by the DC voltage of the drive battery 40. Also, the charging ECU 60 instructs the DC-DC conversion circuit 32 of the output voltage value after boosting or bucking.

[0023] The air conditioner ECU 70 controls the operation of the electric compressor 50. The air conditioner ECU 70 instructs the electric compressor 50, for example, to rotate, stop, rotation speed, etc. Further, the air conditioner ECU 70 instructs the charging ECU 60 to supply a predetermined power from the AC-DC conversion circuit 31 to the electric compressor 50.

[0024] The electric compressor control circuit 10a operates with the power of the drive battery 40. The detailed operation flow of the electric compressor control circuit 10a will be described later.

[0025] (Configuration of In-vehicle Charger) As shown in FIG. 1, the in-vehicle charger 30 includes an AC-DC conversion circuit 31, a DC-DC conversion circuit 32, and a capacitor C.

[0026] The AC-DC conversion circuit 31 converts the alternating current voltage (three-phase alternating current voltage in this embodiment) supplied from the AC power supply 20 into a direct current voltage. The AC-DC conversion circuit 31 is formed, for example, by an inverter circuit that combines six known switching elements in a bridge configuration. The AC-DC conversion circuit 31 outputs a full-wave rectified waveform obtained by full-wave rectifying the alternating current voltage input from the AC power supply 20. The AC-DC conversion circuit 31 can also be used bidirectionally and can convert a direct current voltage input from a subsequent stage into an alternating current voltage and output it. When the AC power supply 20 is single-phase alternating current, the number of switching elements in the inverter constituting the AC-DC conversion circuit 31 is set to four.

[0027] Capacitor C smooths the full-wave rectified waveform output by the AC-DC conversion circuit 31. This generates a DC voltage.

[0028] The DC-DC conversion circuit 32 converts the DC voltage generated by the capacitor C into a desired DC voltage by boosting or stepping it down using the isolation transformer T. The isolation transformer T electrically isolates the DC power on the primary side from the DC power on the secondary side while exchanging power in both directions. At that time, it boosts or steps down the DC voltage in a ratio corresponding to the number of windings in the primary coil and the number of windings in the secondary coil. The onboard charger 30 of this embodiment, via the AC-DC conversion circuit 31 and the DC-DC conversion circuit 32, converts, for example, a 3-phase 200V AC voltage into a 350V DC voltage to charge the drive battery 40.

[0029] The DC-DC conversion circuit 32 includes a full-bridge circuit 33 on the primary side (pre-stage) of the isolation transformer T. Furthermore, the DC-DC conversion circuit 32 includes a full-bridge circuit 34 on the secondary side (post-stage) of the isolation transformer T.

[0030] The full-bridge circuits 33 and 34 perform power conversion in both directions, from the primary side to the secondary side of the isolation transformer T, and from the secondary side to the primary side of the isolation transformer T, by alternately switching four switching elements. The DC-DC conversion circuit 32 can adjust the ON and OFF times of the switching elements constituting the full-bridge circuits 33 and 34 based on instructions from the charging ECU 60. This allows the DC voltage output by the DC-DC conversion circuit 32 to be adjusted to an appropriate value.

[0031] The onboard charger 30 can be used in both directions. Specifically, when charging the drive battery 40, the AC power supply 20 charges the drive battery 40 via the AC-DC conversion circuit 31 and the DC-DC conversion circuit 32. Also, when driving the electric compressor 50, the onboard charger 30 drives the electric compressor 50 from the drive battery 40 via the DC-DC conversion circuit 32 and the AC-DC conversion circuit 31.

[0032] (Configuration of an electric compressor) As shown in Figure 1, the electric compressor 50 is connected in parallel between the AC power supply 20 and the onboard charger 30. The electric compressor 50 includes a switch circuit 51 and a motor 52.

[0033] The switch circuit 51 is a switch for supplying AC power from the AC-DC conversion circuit 31 to the motor 52 when operating the electric compressor 50. The switch circuit 51 is controlled ON / OFF by a command from the air conditioner ECU 70. In this embodiment, the switch circuit 51 is composed of switching elements such as transistors, but the configuration of the switch circuit 51 is not limited. The switch circuit 51 may be composed of, for example, a relay or a photocoupler.

[0034] Motor 52 is, for example, a three-phase AC motor. Motor 52 cools the refrigerant by operating a compression mechanism (not shown) provided in the electric compressor 50.

[0035] (Operation of the electric compressor control circuit) Next, we will explain the operation flow of the electric compressor control circuit 10a using Figure 1.

[0036] The DC voltage output by the drive battery 40 is input to the output terminal of the DC-DC conversion circuit 32 of the onboard charger 30. The DC-DC conversion circuit 32 then boosts or lowers the voltage to convert it to a predetermined DC voltage instructed by the charging ECU 60.

[0037] Next, the DC voltage output by the DC-DC conversion circuit 32 is input to the output terminal of the AC-DC conversion circuit 31 and converted into a predetermined three-phase AC voltage by the AC-DC conversion circuit 31.

[0038] The three-phase alternating current output by the AC-DC conversion circuit 31 drives the motor 52 via a switch circuit 51 that switches in response to operation commands from the air conditioner ECU 70.

[0039] Thus, the electric compressor control circuit 10a of this embodiment is used as a drive circuit for the electric compressor 50 by using the AC-DC conversion circuit 31 as a DC-AC conversion circuit.

[0040] Furthermore, in this embodiment, the electric compressor control circuit 10a can also drive the electric compressor 50 using power supplied from the AC power supply 20 when the onboard charger 30 is charging the drive battery 40.

[0041] (Operation of the electric compressor control circuit in the comparative example) The configuration of the comparative example's electric compressor control circuit will be explained using Figure 2. Figure 2 is a circuit diagram showing an example of the comparative example's electric compressor control circuit.

[0042] Figure 2 shows an example of a conventional electric compressor control circuit 10b.

[0043] The electric compressor control circuit 10b comprises an AC power supply 20, an on-board charger 30, a drive battery 40, an electric compressor 80, a charging ECU 60, and an air conditioning ECU 71.

[0044] The AC power supply 20, the onboard charger 30, the drive battery 40, and the charging ECU 60 are the same as those provided in the aforementioned electric compressor control circuit 10a.

[0045] The electric compressor 80 includes a motor drive circuit 81 and a motor 52.

[0046] The motor drive circuit 81 is an inverter having a configuration equivalent to the AC-DC conversion circuit 31 provided in the onboard charger 30. The motor drive circuit 81 converts the DC voltage output by the drive battery 40 into a three-phase AC.

[0047] Motor 52 is the same motor as the one provided in the aforementioned electric compressor control circuit 10a. Motor 52 is rotationally driven by the three-phase AC power generated by the motor drive circuit 81.

[0048] The charging ECU 60 controls the operation of the on-board charger 30. The charging ECU 60 instructs the on-board charger 30 to, for example, start charging or stop charging.

[0049] The air conditioner ECU 71 instructs the motor drive circuit 81 to rotate the motor 52.

[0050] Comparing the comparative example's electric compressor control circuit 10b with the embodiment's electric compressor control circuit 10a, the comparative example's electric compressor control circuit 10b is driven by the DC voltage of the drive battery 40. Therefore, if the voltage of the drive battery 40 is changed, the motor drive circuit 81 needs to be modified to match the voltage of the drive battery 40. For example, if the voltage of the drive battery 40 is changed from 350V to 600V, the elements used in the motor drive circuit 81 need to be changed to elements with a higher voltage rating.

[0051] In contrast, the electric compressor control circuit 10a described in the embodiment can extract a predetermined voltage from the onboard charger 30 that matches the drive voltage of the motor 52, even when the voltage of the drive battery 40 is changed. Therefore, the motor 52 of the electric compressor 50 can be driven regardless of the voltage of the drive battery 40 and without changing the circuit.

[0052] Furthermore, in the comparative example electric compressor control circuit 10b, the AC-DC conversion circuit 31 provided in the onboard charger 30 and the motor drive circuit 81 provided in the electric compressor 80 use circuits with the same configuration.

[0053] In contrast, the electric compressor control circuit 10a described in the embodiment shares the AC-DC conversion circuit 31 and the motor drive circuit 81 with those of the comparative example electric compressor control circuit 10b, thus reducing the number of components that make up the circuit.

[0054] Furthermore, the scope of application of the vehicle auxiliary control circuit disclosed herein is not limited to the control of the electric compressor 50. For example, it can also be used to control an air compressor in a fuel cell vehicle.

[0055] (Effects of the embodiment) As described above, the electric compressor control circuit 10a (vehicle auxiliary control circuit) of this embodiment has both a bidirectional AC-DC conversion circuit 31 and a DC-DC conversion circuit 32, and drives the electric compressor 50 (auxiliary equipment) connected in parallel between the AC power supply 20 and the onboard charger 30, which is connected to the AC power supply 20 (external power supply) to charge the vehicle's drive battery 40, with a predetermined AC voltage obtained by converting the DC voltage from the drive battery 40 by the DC-DC conversion circuit 32 and the AC-DC conversion circuit 31. Therefore, the drive voltage of the electric compressor 50 can be kept constant regardless of the voltage of the drive battery 40. In addition, since the AC-DC conversion circuit 31 of the onboard charger 30 can be used as the drive circuit for the motor 52, the number of components in the electric compressor control circuit 10a can be reduced.

[0056] Furthermore, in the electric compressor control circuit 10a (vehicle auxiliary equipment control circuit) of this embodiment, the electric compressor 50 (auxiliary equipment) is equipped with a switch circuit to drive itself. Therefore, for example, when the onboard charger 30 is charging the drive battery 40 from the AC power supply 20, it is possible to prevent the motor 52 of the electric compressor 50 from starting on its own. In other words, the motor 52 can be driven at the appropriate timing.

[0057] Furthermore, in the electric compressor control circuit 10a (vehicle auxiliary equipment control circuit) of this embodiment, the auxiliary equipment is an electric compressor 50 mounted on the vehicle. Therefore, the drive voltage of the motor 52 can be kept constant regardless of the voltage of the drive battery 40. In addition, since the AC-DC conversion circuit 31 provided in the on-board charger 30 can be used as the drive circuit for the motor 52, the number of components in the electric compressor control circuit 10a can be reduced.

[0058] Although embodiments of the present invention have been described above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms. Furthermore, various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Moreover, this embodiment is included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0059] 10a Electric compressor control circuit (vehicle auxiliary equipment control circuit) 10b Electric compressor control circuit 20 AC power supply (external power supply) 30 On-board charger 31 AC-DC Conversion Circuit 32 DC-DC conversion circuits 33,34 Full-bridge circuit 40 Power batteries 50,80 Electric compressor (auxiliary equipment) 51 Switch Circuit 52 Motors 60 Charging ECU 70, 71 Air Conditioning ECU 81 Motor drive circuit C Capacitor T Isolation Transformer

Claims

1. Both have a bidirectional AC-DC converter and a DC-DC converter, and are equipped with an on-board charger that connects to an external power source to charge the vehicle's drive battery. The auxiliary equipment of the vehicle, connected in parallel between the external power supply and the on-board charger, is driven by a predetermined AC voltage obtained by converting the DC voltage from the drive battery using the DC-DC conversion circuit and the AC-DC conversion circuit. Vehicle auxiliary control circuit.

2. The aforementioned auxiliary equipment includes a switch circuit for driving itself. Vehicle auxiliary control circuit according to claim 1.

3. The aforementioned auxiliary equipment is an electric compressor mounted on the vehicle. Vehicle auxiliary control circuit according to claim 1 or claim 2.

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