A DC residual current protection device for split-type charging and swapping equipment

Abstract

The present invention discloses a DC residual current protection device for split-type charging and swapping equipment, including a rectifier cabinet and several charging terminals that are communicatively connected to the DC output end of the rectifier cabinet, and the input end of the rectifier cabinet is connected to several AC incoming lines. It also includes a DC residual current detector and a molded case circuit breaker that are arranged corresponding to the AC incoming line. The DC residual current detector is arranged on the AC incoming line and is used to detect the residual current of the loop. The output end of each DC residual current detector is connected to the input end of the leakage concentrator. The leakage concentrator is used to sum the residual current and compare it with a preset value. The output end of the leakage concentrator is connected to the input end of the charging controller. The molded case circuit breaker is used to control the on and off of the AC incoming line and is connected to the output end of the charging controller. The control output end of the charging controller drives the molded case circuit breaker to be on and off through the excitation tripping coil. The leakage current can be collected before shunting, and the AC incoming line end of the charging module can be tripped, so that the protection is more comprehensive.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle charging, and in particular to a DC residual current protection device for split-type charging and swapping equipment. Background Art

[0002] With the popularity of new energy vehicles, how to charge new energy vehicles efficiently and safely has become a problem that needs to be improved. Split charging piles are commonly used equipment for charging new energy vehicles. Split charging piles are generally composed of a rectifier cabinet and several charging terminals. The rectifier cabinet rectifies AC into DC and distributes DC to each charging terminal through power distribution. The rectifier cabinet adjusts the power distribution according to the power demand of the charging vehicle to meet the charging needs. Due to the large power, the rectifier cabinet generally adopts a multi-channel mode. When the charging module inside it adopts a non-isolated topology structure, if DC leakage occurs on the DC side at this time, the leakage current is shunted at the AC incoming line. The leakage current detected at the charging terminal incoming line is only half of the DC leakage current, and the leakage protection action customization cannot be achieved. The circuit breaker will not trip and cannot effectively provide current protection. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings, the purpose of the present invention is to provide a DC residual current protection device for split-type charging and swapping equipment, which can collect leakage current before diversion, can quickly trip the AC input terminal of the charging module, can detect the complete leakage current under various working conditions, and provide more comprehensive protection.

[0004] In order to achieve the above objectives, the technical solution adopted by the present invention is: a DC residual current protection device for split-type charging and swapping equipment, comprising a rectifier cabinet and several charging terminals communicatively connected to the DC output end of the rectifier cabinet, the input end of the rectifier cabinet is connected to several AC incoming lines, characterized in that: it also includes a DC residual current detector and a molded case circuit breaker arranged corresponding to the AC incoming line, the DC residual current detector is arranged on the AC incoming line, and is used to detect the residual current of the loop, the output end of each of the DC residual current detectors is connected to the input end of the leakage concentrator, the leakage concentrator is used to sum the residual current and compare it with a preset value, the output end of the leakage concentrator is connected to the input end of the charging controller, the molded case circuit breaker is used to control the on and off of the AC incoming line and is connected to the output end of the charging controller, and the control output end of the charging controller drives the molded case circuit breaker to be on and off through the excitation trip coil.

[0005] The beneficial effects of the present invention are as follows: the DC residual current detector directly detects the leakage of the AC incoming line terminal, the leakage concentrator is used to compare the residual current of the leakage with the preset value, and when leakage is found, the information is transmitted to the charging controller, the charging controller supplies power to the excitation tripping coil, the molded case circuit breaker trips, and the circuit is disconnected, effectively protecting the charging and swapping equipment. The leakage current can be collected before shunting, the AC incoming line terminal of the charging module can be quickly tripped, and the complete leakage current can be detected under various working conditions, and the protection is more comprehensive.

[0006] Furthermore, the charging controller includes a relay corresponding to the excitation tripping coil, each of the relays includes a normally open contact and a normally closed contact, the normally closed contact is connected to the output end of the leakage concentrator through hard wiring, and the normally open contact is connected to the correspondingly set excitation tripping coil through hard wiring. When the leakage concentrator determines that the residual current is greater than a preset value, the charging controller receives a signal and controls the normally open contact to close, the excitation tripping coil is energized, and the molded case circuit breaker trips.

[0007] Furthermore, the leakage concentrator and the charging controller are also connected via RS485 bus communication to achieve information exchange between the two.

[0008] Furthermore, there are two AC incoming lines.

[0009] Furthermore, the DC residual current detector is connected to the leakage concentrator through the RS485 bus to achieve information exchange between the two.

[0010] Furthermore, the output end of each molded case circuit breaker is connected to a plurality of charging modules, the DC output end of each charging module is connected to a charging terminal, and a power distribution contactor for power distribution is provided on the line between the charging module and the charging terminal.

[0011] Furthermore, the charging controller is also connected to the vehicle BMS via the CAN bus. When the charging controller receives the leakage information, it sends a stop charging message to notify the vehicle to stop charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a connection block diagram of an embodiment of the present invention;

[0013] Figure 2 It is a connection electrical schematic diagram of the leakage concentrator, the charging controller and the excitation tripping coil in the embodiment of the present invention;

[0014] Figure 3 1 is an electrical schematic diagram of the connection between the charging terminal and the battery in an embodiment of the present invention.

[0015] In the figure:

[0016] 100-rectifier cabinet, 1-DC residual current detector, 2-molded case circuit breaker, 3-leakage concentrator, 4-charging controller, 5-excitation trip coil, 7-power distribution contactor, 6-charging module, 200-charging terminal. DETAILED DESCRIPTION

[0017] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0018] Example

[0019] See attached Figure 1-2 As shown, a DC residual current protection device for a split-type charging and swapping device of the present invention includes a rectifier cabinet 100 and a plurality of charging terminals 200 connected to the DC output end of the rectifier cabinet 100. The input end of the rectifier cabinet 100 is connected to a plurality of AC incoming lines, and there are two AC incoming lines.

[0020] It also includes a DC residual current detector 1 and a molded case circuit breaker 2 that are arranged corresponding to the AC incoming line. The DC residual current detector 1 is arranged on the AC incoming line and is used to detect the residual current of the loop. The output end of each DC residual current detector 1 is connected to the input end of the leakage concentrator 3. The leakage concentrator 3 is used to sum the residual current and compare it with the preset value. The DC residual current detector 1 is connected to the leakage concentrator 3 through the RS485 bus to achieve information exchange between the two. The data transmission between the DC residual current detector 1 and the leakage concentrator 3 adopts digital communication, and the communication protocol adopts the master-slave type. The leakage concentrator 3 is the master station and the DC residual current detector 1 is the slave station. The master station sends an inquiry command and the slave station replies in turn.

[0021] The output end of the leakage concentrator 3 is connected to the input end of the charging controller 4. The molded case circuit breaker 2 is used to control the on and off of the AC incoming line and is connected to the output end of the charging controller 4. The control output end of the charging controller 4 drives the molded case circuit breaker 2 to be on and off through the excitation tripping coil 5. The leakage concentrator 3 and the charging controller 4 are also connected through RS485 bus communication to realize information exchange between the two.

[0022] The DC residual current detector 1 directly detects the leakage of the AC incoming line. The leakage concentrator 3 is used to compare the residual current of the leakage with the preset value. When leakage is found, the information is transmitted to the charging controller 4. The charging controller 4 supplies power to the excitation tripping coil 5, and the molded case circuit breaker 2 trips to achieve circuit breaking, effectively protecting the charging and swapping equipment. The leakage current can be collected before shunting, and the AC incoming line of the charging module 6 can be quickly tripped. The complete leakage current can be detected under various working conditions, and the protection is more comprehensive.

[0023] The charging controller 4 includes relays corresponding to the excitation tripping coils 5, each relay includes a normally open contact and a normally closed contact, the normally closed contact is connected to the output end of the leakage concentrator 3 through hard wiring, and the normally open contact is connected to the correspondingly set excitation tripping coil 5 through hard wiring. When the leakage concentrator 3 determines that the residual current is greater than the preset value, the charging controller 4 receives the signal and controls the normally open contact to close, the excitation tripping coil 5 is energized, and the molded case circuit breaker 2 trips.

[0024] The output end of each molded case circuit breaker 2 is connected to a plurality of charging modules 6, and one molded case circuit breaker 2 corresponds to two charging modules 6. The DC output end of each charging module 6 is connected to a charging terminal 200, and a power distribution contactor 7 for power distribution is provided on the line between the charging module 6 and the charging terminal 200. The power distribution contactor 7 includes KM1, KM2, KM3 and KM4 connected in series, and controls the output power of the charging terminal 200 according to the opening and closing of KM1, KM2, KM3 and KM4.

[0025] The charging controller 4 is also connected to the vehicle BMS via the CAN bus. When the charging controller 4 receives the leakage information, it sends a stop charging message to notify the vehicle to stop charging. Figure 3 The electrical schematic diagram of the charging terminal 200 shows that the DC output of the charging terminal 200 is measured with contactors K1 and K2, and the vehicle has contactors K5 and K6 at the front end of the power battery. During the charging process, contactors K1, K2, K5 and K6 are all closed. If the molded case circuit breaker 2 trips during charging, contactors K1, K2, K5 and K6 cannot be disconnected immediately, and the battery voltage of the electric vehicle is returned to the charging terminal 200, and the DC circuit is still energized. Due to the backflow of the vehicle-end voltage, only disconnecting contactors K1 and K2 cannot completely isolate the fault. Therefore, the disconnection of the molded case circuit breaker 2 can quickly isolate the fault and provide more comprehensive protection.

[0026] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A DC residual current protection device for split-type charging and swapping equipment, comprising a rectifier cabinet (100) and a plurality of charging terminals (200) communicatively connected to a DC output terminal of the rectifier cabinet (100), wherein an input terminal of the rectifier cabinet (100) is connected to a plurality of AC incoming lines, characterized in that: It also comprises a DC residual current detector (1) and a molded case circuit breaker (2) arranged corresponding to the AC incoming line, the DC residual current detector (1) being arranged on the AC incoming line and used to detect the residual current of the loop, the output end of each DC residual current detector (1) being connected to the input end of a leakage concentrator (3), the leakage concentrator (3) being used to sum the residual current and compare it with a preset value, the output end of the leakage concentrator (3) being connected to the input end of a charging controller (4), the molded case circuit breaker (2) being used to control the on and off of the AC incoming line and being connected to the output end of the charging controller (4), the control output end of the charging controller (4) driving the molded case circuit breaker (2) to be on and off via an excitation tripping coil (5); The output end of each molded case circuit breaker (2) is connected in parallel to a plurality of charging modules (6), the DC output end of each charging module (6) is connected to a charging terminal (200), and a power distribution contactor (7) for performing power distribution is provided on the line between the charging module (6) and the charging terminal (200); The charging controller (4) comprises relays arranged corresponding to the excitation tripping coils (5), each of the relays comprising a normally open contact and a normally closed contact, the normally closed contact being connected to the output end of the leakage concentrator (3) via hard wiring, and the normally open contact being connected to the correspondingly arranged excitation tripping coil (5) via hard wiring.

2. The DC residual current protection device for split-type charging and swapping equipment according to claim 1 is characterized in that: The leakage current concentrator (3) and the charging controller (4) are also connected in communication via an RS485 bus.

3. The DC residual current protection device for split-type charging and swapping equipment according to claim 1 is characterized in that: There are two AC incoming lines.

4. The DC residual current protection device for split-type charging and swapping equipment according to claim 1 is characterized in that: The DC residual current detector (1) is communicatively connected to the leakage concentrator (3) via an RS485 bus.

5. The DC residual current protection device for split-type charging and swapping equipment according to claim 1 is characterized in that: The charging controller (4) is also connected to the vehicle BMS via a CAN bus.

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