Direct current charging double-gun output power scheduling device and charger

Abstract

The present application relates to a charger, in order to solve the problem of the risk of circulating current between batteries caused by faults when the existing charger outputs two guns, the present application constructs a DC charging double-gun output power scheduling device and a charger, wherein the interlocking device of the scheduling device includes a first and a second output control relay, N power scheduling control relays, a first and a second intermediate relay, each single-pole double-throw relay moving contact is connected with the positive pole of the low-voltage control power supply, the moving contacts are connected with each other and are connected with the corresponding intermediate relay contact and the electromagnetic coil of the first and second output DC contactor at the same time, and the first stationary contact of the first and second output control relays is connected with the electromagnetic coil of the first and second intermediate relays. The present application avoids the risk of circulating current between two charging batteries caused by program errors when the charger outputs two guns for charging by interlocking the simultaneous output of the double guns with the power scheduling control relay, so that one of them must be in the open state to form interlocking.

Description

Technical Field

[0001] This invention relates to a charger, and more specifically, to a DC charging dual-gun output power scheduling device and charger. Background Technology

[0002] Chargers are divided into single-gun output and dual-gun output. In existing dual-gun output chargers, each charging gun is usually equipped with a fixed power supply module on its bus. The charger cannot adjust the power supply module to regulate the output power of the charging gun.

[0003] Chinese patent document CN 207809088U discloses a dual-gun DC charger that utilizes DC contactors to achieve arbitrary power dispatching. In this charger, N power modules are used, with power dispatching DC contactors positioned between adjacent power modules. By controlling the on / off state of these contactors, adjacent power modules can be connected in parallel or disconnected from each other. The DC buses connected to the two charging guns are each connected to the first power module and the Nth power module respectively via output DC contactors.

[0004] In the technology disclosed in the aforementioned documents, N power modules can be arbitrarily connected to the DC bus connected to two charging guns by controlling the on / off state of the output DC contactor and the power dispatch DC contactor. However, in this technical solution, when charging two electric vehicles with dual-gun output, at least one of the N-1 power dispatch DC contactors needs to be disconnected; otherwise, a circulating current may form between the batteries of the two vehicles due to the difference in battery voltage, causing damage to the batteries and charging equipment. In the aforementioned technical solution, during dual-gun output charging, the power dispatch unit relies on software to control the on / off state of the relevant power dispatch DC contactors to avoid circulating current between batteries. However, if a program error occurs, a circulating current may form between the batteries of the two vehicles during charging. Summary of the Invention

[0005] The technical problem to be solved by the present invention is the risk of inter-battery circulating current caused by malfunctions when using dual-gun output in existing chargers. The present invention provides a DC charging dual-gun output power scheduling device and charger to avoid the risk of inter-battery circulating current caused by malfunctions.

[0006] The technical solution of this invention to achieve its objective is as follows: A DC charging dual-gun output power scheduling device is constructed, comprising a low-voltage control power supply, a control unit, and N+1 power modules arranged sequentially. A power scheduling DC contactor is provided between each pair of adjacent power modules to connect the two adjacent power modules in parallel or disconnect them from each other. A first DC bus connecting the first charging gun is connected to the first power module via a first output DC contactor, and a second DC bus connecting the second charging gun is connected to the N+1th power module via a second output DC contactor, where N≥1. The invention is characterized by further including an interlocking device.

[0007] The interlocking device includes a first output control relay, a second output control relay, N power scheduling control relays, a first intermediate relay, and a second intermediate relay;

[0008] The first output control relay, the second output control relay, and the N power scheduling control relays are all single-pole double-throw relays, and each electromagnetic coil is electrically connected to the corresponding control terminal of the control unit. Each moving contact is electrically connected to the positive terminal of the low-voltage control power supply. Each second stationary contact is electrically connected to each other and then electrically connected to one end of the electromagnetic coil of the first output DC contactor via the first intermediate relay contact and to one end of the electromagnetic coil of the second output DC contactor via the second intermediate relay contact.

[0009] The first stationary contact of each of the N power dispatch control relays is electrically connected to one end of the electromagnetic coil of each of the N power dispatch DC contactors.

[0010] The first stationary contact of the first output control relay is electrically connected to one end of the electromagnetic coil of the first intermediate relay; the first stationary contact of the second output control relay is electrically connected to one end of the electromagnetic coil of the second intermediate relay.

[0011] The other end of the electromagnetic coils of each DC contactor, the first intermediate relay, and the second intermediate relay is connected to the negative terminal of the low-voltage control power supply.

[0012] In this invention, when two charging guns simultaneously output to charge two vehicles separately, the control unit controls both the first and second output control relays to be energized and closed. The moving contacts of the first and second output control relays close with the first stationary contact. Among the N power scheduling control relays, one relay must have its moving contact closed with its second stationary contact. This allows the moving contacts of the first and second output control relays to be connected to the positive terminal of the low-voltage control power supply through the power scheduling control relay with its moving contact closed with its second stationary contact. The coils of the first and second output DC contactors are energized and closed. The power scheduling DC contactor connected to the first stationary contact of the power scheduling control relay with its moving contact closed with its second stationary contact is in an open state because its electromagnetic coil is not energized. This disconnects the first DC bus from the second DC bus, preventing the risk of circulating current between the batteries of the two vehicles when the charger simultaneously outputs through the two charging guns. If the control unit malfunctions due to a program error, its output current causes the moving contacts of the first output control relay, the second output control relay, and the N power dispatch control relays to close with their corresponding stationary contacts. Although the electromagnetic coils of the N power dispatch DC contactors are energized and closed, the moving contacts of the first and second output control relays cannot be connected to the positive terminal of the low-voltage control power supply through the power dispatch control relays. As a result, the electromagnetic coils of the first and second output DC contactors are not energized and remain open. Consequently, the DC bus connected to the charging gun is disconnected from all power modules, preventing the vehicle from being charged.

[0013] In this invention, an interlocking device is used to simultaneously close the first and second output DC contactors, while ensuring that one of the N power dispatch control relays is in the open state, thus forming an interlocking relationship. This avoids the risk of circulating current between the two rechargeable batteries due to program errors when the charger is charging with dual gun outputs.

[0014] In the aforementioned DC charging dual-gun output power scheduling device, the second stationary contact of each of the first output control relay, the second output control relay, and the N power scheduling control relays is a normally closed contact. Each of the first output DC contactor, the second output DC contactor, and the N power scheduling DC contactors is a normally open contactor, meaning that each DC contactor is normally in the open state. The first intermediate relay and the second intermediate relay are normally open relays.

[0015] In the aforementioned DC charging dual-gun output power scheduling device, each of the first output DC contactor, the second output DC contactor, and the N power scheduling DC contactors includes a positive DC contactor connected to the positive terminal of the power module and a negative DC contactor connected to the negative terminal of the power module. The electromagnetic coils of the positive DC contactor and the negative DC contactor are connected in parallel.

[0016] In the aforementioned DC charging dual-gun output power scheduling device, each of the first output DC contactor, the second output DC contactor, and the N power scheduling DC contactors is equipped with a contactor status feedback circuit. Each contactor's status feedback circuit includes auxiliary contacts for the positive and negative DC contactors. One end of each auxiliary contact's two terminals is electrically connected to the positive terminal of the low-voltage control power supply, and the other end is electrically connected to the corresponding contactor status feedback signal terminal in the control unit. Alternatively, each contactor's status feedback circuit includes auxiliary contacts for the positive and negative DC contactors. The two ends of the series connection of the positive and negative auxiliary contacts are electrically connected to the positive terminal of the low-voltage control power supply and the corresponding feedback signal terminal in the control unit, respectively. When a DC contactor closes, the auxiliary contact of that output DC contactor also closes, activating the contactor status feedback circuit corresponding to that output DC contactor and transferring the potential to the positive terminal of the low-voltage control power supply to the control unit.

[0017] In the aforementioned DC charging dual-gun output power scheduling device, the first output control relay, the second output control relay, and N power scheduling control relays are all arranged on the system control board of the control unit.

[0018] The technical solution of the present invention to achieve its purpose is as follows: a charger is constructed, characterized by having the aforementioned DC charging dual-gun output power scheduling device.

[0019] Compared with the prior art, the present invention uses an interlocking device to interlock the simultaneous output charging of dual guns with the requirement that one of the N power scheduling control relays must be disconnected, thereby avoiding the risk of circulating current between the two rechargeable batteries due to program errors when the charger is outputting charging from dual guns. Attached Figure Description

[0020] Figure 1 This is a circuit diagram of the DC charging dual-gun output power scheduling device of the present invention.

[0021] Component names and serial numbers in the diagram:

[0022] First DC bus 11, second DC bus 12, first output DC contactor 21, contactor status feedback circuit 211, second output DC contactor 22, power dispatch DC contactor 30, power module 40, first output control relay 51, second output control relay 52, power dispatch control relay 60, system control board 70, contactor status feedback terminal block 71, low-voltage control power supply 80, first intermediate relay 91, second intermediate relay 92. Detailed Implementation

[0023] The specific implementation plan is described below with reference to the attached diagram.

[0024] In the charger of this embodiment, the DC charging dual-gun output power scheduling device is as follows: Figure 1 As shown, it includes a low-voltage control power supply 80, a control unit (not shown in the figure), a power module 40, a DC contactor, an interlocking device, etc.

[0025] The low-voltage control power supply 80 is typically a 12-volt DC power supply or a safe voltage DC power supply of other voltages, providing power to the electromagnetic coils of various relays and contactors.

[0026] There are N+1 power modules (40 in total), where N ≥ 1, and the number can be configured as needed. The N+1 power modules are arranged sequentially.

[0027] The DC contactor includes a first output DC contactor 21, a second output DC contactor 22, and N power dispatching DC contactors 30. Each DC contactor is a normally open type. A power dispatching DC contactor 30 is arranged between two adjacent power modules 40. The closing or opening of each power dispatching DC contactor 30 correspondingly connects or disconnects the two adjacent power modules 40 connected to that power dispatching DC contactor 30 in parallel.

[0028] The first DC bus 11, which connects to the first charging gun (not shown in the figure), is connected to the first power module 30 via the first output DC contactor 21. When the first output DC contactor 21 is open, the first DC bus 11 is not connected to any power module 30, and the first charging gun has no output; when the first output DC contactor 21 is closed, the first DC bus 11 is connected to the first power module 30 via the first output DC contactor 21, and the first charging gun has charging power output.

[0029] The second DC bus 12, which connects to the second charging gun (not shown in the figure), is connected to the (N+1)th power module 40 through the second output DC contactor 22. When the second output DC contactor is open, the second DC bus is not connected to any power module, and the second charging gun has no output. When the second output DC contactor is closed, the second DC bus is connected to the (N+1)th power module through the second output DC contactor, and the second charging gun has charging power output.

[0030] The first output DC contactor 21 includes a positive DC contactor KA2H and a negative DC contactor KA2L. The electromagnetic coils of the positive DC contactor KA2H and the negative DC contactor KA2L are connected in parallel. The two terminals of the main contacts of the positive DC contactor KA2H are electrically connected to the positive bus DC+ in the first DC bus and the positive terminal of the first power module 40, respectively. The two terminals of the main contacts of the negative DC contactor KA2L are electrically connected to the negative bus DC- in the first DC bus 11 and the negative terminal of the first power module 40, respectively.

[0031] The second output DC contactor 12 includes a positive DC contactor KB2H and a negative DC contactor KB2L connected in parallel with electromagnetic coils. The positive DC contactor KB2H is electrically connected to the positive bus DC+ in the second DC bus 12 and the positive terminal of the (N+1)th power module 40. The negative DC contactor KB2L is electrically connected to the negative bus DC- in the second DC bus 12 and the negative terminal of the (N+1)th power module 40.

[0032] Each power dispatching DC contactor also includes a positive DC contactor and a negative DC contactor with electromagnetic coils connected in parallel. The positive DC contactor is connected to the positive pole of the two adjacent power modules, and the negative DC contactor is electrically connected to the negative pole of the two adjacent power modules.

[0033] The first output DC contactor 21 has a contactor status feedback circuit 211. This circuit includes auxiliary contacts for the positive DC contactor KA2H and the negative DC contactor KA2L. The auxiliary contacts of the positive and negative DC contactors KA2H and KA2L are connected in series. One end of this circuit is connected to the positive terminal of the low-voltage control power supply 80, and the other end is connected to the corresponding contactor status feedback terminal 71 on the control unit. When the electromagnetic coil of the first output DC contactor 21 is energized and closed, the auxiliary contacts of the DC contactor close, the contactor status feedback circuit 211 is activated, and the contactor status feedback input terminal on the control unit corresponding to the first output DC contactor 21 receives the positive potential signal from the low-voltage control power supply 80. In the above structure, the positive DC contactor KA2H and the negative DC contactor KA2L share one contactor status feedback circuit 211. In specific implementation, two separate contactor status feedback circuits can also be used to feed back the status of the positive DC contactor KA2H and the negative DC contactor KA2L. That is, the auxiliary contacts of the positive DC contactor and the auxiliary contacts of the negative DC contactor are electrically connected to the positive terminal of the low-voltage control power supply and the corresponding contactor status feedback terminal on the control unit, respectively, forming two circuits to feed back the status of the positive DC contactor and the negative DC contactor.

[0034] The second output DC contactor and each power dispatch DC contactor have a contactor state feedback circuit with the same structure as the contactor state feedback circuit on the first output DC contactor.

[0035] The interlocking device includes a first output control relay 51, a second output control relay 52, N power scheduling control relays 60, a first intermediate relay 91, and a second intermediate relay 92. The first intermediate relay 91 and the second intermediate relay 92 are arranged in the chassis of the charger, while the other relays are arranged on the system control board 70 of the control unit.

[0036] The first output control relay 51, the second output control relay 52, and each power dispatch control relay 60 are all single-pole double-throw relays. The electromagnetic coil of each relay is electrically connected to the corresponding control terminal of the control unit. Each moving contact a is electrically connected to the positive terminal of the low-voltage control power supply. Each second stationary contact c is electrically connected to each other and then electrically connected to one end of the electromagnetic coil of the first output DC contactor 21 via the contact of the first intermediate relay 91. In addition, each second stationary contact c is electrically connected to each other and then electrically connected to one end of the electromagnetic coil of the second output DC contactor 22 via the contact of the second intermediate relay 92.

[0037] The first stationary contact b of N power dispatch control relays 60 is electrically connected one-to-one with one end of the electromagnetic coil of N power dispatch DC contactors 30.

[0038] The first stationary contact b of the first output control relay 51 is electrically connected to one end of the electromagnetic coil of the first intermediate relay 91; the first stationary contact b of the second output control relay 52 is electrically connected to one end of the electromagnetic coil of the second intermediate relay 92.

[0039] The other end of the electromagnetic coil of each DC contactor 30, the electromagnetic coil of the first intermediate relay 91, and the electromagnetic coil of the second intermediate relay 92 are all connected to the negative terminal of the low-voltage control power supply 80.

[0040] The second stationary contact c of each of the first output control relay 51, the second output control relay 52, and each power dispatch control relay 60 is a normally closed contact, the first stationary contact b is a normally open contact, and the first intermediate relay 91 and the second intermediate relay 92 are normally open relays.

[0041] This embodiment also provides a dual-gun output charger, which includes the aforementioned DC charging dual-gun output power scheduling device.

[0042] In this embodiment, the working principle of the DC charging dual-gun output power scheduling device is as follows:

[0043] 1. Dual pistols are idle.

[0044] Neither charging gun outputs charging. The control unit de-energizes the first output control relay 51 and the second output control relay 52. ​​The first intermediate relay and the second intermediate relay are in an open state because their electromagnetic coils are de-energized. The electromagnetic coils of the first output DC contactor 21 and the second DC contactor 22 are not energized. Both charging guns are disconnected from all power modules.

[0045] 2. Single-gun charging.

[0046] The first charging gun outputs charging, while the second charging gun does not. The control unit controls the first output control relay 51 to be energized and the second output control relay 52 to be de-energized. The moving contact a of the first output control relay 51 closes with the first stationary contact b, energizing the first intermediate relay and causing its contacts to close. The moving contact a of the second output control relay 52 closes with the second stationary contact c, causing the positive terminal of the low-voltage control power supply to conduct through the moving contact a of the second output control relay 52, the second stationary contact c, and the contacts of the first intermediate relay to the electromagnetic coil of the first output DC contactor. The first output DC contactor closes due to the energization of its electromagnetic coil. The first charging gun is connected to the first power module 40 through the first DC bus 11 and the first output DC contactor 21, outputting charging current. Correspondingly, since the moving contact a of the second output control relay 52 is disconnected from the first stationary contact b, the electromagnetic coil of the second intermediate relay is open-circuited with the positive terminal of the low-voltage control power supply. The contacts of the first intermediate relay are open, and the second output DC contactor 22 is disconnected because its electromagnetic coil is not energized. The first DC bus 12 connecting the second charging gun is disconnected from the (N+1)th power module 40, and the second charging gun cannot output charging current. The control unit runs the program to output control current, energizing the electromagnetic coils of the power scheduling control relays 60 from the first power module to the Mth power scheduling DC contactor 30. The M power scheduling DC contactors 30 are closed because their electromagnetic coils are energized. A total of M+1 power modules from the 1st to the (M+1)th are connected to the first DC bus 11 and charge the vehicle through the first charging gun, where M is an integer and 0≤M≤N.

[0047] Similarly, when the second charging gun outputs charging and the first charging gun does not charge, the control unit outputs a control current to close the second output DC contactor 22 and open the first output DC contactor 21. The M power scheduling control relays near the N+1th power module 30 close. By controlling the corresponding power scheduling control relays 60, the M+1 power modules connected to the second DC bus charge the vehicle through the second charging gun.

[0048] 3. Dual-gun charging.

[0049] The control unit controls the first output control relay 51 and the second output control relay 52 to be energized. Both the first output control relay 51 and the second output control relay 52 have their moving contact a closed with the first stationary contact b. The first intermediate relay and the second intermediate relay have their contacts closed because their respective electromagnetic coils are energized.

[0050] The control unit controls one of the N power scheduling control relays based on the program execution results. For example, it controls the Mth power scheduling control relay to open, and the moving contact of the Mth power scheduling control relay closes with the second stationary contact. This causes the positive terminal of the low-voltage control power supply to conduct through the moving contact and the second stationary contact of the Mth power scheduling control relay, the contact of the first intermediate relay, and the electromagnetic coil of the first output DC contactor 21, thus closing the first output DC contactor 21. Simultaneously, the positive terminal of the low-voltage control power supply is connected through the moving contact and the second stationary contact of the Mth power scheduling control relay, the contact of the second intermediate relay, and the electromagnetic coil of the second output DC contactor 22, thus closing the second output DC contactor 21. The Mth power scheduling DC contactor corresponding to the Mth power scheduling control relay is in an open state because its electromagnetic coil is de-energized. The power module between the first output DC contactor and the Mth power scheduling DC contactor is connected to the first DC bus and charges the vehicle through the first charging gun. The power module between the second output DC contactor and the Mth power dispatching DC contactor is connected to the second DC bus and charges the vehicle through the second charging gun. The total number of power modules connected to the first and second DC buses is equal to the total number of power modules equipped in the charger.

[0051] During dual-gun charging, the control unit can also supply multiple output control currents to N power dispatch control relays, correspondingly disconnecting multiple power dispatch DC contactors 30. The power module 40 between the first output DC contactor 21 and the nearest disconnected power dispatch DC contactor 30 is connected to the first DC bus 11, charging the vehicle through the first charging gun. The power module 40 between the second output DC contactor 22 and the nearest disconnected power dispatch DC contactor 30 is connected to the second DC bus 12, charging the vehicle through the second charging gun. The total number of power modules 30 connected to the first DC bus 11 and the second DC bus 12 is less than the total number of power modules equipped in the charger.

[0052] During dual-gun output charging, if the control unit's program malfunctions, the control unit outputs a control current that energizes the electromagnetic coils of the first output control relay 51, the second output control relay 52, and N power scheduling control relays 60. The moving contact a of each relay closes with the first stationary contact b. Consequently, the electromagnetic coils of the first and second intermediate relays cannot conduct to the positive terminal of the low-voltage control power supply 80, causing both the first and second intermediate relays to disconnect. The first output DC contactor 21 and the second output DC contactor 22 are also disconnected because their electromagnetic coils are not energized. This disconnects the DC bus connected to the charging gun from all power modules, preventing vehicle charging. This avoids the risk of circulating current between the two batteries due to a program error during dual-gun output charging.

[0053] In this invention, an interlocking device simultaneously closes the first and second output DC contactors while ensuring that one of the N power scheduling control relays remains open, thus preventing the risk of circulating current between the two rechargeable batteries due to program errors during dual-gun charging. This interlocking device, composed of relays, is a mechanical hardware interlock, offering high reliability and preventing circulating current risks even if the control unit's program malfunctions.

Claims

1. A DC charging dual-gun output power scheduling device, comprising a low-voltage control power supply, a control unit, and N+1 power modules arranged sequentially, wherein a power scheduling DC contactor is provided between each pair of adjacent power modules to connect the two adjacent power modules in parallel or disconnect them from each other; a first DC bus connecting the first charging gun is connected to the first power module through a first output DC contactor, and a second DC bus connecting the second charging gun is connected to the N+1th power module through a second output DC contactor, where N≥1; characterized in that... It also includes interlocking devices; The interlocking device includes a first output control relay, a second output control relay, N power scheduling control relays, a first intermediate relay, and a second intermediate relay; The first output control relay, the second output control relay, and the N power scheduling control relays are all single-pole double-throw relays, and each electromagnetic coil is electrically connected to the corresponding control terminal of the control unit. Each moving contact is electrically connected to the positive terminal of the low-voltage control power supply. Each second stationary contact is electrically connected to each other and then electrically connected to one end of the electromagnetic coil of the first output DC contactor via the first intermediate relay contact and to one end of the electromagnetic coil of the second output DC contactor via the second intermediate relay contact. The first stationary contact of each of the N power dispatch control relays is electrically connected to one end of the electromagnetic coil of each of the N power dispatch DC contactors. The first stationary contact of the first output control relay is electrically connected to one end of the electromagnetic coil of the first intermediate relay; the first stationary contact of the second output control relay is electrically connected to one end of the electromagnetic coil of the second intermediate relay. The other end of the electromagnetic coils of each DC contactor, the first intermediate relay, and the second intermediate relay is connected to the negative terminal of the low-voltage control power supply.

2. The DC charging dual-gun output power scheduling device according to claim 1, characterized in that... The second stationary contact of each of the first output control relay, the second output control relay, and the N power dispatch control relays is a normally closed contact; the DC contactor of each of the first output DC contactor, the second output DC contactor, and the N power dispatch DC contactors is a normally open contactor; and the first intermediate relay and the second intermediate relay are normally open relays.

3. The DC charging dual-gun output power scheduling device according to claim 1 or 2, characterized in that... Each of the first output DC contactor, the second output DC contactor, and the N power dispatching DC contactors includes a positive DC contactor connected to the positive terminal of the power module and a negative DC contactor connected to the negative terminal of the power module. The electromagnetic coils of the positive DC contactor and the negative DC contactor are connected in parallel.

4. The DC charging dual-gun output power scheduling device according to claim 3, characterized in that... Each of the first output DC contactor, the second output DC contactor, and the N power dispatching DC contactors is equipped with a contactor status feedback circuit. The contactor status feedback circuit of each DC contactor includes the auxiliary contact of the positive DC contactor and the auxiliary contact of the negative DC contactor. One end of the two terminals of the auxiliary contact of each contactor is electrically connected to the positive terminal of the low-voltage control power supply, and the other end is electrically connected to the corresponding contactor status feedback signal terminal in the control unit.

5. The DC charging dual-gun output power scheduling device according to claim 3, characterized in that... Each of the first output DC contactor, the second output DC contactor, and the N power dispatching DC contactors is equipped with a contactor status feedback circuit. The contactor status feedback circuit of each DC contactor includes the auxiliary contact of the positive DC contactor and the auxiliary contact of the negative DC contactor. The two ends of the auxiliary contact of the positive DC contactor and the auxiliary contact of the negative DC contactor are connected in series to the positive terminal of the low-voltage control power supply and the corresponding contactor status feedback signal terminal in the control unit, respectively.

6. The DC charging dual-gun output power scheduling device according to claim 1, characterized in that... The first output control relay, the second output control relay, and N power scheduling control relays are all arranged on the system control board of the control unit.

7. A charger, characterized in that... A DC charging dual-gun output power scheduling device as described in any one of claims 1 to 6.

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