AC charging pile V2G system, scheduling method and device thereof, and medium

Abstract

The invention relates to the field of alternating current charging piles, in particular to an alternating current charging pile V2G system, a dispatching method and device thereof and a medium. By optimizing the design of the reverse power conversion module, the efficiency of reverse conversion of electric energy between the electric vehicle and the power grid is improved, energy loss is reduced, meanwhile, the discharge power is strictly controlled, and damage to a battery of the electric vehicle is reduced. By monitoring the power grid information in real time and considering the power grid load fluctuation in power distribution, the impact on the power grid caused by large-scale charging or discharging of the charging pile is effectively reduced, and the stability of the power grid is improved. According to the dispatching method, charging and discharging power distribution can be optimized according to the actual requirements of the electric vehicles and the states of the charging piles, the loss of energy in the transmission and conversion process is reduced, and the energy utilization efficiency of the whole V2G system is improved.

Description

Technical Field

[0001] The present invention relates to the field of AC charging piles, and specifically to an AC charging pile V2G system and its scheduling method, device, and medium. Background Art

[0002] With the popularization of electric vehicles and the development of V2G technology, electric vehicles are no longer just a means of transportation, but have become an important energy storage unit in the smart grid. V2G technology allows electric vehicles to feed electricity back to the grid when the grid load is high to achieve stable power flow. However, existing V2G systems mostly focus on hardware design or single-function implementation, lacking a comprehensive scheduling management system, and it is difficult to achieve intelligent and efficient coordination between large-scale electric vehicles and the grid. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an AC charging pile V2G system and its scheduling method, device, and medium, aiming to improve the stability of the grid and the energy utilization efficiency of electric vehicles by efficiently scheduling the power exchange between electric vehicles and the grid.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is: an AC charging pile V2G system, including a microcontroller, a data acquisition unit, and a scheduling platform; the data acquisition unit includes a voltage transformer, a current transformer, and an electric energy metering chip. The voltage transformer and the current transformer respectively collect the grid voltage, grid current, electric vehicle battery voltage, and electric vehicle battery current and transmit the collected data to the electric energy metering chip. The electric energy metering chip samples the signals, calculates the active power, reactive power, and electric energy, and is connected to the microcontroller for transmitting the calculated active power, reactive power, and electric energy to the microcontroller. The microcontroller is connected to the reverse power conversion module, and the microcontroller controls the on and off times of the reverse power conversion module to control the amplitude and frequency of the output AC voltage, thereby converting the direct current output by the electric vehicle battery into AC power meeting the grid requirements; the microcontroller is connected to the scheduling platform, and the microcontroller transmits the signals collected by the data acquisition unit to the scheduling platform. The scheduling platform analyzes the grid load data using a time series analysis algorithm, predicts the grid load change trend in the next period of time, performs power scheduling according to the load peak and valley values provided by the grid, and arranges the discharge tasks of electric vehicles in advance to balance the grid load.

[0005] Further, it further includes a communication unit, which includes an RS485 interface circuit, a CAN bus interface circuit, and a wireless communication module. The RS485 interface circuit is connected between the microcontroller and the data acquisition unit to implement communication between the microcontroller and the data acquisition unit. The CAN bus interface circuit is connected between the microcontroller and the battery management system of the electric vehicle to obtain battery information of the electric vehicle and send control instructions. The wireless communication module is connected between the microcontroller and the dispatching platform for remote monitoring and management.

[0006] Further, it further includes a data visualization tool, which displays the situation of the electric vehicle participating in the V2G task and the discharge power to the user through the data visualization tool.

[0007] The present invention also discloses a dispatching method for an AC charging pile V2G system. The AC charging pile V2G system is the above-mentioned AC charging pile V2G system. The dispatching method includes the following steps: S01. Data acquisition: When the AC charging pile is in a loaded state, the data acquisition module collects and reports valid data every time. The valid data includes the maximum allowable discharge power of the power grid at time t , the battery power S of the electric vehicle, and the status information of the AC charging pile. When the AC charging pile is in an unloaded state, the data acquisition module collects and reports valid data every time. The valid data is only the status information of the AC charging pile. , where is greater than 1 and is a positive integer. Specifically, it can be set according to the reporting frequency of valid data requirements in the unloaded state. In the present invention, is set to 20; S02. Task generation and allocation: The adjustable power range of the AC charging pile is , , where is the minimum value of the power that the charging pile can withstand, is the minimum value of the power that the battery of the electric vehicle can safely discharge. takes the maximum value of the two, and comprehensively considers the maximum allowable discharge power of the power grid and the working status of other charging piles; calculate the total dischargeable power when a single AC charging pile is working according to the following formula : , where is the total number of electric vehicles that are discharging, is the th electric vehicle, is the electric vehicle the current power of the battery, For this electric vehicle the discharge efficiency of the battery; Using the dynamic programming algorithm, the discharge power required by the power grid is allocated to the AC charging piles. The objective function is to minimize the power grid load fluctuation and maximize the overall efficiency of the charging piles and electric vehicles. The constraints are as follows: , where is the number of dischargeable AC charging piles connected to the power grid, is the th AC charging pile; After the scheduling platform obtains the of each AC charging pile, it sends them to the AC charging piles controlled by it through the communication module. The AC charging piles adjust the reverse transmission power of the electric energy according to the received instructions to achieve the discharge control of the electric vehicle; S03. Task execution: The scheduling platform generates a V2G task according to the power grid load prediction. The V2G task includes geographical location, required power value, demand time period, and demander information. It sends a discharge request to all electric vehicle owners registered in the platform system. The owner selects the power value for discharging to the power grid. After the owner confirms, the scheduling platform updates the remaining power value in real time. When the total available discharge power reaches the required power value, the release of the above V2G task is automatically suspended.

[0008] Furthermore, in step S03, if an owner cancels, resulting in the total available discharge power being less than the required power value, the scheduling platform resumes the issuance of the V2G task.

[0009] Furthermore, it also includes step S04. Dynamic adjustment: According to the real-time load change of the power grid, and the state of the electric vehicle, the V2G task is dynamically adjusted. The specific adjustment measure is that when the real-time load of the power grid is lower than the set threshold, the maximum allowable discharge power of the power grid at time t is reduced. At the same time, the state of the electric vehicle is collected to meet the charging needs of the electric vehicles to be charged and reduce the discharge power of the discharging vehicles. Conversely, when the real-time load of the power grid is greater than the set threshold, the maximum allowable discharge power of the power grid at time t is increased. The discharging vehicles are preferentially arranged for discharging operations, and at the same time, the charging power of the charging vehicles is restricted. The system monitors the electricity price information in real time and automatically adjusts the V2G task and discharge strategy according to the electricity price fluctuation. During the peak electricity consumption period, the charging and discharging strategies of the AC charging piles are adjusted to give priority to discharging and restrict charging.

[0010] Furthermore, it also includes step S05. Recording and feedback: The participation situation of the electric vehicle, the change of the power grid load, the recording of the system operation state, and the cost statistics are fed back to the scheduling platform for recording, which is used for subsequent optimization and analysis.

[0011] Further, the status information of the AC charging pile is the discharging power of the AC charging pile .

[0012] The present invention also discloses a scheduling device for an AC charging pile V2G system, including a processor and a memory storing program instructions. The processor is configured to execute the scheduling method of the AC charging pile V2G system as described above when running the program instructions.

[0013] The present invention also discloses a storage medium storing program instructions. The program instructions, when running, execute the scheduling method of the AC charging pile V2G system as described above.

[0014] Advantages of the present invention: By optimizing the design of the reverse power conversion module, the efficiency of reverse conversion of electric energy between electric vehicles and the power grid is improved, energy loss is reduced, and at the same time, the discharging power is strictly controlled to reduce damage to the batteries of electric vehicles. By real-time monitoring of grid information and considering grid load fluctuations in power distribution, the impact on the power grid caused by large-scale charging or discharging of charging piles is effectively reduced, and the stability of the power grid is improved. The scheduling method of the present invention can optimize the charging and discharging power distribution according to the actual needs of electric vehicles and the status of charging piles, reduce energy loss during transmission and conversion, and improve the energy utilization efficiency of the entire V2G system. The charging pile of the present invention has both discharging and charging functions, can charge electric vehicles when the grid load is low, and feed power back to the grid when the grid load is high, reasonably store electric energy, and further improve the utilization efficiency of electric energy. The two-way mode charging pile in this state has a wider range of applications and can reasonably allocate power supply for areas in urgent need in urban intensive areas. Detailed implementation manners

[0015] The following further illustrates the present invention with specific embodiments.

[0016] Embodiment 1 This embodiment discloses an AC charging pile V2G system, which includes a microcontroller (based on STM32F103), a data acquisition unit, a reverse power conversion module, and a scheduling platform; the data acquisition unit includes a voltage transformer, a current transformer, and an electric energy metering chip (HLW8112). The voltage transformer and the current transformer respectively collect the grid voltage, grid current, electric vehicle battery voltage, and electric vehicle battery current, and transmit the collected data to the electric energy metering chip. The electric energy metering chip samples the signals, calculates the active power, reactive power, and electric energy, and is connected to the microcontroller to transmit the calculated active power, reactive power, and electric energy to the microcontroller. The microcontroller is connected to the reverse power conversion module. The microcontroller (based on STM32F103) is responsible for the operation control of the entire charging pile. According to the collected signals (such as grid voltage , current , electric vehicle battery voltage , current and ( , where is the remaining power, and C is the battery capacity), it controls the on and off time of the reverse power conversion module to achieve the control of the amplitude and frequency of the output AC voltage, thereby converting the DC power output by the electric vehicle battery into AC power that meets the grid requirements; the microcontroller is connected to the scheduling platform, and the microcontroller transmits the signals collected by the data acquisition unit to the scheduling platform. The scheduling platform uses a time series analysis algorithm to analyze the grid load data, predicts the grid load change trend in the next period of time, conducts electric energy scheduling according to the load peak and valley provided by the grid, arranges the discharge task of the electric vehicle in advance, and balances the grid load.

[0017] In this embodiment, the AC charging pile realizes the reverse flow of electric energy based on the reverse power conversion module. During the DC-to-AC inversion process (the electric vehicle sends power to the grid) , where is the output AC voltage, is the AC voltage amplitude, is the angular frequency ( , is the grid frequency). By controlling the on and off time of the power semiconductor device, the control of the amplitude and frequency of the output AC voltage is realized, thereby converting the DC power output by the electric vehicle battery into AC power that meets the grid requirements.

[0018] The system described in this embodiment further includes a communication unit, which includes an RS485 interface circuit, a CAN bus interface circuit, and a wireless communication module (4G module). The RS485 interface circuit is connected between the microcontroller and the data acquisition unit, follows the Modbus communication protocol, and is used to implement communication between the microcontroller and the data acquisition unit. The CAN bus interface circuit is connected between the microcontroller and the battery management system of the electric vehicle, and is used to obtain battery information of the electric vehicle and send control instructions. The wireless communication module is connected between the microcontroller and the scheduling platform, and is used for remote monitoring and management.

[0019] In this embodiment, a data visualization tool is further included, and the situation of the electric vehicle participating in the V2G task and the discharge power are displayed to the user through the data visualization tool.

[0020] In this embodiment, a protection unit is further included, which includes overvoltage protection, overcurrent protection, leakage protection, and overheat protection. The protection unit can cut off the circuit immediately in case of abnormal circuit conditions, ensuring personal safety and the safe and stable operation of the equipment.

[0021] The data acquisition unit converts the signals (including voltage, current, temperature, etc.) output by various sensors on the AC charging pile into digital signals through an ADC (analog-to-digital converter), and after filtering and calibration, transmits them wirelessly to the scheduling platform, supporting the MQTTS communication protocol, and real-time obtains the charging pile status, electric vehicle battery information, and grid load data.

[0022] The scheduling platform uses a time series analysis algorithm to analyze the grid load data, predicts the grid load change trend in the next period of time, conducts power scheduling according to the load peak and valley provided by the grid, arranges the discharge tasks of electric vehicles in advance, and balances the grid load. The situation of the electric vehicle participating in the V2G task, statistical information such as discharge power, etc. are displayed to the user through the data visualization tool, facilitating the user to manage the V2G discharge task.

[0023] Embodiment 2 This embodiment discloses a scheduling method for an AC charging pile V2G system, including the following steps: S01. Data acquisition. When the AC charging pile is in the loaded state, the data acquisition module collects and reports valid data every time. The valid data includes the maximum allowable discharge power of the grid at time t , the battery power S of the electric vehicle, and the status information of the AC charging pile. When the AC charging pile is in the unloaded state, the data acquisition module collects and reports valid data every time. The valid data is only the status information of the AC charging pile, , where The value of is greater than 1 and is a positive integer, which can be specifically determined according to the reporting frequency fixed value of the effective data requirement in the non-loaded state. In the present invention, The value of is 20, and the state information is the discharge power of the AC charging pile .

[0024] S02. Task generation and allocation. The adjustable power range of the AC charging pile is , Considering the power limitation of the charging pile itself and the safe discharge limitation of the electric vehicle battery, , where is the minimum value of the power that the charging pile can withstand, is the minimum value of the safe discharge power of the electric vehicle battery, Take the maximum value of the two, Comprehensively consider the maximum allowable discharge power of the power grid and the working status of other charging piles; calculate the total dischargeable power when a single AC charging pile works according to the following formula : , where is the total number of electric vehicles that are discharging, is the th electric vehicle, is the electric vehicle current battery charge, is the discharge efficiency of the battery of this electric vehicle ; Use the dynamic programming algorithm to allocate the discharge power required by the power grid to the AC charging pile. The objective function is to minimize the power grid load fluctuation and maximize the overall efficiency of the charging pile and the electric vehicle. The constraint conditions are: , where is the number of dischargeable AC charging piles connected to the power grid, is the th AC charging pile; After the scheduling platform obtains the of each AC charging pile, it sends it to the AC charging pile controlled by it through the communication module. The AC charging pile adjusts the reverse transmission power of the electric energy according to the received instruction to achieve the discharge control of the electric vehicle.

[0025] S03. Task execution: The scheduling platform generates V2G tasks according to the power grid load forecast. The V2G tasks include geographical location, required power value, demand time period, and demander information. A discharge request is sent to all electric vehicle owners registered in the platform system. The owner selects the power value for discharging to the power grid. After the owner confirms, the scheduling platform updates the remaining required power value in real time. When the total available discharge power reaches the required power value, the release of the above V2G task is automatically suspended. If an owner cancels, resulting in the total available discharge power being less than the required power value, the scheduling platform resumes the issuance of the V2G task.

[0026] S04. Dynamic adjustment: According to the real-time load change of the power grid, and the state of electric vehicles, the V2G tasks are dynamically adjusted. The specific adjustment measures are as follows: when the real-time load of the power grid is light (judged by a threshold, less than the set threshold), a smaller is allowed for the power grid, that is, the maximum allowable discharge power of the power grid at time t is reduced . At the same time, the state of electric vehicles is collected to meet the charging needs of electric vehicles to be charged, and the discharge power of electric vehicles with higher power and whose owners set to allow discharge is reduced; conversely, when the real-time load of the power grid is heavy (judged by a threshold, greater than the set threshold), a larger is allowed for the power grid, that is, the maximum allowable discharge power of the power grid at time t is increased . Electric vehicles with higher power and whose owners set to allow discharge are preferentially arranged for discharge operations, and the charging power of charging vehicles is restricted to ensure the stable operation of the system. At the same time, the system monitors the electricity price information in real time and automatically adjusts the V2G tasks and discharge strategies according to the electricity price fluctuations. During the peak electricity consumption period, the electricity price is high and the electricity demand is large. The charging and discharge strategies of AC charging piles are adjusted to give priority to discharging and restrict charging to meet the stability of the power grid, improve the energy utilization efficiency, maximize the economic benefits, and at the same time protect the legitimate rights and interests of electric vehicle owners.

[0027] Step S05. Recording and feedback: The participation status of electric vehicles, the load change of the power grid, the recording of the system operation status, and the cost statistics are fed back to the scheduling platform for recording, which is used for subsequent optimization and analysis.

[0028] Embodiment 3 The present disclosure embodiment provides an AC charging pile V2G system scheduling device, including a processor and a memory. Optionally, the device may further include a communication interface and a bus. Among them, the processor, the communication interface, and the memory can complete mutual communication through the bus. The communication interface can be used for information transmission. The processor can call the logical instructions in the memory to execute the scheduling method of the AC charging pile V2G system in the above embodiment.

[0029] In addition, when the logical instructions in the above-mentioned memory are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0030] As a computer-readable storage medium, the memory can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the methods in the embodiments of the present disclosure. By running the program instructions / modules stored in the memory, the processor executes functional applications and data processing, that is, implements the scheduling method of the AC charging pile V2G system in the above embodiments.

[0031] The memory may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory may include high-speed random access memory and may also include non-volatile memory.

[0032] Embodiment 4 The embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, and the computer-executable instructions are set to execute the scheduling method of the above AC charging pile V2G system.

[0033] The above computer-readable storage medium may be a transient computer-readable storage medium or a non-transient computer-readable storage medium.

[0034] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present disclosure. The foregoing storage medium may be a non-transient storage medium, including: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs, or may also be a transient storage medium.

[0035] The above description only presents the basic principles and preferred embodiments of the present invention. The improvements and replacements made by those skilled in the art based on the present invention fall within the protection scope of the present invention.

Claims

1. An AC charging pile V2G system, characterized in that: It includes a microcontroller, a data acquisition unit, a reverse power conversion module and a scheduling platform; the data acquisition unit includes a voltage transformer, a current transformer and an electric energy metering chip. The voltage transformer and the current transformer respectively collect the grid voltage, grid current, electric vehicle battery voltage and electric vehicle battery current, and transmit the collected data to the electric energy metering chip. The electric energy metering chip samples the signals, calculates the active power, reactive power and electric energy, and is connected to the microcontroller to transmit the calculated active power, reactive power and electric energy to the microcontroller. The microcontroller is connected to the reverse power conversion module, and the microcontroller controls the on and off time of the reverse power conversion module to control the amplitude and frequency of the output AC voltage, so as to convert the DC power output by the electric vehicle battery into AC power meeting the grid requirements; the microcontroller is connected to the scheduling platform, and the microcontroller transmits the signals collected by the data acquisition unit to the scheduling platform. The scheduling platform uses a time series analysis algorithm to analyze the grid load data, predicts the grid load change trend in a future period of time, conducts power scheduling according to the load peak and valley values provided by the grid, arranges the discharge tasks of electric vehicles in advance, and balances the grid load.

2. The AC charging pile V2G system according to claim 1, characterized in that: It also includes a communication unit, and the communication unit includes an RS485 interface circuit, a CAN bus interface circuit and a wireless communication module. The RS485 interface circuit is connected between the microcontroller and the data acquisition unit to realize the communication between the microcontroller and the data acquisition unit. The CAN bus interface circuit is connected between the microcontroller and the battery management system of the electric vehicle to obtain the battery information of the electric vehicle and send control instructions. The wireless communication module is connected between the microcontroller and the scheduling platform for remote monitoring and management.

3. The AC charging pile V2G system according to claim 1, characterized in that: It also includes a data visualization tool, and the situation of the electric vehicle participating in the V2G task and the discharge power are displayed to the user through the data visualization tool.

4. A scheduling method for an AC charging pile V2G system, characterized in that: The AC charging pile V2G system is the AC charging pile V2G system according to any one of claims 1-3, and the scheduling method includes the following steps: S01. Data acquisition: When the AC charging pile is in the loaded state, the data acquisition module collects and reports valid data every time. The valid data includes the maximum allowable discharge power of the power grid at time t , the battery power S of the electric vehicle, and the status information of the AC charging pile. When the AC charging pile is in the unloaded state, the data acquisition module collects and reports valid data every time. The valid data is only the status information of the AC charging pile. , where takes a value greater than 1 and is a positive integer; S02. Task generation and allocation. The adjustable power range of the AC charging pile is , , where is the minimum value of the power that the charging pile can withstand, is the minimum value of the power at which the electric vehicle battery can be safely discharged, take the maximum value of the two, comprehensively consider the maximum allowable discharge power of the power grid and the working status of other charging piles; calculate the total dischargeable power when a single AC charging pile works according to the following formula : ， wherein is the total number of electric vehicles that are discharging, is the th electric vehicle, is the current battery charge of the electric vehicle , and is the discharge efficiency of the battery of this electric vehicle . The discharge power required by the power grid is allocated to AC charging piles using a dynamic programming algorithm The objective function is to minimize the power grid load fluctuation and maximize the overall efficiency of the charging piles and electric vehicles, and the constraints are as follows: ， wherein is the number of dischargeable AC charging piles connected to the power grid, is the th AC charging pile; After the scheduling platform obtains it, it sends the information to the AC charging piles controlled by it through the communication module. The AC charging piles adjust the reverse transmission power of electric energy according to the received instructions to achieve the discharge control of electric vehicles; S03. Task execution: The scheduling platform generates a V2G task according to the grid load prediction. The V2G task includes geographical location, required power value, demand time period and demander information, and sends a discharge request to all electric vehicle owners registered in the platform system. The owner selects the power value for discharging to the grid. After the owner confirms, the scheduling platform updates the remaining required power value in real time. After the total available discharge power reaches the required power value, the release of the above V2G task is automatically suspended.

5. The scheduling method of the AC charging pile V2G system according to claim 4, characterized in that: In step S03, if an owner cancels, resulting in the total available discharge power being less than the required power value, the scheduling platform resumes the issuance of the V2G task.

6. The scheduling method of the AC charging pile V2G system according to claim 4, characterized in that: It also includes step S04, dynamic adjustment. According to the real-time load change of the power grid and the state of electric vehicles, the V2G task is dynamically adjusted. The specific adjustment measure is that when the real-time load of the power grid is lower than the set threshold, the maximum allowable discharge power of the power grid at time t is reduced . At the same time, the state of electric vehicles is collected to meet the charging needs of the electric vehicles to be charged and reduce the discharge power of the discharging vehicles; on the contrary, when the real-time load of the power grid is greater than the set threshold, the maximum allowable discharge power of the power grid at time t is increased . The discharging vehicles are preferentially arranged for discharging operations, and at the same time, the charging power of the charging vehicles is restricted; the system monitors the electricity price information in real time and automatically adjusts the V2G task and the discharging strategy. During the peak electricity consumption period, the charging and discharging strategies of the AC charging piles are adjusted, giving priority to discharging and restricting charging.

7. The scheduling method of the AC charging pile V2G system according to claim 4, characterized in that: It also includes step S05. Recording and feedback: The participation situation of the electric vehicle, the grid load change, the system operation status record and the cost statistics are fed back to the scheduling platform for recording, which is used for subsequent optimization and analysis.

8. The scheduling method of the AC charging pile V2G system according to claim 4, characterized in that: The status information of the AC charging pile is the discharge power of the AC charging pile .

9. A scheduling device for an AC charging pile V2G system, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the scheduling method of the AC charging pile V2G system according to any one of claims 4 to 8 when running the program instructions.

10. A storage medium stores program instructions, characterized in that, When the program instructions are running, they execute the scheduling method of the AC charging pile V2G system according to any one of claims 4 to 8.

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