Power conversion system, determination method, and program

Abstract

To improve the flexibility of installation methods. [Solution] The power conversion system 1 is installed between the battery of the vehicle C1 and the grid power supply A1. The power conversion system 1 includes a power conversion unit 20. The power conversion unit 20 converts AC power from the grid power supply A1 into DC power and outputs it to the battery. The power conversion system 1 includes a connection determination unit 26. The connection determination unit 26 determines whether the relay device 3, which relays the cable L0, and the power conversion unit 20 are connected. The cable L0 electrically connects the vehicle C1 and the power conversion unit 20.

Description

[Technical Field]

[0001] The present disclosure generally relates to a power conversion system, a determination method, and a program. More specifically, the present disclosure relates to a power conversion system that converts AC power from a grid power supply into DC power and outputs the DC power to a storage battery, a determination method executed by the power conversion system, and a program for causing the determination method to be executed. [Background Art]

[0002] Patent Literature 1 discloses a power conversion system. The power conversion system includes a power converter and a cable supporter. The power converter is capable of adjusting DC power discharged from a storage battery of a moving body. The cable supporter supports a cable. [Prior Art Documents] [Patent Literature]

[0003] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2024-12370 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, a power converter (power conversion device) generally includes a DC / DC converter and a DC / AC converter for performing power conversion. A power conversion device including a DC / DC converter and a DC / AC converter is a relatively large device. Installation modes of a power conversion system, such as installing the relatively large power conversion device near a vehicle in a parking lot or in a backyard or the like away from the parking lot, vary depending on the environment where the power conversion system is to be installed, or the idea of a person considering installation of the power conversion system, etc.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a power conversion system, a determination method, and a program that can improve the flexibility of installation modes. [Means for solving the problem]

[0006] A power conversion system according to one aspect of this disclosure is installed between a vehicle's battery and a grid power source. The power conversion system includes a power conversion unit. The power conversion unit converts AC power from the grid power source into DC power and outputs it to the battery. The power conversion system includes a connection determination unit. The connection determination unit determines whether or not the power conversion unit is connected to a relay device that relays a cable. The cable electrically connects the vehicle and the power conversion unit.

[0007] A determination method according to one aspect of the present disclosure is a method performed in a power conversion system. The power conversion system includes a power conversion device. The power conversion device is installed between a battery in a vehicle and a grid power source, and converts AC power from the grid power source into DC power and outputs it to the battery. The determination method determines whether or not a relay device, which relays a cable portion electrically connecting the vehicle and the power conversion device, is connected to the power conversion device.

[0008] A program according to one aspect of this disclosure is a program for causing one or more processors to execute the determination method described above. [Effects of the Invention]

[0009] According to this disclosure, it is possible to improve the flexibility of the installation method. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of the power conversion system according to this embodiment. [Figure 2] Figure 2 is a schematic diagram showing another embodiment of the same power conversion system. [Figure 3] Figure 3 is a sequence diagram showing the operation of the power conversion system described above. [Figure 4]Figure 4 is a sequence diagram showing another operation of the same power conversion system. [Figure 5] Figure 5 is a schematic diagram showing one embodiment of the power conversion system according to Modification Example 1. [Modes for carrying out the invention]

[0011] Preferred embodiments of this disclosure will be described in detail below with reference to the drawings. Common elements in the embodiments described below are denoted by the same reference numerals, and redundant descriptions of common elements may be omitted. Note that the following embodiments and modifications represent only a portion of the various embodiments of this disclosure. Furthermore, the following embodiments and modifications can be modified in various ways depending on the design, etc., as long as the objectives of this disclosure are achieved. It is also possible to combine the configurations of the embodiments and modifications as appropriate.

[0012] The figures described herein are schematic diagrams, and the ratios of the size and thickness of each component in each figure do not necessarily reflect the actual dimensional ratios.

[0013] (Embodiment) (1) Overview First, an overview of the power conversion system 1 according to this embodiment will be described with reference to Figures 1 and 2.

[0014] The power conversion system 1 is installed between the battery of the vehicle C1 and the grid power supply A1. The power conversion system 1 includes a power conversion device 2. The power conversion unit 20 of the power conversion device 2 converts AC power from the grid power supply A1 into DC power and outputs it to the battery.

[0015] Here, there are a first aspect and a second aspect in the installation modes of the power conversion system 1 of the present embodiment. In the first aspect, as shown in FIG. 1, the power conversion device 2 and the vehicle C1 are electrically connected via the cable portion L0 and the relay device 3. In the second aspect, as shown in FIG. 2, the power conversion device 2 and the vehicle C1 are electrically connected via the cable portion L0. That is, in the second aspect, the relay device 3 of the power conversion system 1 is not installed in the facility.

[0016] The power conversion device 2 of the power conversion system 1 includes a connection determination unit 26. The connection determination unit 26 determines whether or not the relay device 3 that relays the cable portion L0 and the power conversion unit 20 are connected. The cable portion L0 electrically connects the vehicle C1 and the power conversion unit 20.

[0017] Generally, a power conversion device generally includes a DC / DC converter and a DC / AC converter for performing power conversion. A power conversion device including a DC / DC converter and a DC / AC converter is a relatively large device. From the perspective of a user who intends to introduce a power conversion system, for example, the following two aspects are conceivable regarding the installation of the power conversion system. An aspect in which there is sufficient space in the parking lot and around the parking lot, and the power conversion device is installed in the parking lot or the like. An aspect in which there is insufficient space in the parking lot and around the parking lot, or from the viewpoint of appearance, the power conversion device is installed in a location away from the parking lot such as the building side or a backyard.

[0018] That is, in order to meet the demands of users, two different product forms are required. However, it is not reasonable for a single power conversion device manufacturer to develop, manufacture, and sell two different product forms, and it is difficult to provide products that meet the demands of many users. As a result, the user's product choices are limited, and it is conceivable that the user may suffer disadvantages in terms of cost.

[0019] In an aspect where the power converter is installed at a location remote from a parking lot, a cable support device including a charge / discharge connector may be installed in the parking lot or the like, and the cable support device and the power converter may be connected via wiring. For example, the cable support device includes an operation unit that accepts a user's operation related to charging (or charging and discharging) of a storage battery. When a user operates the operation unit of the cable support device, the cable support device transmits operation information to the power converter. Accordingly, the power converter performs control related to charging based on the operation on the operation unit of the cable support device. That is, in a power conversion system including the cable support device, communication is performed between the cable support device and the power converter.

[0020] In communication related to vehicle charging, a communication method based on the CHAdeMO (registered trademark) standard is used. In the communication method based on the CHAdeMO (registered trademark) standard, the power conversion system transmits system operation information to the vehicle. Then, an electronic control unit (ECU: Electronic Control Unit) mounted on the vehicle calculates a charging current value according to the state of the storage battery such as remaining capacity and temperature. The power conversion system receives an instruction of the charging current value from the vehicle via CAN (Controller Area Network) communication, and controls the output current value according to the instruction.

[0021] In CAN communication, a multi-master communication method is used in which a frame is formed when a node other than the transmitting node (a receiving node) returns an ACK in a frame transmitted by the transmitting node. In addition, the CHAdeMO (registered trademark) standard prohibits the use of CAN messages other than the specified CAN messages (information). In the following description, a CAN message may be simply referred to as a "message".

[0022] In the power conversion system 1 installed in the first embodiment, it is conceivable that the power converter 2 and the relay device 3 may exchange CAN messages other than those defined in the CHAdeMO® standard, such as operation information (hereinafter sometimes referred to as "proprietary messages"). However, in the power conversion system 1 installed in the second embodiment, if the power converter 2 transmits a communication signal containing proprietary messages to the vehicle C1, a communication error may occur due to a handshake mismatch.

[0023] Here, the connection determination unit 26 of the power conversion system 1 in this embodiment determines whether the relay device 3, which relays the cable L0, and the power conversion unit 20 (power conversion device 2) are connected. For example, if the connection determination unit 26 determines that the relay device 3 and the power conversion device 2 are not connected (i.e., the power conversion system 1 is installed in the second configuration), the power conversion device 2 does not transmit a communication signal containing a unique message. As a result, in the power conversion system 1 of this embodiment, the occurrence of communication errors can be suppressed in either the case where the power conversion system 1 is installed in the first configuration or the case where the power conversion system 1 is installed in the second configuration. Furthermore, in the power conversion system 1 of this embodiment, the power conversion system 1 can be installed in either the first or second configuration, thus improving the flexibility of the installation configuration.

[0024] (2)Details The detailed configuration of the power conversion system 1 according to this embodiment will be described below with reference to Figures 1 and 2.

[0025] The power conversion system 1 of this embodiment is installed in residential facilities such as detached houses or apartment buildings, or in non-residential facilities such as offices, shops, or nursing care facilities. The power conversion system 1 is a system that can supply power to the facility from the battery of a vehicle C1 (mobile unit). However, it is not essential that the power conversion system 1 can supply power to the facility from the battery of the vehicle C1; it is sufficient that the power conversion system 1 can charge the battery of the vehicle C1. In this embodiment, as an example, the case in which the power conversion system 1 is installed in a detached house will be described.

[0026] As shown in Figure 1, the power conversion system 1 comprises a power converter 2, a relay device 3, and a cable section L0. Note that the power converter 2 and the relay device 3 are separate devices. The power conversion system 1 is a system that charges and discharges the battery of vehicle C1 at the facility. When the battery of vehicle C1 is discharged, for example, power is supplied from the battery of vehicle C1 to equipment installed in the facility, or power is reverse-flowed from the battery of vehicle C1 to the grid power A1.

[0027] As described above, there are two installation configurations for the power conversion system 1 of this embodiment. In the first configuration, as shown in Figure 1, the power conversion device 2 and the vehicle C1 are electrically connected via the cable section L0 (the first cable L1 and the second cable L2, described later) and the relay device 3. In the second configuration, as shown in Figure 2, the power conversion device 2 and the vehicle C1 are electrically connected via the cable section L0 (the first cable L1). In other words, in the second configuration, the relay device 3 of the power conversion system 1 is not installed in the facility.

[0028] (2.1) Cable section configuration The cable section L0 of this embodiment includes a first cable L1 and a second cable L2. However, the second cable L2 is not installed in the facility when the installation configuration of the power conversion system 1 is the second configuration.

[0029] The first cable L1 is, for example, a cabtyre cable. The first cable L1 has one or more power lines and one or more communication lines. The first cable L1 has a first end 4 and a second end L11. The first end 4 is the end that connects to the vehicle C1 and is the vehicle-side end. The first end 4 has a connector that can be connected to the inlet of the vehicle C1. The second end L11 is the end that connects to the relay device 3 or the power converter 2. The second end L11 has a connector that can be connected to the connection part 32 of the relay device 3 (described later) and the connection part 29 of the power converter 2 (described later).

[0030] Furthermore, the length of the first cable L1 is specified to be constant according to the product specifications. In other words, the resistance value of the first cable L1 is approximately constant.

[0031] The second cable L2 is, for example, a cross-linked polyethylene insulated vinyl sheathed cable (CV cable). The second cable L2 has one or more power lines and one or more communication lines. The second cable L2 has a first end L21 and a second end L22. The first end L21 is the end connected to the power converter 2. The first end L21 has a connector that can be connected to the connection part 29 of the power converter 2. The second end L22 is the end connected to the connection part 31 of the relay device 3. In this embodiment, the second end L22 is a round terminal formed from the end of the wire inside the cable. However, the second end L22 may have a connector.

[0032] The length of the second cable L2 varies depending on the installation environment of the user introducing the power conversion system 1. As a result, the resistance value of the second cable L2 varies depending on its length and is not constant.

[0033] When the installation configuration of the power conversion system 1 is the first configuration, the first cable L1 electrically connects the vehicle C1 and the relay device 3. The second cable L2 electrically connects the power conversion unit 20 and the relay device 3.

[0034] When the installation configuration of the power conversion system 1 is the second configuration (see Figure 2), the first cable L1 electrically connects the vehicle C1 and the power conversion device 2.

[0035] (2.2) Configuration of the power converter As shown in Figure 1, the power conversion device 2 comprises a power conversion unit 20, a control unit 23, a voltage estimation unit 24, a signal circuit unit 25, a connection determination unit 26, a display unit 27, an operation unit 28, and a connection unit 29.

[0036] The power conversion unit 20 performs conversion from AC power to DC power and from DC power to AC power. The power conversion unit 20 includes a DC / AC converter 21 and a DC / DC converter 22.

[0037] The DC / AC converter 21 is a bidirectional DC / AC converter. The first terminal of the DC / AC converter 21 is electrically connected to the grid power supply A1, and the second terminal of the DC / AC converter 21 is electrically connected to the DC / DC converter 22. The DC / AC converter 21 has, for example, multiple switching elements connected in a full bridge configuration, and the multiple switching elements are controlled by the control unit 23 using PWM (Pulse Width Modulation) to perform conversion from DC power to AC power, or from AC power to DC power.

[0038] The DC / AC converter 21 has the function of converting the AC power input from the grid power A1 into DC power of a predetermined magnitude and outputting it to the DC / DC converter 22. In this embodiment, the DC / AC converter 21 also has the function of converting the DC power output by the DC / DC converter 22 into AC power of a predetermined magnitude and outputting it to the grid power A1.

[0039] The DC / DC converter 22 is a bidirectional DC / DC converter. The first end of the DC / DC converter 22 is electrically connected to the DC / AC converter 21, and the second end of the DC / DC converter 22 is electrically connected to the relay device 3 or the vehicle C1 via the power lines of the cable section L0.

[0040] The DC / DC converter 22 has the function of converting the DC power output by the DC / AC converter 21 into DC power of a predetermined magnitude and outputting it to the battery of the vehicle C1 via the cable L0, etc. In this embodiment, the DC / DC converter 22 also has the function of converting the DC power discharged from the battery of the vehicle C1 via the cable L0, etc. into DC power of a predetermined magnitude and outputting it to the DC / AC converter 21.

[0041] The control unit 23 primarily consists of a computer system having one or more processors and memory. The functions of the control unit 23 are realized when the computer system's processor executes a program recorded in the computer system's memory or storage unit. The program may be recorded in memory or storage unit, provided via telecommunication lines such as the Internet, or provided on a non-temporary recording medium such as a memory card.

[0042] The control unit 23 controls the charging and discharging operations of the power conversion unit 20. For example, the control unit 23 controls the operation of the power conversion unit 20 based on operation information received by the signal circuit unit 25. The control unit 23 has the function of controlling the power conversion unit 20 to start or stop charging the battery of the vehicle C1 by receiving commands from the vehicle C1 or the relay device 3 via the signal circuit unit 25. In addition, the control unit 23 has the function of controlling the power conversion unit 20 to start or stop charging the battery of the vehicle C1 based on operations on the operation unit 28.

[0043] For example, if the installation configuration of the power conversion system 1 is the first configuration, the control unit 23 of this embodiment controls the operation of the power conversion unit 20 based on the operation information received by the signal circuit unit 25. Here, "operation information received by the signal circuit unit 25" is information relating to an operation performed on the operation unit 36 ​​of the relay device 3, which will be described later. For example, the control unit 23 controls the power conversion unit 20 based on the operation information received by the signal circuit unit 25 to start or stop charging the battery of the vehicle C1.

[0044] For example, if the installation configuration of the power conversion system 1 is the first configuration, the control unit 23 of this embodiment controls the operation of the power conversion unit 20 based on the voltage value information received by the signal circuit unit 25. Here, the "voltage value information received by the signal circuit unit 25" is information regarding the voltage value at the first end 4 (vehicle side end) of the first cable L1, estimated by the voltage estimation unit 33 of the relay device 3, which will be described later. For example, the control unit 23 controls the power conversion unit 20 based on the voltage value information received by the signal circuit unit 25 to control the voltage of the power output by the power conversion unit 20.

[0045] For example, if the installation configuration of the power conversion system 1 is the second configuration, the control unit 23 of this embodiment controls the operation of the power conversion unit 20 based on operation information relating to operations performed on the operation unit 28. For example, the control unit 23 controls the power conversion unit 20 based on operation information relating to operations performed on the operation unit 28 to start or stop charging the battery of the vehicle C1.

[0046] For example, if the installation configuration of the power conversion system 1 is the first configuration, the control unit 23 of this embodiment controls the operation of the power conversion unit 20 based on the voltage value of the first end 4 estimated by the voltage estimation unit 24. For example, the control unit 23 controls the power conversion unit 20 based on the voltage value of the first end 4 estimated by the voltage estimation unit 24 to control the voltage of the power output by the power conversion unit 20.

[0047] Furthermore, the control unit 23 controls the operation of the voltage estimation unit 24, the operation of the signal circuit unit 25, and the operation of the display unit 27.

[0048] For example, the control unit 23 controls the signal circuit unit 25 according to the determination result by the connection determination unit 26. More specifically, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are not connected (i.e., second mode), the control unit 23 controls the signal circuit unit 25 so as not to transmit a communication signal containing a unique message. On the other hand, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., first mode), the control unit 23 allows the signal circuit unit 25 to transmit a communication signal containing a unique message.

[0049] For example, in this embodiment, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first embodiment), the control unit 23 stops the operation of the display unit 27. As a result, the display unit 27 does not display any information regarding the operation of the power converter 20.

[0050] Furthermore, for example, in this embodiment, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first configuration), the control unit 23 stops the operation of the operation unit 28. As a result, the operation unit 28 is in a state where it does not accept operations related to the operation of the power converter 20. Note that if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first configuration), the control unit 23 may be configured not to accept operation information related to operations on the operation unit 28.

[0051] The CHAdeMO (registered trademark) standard specifies that the voltage value at the first end 4 (vehicle-side end) of the first cable L1 be measured or estimated. In this embodiment, the first end 4 of the first cable L1 is not equipped with a voltage sensor or the like. Therefore, the voltage estimation unit 24 estimates the voltage value at the first end 4 of the cable L1. Note that the voltage estimation unit 24 in this embodiment operates when the installation configuration of the power conversion system 1 is the second configuration. For example, the voltage estimation unit 24 estimates the voltage value at the first end 4 of the first cable L1 based on the current value of the current flowing between the power conversion unit 20 and the first cable L1. More specifically, the voltage estimation unit 24 estimates the voltage value at the first end 4 of the first cable L1 based on the voltage value at the connection part 29, the current value of the current flowing between the power conversion unit 20 and the first cable L1, and the resistance value information of the first cable L1. Here, the resistance value information of the first cable L1 is stored in advance in a memory unit provided by the power conversion device 2, for example.

[0052] The signal circuit unit 25 is connected to the communication line of the cable unit L0. The signal circuit unit 25 is an interface that can communicate with the relay device 3 and the vehicle C1 via the communication line of the cable unit L0. The signal circuit unit 25 transmits and receives communication signals with the vehicle C1 or the relay device 3 via the cable unit L0. The signal circuit unit 25 communicates with the relay device 3 and the vehicle C1 using a communication method based on the CHAdeMO (registered trademark) standard.

[0053] If the connection determination unit 26 determines that the relay device 3 and the power converter 2 are not connected (i.e., the second mode), the signal circuit unit 25 transmits and receives a communication signal containing only the CAN message (first information) as defined in the CHAdeMO (registered trademark) standard. In other words, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are not connected, the signal circuit unit 25 transmits and receives a communication signal that contains the first information but does not contain the second information. This prevents the transmission of a communication signal containing a unique message to the vehicle C1 when the relay device 3 is not installed, thereby preventing communication errors due to handshake mismatch.

[0054] On the other hand, when the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first configuration), the signal circuit unit 25 transmits and receives a communication signal that includes a CAN message (first information) defined in the CHAdeMO® standard, as well as a unique CAN message (second information) not defined in the CHAdeMO® standard. Here, the unique CAN message includes information necessary for communication with the relay device 3. This enables the transmission and reception of a communication signal that includes information necessary for communication with the relay device 3.

[0055] For example, if the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first configuration), the signal circuit unit 25 transmits operation information regarding the operating status of the power converter 20 to the relay processing unit 34 of the relay device 3. More specifically, the signal circuit unit 25 transmits a communication signal containing the first information and the second information as a proprietary message (second information) to the relay processing unit 34. Here, "operation information" is information indicating the operating status of the power converter 20. Furthermore, "operating status" includes states such as when the power converter 20 is charging the battery, when the power converter 20 is discharging the battery, or when the power converter 20 is not operating.

[0056] The connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., the first configuration) if the communication signal contains a unique message (second information). On the other hand, the connection determination unit 26 determines that the relay device 3 and the power converter 2 are not connected (i.e., the second configuration) if the communication signal does not contain a unique message (second information). The connection determination unit 26 outputs information indicating the determination result to the control unit 23.

[0057] The display unit 27 is composed of, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. The display unit 27 may also be composed of a touch panel display. Alternatively, the display unit 27 may be composed of lamps such as LEDs. The display unit 27 displays information regarding the operating status of the power conversion unit 20.

[0058] More specifically, the display unit 27 displays information regarding the operating status of the power conversion unit 20 when the connection determination unit 26 determines that the relay device 3 and the power conversion device 2 are not connected (i.e., second mode). On the other hand, the display unit 27 does not display information regarding the operating status of the power conversion unit 20 when the connection determination unit 26 determines that the relay device 3 and the power conversion device 2 are connected (i.e., first mode). In this embodiment, the relay device 3 is equipped with a display unit 35 that displays information regarding the operating status of the power conversion unit 20. Therefore, when the relay device 3 is installed, for example, a user using the power conversion system 1 would normally check the display unit 35 of the relay device 3, which is installed near the vehicle C1. In this embodiment, the display unit 27 does not display information when the relay device 3 is not installed, which can extend the lifespan of the display unit 27 or reduce power consumption.

[0059] The control unit 28 receives commands related to charging (or discharging) the battery of vehicle C1. The control unit 28 includes, for example, a number of control buttons for receiving commands related to charging (or discharging) the battery of vehicle C1. However, if the display unit 27 is configured as a touch panel display, the touch panel display also functions as the control unit 28.

[0060] More specifically, the operation unit 28 accepts operations related to charging (or discharging) the battery of vehicle C1 when the connection determination unit 26 determines that the relay device 3 and the power converter 2 are not connected (i.e., second mode). On the other hand, the operation unit 28 does not accept operations related to charging (or discharging) the battery of vehicle C1 when the connection determination unit 26 determines that the relay device 3 and the power converter 2 are connected (i.e., first mode). In this embodiment, the relay device 3 is equipped with an operation unit 36 ​​that accepts operations related to charging the battery of vehicle C1. Therefore, when the relay device 3 is installed, for example, a user using the power converter system 1 usually operates the operation unit 36 ​​of the relay device 3, which is installed near vehicle C1. Since the operation unit 28 in this embodiment does not accept operations when the relay device 3 is not installed, it is possible to extend the lifespan of the operation unit 28 or reduce power consumption.

[0061] In this embodiment, the connection portion 29 is a connector. The connector on the first end L21 (end) of the second cable L2 and the connector on the second end L11 of the first cable L1 can be connected to the connection portion 29. In other words, when the installation configuration of the power conversion system 1 is the first configuration, the connector on the first end L21 of the second cable L2 is connected to the connection portion 29 (see Figure 1). Also, when the installation configuration of the power conversion system 1 is the second configuration, the connector on the second end L11 of the first cable L1 is connected to the connection portion 29 (see Figure 2). Since the connector on the first end L21 of the second cable L2 and the connector on the second end L11 of the first cable L1 can be connected to the connection portion 29, it is easy to connect the first cable L1 or the second cable L2 to the power conversion device 2.

[0062] (2.3) Configuration of the relay device As shown in Figure 1, the relay device 3 relays the cable section L0 that electrically connects the vehicle C1 and the power converter 2 when the installation configuration of the power conversion system 1 is the first configuration. More specifically, the relay device 3 relays the first cable L1 and the second cable L2. In other words, the relay device 3 separates and relays one or more power lines and one or more communication lines of the cable section L0. The relay device 3 also functions as a cable support device that supports the first cable L1.

[0063] The relay device 3 includes a connection unit 31 (first connection unit), a connection unit 32 (second connection unit), a voltage estimation unit 33, a relay processing unit 34, a display unit 35, and an operation unit 36.

[0064] The second end L22 of the second cable L2 can be connected to the connection part 31. In this embodiment, the connection part 31 is a terminal block to which the second end L22, which is a round terminal, can be connected. However, if the second end L22 of the second cable L2 has a connector, the connection part 31 may be a connector.

[0065] The connection part 32 is a connector. The connector on the first end L21 of the second cable L2 can be connected to the connection part 32.

[0066] The voltage estimation unit 33 estimates the voltage value at the first end 4 of the cable section L0. For example, the voltage estimation unit 33 estimates the voltage value at the first end 4 (vehicle side end) of the first cable L1 based on the current value of the current flowing through the relay device 3. More specifically, the voltage estimation unit 33 estimates the voltage value at the first end 4 of the first cable L1 based on the voltage value at the connection section 32, the current value of the current flowing through the relay device 3, and information on the resistance value of the first cable L1. The "current flowing through the relay device 3" is the current flowing between the power lines of the first cable L1 and the power lines of the second cable L2. Here, information on the resistance value of the first cable L1 is stored in advance in a memory unit provided by the relay device 3, for example.

[0067] When the installation configuration of the power conversion system 1 is the first configuration, the voltage estimation unit 24 of the power conversion device 2 needs to consider the resistance values ​​of the second cable L2 and the relay device 3 in order to determine the voltage value of the first end 4. However, as mentioned above, the resistance value of the second cable L2 varies depending on the installation environment and is not constant. In the power conversion system 1 of this embodiment, when the installation configuration is the first configuration, the voltage estimation unit 33 of the relay device 3 estimates the voltage value of the first end 4. When the voltage estimation unit 33 of the relay device 3 estimates the voltage value of the first end 4, it is not necessary to consider the resistance values ​​of the relay device 3 and the second cable L2, thus improving the accuracy of voltage value estimation.

[0068] The relay processing unit 34 is connected to the communication lines of the first cable L1 and the second cable L2. The relay processing unit 34 includes an interface that allows it to communicate with the power converter 2 and the vehicle C1 via the communication lines of cable L0. The relay processing unit 34 communicates with the relay device 3 and the vehicle C1 using a communication method based on the CHAdeMO (registered trademark) standard.

[0069] Furthermore, the relay processing unit 34 includes a computer system having one or more processors and memory. The functions of the relay processing unit 34 are realized when the processor of the computer system executes a program recorded in the memory or storage unit of the computer system. The program may be recorded in memory or storage unit, provided via a telecommunication line such as the Internet, or provided on a non-temporary recording medium such as a memory card.

[0070] The display unit 35 is composed of, for example, a liquid crystal display or an organic EL display. Alternatively, the display unit 35 may be composed of a touch panel display. Furthermore, the display unit 35 may be composed of lamps such as LEDs. The display unit 35 displays information regarding the operating status of the power conversion unit 20. This allows, for example, a user of the power conversion system 1 to check the operating status of the power conversion unit 20 on the display unit 35 of the relay device 3 installed near the vehicle C1.

[0071] The control unit 36 ​​receives commands related to charging (or discharging) the battery of vehicle C1. The control unit 36 ​​includes, for example, a number of control buttons for receiving commands related to charging (or discharging) the battery of vehicle C1. However, if the display unit 35 is configured as a touch panel display, the touch panel display also functions as the control unit 36.

[0072] The relay processing unit 34 relays the communication signals between the first cable L1 and the second cable L2. In other words, the relay processing unit 34 separates and relays the communication signals of cable L0.

[0073] In multi-master communication systems, there are advantages such as the absence of response frames, which reduces the strain on communication bandwidth. However, it is necessary to return an ACK (specifically, one bit each of ACK and ACK delimiter data) within the transmission frame (i.e., within a predetermined period). This results in an inverse relationship between the communication speed (time per bit) and the limit line length between nodes (propagation time), due to factors such as the electrical signal propagation time during round trip. Furthermore, in reality, waveform distortion occurs due to the influence of transceiver drive capability, EMC countermeasures, communication cable type, impedance caused by wiring length, and inter-line capacitance, so the wiring length at which communication quality can be maintained is significantly shorter than the theoretical limit line length.

[0074] The CHAdeMO (registered trademark) standard specifies a communication speed of 500kbps (relatively high speed and short maximum line length). In other words, randomly extending the CAN communication line (communication line) between the vehicle-side end of the first cable and the power converter in a power conversion system will lead to communication failures, i.e., system instability.

[0075] In this embodiment, the relay processing unit 34 receives a degraded communication signal in the middle of the CAN communication line, corrects (or improves) the received communication signal, and performs relay processing before transmission. This allows the CAN communication line between the power converter 2 and the vehicle C1 to be treated as one long CAN communication line. Furthermore, in the power conversion system 1 of this embodiment, since the relay processing unit 34 corrects and transmits the received communication signal, communication quality and operational stability can be improved.

[0076] The relay processing unit 34 transmits and receives communication signals, including CAN messages (first information) as defined by the CHAdeMO® standard, to the vehicle C1 when the relay processing unit 34 is electrically connected to the vehicle C1 via the first cable L1 and when the relay processing unit 34 is electrically connected to the signal circuit unit 25 via the second cable L2. More specifically, when the relay processing unit 34 receives a communication signal from the power converter 2 that includes the first information and a proprietary CAN message (second information) not defined by the CHAdeMO® standard, it removes the second information from the communication signal and transmits a communication signal containing only the first information to the vehicle C1. The relay processing unit 34 removes the second information by removing the frame of the "proprietary message" corresponding to the second information from the communication signal. This prevents the transmission of a communication signal containing the proprietary message to the vehicle C1 and suppresses the occurrence of communication errors due to handshake mismatch.

[0077] Furthermore, the relay processing unit 34 transmits and receives communication signals, including first information and second information, with the signal circuit unit 25 of the power converter 2 when the relay processing unit 34 is electrically connected to the vehicle C1 via the first cable L1 and the relay processing unit 34 is electrically connected to the signal circuit unit 25 via the second cable L2. For example, the second information includes information indicating that the relay device 3 and the power converter 2 are electrically connected. In other words, the second information includes information indicating that the relay device 3 is installed.

[0078] For example, when an operation related to charging (or discharging) the battery of vehicle C1 is performed on the operation unit 36, the relay processing unit 34 transmits operation information related to the operation performed on the operation unit 36 ​​to the signal circuit unit 25 of the power converter 2. More specifically, the signal circuit unit 25 transmits a communication signal to the signal circuit unit 25, including the operation information as a unique message (second information), which includes the first information and the second information. In other words, the second information includes operation information related to the operation performed on the operation unit 36. For example, the operation information includes information indicating an operation to start charging the battery of vehicle C1, information indicating an operation to start discharging the battery of vehicle C1, or information indicating an operation to stop charging or discharging. As a result, for example, a user using the power converter system 1 can perform operations related to charging (or discharging) the battery of vehicle C1 by performing an operation on the operation unit 36 ​​of the relay device 3 installed near vehicle C1.

[0079] For example, when the voltage estimation unit 33 estimates the voltage value at the first end 4 of the cable L0, the relay processing unit 34 transmits voltage value information related to the voltage value estimated by the voltage estimation unit 33 to the signal circuit unit 25 of the power converter 2. More specifically, the signal circuit unit 25 transmits a communication signal to the signal circuit unit 25 that includes the first information and the second information as a proprietary message (second information). In other words, the second information includes voltage value information related to the voltage value estimated by the voltage estimation unit 33.

[0080] (3) Operation of the power conversion system Next, the operation of the power conversion system 1 will be described with reference to Figures 3 and 4.

[0081] First, with reference to Figure 3, an example of the operation of the power conversion system 1 when the installation configuration of the power conversion system 1 is the first configuration will be described.

[0082] For example, when the connector at the first end 4 of the first cable L1 is connected to the inlet of the vehicle C1, the vehicle C1 sends a communication signal to the relay device 3 that includes only a CAN message (first information) instructing, for example, permission to start charging (step S1).

[0083] The relay device 3 performs relay processing to correct the received communication signal and to include second information indicating that the relay device 3 is installed in the communication signal (step S2). Then, the relay device 3 transmits the communication signal containing the first information and the second information to the power converter 2 (step S3).

[0084] The power converter 2 makes a connection determination based on the received communication signal to determine whether or not the relay device 3 is installed (step S4). In the example in Figure 3, since the second information is included in the communication signal, the power converter 2 determines that the relay device 3 is installed.

[0085] Then, the power converter 2 transmits a communication signal to the relay device 3, which includes, for example, a CAN message (first information) indicating that charging has started, and second information (for example, operation information) (step S5).

[0086] The relay device 3 performs relay processing to remove the second information from the received communication signal and correct the communication signal (step S6). Then, the relay device 3 transmits a communication signal containing only the first information to the vehicle C1 (step S7). This prevents the vehicle C1 from receiving a communication signal containing a message not defined in the CHAdeMO® standard.

[0087] Next, with reference to Figure 4, an example of the operation of the power conversion system 1 when the installation configuration of the power conversion system 1 is the second configuration will be described.

[0088] For example, when the connector at the first end 4 of the first cable L1 is connected to the inlet of the vehicle C1, the vehicle C1 sends a communication signal to the power converter 2 that includes only a CAN message (first information) instructing, for example, permission to start charging (step S11).

[0089] The power converter 2 makes a connection determination based on the received communication signal to determine whether or not the relay device 3 is installed (step S12). In the example in Figure 4, since the second information is not included in the communication signal, the power converter 2 determines that the relay device 3 is not installed.

[0090] Then, the power converter 2 transmits a communication signal to the relay device 3 that includes only a CAN message (first information) indicating, for example, that charging has started (step S13). This prevents the vehicle C1 from receiving a communication signal that includes a message not specified in the CHAdeMO® standard.

[0091] Note that the sequence diagrams shown in Figures 3 and 4 are merely examples, and the order of processing may be changed as appropriate, or processes may be added or deleted as appropriate.

[0092] (4) Variations The following lists some modifications of the above embodiment.

[0093] (4.1) Variation 1 As shown in Figure 5, the power converter 2 may be equipped with a connection part 29A (second connection part) in addition to the connection part 29 (first connection part). The connection part 29A is a terminal block to which terminals, such as ring terminals, can be connected.

[0094] The second cable L2 can be adjusted on-site in the installation environment of the user installing the power conversion system 1. When performing on-site adjustments in the user's installation environment, it may be easier to connect the first end L21 of the second cable L2 to the terminal block connection part 29A as a round terminal than to connect the first end L21 of the second cable L2 to the connector connection part 29 as a connector.

[0095] In the modified example 1 of the power conversion system 1, the power conversion device 2 is equipped with two connection parts 29 and 29A with different connection configurations, which makes the installation of the power conversion system 1 easier.

[0096] (4.2) Other variations Functions equivalent to those of the power conversion system 1 according to the above embodiment may be embodied in a determination method, a (computer) program, or a non-temporary recording medium on which the program is recorded. One determination method is a method executed by the power conversion system 1. The power conversion system 1 includes a power conversion device 2. The power conversion device 2 is installed between the battery of the vehicle C1 and the grid power supply A1, and converts AC power from the grid power supply A1 into DC power and outputs it to the battery. The determination method determines whether or not the relay device 3, which relays the cable L0 that electrically connects the vehicle C1 and the power conversion device 2, is connected to the power conversion device 2. One program according to one embodiment is a program that causes one or more processors to execute the above determination method.

[0097] The entity executing the power conversion system 1 or determination method in this disclosure includes a computer system. The computer system mainly consists of a processor and memory as hardware. The processor executes a program recorded in the computer system's memory to realize the function of the entity executing the power conversion system 1 or determination method in this disclosure. The program may be pre-recorded in the computer system's memory, provided via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that is readable by the computer system. The processor of the computer system consists of one or more electronic circuits including semiconductor integrated circuits (ICs) or large-scale integrated circuits (LSIs). The integrated circuits referred to here, such as ICs or LSIs, are named differently depending on the degree of integration and include integrated circuits called system LSIs, VLSIs (Very Large Scale Integration), or ULSIs (Ultra Large Scale Integration). Furthermore, FPGAs (Field-Programmable Gate Arrays) that are programmed after the manufacture of LSIs, or logic devices that allow for the reconfiguration of junction relationships or circuit compartments within LSIs, can also be used as processors. Multiple electronic circuits may be integrated onto a single chip or distributed across multiple chips. Multiple chips may be integrated onto a single device or distributed across multiple devices. The computer system referred to here includes a microcontroller having one or more processors and one or more memories. Therefore, the microcontroller also consists of one or more electronic circuits, including semiconductor integrated circuits or large-scale integrated circuits.

[0098] Furthermore, it is not essential for the power conversion system 1 to have multiple functions integrated into a single enclosure; the components of the power conversion system 1 may be distributed across multiple enclosures. In addition, at least some of the functions of the power conversion system 1, for example, some of the functions of the power conversion device 2, may be implemented by the cloud (cloud computing), etc.

[0099] The power converter 2 and relay device 3 of the power conversion system 1 in the above embodiment can be sold on the market individually.

[0100] (Appearance) As is clear from the embodiments and modifications described above, the power conversion system (1) according to the first embodiment is installed between the battery of the vehicle (C1) and the grid power supply (A1). The power conversion system (1) includes a power conversion unit (20). The power conversion unit (20) converts AC power from the grid power supply (A1) into DC power and outputs it to the battery. The power conversion system (1) includes a connection determination unit (26). The connection determination unit (26) determines whether the relay device (3) that relays the cable unit (L0) and the power conversion unit (20) are connected. The cable unit (L0) electrically connects the vehicle (C1) and the power conversion unit (20).

[0101] This embodiment allows for increased flexibility in installation configurations.

[0102] The power conversion system (1) according to the second embodiment further comprises a signal circuit unit (25) in the first embodiment. The signal circuit unit (25) transmits and receives communication signals to and from a vehicle (C1) or a relay device (3) via a cable unit (L0). The cable unit (L0) has a first cable (L1) and a second cable (L2). The first cable (L1) electrically connects the vehicle (C1) and the relay device (3). The second cable (L2) electrically connects the power conversion unit (20) and the relay device (3). The relay device (3) has a relay processing unit (34). The relay processing unit (34) relays communication signals between the first cable (L1) and the second cable (L2). The relay processing unit (34) transmits and receives communication signals including first information with the vehicle (C1) when the relay processing unit (34) is electrically connected to the vehicle (C1) via the first cable (L1) and the relay processing unit (34) is electrically connected to the signal circuit unit (25) via the second cable (L2). The relay processing unit (34) transmits and receives communication signals including first information and second information with the signal circuit unit (25) when the relay processing unit (34) is electrically connected to the vehicle (C1) via the first cable (L1) and the relay processing unit (34) is electrically connected to the signal circuit unit (25) via the second cable (L2). The connection determination unit (26) determines that the relay device (3) and the power conversion unit (20) are connected when the communication signal contains second information.

[0103] The power conversion system (1) according to the third embodiment further comprises a control unit (23) in the second embodiment. The control unit (23) controls the operation of the power conversion unit (20). The relay device (3) further comprises an operation unit (36). The operation unit (36) receives operations related to charging the storage battery. The second information includes operation information related to operations performed on the operation unit (36). The control unit (23) controls the operation of the power conversion unit (20) based on the operation information received by the signal circuit unit (25).

[0104] According to this embodiment, by operating the control unit (36) of the relay device (3), operations related to charging (or discharging) the battery of the vehicle (C1) can be performed.

[0105] The power conversion system (1) according to the fourth embodiment further comprises a control unit (23) in the second or third embodiment. The control unit (23) controls the operation of the power conversion unit (20). The first cable (L1) has a vehicle-side end (first end 4) on the side connected to the vehicle (C1). The relay device (3) further comprises a voltage estimation unit (33). The voltage estimation unit (33) estimates the voltage value at the vehicle-side end of the first cable (L1) based on the current value of the current flowing through the relay device (3). The second information includes voltage value information relating to the voltage value estimated by the voltage estimation unit (33). The control unit (23) controls the operation of the power conversion unit (20) based on the voltage value information received by the signal circuit unit (25).

[0106] According to this embodiment, the accuracy of estimating the voltage value at the vehicle-side end (first end 4) can be improved.

[0107] In the power conversion system (1) according to the fifth embodiment, in any of the second to fourth embodiments, the relay device (3) further includes a display unit (35). The display unit (35) displays information regarding the operating status of the power conversion unit (20). The signal circuit unit (25) transmits operation information regarding the operating status of the power conversion unit (20) to the relay processing unit (34) when the connection determination unit (26) determines that the relay device (3) and the power conversion unit (20) are connected. The display unit (35) displays information regarding the operating status based on the operation information received by the relay processing unit (34).

[0108] According to this embodiment, the operating status of the power conversion unit (20) can be checked on the display unit (35) of the relay device (3).

[0109] The power conversion system (1) according to the sixth embodiment further comprises an operation unit (28) and a display unit (27) in any of the second to fifth embodiments. The operation unit (28) accepts operations related to charging the storage battery. The display unit (27) displays the operating status of the power conversion unit (20). The operation unit (28) does not accept operations when the connection determination unit (26) determines that the relay device (3) and the power conversion unit (20) are connected. The display unit (27) does not display anything when the connection determination unit (26) determines that the relay device (3) and the power conversion unit (20) are connected.

[0110] According to this embodiment, it is possible to reduce power consumption, etc.

[0111] The power conversion system (1) according to the seventh embodiment further comprises a connection part (29) in any of the second to sixth embodiments. A connector on the end (L21) of the second cable (L2) can be connected to the connection part (29). The first cable (L1) has a first end (4) connected to a vehicle (C1) and a second end (L11) having a connector that can be connected to a relay device (3). A connector on the second end (L11) of the first cable (L1) can be connected to the connection part (29).

[0112] According to this embodiment, it is easy to connect the first cable (L1) or the second cable (L2) to the power conversion unit (20).

[0113] The power conversion system (1) according to the eighth embodiment further comprises a relay device (3) in any of the first to seventh embodiments. A power conversion device (2), which is a separate device from the relay device (3), has a power conversion unit (20) and a connection determination unit (26).

[0114] This embodiment allows for increased flexibility in installation configurations.

[0115] Configurations other than those in the first embodiment are not essential to the power conversion system (1) and can be omitted as appropriate.

[0116] The determination method relating to the ninth aspect is a method performed in the power conversion system (1). The power conversion system (1) includes a power conversion device (2). The power conversion device (2) is installed between the battery of the vehicle (C1) and the grid power supply (A1), and converts AC power from the grid power supply (A1) into DC power and outputs it to the battery. The determination method determines whether or not the power conversion device (2) is connected to the relay device (3) which relays the cable section (L0) that electrically connects the vehicle (C1) and the power conversion device (2).

[0117] This embodiment allows for increased flexibility in installation configurations.

[0118] The program according to the tenth aspect is a program that causes one or more processors to execute the determination method according to the ninth aspect.

[0119] This embodiment allows for increased flexibility in installation configurations. [Explanation of Symbols]

[0120] 1. Power Conversion System 2 Power converter 20 Power Conversion Unit 23 Control Unit 25 Signal Circuit Section 26 Connection determination unit 27 Display section 28 Control section 29 Connection part 3. Relay device 33 Voltage Estimation Unit 34 Relay Processing Unit 35 Display section 36 Control section 4. First end (vehicle side end) A1 Grid power supply C1 Vehicle L1 1st Cable L11 2nd end L2 2nd cable L21 1st end (end)

Claims

1. A power conversion system comprising a power conversion unit installed between a vehicle's battery and a grid power supply, which converts AC power from the grid power supply into DC power and outputs it to the battery, The system includes a relay device that relays a cable that electrically connects the vehicle and the power conversion unit, and a connection determination unit that determines whether or not the power conversion unit is connected. Power conversion system.

2. The system further comprises a signal circuit section that transmits and receives communication signals to and from the vehicle or the relay device via the cable section, The aforementioned cable section is A first cable electrically connects the vehicle and the relay device, A second cable electrically connects the power conversion unit and the relay device, It has, The relay device has a relay processing unit that relays the communication signals between the first cable and the second cable. The relay processing unit is electrically connected to the vehicle via the first cable, and the relay processing unit is electrically connected to the signal circuit unit via the second cable. The vehicle transmits and receives the communication signal including the first information. The signal circuit unit transmits and receives the communication signal including the first information and the second information. The connection determination unit determines that the relay device and the power conversion unit are connected when the communication signal contains the second information. The power conversion system according to claim 1.

3. The system further comprises a control unit that controls the operation of the power conversion unit, The relay device further includes an operating unit that receives operations related to charging the battery, The second information includes operation information relating to operations performed on the operation unit, The control unit controls the operation of the power conversion unit based on the operation information received by the signal circuit unit. The power conversion system according to claim 2.

4. The system further comprises a control unit that controls the operation of the power conversion unit, The first cable has a vehicle-side end that is connected to the vehicle, The relay device further includes a voltage estimation unit that estimates the voltage value at the vehicle-side end of the first cable based on the current value of the current flowing through the relay device. The second information includes voltage value information relating to the voltage value estimated by the voltage estimation unit, The control unit controls the operation of the power conversion unit based on the voltage value information received by the signal circuit unit. The power conversion system according to claim 2.

5. The relay device further includes a display unit that displays the operating status of the power conversion unit, When the connection determination unit determines that the relay device and the power conversion unit are connected, the signal circuit unit transmits operation information regarding the operating state of the power conversion unit to the relay processing unit. The display unit displays information relating to the operating status based on the operating information received by the relay processing unit. The power conversion system according to claim 2.

6. An operating unit that receives operations related to charging the aforementioned storage battery, A display unit that displays information regarding the operating status of the power conversion unit, Furthermore, The operation unit does not accept operation when the connection determination unit determines that the relay device and the power conversion unit are connected. The display unit does not display anything when the connection determination unit determines that the relay device and the power conversion unit are connected. The power conversion system according to claim 2.

7. The second cable further comprises a connection portion to which a connector has been attached to the end of the cable, The first cable has a first end connected to the vehicle and a second end having a connector that can be connected to the relay device. The connector at the second end of the first cable can be connected to the aforementioned connection portion. The power conversion system according to claim 2.

8. The relay device further comprises, A power conversion device, which is a separate device from the aforementioned relay device, has the power conversion unit and the connection determination unit. The power conversion system according to claim 1.

9. A determination method performed in a power conversion system that includes a power conversion device installed between a vehicle's battery and a grid power supply, which converts AC power from the grid power supply into DC power and outputs it to the battery, A relay device that relays the cable portion electrically connecting the vehicle and the power converter, and a determination of whether or not the power converter is connected. Judgment method.

10. To cause one or more processors to execute the determination method described in claim 9, program.

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