Vehicle charging device and vehicle charging system

Abstract

A vehicle charging device and a vehicle charging system include: a power converter connected to an AC power source external to the first vehicle and converting an AC power input from the AC power source into a first DC power; a voltage converter converting an input DC voltage into a charging voltage of the first battery; a voltage conversion control unit controlling the voltage converter;and a DC input terminal connected to a DC power source external to the first vehicle, wherein the DC input terminal inputs a DC voltage of a second DC power input from the DC power source to the voltage converter, and wherein the voltage converter converts the DC voltage of the first DC power and / or the second DC power into the charging voltage of the first battery according to an instruction from the voltage conversion control unit;

Description

Technical area

[0001] The present invention relates to a vehicle charging device and a vehicle charging system. Background area

[0002] With the increasing popularity of electric vehicles, the possibility of a vehicle becoming unable to drive due to the occurrence of an insufficient electricity condition is also increasing. Therefore, as a method for charging the vehicle at a location other than the power injection location, wireless power injection on a road, battery charging between vehicles, and the like are also being considered as one of the power injection methods. This is a method for charging a battery of an own vehicle by converting a voltage input from another vehicle or an external power source through an output conversion unit and a voltage conversion unit of an on-board charger (OBC) mounted on a vehicle. In such a charging method, a charging device that enables stable charging is important, for example, using a charging device with a charging current of 100 mA.PTL 1 discloses a configuration of a charging device that realizes stable charging by having a power conversion unit control a DC voltage and a frequency of the voltage conversion unit to be constant during the control. Citation listPatent literature

[0003] PTL 1: JP 2021-93788 A Summary of the inventionTechnical problem

[0004] In conventional inter-vehicle charging, there is a problem that charging itself is not possible due to a short circuit when power supply and charging are performed between batteries that have a voltage difference. The present invention is made in view of the above circumstances, and an object of the present invention is to provide a vehicle charging device and a vehicle charging system that realize battery charging from DC power sources with different voltages during inter-vehicle charging. Solution to the problem

[0005] A vehicle charging device and a vehicle charging system that charge a first battery installed in a first vehicle, the vehicle charging device and the vehicle charging system including: a power converter connected to an AC power source external to the first vehicle and converting AC power input from the AC power source into a first DC power; a voltage converter that converts an input DC voltage into a charging voltage of the first battery; a voltage conversion control unit that controls the voltage converter;and a DC input terminal connected to a DC power source outside the first vehicle, wherein the DC input terminal inputs a DC voltage of a second DC power input from the DC power source to the voltage converter, and wherein the voltage converter converts the DC voltage of the first DC power and / or the second DC power into a charging voltage of the first battery according to an instruction from the voltage conversion control unit; Advantageous effects of the invention

[0006] It is possible to provide a vehicle charging device and a vehicle charging system that realize battery charging from DC sources with different voltages when charging between vehicles. Brief description of the drawings Fig. 1 is an explanatory diagram of a vehicle charging device according to an embodiment of the present invention. Fig. 2 is an electrical circuit diagram of the vehicle charging device according to the embodiment of the present invention. Fig. 3 is a first variation. Fig. 4 is a second variation. Fig. 5 is a third variation. Fig. 6 is a flowchart of a control unit of the vehicle charging device according to the embodiment of the present invention. Description of embodiments

[0007] Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are examples for describing the present invention and have been omitted and simplified where appropriate for clarity of description. The present invention may be embodied in various other forms. Unless otherwise specified, each component may be singular or plural.

[0008] The positions, sizes, areas, and the like of the components illustrated in the drawings may not represent actual positions, sizes, shapes, areas, and the like to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, areas, and the like disclosed in the drawings. (An embodiment and overall configuration of the present invention) (Fig. 1)

[0009] As one embodiment of a vehicle employing the present invention, a dedicated vehicle 1 includes a battery 1b and a vehicle charging device 10. The vehicle charging device 10 is, for example, a charging device that performs charging by connecting the vehicle 1 and a charging device 3 outside the vehicle 1. Furthermore, the vehicle charging device 10 is, for example, a charging device that connects the vehicle 1 and the other vehicle 2 and can bidirectionally charge between batteries mounted on the vehicles.

[0010] The vehicle charging device 10 includes a power converter 4 connected to an AC power source 3a of an AC charger 3 outside the vehicle 1 and converting AC power input from the AC power source 3a into DC power, a voltage converter 5 converting an input DC voltage into a charging voltage of the battery 1b, and a voltage conversion control unit 7 controlling the voltage converter 5. Furthermore, the vehicle charging device 10 includes a DC input terminal 1a connected to a DC power source 2a outside the vehicle 1. Note that the AC power source 3a is, for example, a commercially available AC power source. The DC power source 2a outputs a variable voltage or a constant DC voltage.

[0011] In the power converter 4, the AC power is rectified and smoothed by an EMC filter 4a and a power factor correction block (PFC block) 4b improves the power factor and suppresses harmonic components.

[0012] Hereinafter, a DC power obtained by converting an AC power input from the AC power source 3a by the power converter 4 is referred to as first DC power, and a DC power input from the DC input terminal 1a is referred to as second DC power. The DC input terminal 1a inputs the DC voltage of the second DC power input from the DC power source 2a to the voltage converter 5. The voltage converter 5 converts the DC voltage of the first DC power and / or the second DC power into the charging voltage of the first battery 1b according to an instruction from the voltage conversion control unit 7.

[0013] The voltage conversion control unit 7 acquires information about the charging voltage of the battery 1b, reflects the control content for converting the DC voltage of the second DC power inputted from the DC input terminal 1a to the voltage converter 5 into the AC voltage by an H-bridge converter 5a, and converts the converted AC voltage into the DC voltage by an H-bridge converter 5b, thereby realizing the charging of the battery 1b.

[0014] With such a configuration, the vehicle charging device 10 can charge the battery 1b with power supplied from a commercial power source (the AC power source 3a) during regular charging, and can cause the voltage converter 5 to convert the voltage into the charging voltage of the battery 1b even when a DC voltage different from that of the battery 1b is input during inter-vehicle charging or the like. Note that a plurality of other vehicles 2 and a plurality of DC power sources 2a may be connected to the vehicle 1.

[0015] Furthermore, the vehicle charging device 10 is configured to input a DC power from the DC input terminal 1a to the HB circuit of the voltage converter 5, thereby discharging the DC power from the battery 1b to the DC power source 2a. The other vehicle 2 can input and output the second DC power between the own vehicle 1 and the other vehicle 2 by mounting the DC power source 2a and a vehicle charging device (not illustrated) to have the same configuration as that of the own vehicle 1 when performing bidirectional charging. (Fig. 2)

[0016] The AC power source 3a includes, for example, a ground-connected, commercially available three-phase AC power source 108 of a four-wire type, a common-mode choke coil 106, and the like. The AC power source 3a is connected to the power converter 4 via a choke coil 105. The voltage converter 5 is made of, for example, a silicon carbide metal oxide semiconductor field-effect transistor (SiC MOSFET) and includes an isolation transformer 100.

[0017] The vehicle 1 can be converted by connecting it to an AC power source other than the AC power source 3a, and, for example, the battery 1b can be charged by connecting it to a single-wire three-phase AC load 406 or the like via the voltage converter 5. The AC load 406 includes, for example, a plurality of commercially available AC power sources 108 and is connected to the vehicle 1 via a vehicle power supply socket 405. With the AC power input from the vehicle power supply socket 405, the AC power is converted into DC power by a power converter 402 via the common-mode choke coil 106 and a choke coil 408. The DC power converted from the AC power by the power converter 402 is converted into the charging voltage of the battery 1b by the voltage converter 5 via the capacitor 403, the choke coil 408, and the like.

[0018] The DC input terminal 1a is connected to a wiring between the power converter 4 and the voltage converter 5. The DC input terminal 1a is connected to a DC power source (not illustrated). As a result, either the first DC power converted from the AC power by the power converter 4 or the second DC power is input from the DC input terminal 1a to the voltage converter 5. (First modification)(Fig. 3)

[0019] The vehicle charging device 10 includes a voltage detection device 8 between the DC input terminal 1a and the voltage converter 5. Also included is the voltage conversion control unit 7, which acquires information detected by the voltage detection device 8 and information about the battery 1b and functions as control means for the voltage converter 5.

[0020] The voltage detection device 8 detects a DC voltage of the first DC power or the second DC power input to the voltage converter 5 and transmits information about the detected DC voltage to the voltage conversion control unit 7. Based on the difference between the DC voltage detected by the voltage detection device 8 and the charging voltage of the battery 1b, the voltage conversion control unit 7 controls the frequency and / or phase of the AC voltage converted in the process of converting the input DC voltage into the charging voltage of the first battery 1b in the voltage converter 5.

[0021] Specifically, the frequency control in the voltage converter 5 will be described. For example, when the value of the DC voltage (of the battery 2a of the other vehicle 2) detected by the voltage detection device 8 for the DC voltage input from the DC power source 2a is 800V and the charging voltage of the battery 1b is 400V, which are different voltage systems, the voltage conversion control unit 7 performs conversion control on the resonance frequency of the AC voltage converted in a state where the resonance frequency is higher than the resonance frequency of the charging voltage of 400V in the process of converting the input DC voltage of 800V in the voltage converter 5. In this way, the battery 1b of the own vehicle can be charged even if there is a voltage difference.

[0022] On the other hand, when the DC voltage input from the DC power source 2a is in the same voltage system, for example, the value of the DC voltage detected by the voltage detection device 8 is 400 V and the charging voltage of the battery 1b is 400 V, the voltage conversion control unit 7 controls the frequency so that the resonance frequency of the AC voltage obtained by converting the input DC voltage of 400 V in the voltage converter 5 approaches the resonance frequency of the AC voltage for setting the charging voltage to 400 V. In this way, inter-vehicle charging can be realized.

[0023] It should be noted that a configuration for preventing a fault can be added, for example, by providing a surge prevention circuit between the DC input terminal 1a and the voltage detection device 8 to enable control of an inrush current. This not only enables charging at different voltages but also enables a stable charge state. (Second modification)(Fig. 4)

[0024] In addition to the vehicle charging device 10, the host vehicle 1 includes a communication device 11 that transmits information about the charging voltage of the battery 1b to and from a second vehicle 2 different from the host vehicle 1. The communication device 11 transmits and receives information about the charging voltage of the battery 1b and information about the DC voltage that the voltage converter 5 can convert into the charging voltage of the first battery 1b. Note that the charging voltage of the battery 1b is measured by a battery voltage measuring sensor (not shown).

[0025] The communication device 11 acquires information about the charging voltage of the battery detected by the sensor and information about the conversion voltage of the voltage converter 5. Furthermore, the communication device 11 acquires information about the discharging voltage of the DC power source 2a of the other vehicle 2 through a communication device (not illustrated) mounted on the other vehicle 2 and a sensor (not illustrated) that measures the voltage of the DC power source 2a. In the own vehicle 1, the information received from the other vehicle 2 is used as information for performing control so that the voltage converter 5 in the vehicle charging device 10 can convert the voltage into the charging voltage of the battery 1b.

[0026] In this way, the communication devices included in the own vehicle 1 and the other vehicle 2 can transmit and receive each unit of information of the detected voltage through bidirectional wireless communication. Then, the vehicle 2 including a battery capable of discharging a voltage close to the charging voltage of the battery 1b of the own vehicle 1b can be selected from among the plurality of other vehicles 2, and inter-vehicle charging can be realized even if there is a voltage difference. (Third variation)(Fig. 5)

[0027] A fast charging input terminal 13 for connecting to the DC input terminal 1a is provided between the first battery 1b and the voltage converter 5. Accordingly, the DC input terminal 1a is a fast charging input terminal that can directly input the second DC power to the first battery 1b.

[0028] A relay circuit 6, including a first switch 6a that connects or disconnects the DC input terminal 1a and the voltage converter 5, and a second switch 6b that connects or disconnects the DC input terminal 1a and the quick charge input terminal 13, is provided between the quick charge input terminal 13 and the DC input terminal 1a, and between the voltage converter 5 and the DC input terminal 1a. The relay circuit 6 switches the first switch 6a and the second switch 6b when the DC voltage of the second DC power is the same as the charging voltage of the first battery 1b. Note that the DC input terminal 1a and the quick charge input terminal 12a are input terminals, for example, CHAdeMO (registered trademark).

[0029] When the discharge voltage of the DC power source 2a (a battery) of the other vehicle 2 is the same as the charging voltage of the battery 1b of the own vehicle 1, a control unit (not illustrated) of the relay circuit 6 in the vehicle charging device 10 determines that there is no need for conversion by the voltage converter 5, so that the relay circuit 6 switches from the first switch 6a to the second switch 6b in accordance with an instruction from the control unit, and power can be directly supplied from the DC input terminal 1a to the battery 1b. Since the relay circuit 6 can be switched depending on the type of connected external power source, the charging time can be shortened. It should be noted that means for detecting the discharge voltage of the DC power source 2a to instruct the switching of the switch of the relay circuit 6 is not limited, and that, for example,the above-described communication device 11 or the like can be used. (Fig. 6)

[0030] In step S1, the voltage conversion control unit 7 detects the input DC voltage with the voltage detection device 8. In step S2, it is determined whether the detected DC voltage originates from a 400 V system. If so, the process proceeds to step S3; otherwise, the process proceeds to step S6. In step S3, it is determined whether the host vehicle 1 belongs to a 400 V system. If so, the process proceeds to step S4; otherwise, the process proceeds to step S5.

[0031] In step S4, since the voltage systems of the input voltage and the own vehicle 1 are the same (both the input voltage and the own vehicle 1 belong to a 400 V system), the resonance frequency Fsw of the AC voltage converted in the process of converting the input DC voltage by the voltage converter 5 is caused to approach the resonance frequency Fr for causing the AC voltage to become the charging voltage of the battery 1b.

[0032] Since it can be determined in step 5 that the voltage systems of the input voltage and the own vehicle 1 are different, and the voltage system of the own vehicle 1 is higher than the voltage system of the input voltage (the input voltage is from a 400 V system and the own vehicle 1 is an 800 V system), a state is maintained in which the resonance frequency Fsw of the AC voltage converted in the process of converting the input DC voltage by the voltage converter 5 is lower than the resonance frequency Fr for converting the DC voltage into the charging voltage of the battery 1b.

[0033] In step S6, it is determined whether the host vehicle 1 belongs to a 400 V system. If so, the process proceeds to step S7; otherwise, the process proceeds to step 8. In step 7, it can be determined that the voltage systems of the input voltage and the host vehicle 1 are different, and the voltage system of the input voltage is higher than the voltage system of the host vehicle 1 (the input voltage is from an 800 V system, and the host vehicle 1 is a 400 V system). Therefore, a state is maintained in which the resonance frequency Fsw of the AC voltage converted in the process of converting the input DC voltage by the voltage converter 5 is higher than the resonance frequency Fr for converting the DC voltage into the charging voltage of the battery 1b.

[0034] In step 8, since the input voltage and the voltage system of the own vehicle 1 are the same (both the input voltage and the own vehicle 1 belong to an 800 V system), the resonance frequency Fsw of the AC voltage converted in the process of converting the input DC voltage by the voltage converter 5 is caused to approach the resonance frequency Fr for causing the AC voltage to become the charging voltage of the battery 1b.

[0035] According to the above-described embodiment of the present invention, the following operational effects are obtained.

[0036] (1) A vehicle charging device 10 that charges a first battery 1b mounted on a first vehicle 1 includes: a power converter 4 that is connected to an AC power source 3a outside the first vehicle 1 and converts an AC power input from the AC power source 3a into a first DC power; a voltage converter 5 that converts an input DC voltage into a charging voltage of the first battery 1b; a voltage conversion control unit 7 that controls the voltage converter 5; and a DC input terminal 1a that is connected to a DC power source 2a outside the first vehicle 1.The DC input terminal 1a inputs a DC voltage of a second DC power input from the DC power source 2a to the voltage converter 5, and the voltage converter 5 converts the DC voltage of the first DC power and / or the second DC power into a charging voltage of the first battery 1b according to an instruction from the voltage conversion control unit 7. Thus, it is possible to provide the vehicle charging device 10 that converts the discharge voltage of another vehicle into the charging voltage of the own vehicle during inter-vehicle charging to realize charging.

[0037] (2) The vehicle charging device 10 further includes a voltage detection device 8 that detects the DC voltage of the first DC power and / or the second DC power input to the voltage converter 5. The voltage conversion control unit 7 controls, based on the value of the DC voltage detected by the voltage detection device 8 and the charging voltage of the first battery 1b, a frequency and / or a phase of an AC voltage converted in the voltage converter 5 in a process of converting the DC voltage into the charging voltage of the first battery 1b. With this configuration, the voltage converter 5 can be controlled according to the difference between the voltage of the DC power source 2a (a battery) of the other vehicle 2 and the charging voltage of the battery 1b of the own vehicle 1.

[0038] (3) The first vehicle 1 includes a communication device 11 that transmits and receives information about the first battery 1b between the first vehicle 1 and a second vehicle 2 on which a second battery 2a is mounted and which is different from the first vehicle 1. The vehicle charging device 10 transmits and receives, via the communication device 11, information about the charging voltage of the first battery 1b and information about the DC voltage that can be converted into the charging voltage of the first battery by the voltage converter 5. In this way, the vehicle on which the battery 2a is mounted, which has a discharge voltage close to the charging voltage of the battery 1b, can be selected and charged from among the plural other vehicles 2.

[0039] (4) The DC input terminal 1a is a terminal that directly inputs the second DC power to the first battery 1b, and a quick charge input terminal 13 for connecting to the DC input terminal 1a is provided between the first battery 1b and the voltage converter 5. A relay circuit 6 including a first switch 6a that connects or disconnects the DC input terminal 1a and the voltage converter 5, and a second switch 6b that connects or disconnects the DC input terminal 1a and the quick charge input terminal 13 is provided between the quick charge input terminal 13 and the DC input terminal 1a, and between the voltage converter 5 and the DC input terminal 1a.The relay circuit 6 disconnects the DC input terminal 1a and the voltage converter 5, and switches the first switch 6a and the second switch 6b so that the DC input terminal 1a and the fast-charging input terminal 13 are connected when a DC voltage of the second DC power is the same as a charging voltage of the first battery 1b. With this configuration, the relay circuit 6 can be switched depending on the type of external power source connected to the host vehicle 1.

[0040] (5) The DC input terminal 1a is connected to each of a plurality of second vehicles 2 on which a second battery 2a is mounted and which are different from the first vehicle 1, and the DC input terminal 1a inputs and outputs the second DC power between the first vehicle 1 and the plurality of second vehicles 2. In this way, power supply from two or more vehicles to the own vehicle 1 is enabled, and conversely, power supply from the own vehicle 1 to a plurality of other vehicles 2 is enabled.

[0041] (6) A vehicle charging system including the vehicle charging device 10 and the first battery 1b is employed. With this configuration, charging can be realized by converting the discharge voltage of the other vehicle 2 into the charging voltage of the own vehicle 1 during inter-vehicle charging.

[0042] It should be noted that the present invention is not limited to the above embodiments, and various modifications and other configurations can be combined without departing from the gist of the present invention. Furthermore, the present invention is not limited to one that includes all the configurations described in the above embodiment, and includes one in which a portion of the configuration is deleted. List of reference symbols 1 own vehicle 1a DC input connector 1b battery 2 other vehicles 2a DC source 3 AC charging device 3a AC source 4 power converters 4a EMC filter 4b PFC block 5 voltage converters 6 Relay circuit 6a first switch 6b second switch 7 Voltage conversion control unit 8 Voltage detection device 10 Vehicle charging device 11 control device, 13 Fast charging input port 100 Isolation transformer 105 Choke coil (primary switching circuit) 106 Common-mode choke coil 108 commercially available AC power source 206 Choke coil (secondary switching circuit) 402 voltage converter (tertiary-side switching circuit) 403 Capacitor 405 Vehicle power supply socket 406 AC load 408 choke coil QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2021-93788 A

[0003]

Claims

[1] A vehicle charging device that charges a first battery installed in a first vehicle, the vehicle charging device comprising: a power converter connected to an AC power source external to the first vehicle and converting an AC power input from the AC power source into a first DC power; a voltage converter that converts an input DC voltage into a charging voltage of the first battery; a voltage conversion control unit that controls the voltage converter; and a DC input terminal connected to a DC power source external to the first vehicle, wherein the DC input terminal inputs a DC voltage of a second DC power input from the DC power source to the voltage converter, and wherein the voltage converter converts the DC voltage of the first DC power and / or the second DC power into the charging voltage of the first battery according to an instruction from the voltage conversion control unit. [2] Vehicle charging device according to claim 1, further comprising a voltage detection device that detects the DC voltage of the first DC power and / or the second DC power in the voltage converter, wherein the voltage conversion control unit controls, based on the DC voltage detected by the voltage detection device and the charging voltage of the first battery, a frequency and / or a phase of an AC voltage converted in a process of converting the DC voltage into the charging voltage of the first battery in the voltage converter. [3] Vehicle charging device according to claim 1, wherein the first vehicle includes a communication device that sends and receives information about the first battery between the first vehicle and a second vehicle in which a second battery is mounted and which is different from the first vehicle, and wherein the vehicle charging device sends and receives information about the charging voltage of the first battery and information about the DC voltage that can be converted into the charging voltage of the first battery by the voltage converter to and from the second vehicle via the communication device. [4] Vehicle charging device according to claim 1, wherein the DC input terminal is a terminal that inputs the second DC power directly into the first battery, wherein a fast charging input terminal is provided for connection to the DC input terminal between the first battery and the voltage converter, wherein a relay circuit including a first switch connecting or disconnecting the DC input terminal and the voltage converter and a second switch connecting or disconnecting the DC input terminal and the fast charging input terminal is provided between the fast charging input terminal and the DC input terminal and between the voltage converter and the DC input terminal, and wherein the relay circuit disconnects the DC input terminal and the voltage converter and switches the first switch and the second switch such that the DC input terminal and the quick charge input terminal are connected when a DC voltage of the second DC power is the same as a charging voltage of the first battery. [5] Vehicle charging device according to claim 1, wherein the DC input terminal is connected to each of a plurality of second vehicles on which a second battery is mounted and which are different from the first vehicle, and wherein the DC input terminal inputs and outputs the second DC power between the first vehicle and the plurality of second vehicles. [6] Vehicle charging system comprising: the vehicle charging device according to any one of claims 1 to 5; and the first battery.

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