Method and system for evaluating capability of electric vehicle charging load participating in power grid frequency modulation service

Abstract

The invention discloses a method and system for evaluating the ability of electric vehicle charging load participating in power grid frequency modulation service, and relates to the field of power grid frequency modulation. Comprising the following steps: acquiring EV frequency modulation capacity information required in each time period from a power grid dispatching center, acquiring charging pile rated power information from an operating charging pile, and acquiring a charge state and battery parameter information of a network-accessed EV from an EV control center; the EV control center divides EVs into clusters in all time periods according to the initial time information of vehicle network access; dividing each cluster into an instant charging group and a controllable frequency modulation group in combination with the willingness of the user to participate in the frequency modulation response service and the schedulable capacity information; calculating the schedulable capacity and the schedulable power of the individual EV; calculating the schedulable capacity and the schedulable power of each cluster EV; and according to the relationship between the calculated total schedulable frequency modulation capacity and the capacity required by power grid frequency modulation, proportionally distributing frequency modulation tasks to each individual EV, and calculating to obtain the expected charging / discharging power of the EV so as to achieve the purpose of frequency modulation.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid frequency regulation, and in particular to a method and system for evaluating the service capability of electric vehicle charging load participating in power grid frequency regulation. Background Art

[0002] In recent years, with the access of a high proportion of renewable energy power generation and a high proportion of power electronic equipment in the power grid, the randomness, intermittency and volatility of renewable energy output have caused the uncontrollable source of power and the oscillation stability problems caused by the access of large-scale power electronic equipment. The system power fluctuations have become increasingly obvious. Due to the slow response speed and low climbing rate of traditional generators, it is difficult to accurately track the rapid power changes caused by renewable energy. The resulting grid frequency stability problem has become increasingly prominent.

[0003] Introducing demand-side resources to participate in grid frequency control provides a new solution to this problem. At present, my country's electric vehicles are developing on a large scale. The charging load of electric vehicles is random in time and space distribution. When charging disorderly, the peak of the charging load often overlaps with the peak of the residential electricity load. With the large-scale access of new energy power sources, the randomness of the charging load of electric vehicles is superimposed on the randomness of the charging load of electric vehicles, resulting in more prominent frequency stability problems in the power system. At the same time, electric vehicles have the properties of batteries. They are both a typical adjustable flexible load and a distributed energy storage resource. The gradually mature V2G technology realizes the two-way flow of energy between vehicles and the power grid. Therefore, large-scale electric vehicles have huge regulation potential and can provide auxiliary services for grid frequency regulation.

[0004] At present, there is a great deal of uncertainty in the willingness of electric vehicle users to respond to grid frequency regulation, which will affect the final decision of electric vehicles to participate in the dispatch, thereby affecting the dispatch effect. Previous studies lacked analysis of user preferences for participating in different regulation methods, so it is necessary to further consider incorporating the willingness of car owners to participate in the dispatch into the frequency regulation dispatch. The physical conditions for electric vehicles to participate in grid frequency regulation services, including battery capacity and battery state of charge, affect the adjustable capacity of electric vehicles. The frequency regulation output of electric vehicles in the region is jointly determined by the frequency regulation signal issued by the grid dispatch center and the actual adjustable capacity of electric vehicles. Therefore, it is necessary to measure the potential of the adjustable capacity of electric vehicles, which is a key step for electric vehicles to participate in grid frequency regulation.

[0005] In view of the above problems, considering the charging behavior characteristics of electric vehicles and the travel characteristics of users, large-scale electric vehicles are divided into car clusters on a time scale according to the time when electric vehicle users access the grid. The method of decentralized access and hierarchical control is used to calculate the adjustable capacity from individual electric vehicles to cluster electric vehicles. How to accurately distribute the frequency modulation signal of the power grid dispatching center to car clusters and individual cars affects the frequency modulation effect of the power grid. Therefore, it is necessary to allocate frequency modulation tasks from top to bottom according to the adjustable capacity and battery charge state, and consider the different effects of batteries of different models of electric vehicles. Solving the above problems is of great significance for the participation of electric vehicle charging loads in power grid frequency modulation services. Summary of the invention

[0006] In view of the above-mentioned problems, the present invention is proposed.

[0007] Therefore, the technical problem solved by the present invention is: how to effectively evaluate the ability of electric vehicle charging load to participate in the grid frequency regulation service, so as to achieve stable regulation of the grid frequency by optimizing the charging and discharging behavior of electric vehicles.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service, which comprises the following steps:

[0009] Acquire first data information of a first object;

[0010] Acquire the second type of data information of the electric vehicle through the second object;

[0011] Group management is performed according to the second type of data information;

[0012] Electric vehicles are classified into different categories according to user wishes and the service objects are clearly identified;

[0013] Calculate the second category of data information of the second object and summarize and classify it;

[0014] Sequentially adjust the electric vehicles to complete the frequency modulation.

[0015] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service of the present invention, wherein: the first data information is collected and acquired at several time points of the first object;

[0016] The second type of data information includes time data, battery data, and user data of the electric vehicle connected to the network obtained for the second object.

[0017] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service according to the present invention, wherein: the group management according to the second data information includes:

[0018] Set time gaps in the time period, split it into small time periods, and classify the corresponding electric vehicles connected to the network to form several clusters;

[0019] The screening vehicle comprises,

[0020] The second object is to collect user wishes and clarify the service objects.

[0021] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the grid frequency regulation service of the present invention, wherein: the electric vehicles are classified into different categories for screening according to the user's wishes, and the service objects are clearly defined as follows:

[0022] The second object collects information on users' willingness to participate in the grid frequency response. User willingness is divided into not participating in frequency regulation and participating in frequency regulation. Participating in frequency regulation is further divided into participating in charging frequency regulation and participating in charging and discharging frequency regulation. Users of electric vehicles connected to the grid who decide to participate in the grid frequency response are included in the scope of calculating the frequency regulation service capacity.

[0023] If the user is unwilling to participate in the frequency regulation response of the power grid, it is expressed as

[0024]

[0025] If the user is willing to participate in the frequency regulation response of the power grid, it is expressed as

[0026]

[0027] If the user is willing to participate in the grid's one-way charging frequency regulation dispatch response, it is expressed as

[0028]

[0029] If the user is willing to participate in the bidirectional charging and discharging frequency regulation response of the power grid, it is expressed as

[0030]

[0031] Where N is the total number of clusters, N j is the number of connected cars in the jth car cluster; is the willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid frequency response, The willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid's unidirectional charging or bidirectional charging and discharging frequency regulation response.

[0032] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service capability of the present invention, wherein: the second type of data information of the second object is calculated and summarized and classified, including:

[0033] For each electric vehicle cluster user who is willing to participate in frequency regulation, the battery state of charge of the electric vehicle is calculated at a fixed interval. If the minimum state of charge is reached at the current moment, it is classified into the controllable frequency regulation group; if not, it is classified into the immediate charging group and charged at the maximum charging power until the desired state of charge;

[0034] For electric vehicles participating in the frequency modulation of charging and discharging, the switching between frequency modulation charging and frequency modulation discharging of electric vehicles is limited by limiting the number of charging and discharging conversions of electric vehicles;

[0035] The users in each electric vehicle cluster who are willing to participate in frequency regulation response are divided into an immediate charging group and a controllable frequency regulation group;

[0036] After the electric vehicle is connected to the grid, the state of charge of the electric vehicle is recalculated every ΔL minutes and compared with the current state of charge of the electric vehicle. and the minimum state of charge that should be achieved Determine whether the current electric vehicle has the regulation margin to accept the frequency regulation task. The judgment basis includes:

[0037] like Electric vehicles do not have the margin to accept frequency regulation tasks and are classified into the immediate charging group;

[0038] like Electric vehicles have the margin to accept frequency regulation tasks and are classified into the controllable frequency regulation group;

[0039] The charging / discharging power of the i-th electric vehicle in the j-th electric vehicle cluster at time t is expressed as:

[0040]

[0041] The calculation method of the minimum state of charge that the electric vehicle should currently reach and the current state of charge is:

[0042]

[0043] in, is the desired state of charge of the ith electric vehicle in the jth electric vehicle cluster, is the battery capacity of the i-th electric vehicle in the j-th cluster, is the maximum charging power of the i-th electric vehicle in the j-th cluster at time t, is the expected departure time of the i-th electric vehicle in the j-th cluster, η c is the charging efficiency of electric vehicles, η d is the discharge efficiency of electric vehicles;

[0044] Limit the number of charge and discharge conversions of electric vehicles in the controllable frequency regulation group in each vehicle cluster that are willing to participate in the bidirectional charge and discharge scheduling;

[0045] The number of charge-discharge conversions represents the change in the form of charging frequency modulation or discharging frequency modulation when the electric vehicle participates in the charging frequency modulation. When the electric vehicle changes from charging to discharging or from discharging to charging, the number of charge-discharge conversions increases by one. The expression is:

[0046]

[0047] when The electric vehicle will no longer switch between charging and discharging states. The coefficient α is introduced to constrain the electric vehicle to remain in the charging state after exceeding the number of charging and discharging conversions:

[0048]

[0049] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service capability of the present invention, wherein: the second type of data information of the second object is calculated and summarized and classified, and further includes:

[0050] Calculate the dispatchable frequency regulation capacity of individual electric vehicles based on the current charging / discharging power of electric vehicles in the controllable frequency regulation group;

[0051] Calculate the dispatchable frequency regulation capacity of electric vehicles in each cluster and the total dispatchable capacity in a specific area, and consider the impact of response step and response duration on dispatchable response, and recalculate the total dispatchable frequency regulation capacity of electric vehicles;

[0052] The dispatchable capacity of individual electric vehicles is calculated by setting boundaries for the charging process of individual electric vehicles participating in the dispatch. The expression is:

[0053]

[0054] in, is the rechargeable capacity of the i-th electric vehicle in the j-th cluster, is the rechargeable power of the i-th electric vehicle in the j-th cluster, is the dischargeable capacity of the i-th electric vehicle in the j-th cluster, is the dischargeable power of the i-th electric vehicle in the j-th cluster, is the power of the electric vehicle at time t, is the initial charge of the electric vehicle, is the expected power consumption of electric vehicle users, t s is the response step size of the dispatchable capacity update, is the maximum charging power of the electric vehicle at time t, is the maximum discharge power of the electric vehicle at time t;

[0055] The DC fast charging pile reduces the charging power when the SOC is higher than the upper threshold or lower than the lower threshold, while the AC slow charging pile maintains a constant power during the entire charging process. Both charging piles maintain a constant discharge power during the discharge process. remain unchanged, The corrected expression is:

[0056]

[0057] in, is the rated maximum charging power of the i-th EV in the j-th cluster;

[0058] The calculation of the dispatchable capacity of electric vehicle clusters and grid frequency regulation response is that the dispatchable capacity of electric vehicles in each cluster is the Minkowski sum of the dispatchable capacities of individual electric vehicles in the cluster, expressed as:

[0059]

[0060] in, is the dispatchable charging capacity of the jth cluster, is the dispatchable discharge capacity of the jth cluster, is the total dispatchable discharge capacity of all electric vehicles in a specific area;

[0061] Response step length t s It is inversely proportional to the update frequency of the electric vehicle battery SOC and dispatchable capacity, and the expression is:

[0062]

[0063] in, and Considering the response duration t con The cluster dispatchable charging capacity and cluster dispatchable discharging capacity after t.

[0064] As a preferred solution of the method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service capability of the present invention, wherein: the sequential adjustment of electric vehicles to complete the frequency regulation includes:

[0065] According to the controllable frequency regulation capability of each electric vehicle cluster, the frequency regulation task issued by the power grid dispatching center is distributed to each electric vehicle cluster in proportion; according to the controllable frequency regulation capability of individual electric vehicles in each electric vehicle cluster, the charging and discharging power of electric vehicles is sequentially regulated and frequency regulated according to the priority order of the charge state;

[0066] The electric vehicle control center distributes the frequency modulation signal sent by the power grid dispatching center to each electric vehicle cluster according to the proportion of the dispatchable capacity of each electric vehicle cluster. The expression is:

[0067]

[0068] In the formula, and It is the frequency modulation signal of the power grid dispatching center. is the charging frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio, is the discharge frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio;

[0069] When the grid frequency regulation capacity demand is greater than the preset value, the regulation capacity of the electric vehicle cluster that exceeds the limit is limited to and Total FM signal and The remaining frequency modulation capacity is obtained by subtracting the frequency modulation capacity of the cluster in full-power operation state, and then distributed to the remaining vehicle clusters that have not exceeded the limit according to the proportion of the cluster adjustable capacity. The expression is:

[0070] when or When j∈ψ,

[0071] For j∈ψ,

[0072] for

[0073] Where ψ is the cluster number set of the total vehicle cluster whose regulation signal exceeds the limit, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for each vehicle cluster;

[0074] In each electric vehicle cluster, the corresponding frequency modulation task is assigned to each electric vehicle according to its state of charge level, and sent to the electric vehicle through the charging pile. The battery capacity of different models of electric vehicles in each electric vehicle cluster is different. The same SOC level represents different power levels, and the weighting coefficient β is introduced for correction;

[0075] When the power system frequency is increased, each electric vehicle cluster increases the discharge power or reduces the charging power. The SOC level is proportional to the frequency regulation task undertaken by the vehicle, and the expression is:

[0076]

[0077] When the power system frequency is lowered, each electric vehicle cluster reduces the discharge power or increases the charging power. The SOC level is inversely proportional to the frequency regulation task undertaken by the vehicle, and the expression is:

[0078]

[0079] in, and To distribute frequency modulation signals to each vehicle according to the SOC level;

[0080] Limit the vehicle regulation capacity of individual electric vehicles exceeding the limit to and Trunk FM signal and The remaining frequency regulation capacity is obtained by subtracting the frequency regulation capacity of the vehicle in full operation state, and then distributed to the remaining vehicles that have not exceeded the limit according to the SOC level. The expression is:

[0081] when or When i∈φ j ,

[0082] When the power system frequency is adjusted upward,

[0083] For i∈φ j ,

[0084] for

[0085] When the power system frequency is reduced,

[0086] For i∈φ j ,

[0087] for

[0088] Among them, φ j is the set of vehicle numbers whose vehicle adjustment signals exceed the limit in the jth cluster, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for the i-th electric vehicle in the j-th cluster.

[0089] Another object of the present invention is to provide an evaluation system for the ability of electric vehicle charging load to participate in the frequency regulation service of the power grid, which can collect user participation willingness, calculate the dispatchable frequency regulation capacity of electric vehicles, and dynamically allocate frequency regulation tasks based on real-time data of electric vehicles, thereby realizing efficient evaluation and accurate execution of the frequency regulation capacity of electric vehicles. This solves the problem that the frequency regulation resources of electric vehicles cannot be effectively integrated in the prior art, and there is a lack of dynamic management of user participation willingness, resulting in unstable frequency regulation service capacity of the power grid.

[0090] In order to solve the above technical problems, the present invention provides the following technical solutions: an evaluation system for the electric vehicle charging load participating in the power grid frequency regulation service capability, comprising: a data acquisition module, a user willingness collection and screening module, a frequency regulation capability calculation module, a data management and classification module, and a frequency regulation task allocation and execution module;

[0091] The data acquisition module collects data from two objects: the electric vehicle frequency modulation capacity information of the power grid dispatching center and the electric vehicle related data of the electric vehicle control center;

[0092] The user willingness collection and screening module collects information on whether users are willing to participate in the frequency modulation response. Based on user feedback, electric vehicles willing to participate in the frequency modulation response are classified and managed;

[0093] The data management and classification module is used to group and manage the acquired second-category data information, screen electric vehicles according to user wishes, and clearly identify electric vehicles that participate in grid frequency regulation;

[0094] The frequency regulation capacity calculation module is based on the screening results provided by the user willingness collection and screening module, combined with the state of charge and charging and discharging power information of electric vehicles, to calculate the dispatchable frequency regulation capacity of each electric vehicle;

[0095] The frequency regulation task allocation and execution module is based on the frequency regulation capability of the electric vehicle cluster. The dispatch center allocates the frequency regulation task to each electric vehicle cluster in proportion and performs charging and discharging control.

[0096] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for evaluating the ability of a vehicle charging load to participate in a power grid frequency regulation service are implemented as described above.

[0097] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service as described above.

[0098] The beneficial effects of the present invention are as follows: by dividing large-scale electric vehicles into vehicle clusters on a time scale, it is beneficial to relatively independently perform potential measurement and frequency modulation control on each cluster, reducing the pressure of vehicle-grid interactive information transmission and improving the efficiency of grid frequency modulation;

[0099] By incorporating the willingness of electric vehicle users to participate in grid frequency regulation response into the electric vehicle charging load auxiliary grid frequency regulation service, it is helpful to accurately predict the regulation potential of electric vehicle charging load;

[0100] By dividing the vehicle cluster into an immediate charging group and a controllable frequency modulation group, the current charging and discharging state of the vehicle is determined according to the state of charge of the electric vehicle battery, and the number of conversions between charging and discharging of the vehicle is limited, which fully guarantees the actual charging needs of electric vehicle users and reduces the loss of vehicle batteries;

[0101] By allocating frequency regulation tasks according to the proportion of adjustable capacity of the vehicle cluster and the proportion of charge state of individual electric vehicles, the regulation potential of electric vehicles is fully utilized while ensuring user charging expectations.

[0102] Aiming at the problems of inaccurate prediction of electric vehicle charging load regulation capability and inability to meet the charging needs of electric vehicle users, as well as overcharging and over-discharging of vehicle batteries and excessive charging and discharging conversion times during the process of electric vehicles participating in grid frequency regulation, the present invention proposes an evaluation algorithm based on the electric vehicle charging load participating in grid frequency regulation service capability, which effectively provides auxiliary services for grid frequency regulation and improves the power quality and economic operation of the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0103] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0104] Figure 1 A framework diagram of large-scale electric vehicles participating in power grid frequency regulation services with the capability of electric vehicle charging loads participating in power grid frequency regulation services provided by the first embodiment of the present invention;

[0105] Figure 2 A flow chart of calculating the adjustable capacity of an electric vehicle in a method for evaluating the electric vehicle charging load's ability to participate in power grid frequency regulation service provided by the first embodiment of the present invention;

[0106] Figure 3 A schematic diagram of the regulation potential of individual electric vehicles in the method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service provided by the first embodiment of the present invention;

[0107] Figure 4 A flow chart of allocating grid frequency regulation tasks in a method for evaluating the ability of electric vehicle charging load to participate in grid frequency regulation service provided by the first embodiment of the present invention;

[0108] Figure 5 A diagram of an equivalent frequency regulation model of a power system considering the frequency regulation control of electric vehicle clusters in the method for evaluating the ability of electric vehicle charging loads to participate in the frequency regulation service of a power grid provided in the third embodiment of the present invention;

[0109] Figure 6 This is a simulation diagram of large-scale electric vehicles participating in the grid frequency regulation service in the method for evaluating the ability of electric vehicle charging load to participate in the grid frequency regulation service provided by the third embodiment of the present invention. DETAILED DESCRIPTION

[0110] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0111] Example 1, reference Figure 1 to Figure 4 According to an embodiment of the present invention, a method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service is provided, comprising:

[0112] In order to solve the impact of high-proportion new energy generation access and high-proportion power electronic equipment access on the grid frequency, the present invention provides an evaluation algorithm based on the ability of electric vehicle charging load to participate in grid frequency regulation service. The present invention first divides large-scale electric vehicles into vehicle clusters on a time scale according to the grid access time of electric vehicles, and then divides the vehicle clusters into immediate charging groups and controllable frequency regulation groups in combination with the willingness of electric vehicle users to participate in grid frequency regulation response and the state of charge (State of Change, SOC) of electric vehicle batteries. Then, the dispatchable capacity of individual electric vehicles in the controllable frequency regulation group and the dispatchable capacity of vehicle clusters are calculated from bottom to top. Finally, the electric vehicle control center receives the frequency regulation tasks of the grid dispatch center, and distributes the frequency regulation tasks to each vehicle cluster according to the proportion of the adjustable capacity, and then distributes the frequency regulation tasks to individual electric vehicles according to the state of charge of the electric vehicle batteries.

[0113] like Figure 1As shown, the overall framework of the evaluation of the capacity of large-scale electric vehicles to participate in the grid frequency regulation service of the specific implementation method of the present invention is constructed. The adjustable capacity of electric vehicles is calculated from the bottom up. First, the large-scale electric vehicles in a day are divided into 96 car clusters on the time scale at a time interval of 15 minutes. Combined with the willingness of electric vehicle users to participate in the grid frequency regulation response and vehicle status information, it is updated every ΔL minutes. Each car cluster is further divided into an immediate charging group and a controllable frequency regulation group, and the dispatchable capacity of individual electric vehicles and the dispatchable capacity of cluster electric vehicles are calculated and fed back to the grid dispatch center. The frequency regulation task is allocated from top to bottom. The grid dispatch center issues a frequency regulation signal to the electric vehicle control center. The electric vehicle control center allocates the frequency regulation task to each car cluster according to the proportion of the dispatchable capacity of each cluster, and then allocates the frequency regulation task to each car according to the battery charge state of each car. The charging pile adjusts the charging and discharging power of each car to achieve the purpose of frequency regulation.

[0114] The technical solution of the present invention is as follows:

[0115] Acquire first data information of a first object;

[0116] Acquire the second type of data information of the electric vehicle through the second object;

[0117] Group management is performed according to the second type of data information;

[0118] Electric vehicles are classified into different categories according to user wishes and the service objects are clearly identified;

[0119] Calculate the second category of data information of the second object and summarize and classify it;

[0120] Sequentially adjust the electric vehicles to complete the frequency modulation.

[0121] The first data information is collected and obtained at several time points of the first object;

[0122] The second category of data information includes time data, battery data, and user data of the electric vehicle connected to the network obtained for the second object.

[0123] It is further explained that:

[0124] The first object may be a power grid dispatching center, a power plant management platform, or an energy operator object.

[0125] The first data information may be power grid frequency fluctuation data, power grid real-time power demand data, and electric vehicle frequency regulation capacity information.

[0126] The second object can be an electric vehicle control center, a regional electric vehicle management platform, a fleet operator, or a vehicle networking platform.

[0127] The second type of data information may be time data, battery data, and user data.

[0128] In the present invention, the time data is the initial time of the electric vehicle entering the network and the expected time of leaving the network.

[0129] The battery data includes initial state of charge, real-time state of charge, expected state of charge, and battery parameters.

[0130] Battery parameters refer to the constraints of battery hardware, such as the total power of the battery, the fastest charging time, etc.

[0131] User data includes information on users' willingness to participate in grid frequency regulation response and information on the rated power of charging piles obtained by operating charging piles.

[0132] like Figure 2 As shown, the first data information of the first object is obtained, and the second type of data information of the electric vehicle is obtained based on the second object, that is, the power grid dispatching center obtains the electric vehicle frequency regulation capacity information required at each time, the electric vehicle control center obtains the initial time of network access, expected time of leaving, initial state of charge, real-time state of charge, expected state of charge, battery parameters, user's willingness to participate in power grid frequency regulation response, and the operating charging pile obtains the rated power information of the charging pile.

[0133] The group management based on the second type of data information can be to divide the electric vehicles into different clusters based on the initial time of the electric vehicles entering the network collected by the electric vehicle control center;

[0134] At 15-minute intervals, starting from 00:00 in the day, electric vehicles connected to the network between 00:00-00:30 are classified into the first vehicle cluster, electric vehicles connected to the network between 00:30-01:00 are classified into the second vehicle cluster, and so on. Electric vehicles connected to the network between 23:30-24:00 are classified into the 96th vehicle cluster, and ending at 24:00 in the day, the electric vehicles in a day are divided into a total of 96 clusters.

[0135] It is further explained that:

[0136] Electric vehicles are divided into different categories for screening based on user willingness. The service objects are clarified based on the user willingness information collected by the electric vehicle control center to participate in the grid frequency response. Only the users of electric vehicles connected to the grid who decide to participate in the grid frequency response are included in the scope of calculating the frequency regulation service capacity. User willingness is divided into not participating in frequency regulation and participating in frequency regulation. Participation in frequency regulation is further divided into participating in charging frequency regulation and participating in charging and discharging frequency regulation.

[0137] If the user is unwilling to participate in the frequency regulation response of the power grid, it is expressed as

[0138] If the user is willing to participate in the frequency regulation response of the power grid, it is expressed as

[0139] If the user is willing to participate in the grid's one-way charging frequency regulation dispatch response, it is expressed as

[0140]

[0141] If the user is willing to participate in the bidirectional charging and discharging frequency regulation response of the power grid, it is expressed as

[0142]

[0143] Where N j N is the number of connected cars in the jth car cluster; j is the number of connected cars in the jth car cluster; is the willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid frequency response, The willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid's unidirectional charging or bidirectional charging and discharging frequency regulation response.

[0144] For each electric vehicle cluster user who is willing to participate in frequency regulation, the battery state of charge of the individual electric vehicle is calculated at a fixed interval. If the minimum state of charge is reached at the current moment, it is classified into the controllable frequency regulation group; if not, it is classified into the immediate charging group and charged at the maximum charging power until the desired state of charge;

[0145] Frequent switching of the battery's charge and discharge state will accelerate the degradation of the battery's capacity. For electric vehicles participating in the charge and discharge frequency modulation scheduling, the number of charge and discharge conversions of electric vehicles is limited to limit the switching of electric vehicles between frequency modulation charging and frequency modulation discharging;

[0146] The users in each car cluster who are willing to participate in the frequency modulation response are divided into an immediate charging group and a controllable frequency modulation group;

[0147] The charging scheduling of electric vehicles should be based on meeting the charging needs of users. After the electric vehicle is connected to the grid, the state of charge of the electric vehicle is recalculated every ΔL minutes and the current state of charge of the electric vehicle is compared. and the minimum state of charge that should be achieved Determine whether the vehicle has the regulation margin to accept the frequency modulation task, based on the following criteria:

[0148] like Electric vehicles do not have the margin to accept frequency regulation tasks and are classified into the immediate charging group;

[0149] like Electric vehicles have the margin to accept frequency regulation tasks and are classified into the controllable frequency regulation group;

[0150] The charging / discharging power of the i-th electric vehicle in the j-th vehicle cluster at time t is described as:

[0151]

[0152] The calculation method of the minimum state of charge that the electric vehicle should currently reach and the current state of charge is:

[0153]

[0154]

[0155] in, is the desired state of charge of the ith electric vehicle in the jth electric vehicle cluster, is the battery capacity of the i-th electric vehicle in the j-th cluster, is the maximum charging power of the i-th electric vehicle in the j-th cluster at time t, is the expected departure time of the i-th electric vehicle in the j-th cluster, η c is the charging efficiency of electric vehicles, η d is the discharge efficiency of electric vehicles;

[0156] The number of charge and discharge conversions of electric vehicles willing to participate in the bidirectional charge and discharge scheduling of the controllable frequency regulation group in each vehicle cluster is limited;

[0157] The number of charge-discharge conversions represents the change in the form of charging frequency modulation or discharging frequency modulation of electric vehicles. Every time the electric vehicle switches from charging to discharging or from discharging to charging, the number of charge-discharge conversions increases once. The specific description is:

[0158]

[0159] limit Otherwise, the electric vehicle will no longer be able to switch between charging and discharging states. The coefficient α is introduced to constrain the vehicle to only work in the charging state after exceeding the number of charging and discharging conversions:

[0160]

[0161] It is further explained that:

[0162] Calculating the second type of data information of the second object and summarizing and classifying means calculating the dispatchable frequency regulation capacity of individual electric vehicles according to the current charging / discharging power of the electric vehicles in the controllable frequency regulation group;

[0163] Calculate the dispatchable frequency regulation capacity of electric vehicles in each cluster and the total dispatchable capacity in a specific area, and consider the impact of response step and response duration on dispatchable response, and recalculate the total dispatchable frequency regulation capacity of electric vehicles;

[0164] like Figure 3 As shown in the figure, the calculation method of the dispatchable capacity of individual electric vehicles participating in the grid frequency regulation response is:

[0165] The charging process of individual electric vehicles participating in scheduling is a quantitative feasible domain. The dispatchable capacity of individual electric vehicles is calculated through its boundary, and the dispatchable potential of individual electric vehicles is described by rechargeable capacity, rechargeable power, dischargeable capacity, and dischargeable power:

[0166]

[0167] in, is the rechargeable capacity of the i-th electric vehicle in the j-th cluster, is the rechargeable power of the i-th electric vehicle in the j-th cluster, is the dischargeable capacity of the i-th electric vehicle in the j-th cluster, is the dischargeable power of the i-th electric vehicle in the j-th cluster, is the power of the electric vehicle at time t, is the initial charge of the electric vehicle, is the expected power consumption of electric vehicle users, t s is the response step size of the dispatchable capacity update, is the maximum charging power of the electric vehicle at time t, is the maximum discharge power of the electric vehicle at time t;

[0168] The charging power of a DC fast charging station will decrease when the SOC is too low or too high. As the SOC level changes, the AC slow charging pile can maintain a constant power throughout the charging process, and both charging piles can maintain a constant discharge power during the discharge process. Can remain unchanged, The correction method is:

[0169]

[0170] In the formula, is the rated maximum charging power of the i-th EV in the j-th cluster;

[0171] The calculation method of the dispatchable capacity of cluster electric vehicles participating in the grid frequency regulation response is:

[0172] The dispatchable capacity of each cluster of electric vehicles is the Minkowski sum of the dispatchable capacities of individual electric vehicles in the cluster:

[0173]

[0174] in, is the dispatchable charging capacity of the jth cluster, is the dispatchable discharge capacity of the jth cluster, is the total dispatchable discharge capacity of all electric vehicles in a specific area;

[0175] Response step length t s The update frequency that affects the battery SOC and dispatchable capacity of electric vehicles, t s The smaller it is, the faster the update frequency is, the more accurate the calculated real-time dispatchable capacity is, and the response duration t cont The required holding time of the available capacity, t cont The larger it is, the smaller the actual dispatchable capacity is. The specific correction method is:

[0176]

[0177] in, and Considering the response duration t cont The cluster dispatchable charging capacity and cluster dispatchable discharging capacity are calculated.

[0178] like Figure 4 As shown, it should be further explained that the electric vehicles are adjusted sequentially. Completing the frequency regulation means allocating the frequency regulation tasks issued by the power grid dispatching center to each electric vehicle cluster in proportion according to the controllable frequency regulation capabilities of each electric vehicle cluster; according to the controllable frequency regulation capabilities of individual electric vehicles in each electric vehicle cluster, the charging and discharging power of the electric vehicles is sequentially controlled in the priority order of the charge state, so as to achieve the purpose of frequency regulation.

[0179] The electric vehicle control center distributes the frequency modulation signal sent by the power grid dispatching center to each electric vehicle cluster according to the proportion of the dispatchable capacity of each electric vehicle cluster. The specific method is as follows:

[0180]

[0181] In the formula, and It is the frequency modulation signal of the power grid dispatching center. is the charging frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio, is the discharge frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio;

[0182] When the grid frequency regulation capacity demand is too large, it will exceed the adjustable capacity limit of the electric vehicle cluster, and the regulation capacity of the electric vehicle cluster that exceeds the limit will be limited to and Total FM signal and The remaining frequency modulation capacity is obtained by subtracting the frequency modulation capacity of the cluster in full-power operation state, and then distributed to the remaining vehicle clusters that have not exceeded the limit according to the proportion of the cluster adjustable capacity. The specific method is as follows:

[0183] when or When j∈ψ,

[0184] For j∈ψ,

[0185] for

[0186] Where ψ is the cluster number set of the total vehicle cluster whose regulation signal exceeds the limit, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for each vehicle cluster;

[0187] In each electric vehicle cluster, the corresponding frequency modulation task is allocated to each electric vehicle according to its state of charge level, and sent to the electric vehicle through the charging pile; the battery capacity of different models of electric vehicles in each electric vehicle cluster is different, and the same SOC level represents different power levels. The weighting coefficient β is introduced for correction. For example, the battery capacity of each car is different, SOC = 50%, for car A with a full charge of 20, the current power is 10; for car B with a full charge of 18, the current power is 9; 10 and 9 represent different levels.

[0188] When the power system frequency is adjusted upward, each electric vehicle cluster increases the discharge power or reduces the charging power. The vehicles with higher SOC levels bear heavier frequency regulation tasks:

[0189]

[0190] When the power system frequency is lowered, each electric vehicle cluster reduces discharge power or increases charging power. The vehicles with lower SOC levels bear heavier frequency regulation tasks:

[0191]

[0192] in, and To distribute frequency modulation signals to each vehicle according to the SOC level;

[0193] The adjustable capacity of individual electric vehicles will also be limited, limiting the adjustable capacity of vehicles exceeding the limit to and Trunk FM signal and The remaining frequency regulation capacity is obtained by subtracting the frequency regulation capacity of the vehicle in full-power operation state, and then distributed to the remaining vehicles that have not exceeded the limit according to the SOC level. The specific method is as follows:

[0194] when or When i∈φ j ,

[0195] When the power system frequency is adjusted upward,

[0196] For i∈φ j ,

[0197] for

[0198] When the power system frequency is reduced,

[0199] For i∈φ j ,

[0200] for

[0201] Among them, φ j is the set of vehicle numbers whose vehicle adjustment signals exceed the limit in the jth cluster, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for the i-th electric vehicle in the j-th cluster.

[0202] Embodiment 2 is an embodiment of the present invention, which provides a system for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service, including: a data acquisition module, a user willingness collection and screening module, a frequency regulation capability calculation module, a data management and classification module, and a frequency regulation task allocation and execution module;

[0203] The data acquisition module collects data from two objects: the electric vehicle frequency modulation capacity information of the power grid dispatching center and the electric vehicle related data of the electric vehicle control center;

[0204] The user willingness collection and screening module collects information on whether users are willing to participate in the frequency modulation response. Based on user feedback, electric vehicles willing to participate in the frequency modulation response are classified and managed;

[0205] The data management and classification module is used to group and manage the acquired second-category data information, screen electric vehicles according to user wishes, and clearly identify electric vehicles that participate in grid frequency regulation;

[0206] The frequency regulation capacity calculation module is based on the screening results provided by the user willingness collection and screening module, combined with the state of charge and charging and discharging power information of electric vehicles, to calculate the dispatchable frequency regulation capacity of each electric vehicle;

[0207] The frequency regulation task allocation and execution module is based on the frequency regulation capability of the electric vehicle cluster. The dispatch center allocates the frequency regulation task to each electric vehicle cluster in proportion and performs charging and discharging control.

[0208] If the functions 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. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

[0209] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0210] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0211] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0212] Example 3, reference Figure 5-6 This is another embodiment of the present invention. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments. This embodiment experiments the existing traditional method and the method of this embodiment respectively.

[0213] like Figure 5 As shown, by adopting the equivalent frequency regulation model of the power system considering the frequency regulation control of electric vehicle clusters, the effect of the evaluation algorithm for the electric vehicle charging load participating in the frequency regulation service capability of the power grid is simulated and verified.

[0214] In the model, Δf is the deviation of the system frequency from the standard value of the system reference frequency 50Hz; the traditional generator is a thermal power unit, and the generator-load model is represented by a first-order transfer function, H eq is the total inertia constant of the system, D eq is the total load damping coefficient of the system; the model takes into account the damping characteristics of the generator, T G is the time constant of the speed regulator, T 1 、T 2 is the time constant of the transfer function between the governor and the turbine, T T is the time constant of the turbine; R eq is the regulating rate of the generator speed governor; T EVis the time constant of the electric vehicle cluster; T delay is the control and communication delay time constant of the system; assuming that the power generation power of the system is 500MW, the simulation parameters of the system model are shown in Table 1.

[0215] Table 1 Simulation parameters of the system model

[0216] parameter Numeric Total inertia constant of the system H / s 4.44 System total load damping coefficient D / pu 1.0 <![CDATA[Time constant T of the governor G / s]]> 0.2 <![CDATA[The time constant T of the transfer function between the governor and the turbine a / s]]> 2 <![CDATA[The time constant T of the transfer function between the governor and the turbine b / s]]> 12 <![CDATA[Time constant T of the turbine T / s]]> 0.3 Regulation rate of generator speed regulator R / pu 0.1 <![CDATA[Time constant T of the electric vehicle cluster EV / s]]> 0.035

[0217] The model includes 10,000 electric vehicles, each with a battery capacity of 30 KWh. The battery charging / discharging efficiency obeys the uniform distribution U(0.85,0.95), the battery SOC maximum / minimum boundary values ​​are 1.0 / 0.1, the rated charging / discharging power of the charging pile is 6 KW, the initial state of charge of the electric vehicle obeys the normal distribution N(0.3,0.05)∈[0.2,0.4], and the expected state of charge of the electric vehicle obeys the normal distribution N(0.8,0.03)∈[0.7,0.9].

[0218] Take 12:00 as the initial simulation time, and assume that the system has a load power disturbance of 0.05 pu at 1 second. Figure 6 As shown, through the above simulation, it can be seen that when the car cluster does not participate in the system frequency regulation, the maximum system frequency deviation is 0.03872Hz, which occurs at 7.857s; in contrast, when the car cluster participates in the system frequency regulation, the maximum system frequency deviation is 0.02231Hz, which occurs at 9.643s; this shows that when the electric vehicle charging load participates in the grid frequency regulation service, the system frequency deviation is smaller and the regulation time is shorter. The simulation verifies that when the evaluation algorithm of the electric vehicle charging load participating in the grid frequency regulation service capability of the present invention is adopted, it has a good frequency regulation effect.

[0219] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service, characterized in that: include: Acquire first data information of a first object; Acquire the second type of data information of the electric vehicle through the second object; Group management is performed according to the second type of data information; Electric vehicles are classified into different categories according to user wishes and the service objects are clearly identified; Calculate the second category of data information of the second object and summarize and classify it; Sequentially adjust the electric vehicles to complete the frequency modulation.

2. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 1, characterized in that: The first data information is collected and acquired at several time points of the first object; The second type of data information includes time data, battery data, and user data of the electric vehicle connected to the network obtained for the second object.

3. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 2, characterized in that: The group management according to the second type of data information includes: Set time gaps in the time period, split it into small time periods, and classify the corresponding electric vehicles connected to the network to form several clusters; The screening vehicle comprises, The second object is to collect user wishes and clarify the service objects.

4. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 3, characterized in that: The electric vehicles are classified into different categories according to the user's wishes for screening, and the service objects are clearly defined as follows: User willingness is divided into not participating in frequency regulation and participating in frequency regulation. Participating in frequency regulation is further divided into participating in charging frequency regulation and participating in charging and discharging frequency regulation. Users of electric vehicles connected to the grid who decide to participate in the frequency regulation response of the power grid are included in the scope of calculating the frequency regulation service capacity. If the user is unwilling to participate in the frequency regulation response of the power grid, it is expressed as If the user is willing to participate in the frequency regulation response of the power grid, it is expressed as If the user is willing to participate in the grid's one-way charging frequency regulation dispatch response, it is expressed as If the user is willing to participate in the bidirectional charging and discharging frequency regulation response of the power grid, it is expressed as Where N is the total number of clusters, N j is the number of connected cars in the jth car cluster; is the willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid frequency response, The willingness of the i-th electric vehicle user in the j-th vehicle cluster to participate in the grid's unidirectional charging or bidirectional charging and discharging frequency regulation response.

5. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 4, characterized in that: The calculating and summarizing of the second category of data information of the second object includes: For each electric vehicle cluster user who is willing to participate in frequency regulation, the battery state of charge of the electric vehicle is calculated at a fixed interval. If the minimum state of charge is reached at the current moment, it is classified into the controllable frequency regulation group; if not, it is classified into the immediate charging group and charged at the maximum charging power until the desired state of charge; For electric vehicles participating in the frequency modulation of charging and discharging, the switching between frequency modulation charging and frequency modulation discharging of electric vehicles is limited by limiting the number of charging and discharging conversions of electric vehicles; The users in each electric vehicle cluster who are willing to participate in frequency regulation response are divided into an immediate charging group and a controllable frequency regulation group; After the electric vehicle is connected to the grid, the state of charge of the electric vehicle is recalculated every ΔL minutes and compared with the current state of charge of the electric vehicle. and the minimum state of charge that should be achieved Determine whether the electric vehicle currently has the regulation margin to accept the frequency regulation task. The judgment basis includes: like Electric vehicles do not have the margin to accept frequency regulation tasks and are classified into the immediate charging group; like Electric vehicles have the margin to accept frequency regulation tasks and are classified into the controllable frequency regulation group; The charging / discharging power of the i-th electric vehicle in the j-th electric vehicle cluster at time t is expressed as: The calculation method of the minimum state of charge that the electric vehicle should currently reach and the current state of charge is: in, is the desired state of charge of the ith electric vehicle in the jth electric vehicle cluster, is the battery capacity of the i-th electric vehicle in the j-th cluster, is the maximum charging power of the i-th electric vehicle in the j-th cluster at time t, is the expected departure time of the i-th electric vehicle in the j-th cluster, η c is the charging efficiency of electric vehicles, η d is the discharge efficiency of electric vehicles; Limit the number of charge and discharge conversions of electric vehicles in the controllable frequency regulation group in each vehicle cluster that are willing to participate in the bidirectional charge and discharge scheduling; The number of charge-discharge conversions represents the change in the form of charging frequency modulation or discharging frequency modulation when the electric vehicle participates in the charging frequency modulation. When the electric vehicle changes from charging to discharging or from discharging to charging, the number of charge-discharge conversions increases by one. The expression is: when The electric vehicle will no longer switch between charging and discharging states. The coefficient α is introduced to constrain the electric vehicle to remain in the charging state after exceeding the number of charging and discharging conversions:

6. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 5, characterized in that: The calculating the second type of data information of the second object and summarizing and classifying it further comprises: Calculate the dispatchable frequency regulation capacity of individual electric vehicles based on the current charging / discharging power of electric vehicles in the controllable frequency regulation group; Calculate the dispatchable frequency regulation capacity of electric vehicles in each cluster and the total dispatchable capacity in a specific area, and consider the impact of response step and response duration on dispatchable response, and recalculate the total dispatchable frequency regulation capacity of electric vehicles; The dispatchable capacity of individual electric vehicles is calculated by setting boundaries for the charging process of individual electric vehicles participating in the dispatch. The expression is: in, is the rechargeable capacity of the i-th electric vehicle in the j-th cluster, is the rechargeable power of the i-th electric vehicle in the j-th cluster, is the dischargeable capacity of the i-th electric vehicle in the j-th cluster, is the dischargeable power of the i-th electric vehicle in the j-th cluster, is the power of the electric vehicle at time t, is the initial charge of the electric vehicle, is the expected power consumption of electric vehicle users, t s is the response step size of the dispatchable capacity update, is the maximum charging power of the electric vehicle at time t, is the maximum discharge power of the electric vehicle at time t; The DC fast charging pile reduces the charging power when the SOC is higher than the upper threshold or lower than the lower threshold, while the AC slow charging pile maintains a constant power during the entire charging process. Both charging piles maintain a constant discharge power during the discharge process. remain unchanged, The corrected expression is: in, is the rated maximum charging power of the i-th EV in the j-th cluster; The calculation of the dispatchable capacity of electric vehicle clusters and grid frequency regulation response is that the dispatchable capacity of electric vehicles in each cluster is the Minkowski sum of the dispatchable capacities of individual electric vehicles in the cluster, expressed as: in, is the dispatchable charging capacity of the jth cluster, is the dispatchable discharge capacity of the jth cluster, is the total dispatchable discharge capacity of all electric vehicles in a specific area; Response step length t s It is inversely proportional to the update frequency of the electric vehicle battery SOC and dispatchable capacity, and the expression is: in, and Considering the response duration t cont The cluster dispatchable charging capacity and cluster dispatchable discharging capacity are calculated.

7. The method for evaluating the electric vehicle charging load's ability to participate in the power grid frequency regulation service as claimed in claim 6, characterized in that: The sequential adjustment of the electric vehicle to complete the frequency modulation includes: According to the controllable frequency regulation capability of each electric vehicle cluster, the frequency regulation task issued by the power grid dispatching center is distributed to each electric vehicle cluster in proportion; according to the controllable frequency regulation capability of individual electric vehicles in each electric vehicle cluster, the charging and discharging power of electric vehicles is sequentially regulated and frequency regulated according to the priority order of the charge state; The electric vehicle control center distributes the frequency modulation signal sent by the power grid dispatching center to each electric vehicle cluster according to the proportion of the dispatchable capacity of each electric vehicle cluster. The expression is: In the formula, and It is the frequency modulation signal of the power grid dispatching center. is the charging frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio, is the discharge frequency modulation signal allocated to the jth vehicle cluster according to the capacity ratio; When the grid frequency regulation capacity demand is greater than the preset value, the regulation capacity of the electric vehicle cluster that exceeds the limit is limited to and Total FM signal and The remaining frequency modulation capacity is obtained by subtracting the frequency modulation capacity of the cluster in full-power operation state, and then distributed to the remaining vehicle clusters that have not exceeded the limit according to the proportion of the cluster adjustable capacity. The expression is: when or When j∈ψ, for for Where ψ is the cluster number set of the total vehicle cluster whose regulation signal exceeds the limit, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for each vehicle cluster; In each electric vehicle cluster, the corresponding frequency modulation task is assigned to each electric vehicle according to its state of charge level, and sent to the electric vehicle through the charging pile. The battery capacity of different models of electric vehicles in each electric vehicle cluster is different. The same SOC level represents different power levels, and the weighting coefficient β is introduced for correction; When the power system frequency is increased, each electric vehicle cluster increases the discharge power or reduces the charging power. The SOC level is proportional to the frequency regulation task undertaken by the vehicle, and the expression is: When the power system frequency is lowered, each electric vehicle cluster reduces the discharge power or increases the charging power. The SOC level is inversely proportional to the frequency regulation task undertaken by the vehicle, and the expression is: in, and To distribute frequency modulation signals to each vehicle according to the SOC level; Limit the vehicle regulation capacity of individual electric vehicles exceeding the limit to and Trunk FM signal and The remaining frequency regulation capacity is obtained by subtracting the frequency regulation capacity of the vehicle in full operation state, and then distributed to the remaining vehicles that have not exceeded the limit according to the SOC level. The expression is: when or When i∈φ j , When the power system frequency is adjusted upward, for for When the power system frequency is reduced, for for Among them, φ j is the set of vehicle numbers whose vehicle adjustment signals exceed the limit in the jth cluster, and The dispatchable charging frequency regulation capacity and dispatchable discharging frequency regulation capacity actually provided for the i-th electric vehicle in the j-th cluster.

8. A system using the method for evaluating the ability of electric vehicle charging load to participate in power grid frequency regulation service as claimed in any one of claims 1 to 7, characterized in that: It includes data acquisition module, user willingness collection and screening module, frequency modulation capability calculation module, data management and classification module, and frequency modulation task allocation and execution module; The data acquisition module collects data from two objects: the electric vehicle frequency modulation capacity information of the power grid dispatching center and the electric vehicle related data of the electric vehicle control center; The user willingness collection and screening module is used to collect information on whether the user is willing to participate in the frequency modulation response. Based on user feedback, electric vehicles willing to participate in frequency modulation response will be classified and managed; The data management and classification module is used to group and manage the acquired second-category data information, screen electric vehicles according to user wishes, and clearly identify electric vehicles that participate in grid frequency regulation; The frequency regulation capacity calculation module is based on the screening results provided by the user willingness collection and screening module, combined with the state of charge and charging and discharging power information of electric vehicles, to calculate the dispatchable frequency regulation capacity of each electric vehicle; The frequency regulation task allocation and execution module is based on the frequency regulation capability of the electric vehicle cluster. The dispatch center allocates the frequency regulation task to each electric vehicle cluster in proportion and performs charging and discharging control.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for evaluating the ability of a vehicle charging load to participate in power grid frequency regulation service as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the ability of a vehicle charging load to participate in power grid frequency regulation services as described in any one of claims 1 to 7 are implemented.

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