CN-122026385-A - New energy power system stable economic dispatching method for cooperative electric vehicle demand response and space-time flexible load

CN122026385ACN 122026385 ACN122026385 ACN 122026385ACN-122026385-A

Abstract

The invention relates to a new energy power system stable economic dispatching method for cooperative electric vehicle demand response and space-time flexible load, which comprises the steps of obtaining output prediction data of new energy, establishing a dispatching model of a supply side generator set and the new energy system, embedding small signal stability constraint, further establishing an electric vehicle demand response model based on self-adaptive time-of-use electricity price at the demand side to convert charging load into schedulable resources, simultaneously establishing a unified space-time flexible load model to cooperatively dispatch time and space flexible load, and finally implementing a two-stage optimization strategy in the stable economic dispatching process, namely screening a dispatching scheme set meeting the small signal stability constraint in the first stage as a safe feasible domain, and iteratively searching a dispatching scheme with optimal comprehensive operation index of the system in the safe feasible domain by taking minimum total operation cost as an objective function in the second stage. The invention realizes economic optimal dispatching under the condition of ensuring dynamic stability of the power grid.

Inventors

LUO JIANQIANG
DENG JIAJIE
CHEN SHUXUAN
Ling Langhui
YIN HAO
MENG ANBO
WANG XIAOLIN

Assignees

广东工业大学

Dates

Publication Date: 20260512
Application Date: 20260212

Claims (7)

1. A new energy power system stable economic dispatching method for cooperative electric automobile demand response and space-time flexible load is characterized by comprising the following steps: S1, acquiring output prediction data of new energy, establishing a scheduling model of a supply side generator set and a new energy system, and embedding small signal stability constraint; s2, an electric vehicle demand response model based on self-adaptive time-of-use electricity price is established at a demand side and is used for converting electric vehicle charging load into schedulable resources; s3, establishing a unified space-time flexible load model at a demand side so as to cooperatively schedule load flexibility of time and space dimensions; And S4, adopting a two-stage optimization strategy for the constructed supply and demand side model, completing two-stage solution by using an optimization algorithm, and outputting an optimal scheduling scheme considering dynamic stability and economy according to an optimization result.
2. The method for stable and economic scheduling of the new energy power system for collaborative electric vehicle demand response and space-time flexible load according to claim 1, characterized in that the specific steps of the scheduling model of the supply side generator set and the new energy system are as follows: Firstly, establishing a daily economic dispatching basic model comprising conventional generator sets and a new energy system, wherein the new energy system comprises full converter wind power generation and full converter photovoltaic power generation, the model aims at minimizing the total running cost, decision variables comprise the output of each conventional generator set in each period, and constraints comprise system power balance, upper and lower limits of unit output and climbing rate; to evaluate the dynamic stability of the system under any candidate scheduling scheme, it is necessary to use a single scheduling time And then, the new energy system is used as a dynamic element to be coupled with the external alternating current power system, and a closed-loop state space model reflecting the dynamic interaction of the external alternating current power system and the new energy system is established, wherein the form is as follows: ; Wherein, the Representation of State vector of a table synchronous generator , , , An open loop state space matrix for an external ac power system, Representing the state variables of the new energy system, , , , Is an open-loop state matrix of the new energy system.
3. The method for stable economic dispatch of a new energy power system for collaborative electric vehicle demand response and space-time flexible load according to claim 2, wherein the small signal stability constraint comprises: performing eigenvalue analysis and participation factor analysis on the closed-loop state matrix to obtain all electromechanical oscillation modes of the system, finding out electromechanical oscillation modes with obvious participation factors of the new energy system from the electromechanical oscillation modes, defining the electromechanical oscillation modes as critical modes, and setting eigenvalues of the critical modes as Wherein, the method comprises the steps of, As the real part of the eigenvalue, Calculating damping ratio according to the characteristic value: ; Converting the dynamic stability assessment process into constraint conditions on the scheduling model, wherein the constraint conditions require that all time periods are in the whole scheduling period Critical modal damping ratio of (2) Are not lower than a preset minimum stable damping ratio threshold : ; The constraint is the small signal stability constraint of the embedded scheduling model, which means that when the optimization algorithm searches the scheduling scheme, the system operating point determined by the scheme at each moment is ensured, and the linearization model of the system operating point meets the small signal stability requirement.
4. The method for stable economic dispatching of the new energy power system by cooperative electric vehicle demand response and space-time flexible load according to claim 1, wherein the method for establishing the electric vehicle demand response model based on the self-adaptive time-of-use electricity price specifically comprises the following steps: The random running and charging behavior of the electric automobile is simulated by utilizing a Monte Carlo algorithm, the random running and charging behavior is used for determining the basic charging load before non-response, firstly, the daily driving distance of the electric automobile is set to follow normal distribution, and the probability density function is expressed as follows: ; Wherein, the The travel distance is indicated as the distance traveled, And Mean and standard deviation of the number of routes; generating daily charging power of the electric automobile based on the driving mileage: ; Wherein, the Is the charging path of the electric automobile, Indicating an initial state of charge of the battery, Representing the charge cycle of an electric vehicle, Represents the battery capacity of the electric vehicle, And Respectively representing the charging power and the efficiency of the battery, Indicating the moment the EV leaves the charging station, It is the time that the EV is connected to the charging station, To be at the time of Is used for controlling the power of the electric automobile, Represent the first The power requirements of an electric vehicle, Representing the total number of electric vehicles; In the overall dispatching framework, the model optimizes the electric automobile cluster charging power change under the self-adaptive electricity price mechanism as a whole, namely, the distributed charging behaviors are aggregated into a group of power instructions which can be flexibly adjusted on a time axis on the premise of meeting the condition that the total charging energy requirement of a user is unchanged by taking an electricity price adjustment coefficient or expected load transfer quantity as an optimization variable; finally, the charging power adjustment quantity of each period obtained by optimizing and solving can be used for forming a schedulable demand side resource which can directly participate in power grid scheduling and is used for stabilizing fluctuation and supporting stability.
5. The method for stable economic dispatch of a new energy power system for collaborative electric vehicle demand response and space-time flexible load according to claim 1, wherein the self-adaptive time-of-use electricity price comprises: ; ; Wherein, the And At the peak and valley times, respectively Is used for the rate of the tilting block, Is the time of A specified charge amount threshold of (a); Is three price values of the self-adaptive time-sharing electricity price in the peak period, Is three price values during the valley period, Is the time of Is set, the current charge amount of the battery is set.
6. The method for stable economic dispatch of a new energy power system for collaborative electric vehicle demand response and space-time flexible load according to claim 1, wherein the space-time flexible load model comprises: The system comprises a space flexible load model, a load flow distribution control module and a load control module, wherein the space flexible load model is used for representing the schedulability of the load in a geographic position and changing the load flow distribution of the system by redistributing the transferable load in a network among different nodes; the time flexible load model comprises a transferable load and a movable load, wherein the transferable load flexibly distributes power consumption in a dispatching cycle on the premise of meeting the total energy requirement of a user, and the movable load translates running time in an allowable time window on the premise of keeping fixed power and fixed duration to generate a dispatched power vector.
7. The method for stable economic dispatch of a new energy power system for collaborative electric vehicle demand response and space-time flexible load according to claim 2, characterized in that targeting the total operating cost minimization comprises: ; Wherein, the A representation constant for dividing the stable region and the unstable region; Representing the damping ratio of the critical mode in the current scheduling scheme, For the operating costs of the generator set, For flexible post-load dispatch subsidy costs, In order to achieve a damping ratio, The method is the use cost for the electric automobile demand response.

Description

New energy power system stable economic dispatching method for cooperative electric vehicle demand response and space-time flexible load Technical Field The invention relates to the technical field of power system dispatching, in particular to a new energy power system stable economic dispatching method for coordinating electric automobile demand response and space-time flexible load. Background With the continuous improvement of the permeability of new energy in an electric power system and the rapid popularization of novel loads such as electric vehicles, the operation and the scheduling of the electric power system face new challenges. The intermittent and fluctuating properties of the new energy source impact the stability of the power grid, and the unordered charging of a large number of electric vehicles can aggravate the peak-valley difference of the load, so that the economic operation, safety and stability of the power grid are affected. Currently, existing scheduling methods attempt to utilize demand side resources to smooth out fluctuations. However, existing scheduling strategies tend to focus on economic optimization, while either the system dynamic stability is under consideration, or the time-transferable or mobile load and the space-schedulable load are not effectively coordinated. The traditional economic dispatch model mainly depends on static constraint, such as power balance, line capacity and the like, and cannot capture broadband oscillation risks caused by dynamic interaction between the power electronic converter and the power grid, so that the system faces potential instability threats in a high-proportion new energy scene. In addition, the resource on the demand side is generally simplified into a single-dimension adjustment means, and the lack of a space-time cooperative scheduling mechanism limits the role of the space-time cooperative scheduling mechanism in solving the problem of local stability. Therefore, a unified scheduling method capable of cooperating with the electric vehicle demand response and the space-time flexible load is needed, so that the optimal economic benefit is realized on the premise of ensuring the dynamic stability of the electric power system. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide a new energy power system stable economic dispatching method for coordinating the demand response and space-time flexible load of an electric vehicle, so as to solve the defects of the existing dispatching method in the aspects of dynamic stability guarantee and demand side resource coordination and improve the operation stability and economy of the power system after high-proportion new energy is accessed. In order to achieve the above object, the present invention provides the following solutions: A new energy power system stable economic dispatching method for cooperative electric automobile demand response and space-time flexible load comprises the following steps: S1, acquiring output prediction data of new energy, establishing a scheduling model of a supply side generator set and a new energy system, and embedding small signal stability constraint; s2, an electric vehicle demand response model based on self-adaptive time-of-use electricity price is established at a demand side and is used for converting electric vehicle charging load into schedulable resources; s3, establishing a unified space-time flexible load model at a demand side so as to cooperatively schedule load flexibility of time and space dimensions; And S4, adopting a two-stage optimization strategy for the constructed supply and demand side model, completing two-stage solution by using an optimization algorithm, and outputting an optimal scheduling scheme considering dynamic stability and economy according to an optimization result. Optionally, the specific steps of the scheduling model of the supply side generator set and the new energy system are as follows: Firstly, establishing a daily economic dispatching basic model comprising conventional generator sets and a new energy system, wherein the new energy system comprises full converter wind power generation and full converter photovoltaic power generation, the model aims at minimizing the total running cost, decision variables comprise the output of each conventional generator set in each period, and constraints comprise system power balance, upper and lower limits of unit output and climbing rate; to evaluate the dynamic stability of the system under any candidate scheduling scheme, it is necessary to use a single scheduling time And then, the new energy system is used as a dynamic element to be coupled with the external alternating current power system, and a closed-loop state space model reflecting the dynamic interaction of the external alternating current power system and the new energy system is established, wherein the form is as follows: ; Wherein, the Representation ofState vector