Virtual-synchronization-based charging / discharging control method and system for electric vehicle

Abstract

The present invention relates to the technical field of virtual synchronization. Disclosed are a virtual-synchronization-based charging / discharging control method and system for an electric vehicle. The method comprises: establishing a connection between a power grid and an electric vehicle, so as to obtain a charging / discharging operation requirement; on the basis of the charging / discharging operation requirement, acquiring a corresponding control instruction and constraint condition, and executing a charging / discharging operation; and providing a human-computer interaction interface, so as to perform measurement and settlement regarding charging / discharging energy, and perform authentication. The present invention flexibly allocates system resources according to actual requirements, thereby improving the security and adaptability of a system, realizing efficient and smooth charging / discharging control, and meeting the requirements of multiple parties; and the present invention is more energy-saving and environmentally-friendly, and realizes both accurate measurement and convenient authentication, thereby enhancing the usability and reliability of the system, and improving user satisfaction. The present invention helps to accelerate the integration of vehicles, charging piles and power grids, thereby promoting the healthy and stable development of related industries.

Description

A virtual synchronization-based electric vehicle charging and discharging control method and system TECHNICAL FIELD

[0001] The present application relates to the technical field of virtual synchronization, in particular to a virtual synchronization-based electric vehicle charging and discharging control method and system. BACKGROUND

[0002] With large-scale access of new energy to the power grid, the "double high" characteristics of the power system are deeply affecting the form and operating characteristics of the power grid. The traditional power grid dominated by synchronous machines is undergoing a transformation, with significantly reduced system inertia and damping, insufficient dynamic regulation capacity of the power grid, and widespread concern about new energy power system stability analysis and control technology. The virtual synchronous machine control strategy enables the device to have the characteristics of a traditional synchronous machine, providing inertia and damping to improve the frequency stability of the new energy power system, and has important theoretical value and practical significance for building a new type of power system. At the same time, with the rapid penetration of new energy electric vehicles, as of the third quarter of 2023, the number of new energy vehicles in China has reached 1817 million, of which 1401 million are pure electric vehicles, accounting for 76.9% of the total number of new energy vehicles. With the occurrence of large-scale, multi-period charging behavior of electric vehicles, the impact on the safe operation of the power grid is increasing, and how to ensure the rapid and healthy development of the electric vehicle industry while also ensuring the safe operation of the power grid has become a problem that needs to be solved. At the same time, electric vehicle energy storage batteries have flexible configuration and fast response capability, and can provide necessary power support for virtual synchronous machine control to participate in power grid regulation. The resulting V2G charging and discharging technology provides a possibility for solving this problem. However, if the charging and discharging behavior is not controlled, it will not only not improve the impact on the power grid, but also exacerbate its severity. Therefore, the virtual synchronous charging and discharging machine adds virtual synchronous charging and discharging machine technology to the original V2G charging and discharging technology, which utilizes the mobile energy storage characteristics of electric vehicles to overcome the defect of fast response speed of the charging / discharging machine, making the dynamic response process of the electric vehicle more similar to that of a traditional power element, providing frequency and voltage support for the power grid. The application of this technology will help to accelerate the integration of vehicles, piles and grids, and promote the healthy and stable development of related industries.

[0003] SUMMARY

[0004] In view of the above problems, the present application is proposed.

[0005] Therefore, in order to solve the above technical problems, the present application provides the following technical scheme: a virtual synchronization-based electric vehicle charging and discharging control method, comprising: establishing a connection between the power grid and the electric vehicle to obtain charging and discharging operation requirements;

[0006] According to the charging and discharging operation requirements, the corresponding control instructions and constraint conditions are obtained, and the charging and discharging operation is performed;

[0007] The application provides a human-computer interaction interface, and energy during charging and discharging is metered and settled, and authentication is performed.

[0008] As a preferred scheme of the electric vehicle charging and discharging control method based on virtual synchronization, the method comprises the following steps:

[0009] The virtual synchronization charging and discharging device is connected with the power grid through an AC grid-connected interface, and is connected to the electric vehicle through a charging interface.

[0010] A data exchange path is established with a communication module of the electric vehicle through a central control interface, and battery state information of the electric vehicle is acquired.

[0011] The AC grid-connected interface comprises an AC power distribution mechanical switch device and a leakage protection device.

[0012] As a preferred scheme of the electric vehicle charging and discharging control method based on virtual synchronization, the method comprises the following steps:

[0013] The charging control instruction, the discharging control instruction, the virtual synchronization control instruction, the reactive power compensation control instruction, the harmonic compensation control instruction on the power grid side, and the constraint condition on the electric vehicle side are acquired.

[0014] The charging control instruction comprises instant start charging, timing start charging, pause charging, resume charging, stop charging and orderly charging control.

[0015] The discharging control instruction comprises instant start discharging, timing start discharging, pause discharging, resume discharging, stop discharging and orderly discharging control.

[0016] The virtual synchronization control instruction comprises starting a virtual synchronization operation mode, inertia response, primary frequency modulation, reactive voltage regulation and damping control.

[0017] The reactive power compensation control instruction comprises a reactive power compensation mode, setting a reactive power compensation amount, pausing reactive power compensation, resuming reactive power compensation, stopping reactive power compensation and automatic reactive power adjustment.

[0018] The harmonic compensation control instruction comprises starting a harmonic compensation mode, setting a harmonic compensation number, pausing harmonic compensation, resuming harmonic compensation, stopping harmonic compensation and automatic harmonic compensation.

[0019] The constraint condition on the electric vehicle side comprises a charging and discharging power requirement, a battery capacity, an upper and lower limit of an SOC and an available time.

[0020] According to the acquired control instruction and constraint condition, a behavior mode is determined.

[0021] The behavior modes include a charging mode, a discharging mode, a virtual synchronization mode, a reactive power compensation mode, and a harmonic compensation mode.

[0022] The active-frequency module and the reactive-voltage module are dynamically adjusted in operation state, and the power and voltage state of the bidirectional AC / DC unit are adjusted simultaneously.

[0023] As a preferred scheme of the virtual synchronization-based electric vehicle charging and discharging control method, the charging mode includes,

[0024] During charging, the alternating current power of the power grid is converted into direct current power by the bidirectional AC / DC bidirectional conversion inverter, and the direct current power is used to charge the electric vehicle.

[0025] According to the instruction of the virtual synchronization control unit, the charging power limit value and the constant voltage / constant current value are adjusted to achieve optimal charging efficiency and power grid load balance.

[0026] The charging demand of the electric vehicle and the frequency and voltage regulation demand of the power grid are received.

[0027] According to the charging demand and the state of the power grid, the most suitable charging strategy is calculated by the central control unit.

[0028] The charging strategy includes charging time calculation and power adjustment.

[0029] The charging operation is performed while the charging state is monitored.

[0030] As a preferred scheme of the virtual synchronization-based electric vehicle charging and discharging control method, the discharging mode includes,

[0031] During discharging, the direct current power of the electric vehicle is converted into alternating current power by the bidirectional AC / DC bidirectional conversion inverter.

[0032] The discharging power limit value and the constant voltage / constant current value are dynamically adjusted according to the real-time demand of the power grid, and the discharging demand of the electric vehicle and the frequency and voltage regulation demand of the power grid are received.

[0033] After the discharging strategy is determined, the DC / DC and AC / DC conversion circuit starts to feedback power to the power grid.

[0034] During discharging, the state of the power grid and the discharging state of the electric vehicle battery are continuously monitored, and the demand of the power grid is met.

[0035] As a preferred scheme of the virtual synchronization-based electric vehicle charging and discharging control method, the virtual synchronization mode includes,

[0036] The inertia of a synchronous generator and the primary frequency regulation control characteristics of the system are simulated.

[0037] Initially, the virtual inertia active power command and the primary frequency regulation control characteristic of the system are set to 0;

[0038] Detect whether the mechanical angular velocity has changed, and whether the current mechanical angular velocity deviates from the mechanical angular velocity reference value;

[0039] When the mechanical angular velocity changes, the virtual inertia active power command P is recalculated. int And update, P int The calculation formula is as follows:

[0040] Where J is the rotor moment of inertia and ω is the mechanical angular velocity;

[0041] When the mechanical angular velocity remains unchanged, maintain the virtual inertia active power command P. int constant;

[0042] If the current mechanical angular velocity deviates from the mechanical angular velocity reference value, the frequency modulation control characteristic P is recalculated. droop And update, P droop The calculation formula is as follows:

[0043] Where, ω ref Here is the reference value for the mechanical angular velocity, and m is the droop coefficient;

[0044] The virtual speed controller outputs the active power command P. ref The signal is sent to the active-frequency module, P. ref The calculation formula is as follows: P ref =P int +P droop

[0045] Active power command P ref It is sent to the active power-frequency module and the grid-connected current is adjusted through current closed-loop feedback control.

[0046] The reactive voltage characteristics of the virtual exciter-controlled synchronous generator, and the output reactive power command Q of the virtual synchronous charge-discharge machine. ref For: Q ref =K V S N (UU ref ) / U N

[0047] Among them, K V S is the reactive power voltage regulation coefficient. N U is the rated apparent power, U is the grid voltage, U ref U is the reference voltage. N Rated voltage;

[0048] detecting whether there is an external factor affecting;

[0049] The external influence detection includes load mutation detection and power grid frequency deviation detection;

[0050] The load mutation detection includes,

[0051] Periodically acquiring load power sample value P load (k), calculating load power change amount ΔP load (k), ΔP load (k) is calculated as follows: ΔP load (k) = ΔP load (k-1) + dP load (k) / dt*T

[0052] Wherein, k is the sample serial number, and T is the sampling period;

[0053] If the load power change amount |ΔP load (k)|> load mutation criterion threshold P ld , it is considered that the load mutation occurs;

[0054] Real-time monitoring power grid frequency f grid and calculating frequency deviation Δf grid , Δf grid is calculated as follows: Δf grid = f grid -f ref

[0055] Wherein, f ref is the power grid rated frequency reference value;

[0056] If |Δf grid |> frequency deviation criterion threshold f gd , it is considered that the power grid frequency deviation occurs;

[0057] If there is, the active power instruction P ref is compensated accordingly, so that the grid-connected current remains at a predetermined value;

[0058] The compensation component includes load mutation compensation and power grid frequency deviation compensation;

[0059] The calculation formula of the load mutation compensation component ΔP load_comp is as follows: ΔP load_comp =-ΔP load (k)

[0060] The calculation formula of the power grid frequency deviation compensation component ΔP fgrid_comp is as follows: ΔP fgrid_comp =k f *Δf grid

[0061] wherein, k f is a frequency-active control coefficient;

[0062] The active power instruction is recalculated according to the compensation component to obtain a final active power instruction P ref_new , and the calculation formula is as follows: P ref_new =P ref +ΔP fgrid_comp +ΔP load_comp

[0063] The coordination control module uses parallel bus communication to issue operation parameters, and dynamically adjusts the operation state of the active-frequency module and the reactive-voltage module;

[0064] The reactive power of the bidirectional AC / DC unit and the charge and discharge power limit value of the DC / DC module are adjusted to realize the function of the virtual synchronous charge and discharge machine participating in grid frequency and voltage regulation.

[0065] As a preferred scheme of the virtual synchronization-based electric vehicle charging and discharging control method, the metering and settlement include,

[0066] The energy flow in the charging and discharging process is accurately measured by the bidirectional metering unit to provide accurate billing and settlement information for the user.

[0067] The authentication includes,

[0068] The user performs charging authentication by swiping a card, scanning a two-dimensional code or inputting a password, and views related data during the charging and discharging process.

[0069] The related data includes energy flow, power level and charging duration.

[0070] Another object of the present application is to provide a virtual synchronization-based electric vehicle charging and discharging control system, to solve the above technical problems, the present application provides the following technical scheme: a virtual synchronization-based electric vehicle charging and discharging control system, comprising: an AC grid interface unit, a bidirectional AC / DC unit, a bidirectional DC / DC unit, a switch control unit, a bidirectional metering unit, a central control unit, a charging interface unit and a virtual synchronization control unit.

[0071] The AC grid interface unit is used to connect the virtual synchronous charge and discharge machine with the grid when starting and to disconnect the virtual synchronous charge and discharge machine from the grid when a problem occurs.

[0072] The bidirectional AC / DC unit is used to convert AC grid-side electric energy into DC electric energy after filtering, and convert electric energy of the electric vehicle into AC electric energy to be fed back to the grid, and is connected with the virtual synchronization control unit to adjust the active / reactive operation state according to the instruction of the central control unit.

[0073] The bidirectional DC / DC unit is used to realize power conversion with the direct current port of the electric vehicle side;

[0074] The switch control unit is used to control the direct current connection state with the electric vehicle battery;

[0075] The bidirectional metering unit is used to provide a man-machine interface and record various data in the charging and discharging process;

[0076] The central control unit is used to process the grid frequency and voltage regulation instructions, receive the battery state information of the vehicle end, coordinate the operation of each unit, and realize the overall control of the virtual synchronous charging and discharging;

[0077] The charging interface unit is used for the connection between the virtual synchronous charging and discharging machine and the electric vehicle during charging and discharging;

[0078] The virtual synchronous control unit is used to dynamically adjust the charging operation parameters according to the upper-level instructions, simulate the electromechanical transient characteristics, construct the virtual inertia and primary frequency regulation power instructions, and adjust the grid current through the current closed loop.

[0079] A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to realize the steps of the virtual synchronous electric vehicle charging and discharging control method described above.

[0080] A computer readable storage medium having a computer program stored thereon, characterized in that the computer program is executed by a processor to realize the steps of the virtual synchronous electric vehicle charging and discharging control method described above.

[0081] The virtual synchronous charging and discharging machine designed by the scheme has continuous smooth adjustment of active power, inertia response, damping control and other functions, which is beneficial to overcome the defect of the fast response speed of the electric vehicle battery charging / discharging machine, make the dynamic response process of the electric vehicle energy storage battery more close to the traditional power element, provide frequency and voltage support for the grid and adjust the system active / reactive power to provide frequency and voltage regulation for the grid. The application of this technology will be beneficial to accelerate the integration of vehicle, pile and grid, and promote the healthy and stable development of related industries. BRIEF DESCRIPTION OF DRAWINGS

[0082] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0083] Fig. 1 is a schematic diagram of the structure of a terminal in the first embodiment of the present application;

[0084] Fig. 2 is a schematic diagram of the flow in the first embodiment of the present application;

[0085] Fig. 3 is a schematic diagram of the structure of a computer device in the third embodiment of the present application;

[0086] Fig. 4 is a schematic diagram of the system modules in the second embodiment of the present application;

[0087] Fig. 5 is a virtual control flow topology diagram in the fourth embodiment of the present application. DETAILED DESCRIPTION

[0088] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the protection scope of the present application.

[0089] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from the description, and those of ordinary skill in the art can make similar generalizations without departing from the concept of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0090] Embodiment 1

[0091] Referring to Figs. 1-5, in one embodiment of the present application, a virtual synchronization-based electric vehicle charging and discharging control method is provided.

[0092] Firstly, the virtual synchronization-based electric vehicle charging and discharging control method provided by the present application can be applied to a terminal as shown in Fig. 1. As shown in Fig. 1, the terminal can include one or two (only one is shown in Fig. 1) processors and a memory for storing data, wherein the processor can include but is not limited to a processing system such as a microprocessor MCU or a programmable logic device FPGA. The above terminal can also include a transmission device for communication function and an input and output device. Those of ordinary skill in the art can understand that the structure shown in Fig. 1 is only schematic, which does not limit the structure of the above terminal. For example, the terminal can include more or less components than those shown in Fig. 1, or have a different configuration from that shown in Fig. 1.

[0093] The memory can be used to store a computer program, such as a computer program corresponding to the virtual synchronization-based electric vehicle charging and discharging control method in the embodiment, and the processor executes various function applications and data processing by running the computer program stored in the memory, that is, implements the method described above. The memory can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage systems, flash memories, or other non-volatile solid-state memories. In some examples, the memory can further include a memory remotely arranged with respect to the processor, and the remote memory can be connected to the terminal through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0094] The transmission device is used to receive or send data via a network. The network described above includes a wireless network provided by a communication provider of the terminal. In an example, the transmission device includes a network adapter (NIC) which can be connected to other network devices through a base station so as to communicate with the Internet. In an example, the transmission device can be a radio frequency (RF) module which is used to communicate with the Internet in a wireless manner.

[0095] As shown in FIG. 2, the embodiment of the present application provides a virtual synchronization-based electric vehicle charging and discharging control method. Taking the terminal in FIG. 1 as an example, the method includes the following steps:

[0096] S1: Establishing a connection between the power grid and the electric vehicle to obtain charging and discharging operation requirements;

[0097] S1.1: Connecting the virtual synchronization charging and discharging device to the power grid through an AC grid-connected interface, and connecting to the electric vehicle through a charging interface;

[0098] The AC grid-connected interface includes an AC power distribution mechanical switch device and a leakage protection device;

[0099] The functions of the AC grid-connected interface include AC on-off and leakage protection;

[0100] S1.2: The AC / DC unit is used for bus voltage stabilization and reactive power control;

[0101] The DC / DC unit is used for bidirectional constant voltage and constant current control, and controls active power of charging and discharging;

[0102] The AC / DC unit issues an active control upper limit value to the DC / DC unit through a communication mode;

[0103] The active control upper limit value takes the minimum value of the ordered charging limit power value, the BCL demand power, and the active value given by primary frequency modulation, inertia response, and damping control.

[0104] The difference from the prior art is that the AC / DC unit is only responsible for reactive and harmonic control, the DC / DC unit is only responsible for active control, the active control and the reactive control are completely decoupled, and the charging and discharging share one set of hardware circuit and one set of control algorithm.

[0105] S1.2: Establish a data exchange path with the communication module of the electric vehicle through the central control interface, and obtain the battery state information of the electric vehicle.

[0106] S2: According to the charging and discharging operation demand, obtain the corresponding control instruction and constraint condition, and execute the charging and discharging operation;

[0107] S2.1: The corresponding control instruction and constraint condition include,

[0108] The corresponding control instruction and constraint condition include,

[0109] The charging control instruction, the discharging control instruction, the virtual synchronous control instruction, the reactive compensation control instruction, the harmonic compensation control instruction of the grid side, and the electric vehicle side constraint condition are obtained;

[0110] The charging control instruction includes immediate start charging, timing start charging, pause charging, resume charging, stop charging, and orderly charging control;

[0111] The discharging control instruction includes immediate start discharging, timing start discharging, pause discharging, resume discharging, stop discharging, and orderly discharging control;

[0112] The virtual synchronous control instruction includes starting the virtual synchronous operation mode, inertia response, primary frequency modulation, reactive voltage regulation, and damping control;

[0113] The reactive compensation control instruction includes the reactive compensation mode, setting the reactive compensation amount, pausing the reactive compensation, resuming the reactive compensation, stopping the reactive compensation, and automatic reactive adjustment;

[0114] The harmonic compensation control instruction includes starting the harmonic compensation mode, setting the harmonic compensation times, pausing the harmonic compensation, resuming the harmonic compensation, stopping the harmonic compensation, and automatic harmonic compensation;

[0115] The difference from the prior art is that it can accept the orderly charging instruction, and can also work in the virtual synchronous mode, and can automatically perform reactive compensation and harmonic compensation, thereby maximizing the role of the virtual synchronous charging and discharging machine.

[0116] The electric vehicle side constraints include charging and discharging power demand, battery capacity, SOC upper and lower limits, and available time;

[0117] According to the obtained control instructions and constraints, the behavior mode of operation is determined;

[0118] The behavior mode includes charging mode, discharging mode, virtual synchronous mode, reactive power compensation mode, and harmonic compensation mode;

[0119] The active-frequency module and the reactive-voltage module are dynamically adjusted in operation state, and the power and voltage state of the bidirectional AC / DC unit are adjusted.

[0120] S2.2: The charging mode includes,

[0121] When charging, the AC power grid side electrical energy is converted into DC power through the bidirectional AC / DC bidirectional converter, and the electric vehicle is charged;

[0122] According to the instructions of the virtual synchronous control unit, the charging power limit and the constant voltage / current value are adjusted to achieve optimal charging efficiency and grid load balancing;

[0123] The charging demand of the electric vehicle and the frequency and voltage regulation demand of the power grid are received;

[0124] According to the charging demand and the grid state, the most suitable charging strategy is calculated through the central control unit;

[0125] The charging strategy includes charging time, power adjustment, etc.;

[0126] The charging operation is performed while the charging state is monitored to ensure safe and efficient charging.

[0127] S2.3: The discharging mode includes,

[0128] When discharging, the DC power of the electric vehicle is converted into AC power through the bidirectional AC / DC bidirectional converter;

[0129] The discharging power limit and constant voltage / current value are dynamically adjusted according to the real-time demand of the power grid, and the discharging demand of the electric vehicle and the frequency and voltage regulation demand of the power grid are received;

[0130] After the discharging strategy is determined, the DC / DC and AC / DC conversion circuit starts to feedback electrical energy to the power grid;

[0131] During the discharging process, the grid state and the discharging state of the electric vehicle battery are continuously monitored while meeting the demand of the power grid.

[0132] S2.4: The virtual synchronous mode includes,

[0133] The inertia of the synchronous generator and the primary frequency control characteristics of the system are simulated.

[0134] Initially, the virtual inertia active power instruction and the primary frequency modulation control characteristic of the system are set to 0;

[0135] Detecting whether the mechanical angular velocity changes and whether the current mechanical angular velocity deviates from the mechanical angular velocity reference value;

[0136] When the mechanical angular velocity changes, the virtual inertia active power instruction P int is recalculated and updated, and the calculation formula of P int is as follows:

[0137] Wherein, J is the rotor moment of inertia, and ω is the mechanical angular velocity;

[0138] When the mechanical angular velocity does not change, the virtual inertia active power instruction P int remains unchanged;

[0139] If the current mechanical angular velocity deviates from the mechanical angular velocity reference value, the primary frequency modulation control characteristic P droop is recalculated and updated, and the calculation formula of P droop is as follows:

[0140] Wherein, ω ref is the mechanical angular velocity reference value, and m is the droop coefficient;

[0141] The virtual governor outputs the active power instruction P ref to the active-frequency module, and the calculation formula of P ref is as follows: P ref =P int +P droop

[0142] The virtual excitation controller controls the reactive voltage characteristic of the synchronous generator, and the output reactive power instruction Q ref of the virtual synchronous charge-discharge machine is Q ref =K V S N (U-U ref ) / U N

[0143] Wherein, K V is the reactive voltage regulation coefficient, S N is the rated apparent power, U is the grid voltage, U ref is the reference voltage, and U N is the rated voltage;

[0144] Detecting whether there is an external factor;

[0145] The external influence detection includes load mutation detection and grid frequency deviation detection;

[0146] The load mutation detection includes,

[0147] Periodically acquiring load power sample value P load (k), calculating load power variation ΔP load (k), ΔP load (k) is calculated according to the following formula: ΔP load (k) = ΔP load (k-1) + dP load (k) / dt*T

[0148] Wherein, k is the sample serial number, and T is the sampling period;

[0149] If the load power variation |ΔP load (k)|> load mutation criterion threshold Pld, it is considered that the load mutation occurs;

[0150] Real-time monitoring grid frequency f grid and calculating frequency deviation Δf grid , Δf grid is calculated according to the following formula: Δf grid = f grid -f ref

[0151] Wherein, f ref is the grid rated frequency reference value;

[0152] If |Δf grid |> frequency deviation criterion threshold f gd , it is considered that the grid frequency deviation occurs;

[0153] If it exists, the active power instruction P ref is compensated accordingly, so that the grid-connected current remains at a predetermined value;

[0154] The compensation component includes load mutation compensation and grid frequency deviation compensation;

[0155] The calculation formula of the load mutation compensation component ΔP load_comp is as follows: ΔP load_comp =-ΔP load (k)

[0156] The calculation formula of the grid frequency deviation compensation component ΔP fgrid_comp is as follows: ΔP fgrid_comp =k f *Δf grid

[0157] Wherein, k f is the frequency-active control coefficient;

[0158] According to the compensation component, the active power instruction is recalculated to obtain a final active power instruction P ref_new , and the calculation formula is as follows: P ref_new =P ref +ΔP fgrid_comp +ΔP load_comp

[0159] The coordination control module uses parallel bus communication to issue operation parameters, and dynamically adjusts the operation state of the active-frequency module and the reactive-voltage module.

[0160] The reactive power of the bidirectional AC / DC unit and the charge and discharge power limit value of the DC / DC module are adjusted to realize the function of the virtual synchronous charge and discharge machine participating in grid frequency and voltage regulation.

[0161] S3: Provide a human-computer interaction interface to meter and settle the energy of charging and discharging, and perform authentication.

[0162] S3.1: Accurately measure the energy flow in the charging and discharging process through the bidirectional metering unit, and provide accurate billing and settlement information for users;

[0163] S3.2: Users can perform charging authentication through card swiping, two-dimensional code scanning, or password input, and view related data during the charging and discharging process.

[0164] The related data includes energy flow, power level, and charging duration.

[0165] Embodiment 2

[0166] Referring to FIG. 4, an embodiment of the present application provides a virtual synchronous based electric vehicle charging and discharging control system, which includes an alternating current grid connection interface unit, a bidirectional AC / DC unit, a bidirectional DC / DC unit, a switch control unit, a bidirectional metering unit, a central control unit, a charging interface unit, and a virtual synchronous control unit.

[0167] The alternating current grid connection interface unit includes an alternating current power distribution mechanical switch and a leakage protection, which is used to connect the virtual synchronous charge and discharge machine with the grid and disconnect the virtual synchronous charge and discharge machine from the grid when a problem occurs when starting.

[0168] The bidirectional AC / DC unit includes an AC / DC bidirectional conversion inverter and an auxiliary cooling system, which is used to convert alternating current grid side electric energy into direct current after filtering, and convert electric vehicle direct current into alternating current to feedback to the grid, and is connected with the virtual synchronous control unit to adjust the active / reactive operation state according to the central control unit instruction.

[0169] The bidirectional DC / DC unit comprises a DC / DC bidirectional conversion inverter and an auxiliary heat dissipation system device, for realizing power conversion with a direct current port of an electric vehicle side;

[0170] The switch control unit comprises a direct current mechanical switch device, for controlling a direct current connection state with a battery of an electric vehicle;

[0171] The bidirectional metering unit comprises an integrated metering, authentication, settlement and human-computer interaction function module, for providing a human-computer interaction interface and recording various data in the charging and discharging processes;

[0172] The central control unit comprises a charging connection control guide, a direct current acquisition and control and a battery management system communication module, for processing power grid frequency and voltage regulation instructions, receiving vehicle end battery state information, coordinating operation of each unit and realizing overall control of virtual synchronous charging and discharging;

[0173] The charging interface unit comprises a vehicle plug and a charging cable, for connection of the virtual synchronous charging and discharging machine and an electric vehicle during charging and discharging;

[0174] The virtual synchronous control unit comprises an active-frequency module, a coordination control module and a reactive-voltage module, for dynamically adjusting charging operation parameters according to superior instructions, simulating electromechanical transient characteristics such as inertia and damping of a synchronous machine, constructing virtual inertia and primary frequency regulation power instructions, adjusting grid current through a current closed loop and simulating inertia of a synchronous generator and system primary frequency control.

[0175] Specific limitations of the virtual synchronous electric vehicle charging and discharging control system can be seen from the limitations of the virtual synchronous electric vehicle charging and discharging control method in the foregoing, which will not be repeated here. Each module in the virtual synchronous electric vehicle charging and discharging control system can be realized by software, hardware and combinations thereof in whole or in part. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in a computer device in software form, so as to be called and executed by a processor to perform operations corresponding to each module.

[0176] Embodiment 3

[0177] Referring to FIG. 3, for the third embodiment of the present application, on the basis of the first two embodiments, the present embodiment provides a computer device, which can be a server, and the internal structure diagram of the computer device can be as shown in FIG. 3. The computer device includes a processor, a memory and a network interface connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run.

[0178] The database of the computer device is configured to store action detection data. The network interface of the computer device is configured to communicate with an external terminal through a network connection. The computer program, when executed by the processor, implements the steps in any of the sparse tensor operation acceleration method embodiments described above.

[0179] Those skilled in the art can understand that the structure shown in FIG. 3 is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0180] In an embodiment, the present embodiment provides a computer readable storage medium having a computer program stored thereon, and the computer program, when executed by a processor, implements the steps in any of the sparse tensor operation acceleration method embodiments described above.

[0181] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to a memory, storage, database or other medium used in the embodiments provided by the present application can include at least one of a non-volatile and volatile memory. The non-volatile memory can include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory or an optical storage, etc. The volatile memory can include a random access memory (RAM) or an external cache memory. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0182] Embodiment 4

[0183] Referring to FIG. 5, for one embodiment of the present application, a virtual synchronization-based electric vehicle charging and discharging control method is provided. In order to verify the beneficial effects of the present application, economic benefit calculation and simulation experiments are carried out for scientific demonstration.

[0184] Test preparation and detailed process

[0185] In order to verify the effectiveness and superiority of the virtual synchronization-based electric vehicle charging and discharging control method, the following tests are carried out.

[0186] The test platform includes an alternating current power supply simulator (for simulating the power grid), a battery simulator (for simulating the electric vehicle battery), and a virtual synchronization charging and discharging control system. The virtual synchronization control system mainly consists of an alternating current grid-connected interface, a bidirectional AC / DC converter, a bidirectional DC / DC converter, a switching module, a metering module, a central controller, a charging interface, and a virtual synchronization control module.

[0187] The test is divided into three scenarios: charging mode, discharging mode, and virtual synchronization mode. Each mode is compared with the prior art.

[0188] Charging mode test

[0189] First, connect the alternating current power supply simulator to the alternating current grid-connected interface of the virtual synchronization system, and connect the charging interface to the battery simulator. Set the charging demand to 20kW in the central controller, and the initial SOC of the battery to 30%.

[0190] The traditional charging method is to directly convert alternating current into constant current / constant voltage charging through AC / DC and DC / DC conversion, without adjusting according to the load state of the power grid. However, the method of the present application dynamically adjusts the charging power and voltage under the guidance of the virtual synchronization control module, achieving optimal charging efficiency and peak shaving and valley filling.

[0191] The specific method is first to calculate a reasonable charging power curve according to the current load state of the power grid, for example, to increase the power in the valley section and appropriately reduce it in the peak section; secondly, dynamically adjust the operating point of AC / DC and DC / DC to output the corresponding power and voltage values. At the same time, monitor the change of the battery SOC, and automatically stop charging when the power is sufficient.

[0192] Discharging mode test

[0193] Set the battery simulator to an SOC of 70% and connect it to the virtual synchronization system. Simulate the power grid issuing a 10kW reactive power adjustment instruction, which requires execution within 5 minutes.

[0194] The traditional method is directly discharged from the battery, and the fixed power output cannot meet the flexible adjustment demand of the power grid. The present application dynamically adjusts the discharge power in the range of 1-20 kW continuously according to the real-time demand of the power grid.

[0195] The specific implementation is that the grid instruction is issued to the virtual synchronization module through the central controller, the working state of the DC / DC and AC / DC converters is coordinated, the reactive power meeting the demand is output, and whether the grid voltage is qualified is monitored in real time.

[0196] Virtual synchronization mode test

[0197] The frequency and voltage adjustment instructions are sent by the simulated power grid, and the requirement is completed within 5 seconds. At the same time, the battery SOC is 60%, and the available time is 3 hours. The above information is transmitted to the central controller.

[0198] The prior art cannot smoothly adjust active power and reactive power like a synchronous generator due to the lack of inertia and damping link, and can only steeply adjust to cause power grid oscillation.

[0199] In each mode, the data is automatically recorded by the bidirectional metering module and displayed in the human-computer interaction interface, and the user can view and settle. The manual authentication link is realized by the way of card swiping, two-dimensional code or password.

[0200] According to the above experimental operation, the experimental comparison data table is given, and the table is as follows:

[0201] Table 1 Experimental comparison table

[0202] From the above table, it can be seen that the present application method has obvious advantages and innovation in the charging, discharging and virtual synchronization three modes.

[0203] In the charging mode, the traditional method keeps the power at the peak value of 20 kW, causing the power grid loss of 3 kWh within 2 hours. The present application method controls the peak power to 15 kW through the peak clipping and valley filling strategy, and only lasts for 8 minutes, so the power grid loss in the peak segment is only 1.2 kWh, and the loss in the valley segment is further reduced to 0.6 kWh, which is reduced by more than 50%. On the other hand, due to the dynamic optimization of the charging curve, the charging efficiency of the present application method can reach 0.95, which is 3 percentage points higher than that of the traditional method.

[0204] The discharging mode is an important function to support the adjustment of the power grid. The traditional method is to discharge at a fixed power of 10 kW, which cannot meet the dynamic adjustment demand of the power grid and is also an inefficient power transmission method. The present application method can continuously adjust the discharge power in the range of 1-20 kW under the cooperation of the central control and the virtual synchronization control, the response speed is less than 0.2 s, and the real-time requirement of the power grid adjustment is met. The discharge efficiency is also increased from 0.93 to 0.96.

[0205] The virtual synchronization mode is the most innovative mode. The prior art cannot simulate the inertia and damping characteristics of the synchronous generator, and can only forcibly change the power output to cause power grid oscillation. The method of the application can make the virtual synchronous charge-discharge generator smoothly adjust the active power like the synchronous generator, while realizing precise control of the voltage, and ensuring stable operation of the power grid. As can be seen from the data, the method responds extremely quickly, only 0.1 seconds, and the voltage deviation is controlled within ±1%.

[0206] In summary, through comparison of the test data, it can be clearly seen that the application exhibits unique innovation points and excellent performance in the three operating modes, fully verifying the effectiveness and superiority of the method. Thus, an important technical solution is contributed for promoting efficient collaborative operation of electric vehicles and power grids.

[0207] It should be noted that the above embodiments are only used to illustrate the technical solutions of the application and not limit the application. Although the application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the application can be modified or replaced by equivalents without departing from the spirit and scope of the application, and all should be covered in the scope of the claims of the application.

Claims

1. A charging and discharging control method for electric vehicles based on virtual synchronization, characterized in that, include: Establish a connection between the power grid and electric vehicles to obtain charging and discharging operation requirements; Based on the charging and discharging operation requirements, obtain the corresponding control commands and constraints, and execute the charging and discharging operation; It provides a human-computer interaction interface to measure, calculate, and authenticate the energy of charging and discharging.

2. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 1, characterized in that: The establishment of the connection between the power grid and the electric vehicle includes, The virtual synchronous charging and discharging device is connected to the power grid via the AC grid interface and then connected to the electric vehicle via the charging interface. A data exchange channel is established between the central control interface and the communication module of the electric vehicle to obtain the battery status information of the electric vehicle. The AC grid connection interface includes AC power distribution mechanical switchgear and leakage protection device.

3. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 2, characterized in that: The acquisition of the corresponding control commands and constraints includes... Obtain charging control commands, discharging control commands, virtual synchronization control commands, reactive power compensation control commands, harmonic compensation control commands, and electric vehicle-side constraints from the power grid side. The charging control commands include immediate charging start, timed charging start, pause charging, resume charging, stop charging, and orderly charging control; The discharge control commands include immediate discharge start, timed discharge start, pause discharge, resume discharge, stop discharge, and orderly discharge control; The virtual synchronization control commands include starting the virtual synchronization operation mode, inertia response, primary frequency regulation, reactive power regulation, and damping control. The reactive power compensation control commands include reactive power compensation mode, setting reactive power compensation amount, pausing reactive power compensation, resuming reactive power compensation, stopping reactive power compensation, and automatic reactive power adjustment; The harmonic compensation control commands include starting the harmonic compensation mode, setting the number of harmonic compensation cycles, pausing harmonic compensation, resuming harmonic compensation, stopping harmonic compensation, and automatic harmonic compensation. The constraints on the electric vehicle side include charging and discharging power requirements, battery capacity, SOC upper and lower limits, and available time. Based on the acquired control instructions and constraints, determine the operating behavior mode; The behavioral modes include charging mode, discharging mode, virtual synchronization mode, reactive power compensation mode, and harmonic compensation mode; The operating status of the active-frequency module and the reactive-voltage module is dynamically adjusted, while the power and voltage status of the bidirectional AC / DC unit are also adjusted.

4. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 3, characterized in that: The charging modes include, During charging, the electrical energy from the AC grid is converted into DC power through a bidirectional AC / DC converter to charge the electric vehicle. According to the instructions of the virtual synchronous control unit, the charging power limit and constant voltage / constant current values ​​are adjusted to achieve optimal charging efficiency and grid load balance; It receives the charging needs of electric vehicles and the frequency and voltage regulation needs of the power grid. Based on charging demand and grid conditions, the most suitable charging strategy is calculated by the central control unit. The charging strategy includes charging time calculation and power adjustment; Perform the charging operation while monitoring the charging status.

5. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 4, characterized in that: The discharge modes include, During discharge, the electric vehicle's DC power is converted into AC power through a bidirectional AC / DC converter. The discharge power limit and constant voltage / constant current values ​​are dynamically adjusted according to the real-time demand of the power grid, and the discharge demand of electric vehicles and the frequency and voltage regulation demand of the power grid are received. After the discharge strategy is determined, the control DC / DC and AC / DC conversion circuits begin to feed electrical energy back to the grid; During the discharge process, the grid status and the discharge status of the electric vehicle battery are continuously monitored, while meeting the grid's requirements.

6. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 5, characterized in that: The virtual synchronization mode includes, Simulate the inertia of a synchronous generator and the primary frequency regulation control characteristics of the system; Initially, the virtual inertia active power command and the primary frequency regulation control characteristic of the system are set to 0; Detect whether the mechanical angular velocity has changed, and whether the current mechanical angular velocity deviates from the mechanical angular velocity reference value; When the mechanical angular velocity changes, the virtual inertia active power command P is recalculated. int And update, P int The calculation formula is as follows: Where J is the rotor moment of inertia and ω is the mechanical angular velocity; When the mechanical angular velocity remains unchanged, maintain the virtual inertia active power command P. int constant; If the current mechanical angular velocity deviates from the mechanical angular velocity reference value, the frequency modulation control characteristic P is recalculated. droop And update, P droop The calculation formula is as follows: Where, ω ref Here is the reference value for the mechanical angular velocity, and m is the droop coefficient; The virtual speed controller outputs the active power command P. ref The signal is sent to the active-frequency module, P. ref The calculation formula is as follows: P ref =P int +P droop Active power command P ref It is sent to the active power-frequency module and the grid-connected current is adjusted through current closed-loop feedback control. The reactive voltage characteristics of the virtual exciter-controlled synchronous generator, and the output reactive power command Q of the virtual synchronous charge-discharge machine. ref for: Q ref =K V S N (U-U ref ) / U N Among them, K V S is the reactive power voltage regulation coefficient. N U is the rated apparent power, U is the grid voltage, U ref As the reference voltage, U N Rated voltage; To detect whether there are external factors affecting the process; External impact detection includes load change detection and power grid frequency deviation detection; Load mutation detection includes, Periodically acquire load power sample value P load (k), calculate the load power change ΔP load (k), ΔP load The formula for calculating (k) is as follows: ΔP load (k)=ΔP load (k-1)+dP load (k) / dt*T Where k is the sampling sequence number and T is the sampling period; If the load power change is |ΔP load (k)|>Load mutation criterion threshold P ld This is considered a load mutation. Real-time monitoring of power grid frequency f grid And calculate the frequency deviation Δf grid , Δf grid The calculation formula is as follows: Δf grid =f grid -f ref Among them, f ref This is a reference value for the rated frequency of the power grid. If |Δf grid |> Frequency deviation criterion threshold f gd This is considered as a deviation in the power grid frequency. If it exists, the active power command P ref Appropriate compensation should be made to maintain the grid-connected current at a predetermined value; Compensation for load mutations and power grid frequency deviations; Load mutation compensation component ΔP load_comp The calculation formula is as follows: ΔP load_comp =-ΔP load (k) Grid frequency deviation compensation component ΔP fgrid_comp The calculation formula is as follows: ΔP fgrid_comp =k f *Δf grid Where, k f This refers to the frequency-active power control coefficient. The active power command is recalculated based on the compensation component to obtain the final active power command P. ref_new The calculation formula is as follows: P ref_new =P ref +ΔP fgrid_comp +ΔP load_comp The coordination and control module uses parallel bus communication to send out operating parameters and dynamically adjust the operating status of the active power-frequency module and the reactive power-voltage module; Adjust the reactive power of the bidirectional AC / DC unit and the charging and discharging power limits of the DC / DC module to enable the virtual synchronous charge / discharge machine to participate in the power grid frequency and voltage regulation function.

7. The electric vehicle charging and discharging control method based on virtual synchronization as described in claim 6, characterized in that: The measurement and settlement process includes, The bidirectional metering unit accurately measures the energy flow during charging and discharging, providing users with precise billing and settlement information. The authentication process includes, Users can authenticate charging by swiping a card, scanning a QR code, or entering a password, and view relevant data during the charging and discharging process; The relevant data includes energy flow, power level, and charging time.

8. A system employing the electric vehicle charging and discharging control method based on virtual synchronization as described in any one of claims 1 to 7, characterized in that, include: AC grid-connected interface unit, bidirectional AC / DC unit, bidirectional DC / DC unit, switch control unit, bidirectional metering unit, central control unit, charging interface unit, and virtual synchronization control unit; The AC grid-connected interface unit is used to connect the virtual synchronous charger and discharger to the power grid during startup and to isolate it from the power grid in case of problems. The bidirectional AC / DC unit is used to convert AC grid power into DC power after filtering. The DC power of the electric vehicle is converted into AC power and fed back to the grid. It is connected to the virtual synchronous control unit and adjusts the active / reactive power operation status according to the instructions of the central control unit. The bidirectional DC / DC unit is used to achieve power conversion with the DC port on the electric vehicle side; The switch control unit is used to control the DC connection status with the electric vehicle battery; The bidirectional metering unit package is used to provide a human-machine interface and record various data during the charging and discharging process; The central control unit is used to process power grid frequency and voltage regulation commands, receive vehicle battery status information, coordinate the operation of each unit, and realize the overall control of virtual synchronous charging and discharging. The charging interface unit is used for connection between the virtual synchronous charger and the electric vehicle during charging and discharging. The virtual synchronous control unit is used to dynamically adjust charging operation parameters according to instructions from the superior unit, simulate electromechanical transient characteristics, construct virtual inertia and primary frequency regulation power commands, and adjust the grid-connected current through current closed loop.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the electric vehicle charging and discharging control method based on virtual synchronization as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the electric vehicle charging and discharging control method based on virtual synchronization as described in any one of claims 1 to 7.

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