Charging device

Abstract

The invention relates to a charging device. In a charging device having a first switch capable of connecting outputs of a plurality of power converters to each other, welding of the first switch is detected without providing a dedicated mechanism. This charging device is provided with: a plurality of power converters; a first switch capable of connecting outputs of a pair of power converters among the plurality of power converters to each other; a plurality of second switches respectively connected between the output of each of the plurality of power converters and each of the plurality of charging ports; voltage sensors that detect voltage values of a plurality of voltage lines that respectively connect outputs of the plurality of power converters and the plurality of second switches; and a failure detection unit that, in a state in which the outputs of a pair of power converters that output the DC voltage are connected to each other by the first switch, detects a welding failure of the first switch when the difference between the voltage values of a pair of voltage lines connected to the outputs of the pair of power converters detected by the voltage sensor is greater than a threshold value.

Description

Technical Field

[0001] This invention relates to a charging device. Background Technology

[0002] Patent Document 1 discloses a fast charger having multiple power conversion units that generate DC voltage and multiple switches that can connect the outputs of the multiple power conversion units to one or more of a plurality of power supply connectors, enabling simultaneous charging of batteries for multiple electric vehicles. The fast charger in Patent Document 1 connects multiple auxiliary contacts corresponding to the multiple switches in parallel, and detects the connection of any one of the multiple switches by identifying the closure of any auxiliary contact among the multiple auxiliary contacts.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-180549 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The technology disclosed in Patent Document 1 has a dedicated weld detection mechanism that includes multiple auxiliary contacts and signal lines connected to the multiple auxiliary contacts in order to detect welds in any of the multiple switches, which leads to high costs.

[0008] The object of the present invention is to detect the welding of the first switch in a charging device having a first switch capable of interconnecting the outputs of multiple power converters without providing a dedicated mechanism.

[0009] Solution for solving the problem

[0010] The charging device of the present invention includes: a plurality of power converters that convert AC voltage into DC voltage respectively; a first switch capable of interconnecting the outputs of a pair of power converters among the plurality of power converters; a plurality of second switches respectively connected between the outputs of the plurality of power converters and each of a plurality of charging ports capable of being connected to a device to be charged; a voltage sensor that detects the voltage values ​​of a plurality of voltage lines that connect the outputs of the plurality of power converters to the plurality of second switches respectively; and a fault detection unit that, when the outputs of a pair of power converters that output DC voltage are interconnected via the first switch, detects a welding fault in the first switch if the difference between the voltage values ​​of the pair of voltage lines connected to the outputs of the pair of power converters detected by the voltage sensor is greater than a threshold.

[0011] The effects of the invention

[0012] According to the present invention, in a charging device having a first switch capable of interconnecting the outputs of multiple power converters, the welding of the first switch can be detected without providing a dedicated mechanism. Attached Figure Description

[0013] Figure 1 This is a circuit block diagram illustrating an example of a charging device according to an embodiment of the present invention.

[0014] Figure 2 It means by Figure 1 A flowchart illustrating an example of the charging control unit's action in determining a welding fault in the switching switch SW1.

[0015] Figure 3 It means by Figure 1 A flowchart illustrating an example of how the charging control unit determines other faults in the switching switch SW1.

[0016] Explanation of reference numerals in the attached figures

[0017] 100: Charging device; 110a, 110b: AC / DC converter; 120a, 120b: Voltage sensor; 130: Charging control unit; 132: Fault detection unit; 200a, 200b: Charging port; 300a, 300b: Vehicle; AC: Alternating current power supply; DCa, DCb: Direct current voltage; Ia, Ib: Charging current; SW1, SW2a, SW2b: Switch; VDCa, VDCb: Voltage value. Detailed Implementation

[0018] The embodiments will now be described using the accompanying drawings. In the drawings, the same reference numerals are used to denote the same structural parts, and sometimes repeated descriptions are omitted. Reference numerals indicating voltage are also used to denote voltage lines.

[0019] Figure 1 This is a circuit block diagram illustrating an example of a charging device according to an embodiment of the present invention. Figure 1 The charging device 100 shown includes multiple AC / DC converters 110a and 110b, voltage sensors 120a and 120b, a charging control unit 130 including a fault detection unit 132, a switching switch SW1, and multiple switching switches SW2a and SW2b. The AC / DC converters 110a and 110b are examples of power converters. The switching switch SW1 is an example of a first switch. The switching switches SW2a and SW2b are examples of second switches.

[0020] The charging device 100 has the function of outputting DC voltage to one or both of a plurality of charging ports 200a and 200b. For example, the charging device 100 can simultaneously charge the batteries of multiple vehicles 300a and 300b, such as electric vehicles, connected to charging ports 200a and 200b. Vehicles 300a and 300b are examples of charging devices. In the following description, without distinguishing between charging ports 200a and 200b, charging port 200 will also be referred to as charging port 200. Without distinguishing between vehicles 300a and 300b, vehicle 300 will also be referred to as vehicle 300.

[0021] AC / DC converters 110a and 110b convert AC voltage from AC power supply AC into DC voltages DCa and DCb, respectively. A switch SW1 connects the outputs of AC / DC converter 110a and AC / DC converter 110b to each other. One end of switch SW2a is connected to the output of AC / DC converter 110a via voltage line DCa, and the other end of switch SW2a is connected to charging port 200a. One end of switch SW2b is connected to the output of AC / DC converter 110b via voltage line DCb, and the other end of switch SW2b is connected to charging port 200b.

[0022] Voltage sensor 120a detects the DC voltage DCa value VDCa and outputs the detected voltage value VDCa to fault detection unit 132. Voltage sensor 120b detects the DC voltage DCb value VDCb and outputs the detected voltage value VDCb to fault detection unit 132. Fault detection unit 132 detects a fault in switch SW1 based on the voltage values ​​VDCa and VDCb received from voltage sensors 120a and 120b. Figure 2 and Figure 3 The following is an example illustrating the operation of the fault detection unit 132. It should be noted that the charging control unit 130 uses the DC voltage values ​​VDCa and VDCb detected by the voltage sensors 120a and 120b to control the charging of the vehicle 300.

[0023] If the fault detection unit 132 detects a fault in the switch SW1, the charging control unit 130 may also display the fault information and a warning message to the user on a display unit (not shown) provided on the charging device 100. Additionally, if the fault detection unit 132 detects a fault in the switch SW1, the charging control unit 130 may also output the fault information and a warning sound to the user from a speaker (not shown) provided on the charging device 100.

[0024] For example, the charging control unit 130 can also implement the charging control program through a processor such as a CPU (Central Processing Unit) mounted on the charging control unit 130. The charging control unit 130 outputs control signals to the AC / DC converters 110a and 110b to control their operation / stop. The charging control unit 130 also outputs control signals to the switches SW1, SW2a, and SW2b to control their on / off states.

[0025] exist Figure 1 The diagram illustrates an example where switch SW1 and SW2b are switched on, switch SW2a is switched off, and AC / DC converters 110a and 110b operate in parallel. Thus, the charging device 100 can use the charging currents Ia+Ib from both AC / DC converters 110a and 110b to quickly charge the vehicle 300b connected to the charging port 200b.

[0026] Figure 2 It means by Figure 1 A flowchart illustrating an example of the operation of the charging control unit 130 in determining a welding fault in the switching switch SW1. Figure 2 The fault determination operation of the switch SW1 shown is performed when multiple AC / DC converters 110a and 110b output charging current to one charging port 200a (or 200b). That is, the charging control unit 130 can determine the fault of the switch SW1 while charging the vehicle 300.

[0027] First, in S10, the charging control unit 130 turns on the switching switch SW1 and one of the switching switches SW2a and SW2b. This connects the voltage lines DCa and DCb, and the outputs of the AC / DC converters 110a and 110b are connected to one of the charging ports 200. Furthermore, the charging control unit 130 causes the AC / DC converter 110a to output a DC voltage DCa and the AC / DC converter 110b to output a DC voltage DCb, supplying the charging current Ia+Ib to one of the charging ports.

[0028] Next, in S11, the fault detection unit 132 calculates the difference between the voltage values ​​VDCa and VDCb from the voltage sensors 120a and 120b when the voltage lines DCa and DCb are connected. The fault detection unit 132 determines whether the calculated difference is greater than a preset threshold. If the difference between the voltage values ​​VDCa and VDCb is below the threshold, the fault detection unit 132 determines that the on-resistance of the switch SW1 is low and proceeds to S12. If the difference between the voltage values ​​VDCa and VDCb is greater than the threshold, the fault detection unit 132 determines that the on-resistance of the switch SW1 is high and proceeds to S13.

[0029] In step S12, the fault detection unit 132 determines that no welding fault has occurred in the switch SW1, and the process ends. Figure 2 The system proceeds with the determination and processing of the fault, and continues charging of vehicle 300. In S13, the fault detection unit 132 determines that there is a welding fault in the switch SW1, and executes S14.

[0030] In step S14, the charging control unit 130 displays the fault information and warning messages to the user, etc., on the display unit of the charging device 100, and then ends the process. Figure 2 The system then processes the fault. Alternatively, the charging control unit 130 outputs fault information and a warning sound to the user from the speaker of the charging device 100, and then terminates the process. Figure 2 The user who is charging the vehicle 300 using the charging device 100 can stop the charging operation based on a warning from the charging device 100.

[0031] It should be noted that if a welding fault is detected in the switching switch SW1 in S13, the charging control unit 130 can also stop charging the vehicle 300. Alternatively, the charging control unit 130 can also terminate the process without implementing S14 after S13. Figure 2 The determination and processing are as follows. In this case, the charging control unit 130 may also automatically stop the charging operation.

[0032] Figure 3 It means by Figure 1 A flowchart illustrating an example of the operation of the charging control unit 130 in determining other faults in the switching switch SW1. For example, Figure 3 The fault determination action of the switch SW1 shown is performed before the vehicle 300 is charged using the charging device 100.

[0033] First, in S20, the charging control unit 130 disconnects the switching switch SW1, causing the AC / DC converter 110a to output a DC voltage DCa.

[0034] Next, in S21, the fault detection unit 132 determines whether the voltage value VDCa is detected by the voltage sensor 120a and the voltage value VDCb is not detected by the voltage sensor 120b. If the voltage value VDCa is detected and the voltage value VDCb is not detected (e.g., 0V), the fault detection unit 132 proceeds to S22. If both voltage values ​​VDCa and VDCb are detected, the fault detection unit 132 proceeds to S26.

[0035] In S22, the charging control unit 130 turns on the switching switch SW1, causing the AC / DC converter 110a to output a DC voltage DCa.

[0036] Next, in S23, the fault detection unit 132 determines whether the voltage value VDCa detected by the voltage sensor 120a is equal to the voltage value VDCb detected by the voltage sensor 120b. If the voltage values ​​VDCa and VDCb are equal, the fault detection unit 132 performs S24; if the voltage values ​​VDCa and VDCb are not equal, it performs S25.

[0037] In step S24, the fault detection unit 132 determines that the changeover switch SW1 is normal and ends the process. Figure 3 The determination and processing.

[0038] In S25, the fault detection unit 132 detects an open-circuit fault in the switching switch SW1 and implements S27. When the fault detection unit 132 detects an open-circuit fault in the switching switch SW1, the charging control unit 130 disables power sharing and activates the AC / DC converters 110a and 110b in power sharing to charge the vehicle 300 using the charging current Ia+Ib.

[0039] On the other hand, in S26, the fault detection unit 132 detects a short-circuit fault in the switch SW1 and implements S27. When the fault detection unit 132 detects a short-circuit fault in the switch SW1, the charging control unit 130 prohibits the simultaneous use of multiple charging ports 200. Simultaneous use of multiple charging ports 200 refers to the operation of simultaneously using multiple charging ports 200 to charge multiple vehicles 300 at the same time.

[0040] In step S27, the charging control unit 130 displays the fault information and warning messages to the user, etc., on the display unit of the charging device 100, and then ends the process. Figure 3 The system then processes the fault. Alternatively, the charging control unit 130 outputs fault information and a warning sound to the user from the speaker of the charging device 100, and then terminates the process. Figure 3The determination and processing are as follows. Users who use the charging device 100 to charge the vehicle 300 can identify the unusable charging mode among the multiple charging modes of the charging device 100. It should be noted that the charging control unit 130 may also end after S25 and S26 without implementing S27. Figure 3 The determination and processing.

[0041] It should be noted that, in Figure 3 Even if the labels DCa of S20 and S22 are changed to DCb and the labels VDCa and VDCb of S21 and S23 are swapped, the open circuit fault and short circuit fault of the switching switch SW1 can still be detected.

[0042] In this embodiment, the charging device 100, which has a switching switch SW1 capable of interconnecting the outputs of multiple AC / DC converters 110a and 110b, can detect the welding fault of the switching switch SW1 without a dedicated mechanism. At this time, the charging control unit 130 can determine the welding fault of the switching switch SW1 while charging the vehicle 300.

[0043] It should be noted that, in Figure 1 The example described is a charging device 100 having two AC / DC converters 110a and 110b connected to two charging ports 200a and 200b. However, the charging device 100 may also have three or more AC / DC converters connected to three or more charging ports.

[0044] Although the illustrations are omitted, for example, the charging device 100 is assumed to have three AC / DC converters 110a, 110b, and 110c, connected to three charging ports 200a, 200b, and 200c. In this case, two switching switches SW1 are respectively configured between the outputs of a pair of AC / DC converters. The charging device 100 has three switching switches SW2a, SW2b, and SW2c respectively connected to the outputs of the three AC / DC converters 110a, 110b, and 110c. Additionally, the charging device 100 has three voltage sensors 120a, 120b, and 120c respectively connected to the outputs of the three AC / DC converters 110a, 110b, and 110c.

[0045] The fault detection unit 132, for example, uses two of the voltage values ​​VDCa, VDCb, and VDCc detected by three voltage sensors 120a, 120b, and 120c respectively to perform two separate fault detection operations. Figure 2 The process is as follows. Therefore, the fault detection unit 132 can determine whether there is a welding fault in the two switch SW1.

[0046] In addition, the fault detection unit 132, for example, uses two of the voltage values ​​VDCa, VDCb, and VDCc detected by the three voltage sensors 120a, 120b, and 120c respectively to perform the fault detection twice. Figure 3 The process is as follows. Therefore, the fault detection unit 132 can determine whether the two changeover switches SW1 have open-circuit faults or short-circuit faults. It should be noted that when using voltage values ​​VDCb and VDCc, Figure 2 , Figure 3 In the process, the labels DCa and VDCa are replaced with the labels DCc and VDCc.

[0047] The above describes in detail the methods for implementing the present invention. However, the present invention is not limited to this specific implementation method. Various modifications and improvements can be made without departing from the spirit of the present invention.

Claims

1. A charging device, wherein, The charging device has the following features: Multiple power converters convert AC voltage into DC voltage respectively; The first switch is capable of connecting the outputs of a pair of power converters among the plurality of power converters; Multiple second switches are respectively connected between the output of each of the multiple power converters and each of the multiple charging ports that can be respectively connected to the charging target device; Voltage sensors detect the voltage values ​​of multiple voltage lines that connect the outputs of the multiple power converters to the multiple second switches, respectively. as well as The fault detection unit detects a welding fault in the first switch when the outputs of a pair of power converters that output DC voltage are interconnected via the first switch, and the voltage difference between the voltage values ​​of the pair of voltage lines connected to the outputs of the pair of power converters, as detected by the voltage sensor, is greater than a threshold.

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