Electric vehicle charging system and method

Abstract

An electric vehicle charging system and method includes: a controller, a power unit, an auxiliary charging unit, and at least one charging pile; the auxiliary charging unit provides a target charging voltage and a set charging current to a target electric vehicle via a target charging pile, the set charging current being less than the current provided by the power unit when charging the target electric vehicle; the controller controls the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle via the target charging pile, and then controls the power unit to stop charging the target electric vehicle; when the target electric vehicle resumes charging, the power unit controls the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle via the target charging pile after charging the target electric vehicle. Utilizing the system provided by this application, charging of an electric vehicle can be suspended at any time, and charging of the electric vehicle can be resumed without user intervention.

Description

Technical Field

[0001] The present application relates to the field of electric vehicle charging, and in particular to an electric vehicle charging system and method. Background Art

[0002] With the gradual development and increasing popularity of electric vehicles, charging power requirements are increasing to enable faster charging. Peak charging times can further strain the entire power system. Failure to impose limits on the charging load provided to electric vehicles will inevitably increase investment in power generation facilities and transmission and distribution infrastructure. Furthermore, peak EV charging loads can also cause overloads on local distribution transformers, leading to increased transformer temperatures and accelerated transformer wear, ultimately compromising power system reliability.

[0003] Some automakers are currently calling for using a battery management system (BMS) to actively suspend charging, or using charging piles to passively suspend charging. This allows for charging to be suspended during peak hours or when the electric vehicle's power battery overheats. However, since the BMS and / or charging pile cannot maintain the charging voltage requested by the electric vehicle's power battery during active or passive charging pauses, the BMS will determine that the charging pile has stopped outputting power and enter a dormant state. When the charging pile resumes charging, the BMS will have already entered a dormant state, requiring the charging cable to be manually reconnected to wake it up. This results in an inflexible charging resumption process and a poor user experience.

[0004] In view of this, it is necessary to propose a new electric vehicle charging system that can not only suspend charging of electric vehicles at any time under different working conditions, but also resume charging of electric vehicles without user participation. Summary of the Invention

[0005] The present application provides an electric vehicle charging system and method, which can be used to pause charging of the electric vehicle at any time and resume charging of the electric vehicle without user intervention.

[0006] In a first aspect, the present application provides an electric vehicle charging system, which includes: a controller, a power unit, an auxiliary charging unit and at least one charging pile, the power unit being connected to a power supply; the power unit being used to charge the electric vehicle connected to the at least one charging pile; the auxiliary charging unit being used to provide a target charging voltage and a set charging current to the target electric vehicle through the target charging pile; the target electric vehicle is an electric vehicle whose charging is suspended, the target charging pile is connected to the target electric vehicle, the target charging voltage is the rated charging voltage requested by the target electric vehicle, and the set charging current is less than the rated charging current provided by the power unit when charging the target electric vehicle; the controller being used to determine the target electric vehicle whose charging is suspended, controlling the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, and then controlling the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, controlling the power unit to charge the target electric vehicle through the target charging pile, and then controlling the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

[0007] The auxiliary charging unit in the electric vehicle charging system of the present application provides a target charging voltage and a set charging current to the target electric vehicle through the target charging pile. The target charging voltage is the same as the charging voltage requested by the target electric vehicle connected to the target charging pile, and the set charging current is less than the current provided by the power unit when charging the target electric vehicle connected to the target charging pile. This minimizes the power usage of the target electric vehicle during charging suspension without causing the BMS to enter a dormant state.

[0008] As a possible implementation method, the target electric vehicle for suspending charging is determined, and the controller is specifically used to: after receiving the charging suspension instruction sent by the target electric vehicle, determine the charging pile connected to the target electric vehicle as the target charging pile. In order to prevent the power battery of the electric vehicle from overheating, when the temperature of the power battery is too high, the BMS in the target electric vehicle will send a charging suspension instruction (i.e., an over-temperature protection mechanism) to the controller. Thereby protecting the charging safety of the target electric vehicle. After the temperature of the power battery in the target electric vehicle returns to normal, a charge resumption instruction is sent to the controller to quickly resume charging.

[0009] In addition, based on the electric vehicle charging system provided by this application, users can set a scheduled charging mode in the BMS, that is, after the electric vehicle is connected to the charging pile, a pause charging instruction is first sent to the controller to stop charging the electric vehicle. When it reaches the night when the electricity consumption is low, the controller sends a resume charging instruction to resume charging the electric vehicle, thereby completing the pause and resume switching of the electric vehicle without human intervention to reduce charging costs.

[0010] To achieve active peak shaving on the power grid and thus prevent transformers connected to the grid from exceeding load limits, one possible implementation involves determining a target electric vehicle for which charging should be suspended. The controller is specifically configured to, when the load rate of the power supply exceeds a load rate threshold, select a target electric vehicle from among the electric vehicles connected to at least one charging station according to preset rules. The controller can obtain the grid's rated load data from the charging operations platform and the power platform, and then obtain station load data from station meters. The current load rate is determined based on the rated load data and station load data. By suspending charging for the target electric vehicle, the load rate of the power supply is reduced to below the load rate threshold, thereby avoiding problems such as transformer overheating and accelerated losses caused by excessive load rates. Charging for the target electric vehicle is then resumed after the load rate has been reduced again.

[0011] In order to achieve optimal power allocation, as a possible implementation method, a target electric vehicle for suspending charging is determined, and the controller is specifically used to: when any one of the at least one charging piles is connected to an electric vehicle of a set type, select the target electric vehicle from the electric vehicles connected to the at least one charging pile according to preset rules.

[0012] As a possible implementation method, the power unit includes multiple power modules, and each of the multiple power modules is assigned a rated power size; when charging an electric vehicle connected to at least one charging pile, the power unit is specifically used to: assign a target power module group to the electric vehicle connected to the charging pile, and the target power module group includes at least one power module among the multiple power modules; the preset rule is: select the target electric vehicle from the electric vehicles connected to the at least one charging pile according to the power utilization rate of the electric vehicle connected to the charging pile, and the power utilization rate is the ratio of the rated charging power of the electric vehicle connected to the charging pile to the sum of the rated powers of the target power module group.

[0013] In the above embodiment, the rated power allocated to each power module in the at least one power module can be the same or different, thereby meeting the charging needs of electric vehicles with different charging power in a single or combined manner and improving power utilization.

[0014] In addition, the preset rules may also include, but are not limited to: sorting the electric vehicles connected to the charging piles according to their current power levels, and determining the electric vehicle with the highest current power level among the connected electric vehicles as the target electric vehicle; sorting the electric vehicles connected to the charging piles according to their charging power levels, and determining the electric vehicle with the lowest charging power level among the connected electric vehicles as the target electric vehicle.

[0015] As a possible implementation, the system also includes: at least one first switch and at least one second switch; each first switch is connected between the power unit and the electric vehicle connected to at least one charging pile, and each second switch is connected between the auxiliary charging unit and the electric vehicle connected to at least one charging pile.

[0016] As a possible implementation manner, the controller is specifically used to: determine a target electric vehicle for suspending charging, close a second switch connected to the target electric vehicle, control the auxiliary charging unit to provide a target charging voltage and a set charging current to the target electric vehicle through a target charging pile, disconnect a first switch connected to the target electric vehicle, and control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, close the first switch connected to the target electric vehicle, control the power unit to charge the target electric vehicle through the target charging pile, disconnect the second switch connected to the target electric vehicle, and control the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

[0017] By controlling the order in which the first and second switches connected to the target charging pile are turned off, it is possible to ensure that the BMS does not accidentally enter a dormant state due to power outages during the process of switching the charging current between the power unit and the auxiliary charging unit. During the process of suspending charging of the target electric vehicle, the auxiliary charging unit first provides the target charging voltage and set charging current to the target electric vehicle, and then the power unit stops charging the target electric vehicle. During the process of resuming charging of the target electric vehicle, the controller can first control the power unit to charge the target electric vehicle, and then control the auxiliary charging unit to stop providing the target charging voltage and set charging current to the target electric vehicle.

[0018] As a possible implementation method, the power unit includes an AC-DC circuit and a DC-DC circuit; the AC-DC circuit is used to convert the AC power provided by the power supply into DC power; the DC-DC circuit is used to adjust the DC power converted by the AC-DC circuit to the charging voltage requested by the electric vehicle connected to the charging pile.

[0019] As a possible implementation, the auxiliary charging unit includes at least one auxiliary power supply; any one of the at least one auxiliary power supply is used to provide a target charging voltage and a set charging current to a target electric vehicle through a target charging pile.

[0020] To save costs, the auxiliary charging unit can include only one auxiliary power supply, which is connected to each electric vehicle on at least one charging pile. The auxiliary charging unit can maintain the charging status of a target electric vehicle to extend the charging time, thereby allowing the BMS in the target electric vehicle to remain in a charging state and not enter a dormant state. The number of auxiliary power supplies is less than the number of at least one charging pile, and the auxiliary power supply can be connected to at least one charging pile. In this way, the auxiliary charging unit can also maintain the charging status of multiple target electric vehicles to extend the charging time, thereby allowing the BMS in multiple target electric vehicles to remain in a charging state and not enter a dormant state.

[0021] As one possible implementation, the auxiliary charging unit includes at least one diode, one-to-one with at least one auxiliary power source. The anode of each diode is connected to the output of the auxiliary power source, and the cathode of each diode is connected to the input of the charging station. By placing a diode at the output of the auxiliary power source, functions such as backflow prevention and reverse current prevention can be implemented.

[0022] The BMS can send a message carrying the rated charging voltage and the rated charging current to the charging side according to the rated charging voltage and the rated charging current provided by the charging management strategy of the vehicle. As a possible implementation method, the battery management system is used to: send a charging request to the controller, where the charging request carries the rated charging voltage and the rated charging current.

[0023] In addition, since the present application uses an auxiliary charging unit to provide the target charging voltage and set charging current to the target electric vehicle through the target charging pile, the BMS can be prevented from entering a dormant state. As a possible implementation method, the controller is further used to: when determining the target electric vehicle to suspend charging, send a charging suspension parameter message to the battery management system of the target electric vehicle, the charging suspension parameter message carrying the target charging voltage and set charging current; when the target electric vehicle resumes charging, send a charging resumption parameter message to the battery management system of the target electric vehicle, the charging resumption parameter message carrying the charging voltage and charging current provided by the power unit to the target electric vehicle through the target charging pile.

[0024] In order to improve the redundancy of the electric vehicle charging system, as a possible implementation method, the controller includes: a power controller and an auxiliary source controller; the auxiliary source controller is used to: determine the target electric vehicle for suspending charging, and control the auxiliary charging unit to provide the target charging voltage and set charging current to the target electric vehicle through the target charging pile; the power controller is used to: after the auxiliary charging unit provides the target charging voltage and set charging current to the target electric vehicle through the target charging pile, control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, control the power unit to charge the target electric vehicle through the target charging pile; the auxiliary source controller is also used to: after the power unit resumes charging the target electric vehicle, control the auxiliary charging unit to stop providing the target charging voltage and set charging current to the target electric vehicle through the target charging pile.

[0025] In a second aspect, the present application provides an electric vehicle charging method, which is applied to any electric vehicle charging system of the first aspect, and the method includes:

[0026] Determine the target electric vehicle for which charging is suspended, control the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, and then control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, control the power unit to charge the target electric vehicle through the target charging pile, and then control the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

[0027] The technical effects that can be achieved in the second aspect can be described with reference to the effects that can be achieved by each possible design in the first aspect mentioned above, and these aspects or other aspects of the present application will be more concise and easy to understand in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of charging an electric vehicle;

[0029] Figure 2 A schematic diagram of the structure of an electric vehicle charging system Figure 1 ;

[0030] Figure 3 A schematic diagram of the structure of an electric vehicle charging system Figure 2 ;

[0031] Figure 4 A schematic diagram of the structure of an electric vehicle charging system Figure 3 ;

[0032] Figure 5A A schematic diagram of the structure of an auxiliary charging unit in an electric vehicle charging system Figure 1 ;

[0033] Figure 5B A schematic diagram of the structure of an auxiliary charging unit in an electric vehicle charging system Figure 2 ;

[0034] Figure 5C A schematic diagram of the structure of an auxiliary charging unit in an electric vehicle charging system Figure 3 ;

[0035] Figure 6 A schematic diagram of the structure of an electric vehicle charging system Figure 4 ;

[0036] Figure 7 A schematic diagram of a complete pause / resume charging process for an electric vehicle. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be understood as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided to make the present application more comprehensive and complete, and to fully convey the concepts of the example embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in this application are all explained using the accompanying drawings as examples, but changes can be made as needed, and all changes are included in the scope of protection of this application. The drawings in this application are only used to illustrate relative position relationships and do not represent true proportions.

[0038] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operating methods in the method embodiments can also be applied to device embodiments or system embodiments. It should be noted that in the description of the present application, "at least one" refers to one or more, wherein a plurality refers to two or more. In view of this, "a plurality" can also be understood as "at least two" in the embodiments of the present application. In addition, it should be understood that in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0039] It should be noted that in the embodiments of the present application, "connection" refers to electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components. For example, the connection between A and B can also be a direct connection between A and C, and C and B can be directly connected, with A and B connected through C.

[0040] Electric vehicles, also known as new energy vehicles, are vehicles that are powered by electricity. Figure 1 As shown, the electric vehicle 10 mainly includes a battery management system (BMS) 11 , a power battery 12 , a motor 13 and wheels 14 .

[0041] Among them, the power battery 12 is a large-capacity, high-power battery. The power battery 12 can provide electrical energy to some or all components of the electric vehicle 10. In some examples, the power battery 12 can be composed of one or more rechargeable lithium-ion or lead-acid batteries. In addition, the power battery 12 can also use other battery materials and configurations, which are not limited here. When the electric vehicle 10 is running, the power battery 12 can power the motor 13 through the motor controller (MCU) in the battery management system 11. The motor 13 converts the electrical energy provided by the power battery 12 into mechanical energy, thereby driving the wheels 14 to rotate, thereby realizing the running of the electric vehicle 10.

[0042] When the electric vehicle 10 is charged, the power battery 12 of the electric vehicle 10 can generally be charged through the charging pile 20. Figure 1 As shown, the charging pile 20 mainly includes a charging circuit ( Figure 1 The charging station 20 includes a charging gun 21 (not shown). One end of the charging circuit is connected to the power grid 30, and the other end is connected to the charging gun 21 via a cable. The operator can insert the charging gun 21 into the charging socket of the electric vehicle 10 to connect the charging gun 21 to the battery management system 11 in the electric vehicle 10. The power circuit of the charging station 20 can then charge the power battery 12 through the charging gun 21.

[0043] After the charging gun 21 is inserted into the charging socket, the battery management system 11 establishes communication with the charging circuit to determine the power supply capacity of the charging pile 20 and the type of charging cable connecting the charging pile 20 and the battery management system 11; after the battery management system 11 completes the relevant charging configuration according to the power supply capacity and output power of the charging pile 20, the battery management system 11 controls the on-board charger (OBC) inside the electric vehicle 10 to receive the power provided by the charging pile 20, thereby charging the power battery 12.

[0044] To achieve rapid charging of electric vehicles, the charging power of electric vehicles has gradually increased. During peak charging times, the higher power input from electric vehicles can further strain the entire power system. Currently, some automakers are proposing to use a battery management system 11 to actively suspend charging, or a charging station 20 to passively suspend charging. However, according to the national standard "Electric Vehicle Conductive Power Supply System Standard," when the charging station 20 is not supplying power to the electric vehicle 10, the battery management system 11 in the electric vehicle 10 enters a dormant state to prevent the power battery 12 from running low, thereby conserving energy. At this point, to resume charging the power battery 12, a human must be present on-site to reconnect the charging plug 21 to the electric vehicle 10's charging port or restart the electric vehicle 10 or charging station 20 to wake up the battery management system 11 and resume charging. Currently, waking up the battery management system 11 requires manual intervention, resulting in a poor user experience. Therefore, there is an urgent need for a new electric vehicle charging system that can both suspend charging of the electric vehicle at any time under different operating conditions and resume charging without user intervention.

[0045] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0046] See Figure 2 As shown, the present application provides an electric vehicle charging system 200, which includes: a controller 201, a power unit 202, an auxiliary charging unit 203 and at least one charging pile 204, wherein the power unit 202 is connected to a power supply 205; the power unit 202 is used to charge the electric vehicle connected to the at least one charging pile 204.

[0047] The auxiliary charging unit 203 is used to: provide a target charging voltage and a set charging current to the target electric vehicle 2042 through the target charging pile 2041; the target electric vehicle 2042 is an electric vehicle that has suspended charging, the target charging pile 2041 is connected to the target electric vehicle 2042, the target charging voltage is the rated charging voltage requested by the target electric vehicle 2042, and the set charging current is less than the rated charging current provided by the power unit 202 when charging the target electric vehicle 2042.

[0048] The controller 201 is used to: determine the target electric vehicle 2042 that has suspended charging, control the auxiliary charging unit 203 to provide the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041, and then control the power unit 202 to stop charging the target electric vehicle 2042 through the target charging pile 2041; when the target electric vehicle 2042 resumes charging, control the power unit 202 to charge the target electric vehicle through the target charging pile 2041, and then control the auxiliary charging unit 203 to stop providing the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041.

[0049] Each of the at least one charging pile 204 may include: a charging display module and a plurality of charging guns; wherein each charging gun is used to connect to an electric vehicle and provide the electric energy received from the charging pile to the power battery of the electric vehicle.

[0050] The power supply 205 in the embodiment of the present application is a power source for supplying electric energy from fixed facilities (such as buildings, power grids) to electric vehicles, and it needs to meet the charging mode and connection method specified by the charging standard. In addition, the power supply 205 can also be a power frequency power grid, or it can be connected to the power frequency power grid to receive the power provided by the power frequency power grid, thereby providing a stable output for the electric vehicle. The following embodiment is introduced by taking the power supply 205 as an example of a power grid. After the charging pile is connected to the electric vehicle, it provides power to the power battery of the electric vehicle. In addition to providing power to the power battery, it can also power the on-board electrical equipment of the electric vehicle (such as car audio, car navigation system, etc.). The power supply 205 and the power unit 202 can be connected using a charging cable. Among them, the charging cable can be part of the power unit 202 or part of the power supply 205. In addition, the charging cable can also be a detachable structure, independent of the power unit 202 and the power supply 205. Those skilled in the art should know that there is no excessive limitation here.

[0051] The controller 201 can be a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute the various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The above-mentioned processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of DSP and microprocessor, and the like. The controller 201 can be divided into multiple sub-controllers in a distributed form and arranged on the power unit 202 and / or the auxiliary charging unit 203 to improve the redundancy of the electric vehicle charging system 200.

[0052] The power unit 202 is used to convert the electrical energy provided by the power supply 205 into the voltage and current required by the electric vehicle or the BMS in the electric vehicle, thereby providing stable charging for the electric vehicle. For example, the power unit 202 may include an AC-DC circuit and a DC-DC circuit. The AC-DC circuit is used to convert the alternating current provided by the power supply 205 into direct current; the DC-DC circuit is used to adjust the direct current converted by the AC-DC circuit to the charging voltage requested by the electric vehicle connected to the charging station.

[0053] Since the power battery capacity and required charging power of various electric vehicles vary, the output power requirements of the power unit 202 vary greatly. To meet the charging needs of various electric vehicles, the output power of the power unit 202 is designed to be very large. However, when charging electric vehicles with smaller power battery capacity / required charging power, charging power will be wasted, resulting in low power utilization. If the output power of the power unit 202 is designed to be smaller, although power utilization can be improved, charging time will be extended when charging electric vehicles with larger power battery capacity / required charging power, which is very inconvenient. As a possible implementation, the power unit 202 may include multiple power modules, each of which corresponds to a rated charging power. When charging an electric vehicle with a smaller power battery capacity / required charging power, the power module with the smaller rated charging power is used to charge the electric vehicle. When charging an electric vehicle with a larger power battery capacity / required charging power, the power module with the larger rated charging power is used to charge the electric vehicle. This not only meets the charging needs of electric vehicles with different power battery capacities and different charging power, but also further improves power utilization.

[0054] As the charging power of electric vehicles gradually increases, the electric vehicle charging system 200 can proactively suspend charging for certain electric vehicles when the power grid's load is at its peak, thereby reducing the transformer load peak and preventing problems such as transformer overheating and accelerated loss caused by excessive load factors. When the load factor decreases again, power is resumed for the previously paused electric vehicles. It should be noted that the reasons for the electric vehicle charging system 200 to proactively suspend charging for certain electric vehicles are not limited to those described in the above embodiments and are not defined herein.

[0055] Furthermore, some electric vehicles require a BMS to automatically pause charging. Reasons for BMS pausing charging include, but are not limited to, overheating of the power battery to protect the battery, manually setting a scheduled charging time to stagger charging and reduce charging costs, and other reasons. It should also be noted that the reasons for BMS actively pausing charging are not limited to those described in the above embodiments and are not defined here.

[0056] Under existing technology, if the electric vehicle charging system 200 wants to suspend charging the electric vehicle, it will directly stop inputting power to the electric vehicle's power battery. However, since the charging voltage and charging current input to the electric vehicle by the power unit 202 have both become zero, and according to the provisions of the "Electric Vehicle Conductive Power Supply System Standard", if the required charging voltage cannot be maintained for the electric vehicle's power battery, the BMS will determine that there is no output from the charging pile after detection. At this time, the BMS will enter a dormant state and actively stop charging. To resume charging, the user needs to manually re-insert the charging plug to wake up the BMS and resume charging the electric vehicle.

[0057] To address the above-mentioned issues, the auxiliary charging unit 203 in the electric vehicle charging system 200 of the present application provides a target charging voltage and a set charging current to the target charging vehicle 2042. The target charging voltage is the same as the charging voltage requested by the target electric vehicle 2042, and the set charging current is less than the current provided by the power unit 202 when charging the target electric vehicle 2042. This minimizes the power usage of the electric vehicle whose charging is suspended without causing the BMS to enter a dormant state.

[0058] In other words, to prevent the BMS from entering a dormant state, the auxiliary charging unit 203 provides the same charging voltage as the power unit 202 to the target electric vehicle 2042, compared to using the power unit 202 to power the target charging station 2041. To reduce the power consumed by the target electric vehicle 2042, the charging current of the auxiliary charging unit 203 needs to be reduced. Therefore, the charging current provided by the auxiliary charging unit 203 to the target electric vehicle 2042 can be adjusted to be significantly less than the charging current provided by the power unit 202. For example, if the charging voltage required by the target electric vehicle 2042 connected to the target charging station 2041 is in the range of 200-1000V, the charging current provided by the auxiliary charging unit 203 to the target electric vehicle 2042 can be reduced to less than 50mA. This reduces the actual power consumed by the target electric vehicle 2042, allowing the BMS to minimize power consumption without entering a dormant state.

[0059] It should be noted that the auxiliary charging unit 203 can also share the power supply 205 with the power unit 202. Exemplarily, the auxiliary charging unit 203 can also include an AC-DC circuit and a DC-DC circuit, so as to adjust the DC / AC power provided by the power supply 205 to the charging voltage and set charging current requested by the electric vehicle connected to the charging pile.

[0060] In order to ensure that the BMS does not accidentally enter a dormant state due to power failure during the process of switching the charging current between the power unit 202 and the auxiliary charging unit 203, when suspending charging for the target charging pile 2041, the controller 201 can first control the auxiliary charging unit 203 to provide the target electric vehicle 2042 with the target charging voltage and the set charging current, and then control the power unit 202 to stop charging the target electric vehicle 2042. In the process of resuming charging for the target electric vehicle 2042, the controller 201 can first control the power unit 202 to charge the target electric vehicle 2042, and then control the auxiliary charging unit 203 to stop providing the target electric vehicle 2042 with the target charging voltage and the set charging current.

[0061] As a possible implementation manner, the target electric vehicle 2042 for suspending charging is determined, and the controller 201 is specifically configured to: determine the electric vehicle that sends the charging suspension instruction as the target electric vehicle 2042.

[0062] The reasons for triggering the target electric vehicle 2042 to send a charging pause instruction to the controller 201 may include, but are not limited to, the following:

[0063] Reason 1: To prevent the electric vehicle's power battery from overheating, the BMS is equipped with a temperature sampling module. This module is used to monitor the temperature of the electric vehicle's power battery in real time. If the temperature of the power battery is too high, the BMS in the target electric vehicle 2042 will send a charging pause instruction to the controller 201 (i.e., an overtemperature protection mechanism). This protects the charging safety of the target electric vehicle 2042. After the temperature of the power battery in the target electric vehicle 2042 returns to normal, a charge resumption instruction is sent to the controller 201 to quickly resume charging.

[0064] Reason 2: BMS implements scheduled charging. In order to perform load peak shaving, the power supply 205 sets different prices for electricity prices in different time periods. For example, the price of electricity in the evening (18:00-21:00) when electricity consumption is at its peak will be much higher than that at night (01:00-04:00) when electricity consumption is at its trough. Assuming that it takes 3 hours to fully charge an electric car with rated power, the cost of charging can be significantly reduced if the electric car is charged at night when electricity consumption is at its trough, compared to charging the electric car in the evening when electricity consumption is at its peak. However, users usually connect electric cars to charging piles at night. Under the existing technology, if the switching between suspending charging and resuming charging cannot be completed well, the electric car can only be charged after it is connected to the charging pile through a charging gun. In this way, it is difficult to achieve the goal of reducing charging costs. Based on the electric vehicle charging system 200 provided in the present application, the user can set a scheduled charging mode in the BMS, that is, after the electric vehicle is connected to the charging pile through the charging gun, a pause charging instruction is first sent to the controller 201 to stop charging the electric vehicle. When it reaches the night when the electricity consumption is off, the controller 201 sends a resume charging instruction to resume charging the electric vehicle, thereby completing the pause and resume switching of the electric vehicle without human intervention, thereby reducing the charging cost.

[0065] Reason three: BMS achieves orderly charging. Orderly charging refers to the use of practical and effective economic or technical measures to guide and control the orderly charging of electric vehicles, while meeting the charging needs of electric vehicles, thereby shaving the load curve and reducing the cost of power generation capacity construction. In this application, the BMS makes a judgment based on the load curve of the power grid. After the electric vehicle is connected to the charging pile, it allocates a charging time period for the electric vehicle. During the charging stop period, it sends a charging pause instruction to the controller 201, and during the charging period, it sends a charging resume instruction to the controller 201.

[0066] According to the provisions of the "Electric Vehicle Conductive Power Supply System Standard", the BMS can send a message carrying the rated charging voltage and rated charging current to the charging side based on the rated charging voltage (currently the highest allowable charging voltage) and rated charging current (currently the highest allowable charging current) provided by the vehicle's charging management strategy. As a possible implementation method, the battery management system is used to: send a charging request to the controller, and the charging request carries the rated charging voltage and rated charging current.

[0067] In addition, since the present application uses the auxiliary charging unit 203 to provide the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041, the BMS can be prevented from entering a dormant state. As a possible implementation, the controller 201 is further used to: when determining that the target electric vehicle 2042 is to suspend charging, send a charging suspension parameter message to the battery management system of the target electric vehicle 2042, the charging suspension parameter message carrying the target charging voltage and the set charging current; when the target electric vehicle resumes charging, send a charging resumption parameter message to the battery management system of the target electric vehicle, the charging resumption parameter message carrying the charging voltage and charging current provided by the power unit to the target electric vehicle through the target charging pile.

[0068] Similarly, according to the provisions of the "Electric Vehicle Conductive Power Supply System Standard," when the target electric vehicle is determined to have suspended charging, the controller 201 in the electric vehicle charging system 200 on the charging side can send / feed back the charging voltage and charging current provided by the auxiliary charging unit 203 to the target electric vehicle 2042 in the form of a message to the BMS. Furthermore, when the target electric vehicle 2042 resumes charging, the charging voltage and charging current of the target electric vehicle 2042 provided by the power unit 202 can be sent / feed back to the BMS in the form of a message.

[0069] In the above embodiment, the BMS and the controller 201 can establish communication through wired transmission or wireless transmission: the charging pause instruction, the charging resume instruction, and the message (carrying the current value & voltage value) can establish communication through wired transmission or wireless transmission. For example, wired transmission may include: wired local area network (LAN), serial bus, controller area network (CAN), and power line communication (PLC), and wireless transmission may include 6G\5G\4G\3G\2G, general packet radio service (GPRS), wireless network (WiFi), Bluetooth, Zigbee, and infrared.

[0070] To achieve active peak shaving on the power grid and thereby prevent excessive load on transformers connected to the power grid, as a possible implementation, the target electric vehicle 2042 for charging suspension is determined by the controller 201, which is specifically configured to: when the load on the power supply 205 exceeds a load threshold, select the target electric vehicle 2042 from the electric vehicles connected to the at least one charging pile 204 according to a preset rule. The controller 201 may obtain the current load on the power grid from a station controller. The station controller may obtain rated load data on the power grid via the charging operation platform and the power platform, and then obtain station load data via the station meter. The current load rate is determined based on the rated load data and the station load data.

[0071] By suspending charging for the target electric vehicle 2042, the load rate of the power supply 205 is reduced to below the load rate threshold, thereby avoiding problems such as transformer overheating and accelerated loss caused by excessive load rate. After the load rate is reduced again, power supply to the target electric vehicle 2042 is resumed. The preset rule can prioritize the charging piles according to their priority, determining the charging pile with the lowest priority as the target charging pile 2041, and the electric vehicle connected to it as the target electric vehicle 2042. Alternatively, the preset rule can prioritize the electric vehicles connected to the charging piles according to their priority, with the electric vehicle with the lowest priority being determined as the target electric vehicle 2042.

[0072] In order to achieve optimal power allocation, as a possible implementation method, the target electric vehicle 2042 to be suspended from charging is determined, and the controller 201 is specifically used to: when any one of the at least one charging pile 204 is connected to an electric vehicle of a set type, select the target electric vehicle 2042 from the electric vehicles connected to the at least one charging pile 204 according to preset rules.

[0073] Among them, the set type of electric vehicles may include, but are not limited to: electric vehicles that support supercharging and electric vehicles that pay a charging price higher than the normal price, etc. The technical indicators of the supercharging (high-power DC fast charging) refer to the charging voltage reaching 1000V, the charging current reaching 120A, and the charging power being greater than or equal to 120KW under the non-cooling working condition, and the charging current reaching 400A~500A and the charging power being greater than or equal to 350KW under the cooling working condition. When the above-mentioned type of electric vehicle is connected to the at least one charging pile 204, the charging of the target electric vehicle 2042 is suspended, so that the power unit 202 gives priority to charging the electric vehicle connected to the above-mentioned type of vehicle.

[0074] See Figure 3As shown, as a possible implementation, the power unit 202 includes multiple power modules 2021, and each power module in the multiple power modules 2021 is assigned a rated power size; when charging an electric vehicle connected to the at least one charging pile, the power unit 202 is specifically used to: assign a target power module group 2022 to the charging pile, and the target power module group 2022 includes at least one power module in the multiple power modules. It should be noted that the rated power assigned to each power module in the at least one power module can be the same or different, and this is not limited here. Those skilled in the art can set power modules with different rated powers, thereby meeting the charging needs of electric vehicles with different charging powers in a single or combined manner and improving power utilization.

[0075] The preset rule is: the target electric vehicle 2042 is selected from the electric vehicles connected to the at least one charging pile 204 according to the power utilization rate of the electric vehicle connected to the charging pile, and the power utilization rate is the ratio of the rated charging power of the electric vehicle connected to the charging pile to the sum of the rated powers of the target power module group 2022. For example, if the rated power of an electric vehicle connected to the charging pile is 10KW, and the sum of the rated powers of the target power module group 2022 allocated to the electric vehicle is 50KW, then the power utilization rate of the electric vehicle is 20% (10KW / 50KW). When other charging piles are connected to electric vehicles with a rated power of more than 10KW (such as 30KW), the target power module group 2022 can be reallocated to the newly connected electric vehicle, and the power utilization rate can be significantly improved.

[0076] In addition, the preset rules may also include but are not limited to:

[0077] Rule 1: Sort the electric vehicles connected to the charging piles according to their current power levels, and determine the charging pile connected to the electric vehicle with the highest current power level as the target charging pile 2041 .

[0078] Rule 2: Sort the electric vehicles connected to the charging piles according to their charging powers, and determine the charging pile connected to the electric vehicle with the lowest charging power among the connected electric vehicles as the target charging pile 2041 .

[0079] As a possible implementation, see Figure 4As shown, the electric vehicle charging system 200 also includes: at least one first switch 401 and at least one second switch 402; each first switch 401 is connected between the power unit 202 and the electric vehicle connected to the at least one charging pile 204, and each second switch 402 is connected between the auxiliary charging unit 203 and the electric vehicle connected to the at least one charging pile 204.

[0080] The controller 201 is specifically configured to: determine the target electric vehicle 2042 to be suspended from charging, close the second switch 402 connected to the target electric vehicle 2042, control the auxiliary charging unit 203 to provide the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041, disconnect the first switch 401 connected to the target electric vehicle 2042, and control the power unit 202 to stop charging the target electric vehicle 2042 through the target charging pile 2041;

[0081] When the target electric vehicle 2042 resumes charging, after closing the first switch 401 connected to the target electric vehicle 2042, the power unit 202 is controlled to charge the target electric vehicle 2042 through the target charging pile 2041, and then the second switch 402 connected to the target electric vehicle 2042 is disconnected, and the auxiliary charging unit 203 is controlled to stop providing the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041.

[0082] By controlling the order in which the first switch 401 and the second switch 402 connected to the target electric vehicle 2042 are turned off, it is possible to ensure that the BMS will not accidentally enter a dormant state due to power failure during the process of switching the charging current between the power unit 202 and the auxiliary charging unit 203. During the process of suspending charging of the target electric vehicle 2042, the auxiliary charging unit 203 first provides the target charging voltage and the set charging current to the target electric vehicle 2042, and then the power unit 202 stops charging the target electric vehicle 2042. During the process of resuming charging of the target electric vehicle 2042, the controller 201 can first control the power unit 202 to charge the target electric vehicle 2042, and then control the auxiliary charging unit 203 to stop providing the target charging voltage and the set charging current to the target electric vehicle 2042.

[0083] As a possible implementation, the auxiliary charging unit 203 includes at least one auxiliary power supply 2031, and any one of the at least one auxiliary power supply 2031 is used to provide the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041.

[0084] See Figure 5A As shown, in order to save costs, the auxiliary charging unit 203 may include only one auxiliary power supply 2031, and each of the auxiliary power supplies 2031 is connected to the at least one charging pile 204. The auxiliary charging unit 203 can maintain the charging state of an electric vehicle connected to the target charging pile 2041 to extend the charging time, thereby allowing the BMS in the target electric vehicle 2042 connected to the target charging pile 2041 to maintain the charging state and not enter the dormant state.

[0085] See Figure 5B As shown, the auxiliary charging unit 203 may further include a plurality of auxiliary power supplies 2031, wherein the number of the auxiliary power supplies 2031 is less than the number of the at least one charging pile 204 (or the charging guns on the at least one charging pile 204). The auxiliary power supply 2031 is connected to the at least one charging pile 204. In this way, the auxiliary charging unit 203 can maintain the charging status of the plurality of target electric vehicles 2042 to extend the charging time, thereby allowing the BMS in the target electric vehicles 2042 to remain in a charging state without entering a dormant state.

[0086] As a possible implementation, see Figure 5C As shown, the auxiliary charging unit includes at least one diode 501, and the at least one diode 501 corresponds to the at least one auxiliary power supply 2031 one by one; the positive electrode of each diode 501 is connected to the output end of the auxiliary power supply 2031, and the negative electrode of each diode 501 is connected to the input end of the charging pile or the electric vehicle connected to the charging pile ( Figure 5C By providing a diode at the output end of the auxiliary power supply 2031, functions such as anti-backflow and anti-reverse flow can be achieved.

[0087] In order to improve the redundancy of the electric vehicle charging system 200, as a possible implementation method, refer to Figure 6 As shown, the controller 201 includes: a power controller 601 and an auxiliary source controller 602; the auxiliary source controller 602 is used to determine the target electric vehicle 2042 to suspend charging, and control the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041.

[0088] The power controller 601 is used to control the power unit 202 to stop charging the target electric vehicle 2042 through the target charging pile 2041 after the auxiliary charging unit 203 provides the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041; when the target electric vehicle 2042 resumes charging, control the power unit 202 to charge the target electric vehicle 2042 through the target charging pile 2041; the auxiliary source controller 602 is also used to: after the power unit 202 resumes charging the target electric vehicle 2042, control the auxiliary charging unit 203 to stop providing the target charging voltage and the set charging current to the target electric vehicle 2042 through the target charging pile 2041.

[0089] In addition, the controller 201 may also include: a host controller, which is used to establish communication with the auxiliary source controller 602 and the power controller 601 respectively, and inform the auxiliary source controller 602 and the power controller 601 of the target electric vehicle 2042 that has been determined to suspend charging, and then inform the auxiliary source controller 602 and the power controller 601 when the target electric vehicle 2042 resumes charging.

[0090] Based on the above embodiments, this application provides a complete process of pausing / resuming charging of an electric vehicle, see Figure 7 As shown, the process includes the following steps:

[0091] Step S701: Determine whether a charging pause instruction sent by the BMS in the target electric vehicle 2042 is received. If so, execute step S704.

[0092] Step S702: Determine whether the load rate of the power supply 205 is greater than a load rate threshold. If so, execute step S704.

[0093] Step S703: Determine whether any one of the at least one charging pile is connected to the electric vehicle of the set type. If so, execute step S704.

[0094] Step S704: Determine the target electric vehicle 2042 for suspending charging, and send a charging suspension parameter message to the battery management system of the target electric vehicle 2042. The charging suspension parameter message carries the target charging voltage and the set charging current.

[0095] Step S705 : After closing the second switch 402 connected to the target electric vehicle 2042 , the auxiliary charging unit 203 is controlled to provide the target charging voltage and the set charging current to the target electric vehicle 2042 .

[0096] Step S706 : disconnecting the first switch 401 connected to the target electric vehicle 2042 , and controlling the power unit 202 to stop charging the target electric vehicle 2042 .

[0097] Step S707: Determine whether a resume charging instruction sent by the BMS in the target electric vehicle 2042 is received. If so, execute step S710.

[0098] Step S708: Determine whether the load rate of the power supply 205 is greater than a load rate threshold. If not, execute step S710.

[0099] Step S709: Determine whether the charging of the electric vehicle of the set type connected to any one of the at least one charging pile 204 is completed. If so, execute step S710.

[0100] Step S710: Send a recovery charging parameter message to the battery management system of the target electric vehicle 2042, wherein the recovery charging parameter message carries the charging voltage and charging current provided by the power unit 202 to the target electric vehicle 2042 through the target charging pile 2041. After closing the first switch 401 connected to the target electric vehicle 2042, the power unit 202 is controlled to supply power to the target electric vehicle 2042.

[0101] Step S711 : disconnecting the second switch 402 connected to the target electric vehicle 2042 , and controlling the auxiliary charging unit 203 to stop providing the target charging voltage and the set charging current to the target electric vehicle 2042 .

[0102] The auxiliary charging unit in the electric vehicle charging system provided by the present application is used to replace the charging voltage output by the power unit, so that the BMS in the electric vehicle believes that the charging process is normal and does not enter the dormant state, so as to achieve the effect of suspending charging of the electric vehicle at any time under different working conditions and resuming charging of the electric vehicle without user participation. The auxiliary charging unit also uses a lower charging current, which reduces the power occupied by maintaining the charging process. In addition, the advantage of resuming charging without the need for personnel to re-plug the charging gun can be used to actively cut the peak of the power grid in real time to avoid excessive transformer load rate. In addition, the charging of electric vehicles with lower power utilization can be suspended and allocated to electric vehicles of a set type, thereby facilitating charging management. In addition, the BMS side can also actively suspend charging to cope with charging state switching in different charging scenarios.

[0103] Based on the same concept, the present application also provides an electric vehicle charging method, which is applied to the electric vehicle charging system 200 described in the above embodiment. The method includes:

[0104] Determine the target electric vehicle that has suspended charging, control the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, and then control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, control the power unit to charge the target electric vehicle through the target charging pile, and then control the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

[0105] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0106] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0107] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0108] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0109] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. An electric vehicle charging system, characterized in that: The system includes: a controller, a power unit, an auxiliary charging unit and at least one charging pile, wherein the power unit is connected to a power supply; The power unit is used to charge the electric vehicle connected to the at least one charging pile; The auxiliary charging unit is configured to provide a target charging voltage and a set charging current to a target electric vehicle through a target charging pile; the target electric vehicle is an electric vehicle that has suspended charging, the target charging pile is connected to the target electric vehicle, the target charging voltage is the rated charging voltage requested by the target electric vehicle, and the set charging current is less than the rated charging current provided by the power unit when charging the target electric vehicle; The controller is used to: determine the target electric vehicle that has suspended charging, control the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, and then control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, control the power unit to charge the target electric vehicle through the target charging pile, and then control the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

2. The system according to claim 1, wherein: Determine the target electric vehicle to suspend charging, and the controller is specifically configured to: The electric vehicle that sends the charging suspension instruction is determined as the target electric vehicle.

3. The system according to claim 1 or 2, characterized in that Determine the target electric vehicle to suspend charging, and the controller is specifically configured to: When the load rate of the power supply is greater than a load rate threshold, the target electric vehicle is selected from the electric vehicles connected to the at least one charging pile according to a preset rule.

4. The system according to claim 1 or 2, characterized in that Determine the target electric vehicle to suspend charging, and the controller is specifically configured to: When an electric vehicle of a set type is connected to any one of the at least one charging pile, the target electric vehicle is selected from the electric vehicles connected to the at least one charging pile according to a preset rule.

5. The system according to claim 4, characterized in that The power unit includes a plurality of power modules, and each of the plurality of power modules is assigned a rated power size; When charging the electric vehicle connected to the at least one charging pile, the power unit is specifically configured to: allocate a target power module group to the electric vehicle connected to the charging pile, the target power module group including at least one power module from the plurality of power modules; The preset rule is: the target electric vehicle is selected from the electric vehicles connected to the at least one charging pile according to the power utilization rate of the electric vehicle connected to the charging pile, and the power utilization rate is the ratio of the rated charging power of the electric vehicle connected to the charging pile to the sum of the rated powers of the target power module groups.

6. The system according to any one of claims 1, 2 or 5, characterized in that: The system further includes: at least one first switch and at least one second switch; Each first switch is connected between the power unit and the electric vehicle connected to the at least one charging pile, and each second switch is connected between the auxiliary charging unit and the electric vehicle connected to the at least one charging pile.

7. The system according to claim 6, characterized in that The controller is specifically used for: Determining the target electric vehicle to be suspended from charging, closing a second switch connected to the target electric vehicle, controlling the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, disconnecting the first switch connected to the target electric vehicle, and controlling the power unit to stop charging the target electric vehicle through the target charging pile; When the target electric vehicle resumes charging, after closing the first switch connected to the target electric vehicle, controlling the power unit to charge the target electric vehicle through the target charging pile, disconnecting the second switch connected to the target electric vehicle, and controlling the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

8. The system according to any one of claims 1, 2, 5 or 7, characterized in that: The power unit includes an AC-DC circuit and a DC-DC circuit; The AC-DC circuit is used to convert the alternating current provided by the power supply into direct current; The DC-DC circuit is used to adjust the direct current converted by the AC-DC circuit to the charging voltage requested by the electric vehicle connected to the charging pile.

9. The system according to any one of claims 1, 2, 5 or 7, characterized in that: The auxiliary charging unit includes at least one auxiliary power supply; Any one of the at least one auxiliary power supply is used to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

10. The system according to claim 9, characterized in that The auxiliary charging unit includes at least one diode, and the at least one diode corresponds to the at least one auxiliary power source in a one-to-one manner; The anode of each diode is connected to the output end of the auxiliary power supply, and the cathode of each diode is connected to the input end of the electric vehicle connected to the charging pile.

11. The system according to any one of claims 1, 2, 5, 7 or 10, wherein: Each of the electric vehicles connected to the at least one charging pile includes: a battery management system; The battery management system is used to send a charging request to the controller, where the charging request carries a rated charging voltage and a rated charging current.

12. The system according to claim 11, wherein: The controller is further configured to: When the target electric vehicle for charging suspension is determined, a charging suspension parameter message is sent to the battery management system of the target electric vehicle, wherein the charging suspension parameter message carries the target charging voltage and the set charging current; When the target electric vehicle resumes charging, a charging parameter message is sent to the battery management system of the target electric vehicle. The charging parameter message carries the charging voltage and charging current provided by the power unit to the target electric vehicle through the target charging pile.

13. The system according to any one of claims 1, 2, 5, 7, 10 or 12, wherein: The controller includes: a power controller and an auxiliary source controller; The auxiliary source controller is configured to: determine the target electric vehicle to be suspended from charging, and control the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile; The power controller is configured to: after the auxiliary charging unit provides the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, control the power unit to stop charging the target electric vehicle through the target charging pile; when the target electric vehicle resumes charging, control the power unit to charge the target electric vehicle through the target charging pile; The auxiliary source controller is further configured to control the auxiliary charging unit to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile after the power unit resumes charging the target electric vehicle.

14. A method for charging an electric vehicle, characterized in that: Applied to the electric vehicle charging system according to any one of claims 1 to 13, the method comprises: Determining the target electric vehicle to be suspended from charging, controlling the auxiliary charging unit to provide the target charging voltage and the set charging current to the target electric vehicle through the target charging pile, and then controlling the power unit to stop charging the target electric vehicle through the target charging pile; When the target electric vehicle resumes charging, after controlling the power unit to charge the target electric vehicle through the target charging pile, the auxiliary charging unit is controlled to stop providing the target charging voltage and the set charging current to the target electric vehicle through the target charging pile.

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