A split-type low-power DC charging system

Abstract

This utility model provides a split-type low-power DC charging system, including a low-power rectifier cabinet and a charging terminal. The low-power rectifier cabinet is a low-power DC module stack, mainly used for AC-to-DC rectification, power distribution, and cloud communication. The charging terminal is a device that includes vehicle-to-pile communication and charging output capabilities, mainly possessing the function of interacting with users and new energy vehicles. It adopts a modular design, with each module having a power of 7kW. The modules are connected and expanded using connectors / cables, allowing for on-the-spot upgrades to the output capacity. The charging terminal has an output power of 21kW. The modular expansion design, by disassembling the rectifier cabinet into modules, solves the charging rate problem of high-power batteries, improves product utilization, and addresses the difficulty and feasibility of future product upgrades.

Description

Technical Field

[0001] This utility model relates to the field of charging system technology, and in particular to a split-type low-power DC charging system. Background Technology

[0002] With the development of new energy vehicle technology, the requirements for their charging systems are becoming increasingly stringent, especially the need to shorten charging time. Current AC charging systems primarily involve installing an On-Board Charger (OBC) inside the electric vehicle. The OBC converts the AC power output from the AC charging station into high-voltage DC power to charge the vehicle's high-voltage battery, resulting in a relatively slow charging speed. DC charging systems, on the other hand, offer faster charging speeds and are gradually replacing the slower AC charging systems.

[0003] Currently, the status quo of DC charging systems for new energy vehicles is mainly reflected in the following aspects:

[0004] (1) In order to meet the needs of DC charging, some car manufacturers have cancelled or plan to cancel the in-vehicle OBC-related design and replace the AC charging products with DC home charging products.

[0005] (2) The power resources reserved for charging facilities in the community are often not very sufficient, and there are high requirements for the number of charging interfaces, so high-power DC products cannot be deployed.

[0006] (3) Currently, the mainstream small DC products mainly include 7kW small DC and 21kW small DC. The former has a weaker output capability and is not very friendly to the use of high-power batteries. The latter wastes more resources. High-power batteries generally have a low charging frequency and their utilization rate is much lower than other 7kW charging products.

[0007] (4) Low-power split DC products can solve the above problems, but low-power split DC products have weak expansion capabilities and lack flexibility when the number of users changes (e.g., in a community, after a car is replaced, there will be a demand for additional charging interfaces).

[0008] In view of this, it is necessary to improve the existing DC charging system to solve the above problems. Utility Model Content

[0009] The technical problem to be solved by this utility model is as follows: Based on the above background and technical deficiencies, this utility model proposes a brand-new charging method, a split-type low-power DC charging system, which adopts a modular expansion design. By modularly splitting the rectifier cabinet, it not only solves the charging rate problem of high-power batteries (full power output of a single vehicle), but also improves the utilization rate of the product (multi-gun structure to meet the needs of multiple parking spaces), and solves the difficulty and feasibility of subsequent product upgrades.

[0010] The technical solution adopted by this utility model to solve its technical problem is: a split-type low-power DC charging system, comprising a low-power rectifier cabinet and a charging terminal, wherein the low-power rectifier cabinet is connected to the charging terminal via a DC line.

[0011] The low-power rectifier cabinet includes an input module and a power distribution module. There is at least one input module, each with a maximum power of 21kW. Its input terminal is connected to an external AC power supply, and its output terminal is connected to the input terminal of the power distribution module. Each power distribution module includes at least one low-power DC module, which is a module unit with a power value of 7kW. Therefore, the total power of the power distribution module is an integer multiple of 7kW, and the number of low-power DC modules is the same as the number of charging terminals in the station (i.e., there is a one-to-one correspondence between low-power DC modules and charging terminals). Each low-power DC module is equipped with a connector for expansion, and each input module can connect up to three low-power DC modules. The input modules are connected and expanded using connectors (such as copper busbars) and cables, which can be used to upgrade the output capacity at any time. Each low-power DC module is a minimum module unit, and they are assembled as a whole at the factory. On-site, you only need to select the corresponding number of low-power DC modules according to the power requirements and connect them through connectors and cables. The peak output power of each charging terminal is 21kW, including the vehicle-to-charging station communication unit and the charging capacity output unit.

[0012] Furthermore, the incoming line module includes a residual current circuit breaker QF1, a miniature circuit breaker QF2, a switching power supply UR1, and a communication and power distribution controller. The residual current circuit breaker QF1 is installed on the power line between the external AC power supply and the power distribution module, used for controlling the total power supply to the equipment (designed to meet a maximum power of 21kW). The input terminal of the switching power supply UR1 is connected to the external AC power supply, and the output terminal is connected to the communication and power distribution controller, supplying power to the control circuit. The miniature circuit breaker QF2 is installed on the line between the switching power supply UR1 and the external AC power supply, used for controlling the power supply to the control circuit. The communication and power distribution controller is used for power distribution control and network communication.

[0013] Furthermore, the 7kW module unit includes a power input terminal, a 7kW power module, a power output bus, and a power distribution relay. One end of the power input terminal is connected to the output terminal of the input module, and the other end is connected to one 7kW power module or two or three 7kW power modules connected in parallel. The output terminal of each 7kW power module is connected to the power output bus. The power output buses of different 7kW power modules are connected in sequence through a set of power distribution relays to achieve 7kW, 14kW, and 21kW power output.

[0014] Furthermore, each of the charging terminals includes a fuse, a DC relay, a shunt, a charging gun, a meter, a terminal controller, a card reader, and an emergency stop button, wherein...

[0015] The charging gun is connected to the power output bus of the power distribution module via a power cord to form the main power circuit.

[0016] A fuse is installed on the positive line of the main power circuit for short-circuit protection.

[0017] A DC relay is installed on the main power circuit to control the activation and deactivation of the main power circuit, thereby realizing the charging control function.

[0018] The shunt is installed on the negative line of the main power circuit and located between the DC relay and the charging gun. It is used to collect the current of the main power circuit.

[0019] The meter is connected to the copper busbar of the shunt and busbar to collect the current and voltage values ​​on the main power circuit and communicate with the terminal controller via RS485 serial port.

[0020] The card reader communicates with the terminal controller via an RS232 serial port and is used to initiate charging by swiping a card.

[0021] The emergency stop button is connected to the terminal controller via a line and is used to disconnect charging in case of an abnormal situation.

[0022] The terminal controller is used to control the internal devices of the control terminal and for vehicle-to-pile communication.

[0023] The device communicates with the electricity meter via RS485 serial port to read the voltage value on the meter; it also communicates with the card reader to receive the card reader signal, which is used to control DC relays KM1 and KM2 to engage to start charging, and to control DC relays KM1 and KM2 to disengage and stop charging when charging is complete.

[0024] Furthermore, the charging terminal can be wall-mounted or column-mounted.

[0025] The beneficial effects of this utility model are: This utility model provides a split-type low-power DC charging system.

[0026] (1) It can solve the needs of home charging / non-fast charging for mainstream large battery vehicles on the market;

[0027] (2) It can solve the problem of power resource waste in current low-power DC products and improve the utilization rate of power resources;

[0028] (3) Through modular design, the extra DC part can be expanded in a modular way, which can be flexibly expanded between 7-42kW;

[0029] (4) It simultaneously meets the requirements of rapid energy replenishment and multi-vehicle energy replenishment in home charging scenarios. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 This is a schematic diagram of the principle of the split-type low-power DC charging system of this utility model.

[0032] Figure 2 This is a schematic diagram of the incoming line module.

[0033] Figure 3 This is a schematic diagram of the power distribution module in a single-ended system.

[0034] Figure 4 This is a schematic diagram of the power distribution module in a dual-end system.

[0035] Figure 5 This is a schematic diagram of the power distribution module of a three-terminal system.

[0036] Figure 6 This is a schematic diagram of the charging terminal.

[0037] Figure 7 This is a schematic diagram of the principle of a 21kW fully equipped system in a specific embodiment.

[0038] Figure 8 This is a schematic diagram of the principle of a 42kW fully equipped system in specific embodiment two. Detailed Implementation

[0039] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0040] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0042] like Figure 1 As shown, this utility model discloses a split-type low-power DC charging system, comprising two parts: a low-power rectifier cabinet and a charging terminal. The low-power rectifier cabinet is connected to the charging terminal via a DC line. The low-power rectifier cabinet includes an input module and a power distribution module. There is at least one input module, each with a maximum power of 21kW. Its input terminal is connected to an external AC power source, and its output terminal is connected to the input terminal of the power distribution module. The power distribution module includes at least one low-power DC module, which is a module unit with a power value of 7kW. Therefore, the total power of the power distribution module is an integer multiple of 7kW, and the number of low-power DC modules is related to the number of charging terminals in the charging station. The quantities are identical, meaning there is a one-to-one correspondence between the low-power DC modules and the charging terminals. Each low-power DC module is equipped with connectors for expansion, and each input module can connect up to three low-power DC modules. The input modules are connected and expanded using connectors and cables, allowing for on-the-spot upgrades to output capacity. Each low-power DC module is a minimum module unit, and three minimum module units form a large module unit. At the factory, they are assembled as a complete unit. On-site, it is only necessary to select the corresponding number of low-power DC modules according to power requirements and connect them via connectors and cables. The peak output power of each charging terminal is 21kW, including the vehicle-to-charging-pile communication unit and the charging capacity output unit.

[0043] like Figure 2As shown, the incoming line module includes a residual current circuit breaker QF1, a miniature circuit breaker QF2, a switching power supply UR1, and a communication and power distribution controller. The residual current circuit breaker QF1 is installed on the power line between the external AC power supply and the power distribution module, used for controlling the total power supply to the equipment (designed to meet a maximum power of 21kW). The input terminal of the switching power supply UR1 is connected to the external AC power supply, and the output terminal is connected to the communication and power distribution controller, supplying power to the control circuit. The miniature circuit breaker QF2 is installed on the line between the switching power supply UR1 and the external AC power supply, used for controlling the power supply to the control circuit. The communication and power distribution controller is used for power distribution control and network communication.

[0044] The power distribution module consists of several low-power DC modules. Several different system combinations are given below.

[0045] like Figure 3 The diagram shows a schematic of a power distribution module for a single-ended system. It includes a small-power DC module, designated as power distribution module #1, which consists of a single 7kW power module. The input of the 7kW power module is connected to the output of the input module via a power supply line. The output is connected to the power output bus. A set of power distribution relays, #1KM, is pre-installed on the power output bus. #1KM includes two relay contacts, #1KM1 and #1KM2, with a total output power of 7kW. It can connect to a charging terminal, i.e., charging terminal #1.

[0046] like Figure 4 The diagram shows a schematic of the power distribution module of a dual-end system. It includes two low-power DC modules, designated as Power Distribution Module 1 and Power Distribution Module 2, each consisting of two 7kW power modules. The input terminals of the two 7kW power modules are connected to the output terminals of the input module via a power input line, forming a parallel structure. The output terminal of each 7kW power module is connected to a set of power output buses. Each set of power output buses has a reserved set of power distribution relays, designated as 1#KM and 2#KM. 1#KM includes two relay contacts, 1#KM1 and 1#KM2, with an output power of 7kW, and can be connected to the 1# charging terminal. 2#KM includes two relay contacts, 2#KM1 and 2#KM2, with an output power of 7kW, and can be connected to the 2# charging terminal.

[0047] When the power station needs to be upgraded from a 7kW single-terminal system to a 14kW dual-terminal system, it is only necessary to connect the #2 power distribution module to the #1 power distribution module. This includes power supply, connection of power distribution relays #1 and #2 to the power output bus, signal harness connection, etc. The power output buses of the #1 and #2 power distribution modules are connected end to end through #1 and #2 respectively, so that the total output power can reach 14kW. The output of the #1 power distribution module corresponds to the #1 charging terminal, and the output of the #2 power distribution module corresponds to the #2 charging terminal.

[0048] like Figure 5 The diagram shows a power distribution module for a three-terminal system. When the power station needs to be upgraded from 14kW to 21kW (from two terminals to three terminals), the expansion can be carried out according to the diagram. The diagram includes three low-power DC modules, designated as Power Distribution Module 1, Power Distribution Module 2, and Power Distribution Module 3. Each module consists of three 7kW power modules. The input terminals of these three 7kW power modules are connected to the output terminals of the input module via a power input line, forming a parallel structure. The output terminal of each 7kW power module is connected to a set of power output buses. Each set of power output buses has a reserved set of power distribution relays, designated as 1#KM, 2#KM, and 3#KM. 1#KM includes two relay contacts, 1#KM1 and 1#KM2, with an output power of 7kW, and can be connected to the 1# charging terminal. 2#KM includes two relay contacts, 2#KM1 and 2#KM2, with an output power of 7kW, and can be connected to the 2# charging terminal. 3#KM includes two relay contacts, 3#KM1 and 3#KM2, with an output power of 7kW, and can be connected to the 3# charging terminal.

[0049] When the power station needs to be upgraded to a 21kW three-terminal system, it is only necessary to connect power module #3 to power module #2, power module #2 to power module #1, and power module #1 to power module #3. This includes power supply, connection of power distribution relays #1, #2, and #3 to the power output bus, and signal harness connection. The power output buses of power distribution modules #1, #2, and #3 are connected end-to-end through KM #1, KM #2, and KM #3 respectively, so that the total output power can reach 21kW. The output of power distribution module #1 corresponds to charging terminal #1, the output of power distribution module #2 corresponds to charging terminal #2, and the output of power distribution module #3 corresponds to charging terminal #3.

[0050] The above, Figure 3 , Figure 4 and Figure 5 The busbar diagram is simplified, showing only one line. In reality, it includes both positive and negative busbar lines forming a loop. Relay contacts are not shown in the diagram; please refer to [reference needed]. Figure 7Furthermore, the power distribution module in this embodiment adopts a very simple ring scheme. The connection method of the power distribution module can be selected according to the actual needs, such as the number of modules / terminals, and the power distribution function can be customized according to actual requirements.

[0051] like Figure 6 The diagram shows the principle of the charging terminal. Each charging terminal has the same structure, including a fuse (FUSE), a DC relay (KM), a shunt (FL), a charging gun, a meter (WH), a terminal controller, an RFID reader, and an emergency stop button (SB). The charging gun is connected to the power output bus of the power distribution module via a power line, forming the main power circuit. The fuse (FUSE) is located on the positive terminal of the main power circuit for short-circuit protection. The DC relay (KM) is located on the main power circuit and controls its activation and deactivation, thus achieving the charging control function. The DC relay (KM) has two contacts, KM1 and KM2, which are respectively connected to the positive terminal of the main power circuit. On the negative line, KM1 and KM2 operate simultaneously; the shunt FL, located on the negative line of the main power circuit and between the contact KM2 of the DC relay KM and the charging gun, is used to collect the current of the main power circuit; the meter WH, connected to the shunt FL and the copper busbar of the busbar, is used to collect the current and voltage values ​​on the main power circuit and communicates with the terminal controller via RS485 serial port; the RFID reader communicates with the terminal controller via RS232 serial port and is used to start charging by swiping a card; the emergency stop button SB is connected to the terminal controller via a line and is used to disconnect charging in case of abnormality; the terminal controller is used to control the internal devices of the control terminal and the vehicle-charging station communication. It communicates with the meter WH via RS485 serial port to read the voltage value on the meter; it receives the RFID signal from the card reader and uses it to control the contacts KM1 and KM2 of the DC relay to close, starting charging; when charging is complete, it controls the contacts KM1 and KM2 of the DC relay to open, stopping charging. Preferably, the charging terminal is a wall-mounted or column-mounted structure.

[0052] The structure of this utility model's split-type low-power DC charging system is illustrated below, using 21kW and 42kW fully-equipped systems as examples.

[0053] Example 1: 21kW Fully Equipped System

[0054] like Figure 7 As shown, this is a fully configured 21kW power system, which includes a low-power rectifier cabinet and a charging terminal. The low-power rectifier cabinet contains one incoming line module and three power distribution modules. Each power distribution module is connected to one charging terminal, i.e., power distribution module *3 and charging terminal *3.

[0055] Incoming Line Module: This module has a maximum unit power of 21kW and includes a residual current operated circuit breaker QF1 (total power supply for the equipment, designed to meet 21kW), a miniature circuit breaker QF2 (power supply for equipment control), a switching power supply UR1 (low-voltage power supply in the cabinet, AC220V to DC12V), and a communication and power distribution controller (with power distribution and networking functions).

[0056] Power Distribution Module: Three power distribution modules are connected in parallel on the output line of the residual current operated circuit breaker QF1. The power of a single power distribution module is 7kW, including the power input terminal (each phase has a branch line design), three 7kW power modules, a power output bus, and three power distribution relays 1#KM, 2#KM, and 3#KM. Among them, the two sets of contacts 1#KM1 and 1#KM2 of power distribution relay 1#KM are connected to the power output bus between the first and second power distribution modules. The two sets of contacts 2#KM1 and 2#KM2 of power distribution relay 2#KM are connected to the power output bus between the second and third power distribution modules. The two sets of contacts 3#KM1 and 3#KM2 of power distribution relay 3#KM are connected to the power output bus between the third and first power distribution modules.

[0057] Charging Terminals: There are three charging terminals, namely charging terminal #1, charging terminal #2, and charging terminal #3. Each charging terminal is designed with a peak power of 21kW. The charging terminal contains a fuse (short circuit protection element), a DC relay (main circuit closure control), a shunt (current sampling, used for billing), an electricity meter (metering and charging device), a card reader (card swipe start-up), an emergency stop button (emergency shutdown), a terminal controller (controlling the internal components of the terminal), and a charging gun (vehicle-charging station connection device).

[0058] Specifically, the #1 charging terminal includes fuse FUSE1, DC relay 1KM, shunt FL1, meter WH1, #1 terminal controller, RFID card reader 1, emergency stop button SB1, and #1 charging gun. The DC relay 1KM includes two sets of contacts, 1KM1 and 1KM2, with the connection relationship as follows: Figure 7 As shown.

[0059] The #2 charging terminal includes fuse FUSE2, DC relay 2KM, shunt FL2, meter WH2, #2 terminal controller, RFID card reader 2, emergency stop button SB2, and charging gun #2. The DC relay 2KM includes two sets of contacts, 2KM1 and 2KM2, with the connection relationship as follows: Figure 7 As shown.

[0060] The #3 charging terminal includes fuse FUSE3, DC relay 3KM, shunt FL3, meter WH3, #3 terminal controller, RFID card reader 3, emergency stop button SB3, and charging gun #3. The DC relay 3KM comprises two sets of contacts, 3KM1 and 3KM2, connected as follows: Figure 7 As shown.

[0061] Example 2: 42kW Fully Equipped System

[0062] like Figure 8 As shown, the difference between this embodiment and Embodiment 1 is that two 21kW fully-equipped systems are used to form a 42kW fully-equipped system.

[0063] The entire system includes two incoming line modules, namely incoming line module 1 and incoming line module 2. Each incoming line module connects to three 7kW power modules. The power distribution relays 1#KM, 2#KM, and 3#KM corresponding to incoming line module 1 have the same structure in the corresponding charging terminals as in Embodiment 1, and will not be described again here. The power distribution relays 4#KM, 5#KM, and 6#KM corresponding to incoming line module 2 correspond to three charging terminals, namely charging terminal 4, charging terminal 5, and charging terminal 6, as follows:

[0064] The #4 charging terminal includes fuse FUSE4, DC relay 4KM, shunt FL4, meter WH4, #4 terminal controller, RFID card reader 4, emergency stop button SB4, and charging gun #4. The DC relay 4KM includes two sets of contacts, 4KM1 and 4KM2, with the connection relationship as follows: Figure 8 As shown.

[0065] The #5 charging terminal includes a fuse (FUSE5), a DC relay (5KM), a shunt (FL5), a meter (WH5), a #5 terminal controller, an RFID card reader (RFID5), an emergency stop button (SB5), and a #5 charging gun. The DC relay (5KM) comprises two sets of contacts, 5KM1 and 5KM2, connected as follows: Figure 8 As shown.

[0066] The #6 charging terminal includes a fuse (FUSE6), a DC relay (6KM), a shunt (FL6), a meter (WH6), a #6 terminal controller, an RFID reader (6), an emergency stop button (SB6), and a #6 charging gun. The DC relay (6KM) comprises two sets of contacts, 6KM1 and 6KM2, connected as follows: Figure 8 As shown.

[0067] The above embodiments all use a fully configured system as an example. The specific quantity can be configured according to actual needs. For example, when only one charging gun is needed, the charging terminal and power distribution module can be configured as one group; when there are two charging guns, they can be configured as two groups. Every three groups require an additional incoming line module. When there is a fourth power distribution module unit / fourth charging gun, an additional rectifier cabinet-incoming line module is needed to provide power supply. Similarly, when there is a seventh group / 3N+1 group of power distribution (the 7th gun / the 3N+1th gun), a corresponding rectifier cabinet-incoming line module needs to be added, and so on. All power distribution modules can be connected through reserved connecting copper busbars, which can effectively connect all module groups together to maximize the utilization of the equipment.

[0068] Working principle explanation:

[0069] Taking a 21kW fully equipped system as an example, each power distribution module is 7kW. Each module's output section has a set of relays to combine the outputs of the two modules, thereby achieving power dispatching across the entire range from 7kW to 21kW. This can meet the demand for simultaneous charging of multiple vehicles and also improve the demand for rapid high-power charging of a single vehicle.

[0070] Based on this power level, the scenario is expanded as follows:

[0071] Scenario 1: Only one car is charging, charging space #1, and the required current is ≥21kW. In this case, the output power of charging terminal #1 is 21kW.

[0072] Scenario 2: Only one car is charging, charging space #1, and the required current is <21kW. In this case, the output power of charging terminal #1 is the corresponding demand of the car.

[0073] Scenario 3: There are two cars charging, in parking spaces 1 and 2 respectively. The current required by charging gun 1 is ≥14kW and the current required by charging gun 2 is ≥7kW and <14kW. In this case, the output power of charging terminal 1 is 14kW and the output power of charging terminal 2 is 7kW.

[0074] Scenario 4: There are two cars charging, one in parking space #1 and the other in parking space #2. The current required by charging gun #1 is ≥14kW and the current required by charging gun #2 is ≥14kW. Parking space #2 is charged first. At this time, the output power of charging terminal #1 is 7kW and the output power of charging terminal #2 is 14kW.

[0075] Scenario 5: Three vehicles have charging needs at the same time, corresponding to parking spaces 1#, 2#, and 3#. The corresponding demand is all >0kW, so the output of terminals 1#, 2#, and 3# is 7kW.

[0076] like Figure 7As shown, the rectifier cabinet has a power output of 21kW, each module has a power output of 7kW, and it is configured with three rectifier guns per unit. Figure 8 As shown, the rectifier cabinet is 42kW, with a single module of 7kW and a six-gun configuration. The diagram illustrates the most basic power distribution logic. Multiple guns can be based on full matrix power distribution, and can be simplified according to actual application requirements. In practice, the 42kW configuration can be further expanded based on needs, requiring only one incoming line module for every three power distribution modules and adjusting the connection of the first and second heads of the power distribution output section.

[0077] This utility model relates to a split-type low-power DC charging system:

[0078] 1. The power values ​​of a single module and the total power value of the rectifier cabinet can be adjusted accordingly, not limited to 21kW to 42kW. The total power can be expanded by stacking modules.

[0079] 2. The overall power distribution strategy and the number of charging interfaces can be adapted based on the total power value and the power value of a single module.

[0080] 3. Expandable modules are not limited to 7kW, and the power distribution design is not limited to the diagram. Adaptive development can be carried out based on the user's usage scenario.

[0081] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A split-type low-power DC charging system, characterized in that: The system comprises two parts: a low-power rectifier cabinet and a charging terminal. The low-power rectifier cabinet is connected to the charging terminal via a DC line. The low-power rectifier cabinet includes an input module and a power distribution module. There is at least one input module, each with a maximum power of 21kW. Its input terminal is connected to an external AC power source, and its output terminal is connected to the input terminal of the power distribution module. The power distribution module includes at least one low-power DC module with a power value of 7kW. Therefore, the total power of the power distribution module is an integer multiple of 7kW, and the number of low-power DC modules is the same as the number of charging terminals in the station. Each low-power DC module is equipped with a connector for expansion. Each input module can connect to a maximum of three low-power DC modules. Each charging terminal has a peak output power of 21kW and includes a vehicle-to-charging-pile communication unit and a charging capacity output unit.

2. The split-type low-power DC charging system as described in claim 1, characterized in that: The incoming line module includes a residual current operated circuit breaker QF1, a miniature circuit breaker QF2, a switching power supply UR1, and a communication and power distribution controller. The residual current operated circuit breaker QF1 is installed on the power line between the external AC power supply and the power distribution module, and is used for controlling the overall power supply to the equipment. The input terminal of the switching power supply UR1 is connected to the external AC power supply, and the output terminal is connected to the communication and power distribution controller, providing power to the control circuit. The miniature circuit breaker QF2 is installed on the line between the switching power supply UR1 and the external AC power supply, and is used for controlling the power supply to the control circuit. The communication and power distribution controller is used for power distribution control and network communication.

3. The split-type low-power DC charging system as described in claim 2, characterized in that: The 7kW module unit includes a power input terminal, a 7kW power module, a power output bus, and a power distribution relay. One end of the power input terminal is connected to the output terminal of the input module, and the other end is connected to one 7kW power module or two or three 7kW power modules connected in parallel. The output terminal of each 7kW power module is connected to the power output bus. The power output buses of different 7kW power modules are connected end to end by a set of power distribution relays.

4. The split-type low-power DC charging system as described in claim 3, characterized in that: Each of the aforementioned charging terminals includes a fuse, DC relays KM1 and KM2, a shunt, a charging gun, a meter, a terminal controller, a card reader, and an emergency stop button, wherein... The charging gun is connected to the power output bus of the power distribution module via a power cord to form the main power circuit. A fuse is installed on the positive line of the main power circuit for short-circuit protection. A DC relay is installed on the main power circuit to control the activation and deactivation of the main power circuit, thereby realizing the charging control function. The shunt is installed on the negative line of the main power circuit and located between the DC relay and the charging gun. It is used to collect the current of the main power circuit. The meter is connected to the copper busbar of the shunt and busbar to collect the current and voltage values ​​on the main power circuit and communicate with the terminal controller via RS485 serial port. The card reader communicates with the terminal controller via an RS232 serial port and is used to initiate charging by swiping a card. The emergency stop button is connected to the terminal controller via a line and is used to disconnect charging in case of an abnormal situation. The terminal controller is used to control the internal devices of the control terminal and for vehicle-to-pile communication.

5. The split-type low-power DC charging system as described in claim 1, characterized in that: The charging terminal can be wall-mounted or column-mounted.

Images