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 high-voltage equipment control circuit (vehicle auxiliary equipment 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 supply (external power supply) to charge the vehicle's drive battery. An electric compressor and a water heater, which are auxiliary equipment of the vehicle connected in parallel between the AC-DC conversion circuit and the DC-DC conversion circuit, are driven by the DC voltage of the drive battery, which is boosted or stepped down by the DC-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 is 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 includes 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 for charging a driving battery of a vehicle, and drives an accessory of the vehicle with a DC voltage of the driving battery boosted or bucked by the DC-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 circuit according to the present invention, the auxiliary equipment is connected in parallel between the AC-DC conversion circuit and the DC-DC conversion circuit.

[0009] With this configuration, a constant DC voltage can always be obtained from the onboard charger, regardless of the voltage of the drive battery.

[0010] Furthermore, in the vehicle auxiliary equipment control device according to the present invention, the auxiliary equipment includes an electric compressor and a water heating heater mounted on the vehicle.

[0011] With this configuration, the driving voltage of the electric compressor and water heater can 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 a high-voltage equipment control circuit according to an embodiment. [Figure 2] Figure 2 is a circuit diagram showing an example of a high-voltage equipment 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 high-voltage equipment control circuit) The schematic configuration of the high-voltage equipment 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 high-voltage equipment control circuit according to an embodiment.

[0016] The high-voltage equipment 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 high-voltage equipment control circuit 10a also drives a water heater 55 mounted on the vehicle (not shown). The water heater 55 heats the interior of the vehicle by circulating water that has been heated by heating water. Note that the high-voltage equipment control circuit 10a is an example of an auxiliary vehicle control circuit in this disclosure.

[0017] The high-voltage equipment control circuit 10a includes an AC power supply 20, an on-board charger 30, a drive battery 40, an electric compressor 50, a water heating heater 55, 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 high-voltage equipment 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 mounted on a vehicle and serves as a power source for an electrified vehicle such as an electric vehicle, and is a rechargeable battery such as a lithium-ion battery. The drive battery 40 is charged by the in-vehicle charger 30 and the AC power supply 20 connected to the 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 water heater 55 heats water with the heat generated by energizing a resistance element. The heated water is circulated by a water pump to heat the vehicle cabin. The water heater 55 is an example of an auxiliary machine in the present disclosure. Note that the water heater 55 may be a PTC (Positive Temperature Coefficient) heater that heats a PTC element, which is a type of ceramic material, instead of the resistance element. The PTC element has the property that its electrical resistance changes with a positive coefficient as the temperature rises. Therefore, since the PTC element has the characteristic that electricity flows easily when the temperature is low and hardly flows when the temperature is high, it can control its own temperature.

[0023] 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 to the charging operation using 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降压.

[0024] The air conditioning ECU 70 controls the operation of the electric compressor 50 and the water heater 55. The air conditioning ECU 70 instructs the electric compressor 50 to, for example, rotate, stop, and rotate at a specific speed. The air conditioning ECU 70 also instructs the water heater 55 to heat. Furthermore, the air conditioning ECU 70 instructs the charging ECU 60 to supply a predetermined amount of power to the electric compressor 50 and the water heater 55 from the DC-DC conversion circuit 32.

[0025] The high-voltage equipment control circuit 10a operates using the power from the drive battery 40. The detailed operation flow of the high-voltage equipment control circuit 10a will be described later.

[0026] (Configuration of the on-board charger) As shown in Figure 1, the on-board charger 30 includes an AC-DC conversion circuit 31, a DC-DC conversion circuit 32, and a capacitor C.

[0027] 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.

[0028] Capacitor C smooths the full-wave rectified waveform output by the AC-DC conversion circuit 31. This generates a DC voltage.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The onboard charger 30 can be used in both directions. That is, 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 the onboard charger 30 drives the electric compressor 50 and the water heater 55, the DC voltage obtained by boosting or stepping down the drive battery 40 via the DC-DC conversion circuit 32 drives the electric compressor 50 and the water heater 55.

[0033] (Configuration of an electric compressor) As shown in Figure 1, the electric compressor 50 is connected in parallel between the AC-DC conversion circuit 31 and the DC-DC conversion circuit 32. The electric compressor 50 includes a motor drive circuit 51 and a motor 52.

[0034] The motor drive circuit 51 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 of the drive battery 40, which has been boosted or stepped down by the DC-DC conversion circuit 32, into a three-phase AC voltage.

[0035] The motor 52 is, for example, a three-phase AC motor. The motor 52 is driven by the motor drive circuit 51 to cool the refrigerant by operating a compression mechanism (not shown) provided by the electric compressor 50.

[0036] (Operation of high-voltage equipment control circuits) Next, we will explain the operation flow of the high-voltage equipment control circuit 10a using Figure 1.

[0037] 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.

[0038] Next, the DC voltage output by the DC-DC conversion circuit 32 is drawn from connection points A and B in Figure 1 and input to the motor drive circuit 51.

[0039] The DC voltage input to the motor drive circuit 51 is converted to a three-phase AC voltage in response to an operation command from the air conditioner ECU 70. The motor 52 is then driven by the three-phase AC output by the motor drive circuit 51.

[0040] Furthermore, the DC voltages drawn from connection point A and connection point B are also input to the water heater 55, which heats the water heater 55.

[0041] In Figure 1, connection points A and B are located between the output terminal of the DC-DC conversion circuit 32 and capacitor C, as viewed from the side of the drive battery 40. However, the positions of connection points A and B are not limited to this. For example, in Figure 1, connection points A and B may be located between capacitor C and the input terminal of the AC-DC conversion circuit 31, as viewed from the side of the drive battery 40. Alternatively, only the position of connection point B in Figure 1 may be moved to between capacitor C and the input terminal of the AC-DC conversion circuit 31, as viewed from the side of the drive battery 40. Furthermore, only the position of connection point A in Figure 1 may be moved to between capacitor C and the input terminal of the AC-DC conversion circuit 31, as viewed from the side of the drive battery 40.

[0042] (Operation of the high-voltage equipment control circuit in the comparative example) The configuration of the comparative example's high-voltage equipment control circuit will be explained using Figure 2. Figure 2 is a circuit diagram showing an example of the comparative example's high-voltage equipment control circuit.

[0043] Figure 2 shows an example of a conventional high-voltage equipment control circuit 10b.

[0044] The high-voltage equipment control circuit 10b includes an AC power supply 20, an on-board charger 30, a drive battery 40, an electric compressor 80, a water heating heater 55, a charging ECU 60, and an air conditioning ECU 71.

[0045] The AC power supply 20, the onboard charger 30, the drive battery 40, the water heating heater 55, and the charging ECU 60 are the same as those provided in the high-voltage equipment control circuit 10a mentioned above.

[0046] The electric compressor 80 includes a motor drive circuit 81 and a motor 52.

[0047] The motor drive circuit 81 is the same inverter as the motor drive circuit 51 provided in the high-voltage equipment control circuit 10a. The motor drive circuit 81 converts the DC voltage output by the drive battery 40 into a three-phase AC voltage.

[0048] Motor 52 is the same motor as the one provided in the high-voltage equipment control circuit 10a mentioned above. Motor 52 is driven by the three-phase AC power generated by the motor drive circuit 81.

[0049] 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.

[0050] The air conditioner ECU 71 gives an instruction to the motor drive circuit 81 to drive the motor 52.

[0051] Comparing the comparative example high-voltage equipment control circuit 10b with the embodiment high-voltage equipment control circuit 10a, the comparative example high-voltage equipment 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 and the water heating heater 55 must 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 and the water heating heater 55 must be changed to elements with a higher voltage rating.

[0052] In contrast, the high-voltage equipment control circuit 10a described in the embodiment can extract a predetermined DC voltage from connection point A and connection point B of the onboard charger 30 that matches the drive voltage of the motor 52 and the operating voltage of the water heater 55, even when the voltage of the drive battery 40 is changed. Therefore, the motor 52 and water heater 55 of the electric compressor 50 can be driven regardless of the voltage of the drive battery 40 and without changing the circuit.

[0053] Furthermore, the scope of application of the vehicle auxiliary control circuit disclosed herein is not limited to the control of the electric compressor 50 or the water heating heater 55. For example, it can also be used to control the air compressor in a fuel cell vehicle.

[0054] (Effects of the embodiment) As described above, the high-voltage equipment control circuit 10a (vehicle auxiliary equipment control circuit) of the embodiment has both a bidirectional AC-DC conversion circuit 31 and a DC-DC conversion circuit 32, and is equipped with an on-board charger 30 that is connected to an AC power supply 20 (external power supply) and charges the vehicle's drive battery 40, and drives the vehicle's auxiliary equipment (electric compressor 50 and water heating heater 55) with the DC voltage of the drive battery 40, which is boosted or stepped down by the DC-DC conversion circuit 32. Therefore, the drive voltage of the auxiliary equipment can be kept constant regardless of the voltage of the drive battery 40.

[0055] Furthermore, in the high-voltage equipment control circuit 10a (vehicle auxiliary equipment control circuit) of this embodiment, the electric compressor 50 (auxiliary equipment) and the water heating heater 55 (auxiliary equipment) are connected in parallel between the AC-DC conversion circuit 31 and the DC-DC conversion circuit 32. Therefore, a constant DC voltage can always be obtained from the on-board charger 30, regardless of the voltage of the drive battery 40.

[0056] Furthermore, in the high-voltage equipment control circuit 10a (vehicle auxiliary equipment control circuit) of this embodiment, the auxiliary equipment consists of an electric compressor 50 and a water heater 55 mounted on the vehicle. Therefore, the drive voltage of the motor 52 and the water heater 55 can be kept constant regardless of the voltage of the drive battery 40.

[0057] 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]

[0058] 10a High-voltage equipment control circuit (vehicle auxiliary equipment control circuit) 10b High-voltage equipment 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 Motor drive circuit 52 Motors 55 Water heating heater (auxiliary equipment) 60 Charging ECU 70, 71 Air Conditioning ECU 81 Motor drive circuit A,B connection point 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 is driven by the DC voltage of the drive battery, which is boosted or stepped down by the DC-DC conversion circuit. Vehicle auxiliary control circuit.

2. The aforementioned auxiliary equipment is connected in parallel between the AC-DC conversion circuit and the DC-DC conversion circuit. Vehicle auxiliary control circuit according to claim 1.

3. The aforementioned auxiliary equipment consists of an electric compressor and a water heater mounted on the vehicle. Vehicle auxiliary control circuit according to claim 1 or claim 2.

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