CN-122000964-A - Photovoltaic power station super capacitor energy storage configuration method and system for receiving end weak network

CN122000964ACN 122000964 ACN122000964 ACN 122000964ACN-122000964-A

Abstract

The invention discloses a photovoltaic power station super capacitor energy storage configuration method and system for a receiving end weak network. The method comprises the steps of constructing a hybrid super-capacitor model containing a power grid forming type and a power grid following type converter, measuring supporting capacity through indexes such as generalized short circuit ratio, small interference margin, transient voltage margin, frequency nadir margin, frequency change rate improvement and the like, establishing dynamic energy coupling constraint based on multi-fault time domain integration, adopting two-stage five-dimensional target NSGA-II optimization, carrying out scheme decision by combining improved AHP, CRITIC and relative entropy TOPSIS, and outputting capacity configuration meeting voltage and frequency dual supporting requirements. The invention realizes the rapid voltage recovery and frequency suppression of the photovoltaic power station in the receiving-end weak network scene, and combines investment cost and energy safety margin.

Inventors

QUAN XIANGJUN
XIE XINGFENG
WU ZAIJUN
XIONG JUNJIE
WAN ZIJING
WEI ZETAO

Assignees

东南大学
国网江西省电力有限公司电力科学研究院

Dates

Publication Date: 20260508
Application Date: 20251204

Claims (10)

1. The photovoltaic power station super capacitor energy storage configuration method facing the receiving end weak network is characterized by comprising the following steps of: step 1, collecting parameter data of a receiving end power grid, a photovoltaic power station and a super capacitor energy storage system, wherein the parameter data comprises equivalent short circuit capacity of the receiving end power grid Rated active power of photovoltaic power station And topology and control parameters of the super capacitor energy storage system; Step 2, based on parameter data of a receiving end power grid, a photovoltaic power station and a super capacitor energy storage system, establishing a hybrid super capacitor energy storage equivalent model simultaneously comprising a power grid shaping type converter unit GFM and a power grid following type converter unit GFL, wherein the power grid shaping type converter unit GFM is equivalent to a controlled voltage source in a small signal model, and the power grid following type converter unit GFL is equivalent to a controlled current source; Step 3, aiming at preset multiple fault conditions, performing time domain simulation on the combined active power response of the GFM and the GFL, and enabling investment cost to be increased under the condition that all parameter setting conditions are simultaneously met Minimizing and small interference stability margin Maximizing goal, solving for GFM capacity And GFL capacity A kind of electronic device An optimal solution set; Step 4, for And evaluating the supporting capability of all the alternatives in the optimal solution set, and selecting a final configuration result.
2. The photovoltaic power station supercapacitor energy storage configuration method for the receiving end weak network according to claim 1, wherein in step 2, the generalized short-circuit ratio is calculated according to the following formula : ; Wherein the method comprises the steps of Equivalent contribution coefficient of GFM to short circuit ratio; Calculating critical generalized short-circuit ratio based on the mixed model in the following way : ; Wherein, the For the equivalent reactance of the receiving-end power grid, Is the equivalent reactance of the photovoltaic power station, Energy storage equivalent reactance of the super capacitor; Thereby a small interference stability margin is obtained ; For multiple voltage threshold values using multiple binary table criteria And duration threshold Performing transient voltage evaluation by combination to obtain the transient voltage stability margin lifting quantity : ; Based on the inertia of the power grid Virtual inertia coefficient of photovoltaic Virtual inertia coefficient with GFM Obtaining the total inertia of the system : ; Rated active power for the grid-formed converter; Calculating frequency minimum point margin after configuring super capacitor energy storage system : ; Calculating the frequency change rate improvement quantity before and after configuration of the super-capacitor energy storage system : ; Wherein, the As the lowest frequency after the failure, As a frequency safety threshold value, And (3) with The frequency change rates before and after the super capacitor energy storage system is configured are respectively.
3. The photovoltaic power station supercapacitor energy storage configuration method facing to the receiving end weak network according to claim 2, wherein the multi-binary table criteria at least comprises 、、 And three voltage-time thresholds, which are used for judging whether the transient voltage drop degree and the transient voltage drop duration meet the safety requirement, wherein p.u. represents a per unit value.
4. The method for configuring supercapacitor energy storage of a photovoltaic power station facing a receiving end weak network according to claim 2, wherein in the step 3, the parameter setting condition includes: Small interference stability margin A voltage during failure of not lower than a threshold value, 、 And ; Wherein the method comprises the steps of , As a coefficient of energy utilization rate, For a nominal length of support time, Is the upper limit of the allowable frequency change rate.
5. The photovoltaic power station super capacitor energy storage configuration method facing the receiving end weak network according to claim 1, wherein in step 3, a multi-objective optimization algorithm based on NSGA-II is adopted to solve GFM capacity And GFL capacity Pareto optimal solution set of (c).
6. The photovoltaic power station supercapacitor energy storage configuration method facing the receiving end weak network according to claim 5, wherein in a multi-objective optimization algorithm based on NSGA-II, dynamic energy coupling constraint is used as constraint condition, and energy demand of each fault scene is calculated : ; Wherein, the Is the first At the moment of the start of the failure, Is the first The time of system recovery after each failure, Storing energy for the super capacitor to output power; Taking the maximum energy demand in all scenes to form a dynamic energy coupling constraint: ; The annual investment cost is calculated according to the following formula: ; Wherein, the Is the cost per unit of power and, In order to be the unit energy cost, For the rated energy capacity of the vehicle, In order to achieve the discount rate, the product is, Is designed for life span.
7. The method for configuring supercapacitor energy storage of photovoltaic power station facing to receiving end weak network according to claim 6, wherein in step 4, five-dimensional index of each alternative scheme is calculated through transient simulation, and an evaluation matrix containing five-dimensional index is constructed, wherein the five-dimensional index comprises annual investment cost Small interference stability margin Transient voltage stability margin improvement Frequency nadir margin And frequency change rate improvement amount ; The comprehensive weights are obtained by linear weighting by using the improved AHP and CRITIC: ; Wherein, the To the first obtained by improving AHP calculation Subjective weight of the individual indicators; Is calculated by CRITIC Objective weights of the individual indicators; preference coefficients for subjective and objective weights; Determining a positive ideal solution according to the weighted normalization matrix And negative ideal solution : ; ; Respectively calculating the first calculation by using an improved TOPSIS algorithm based on the relative entropy distance Relative entropy distance between individual alternatives and positive and negative ideal solutions And The calculation formula is as follows: ; ; for the purpose of weighting the normalized matrix elements, 、 Respectively positive and negative ideal solutions at the first The value of each index is taken out from the index, The number is the index number; based on the relative entropy distance, calculate the first Relative proximity of individual alternatives : ; Selecting relative proximity Maximum alternatives As a result of the final capacity configuration, and to respond to the GFM capacity GFL capacity Total energy of super capacitor module And transmitting the control parameters to the photovoltaic power station.
8. The photovoltaic power station supercapacitor energy storage configuration method facing the receiving end weak network according to claim 7, wherein in the improved AHP, the improved method is to construct a judgment matrix by adopting a three-scale method (0, 1, 2); The modified TOPSIS algorithm refers to the TOPSIS algorithm, wherein the relative entropy distance is used for replacing the traditional Euclidean distance.
9. A computer device comprising a memory, a processor to store a computer program executable on the processor, wherein the processor executes the computer program to implement the method of photovoltaic power plant supercapacitor energy storage configuration for a recipient weak network according to any one of claims 1-8.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements a method for configuring supercapacitor energy storage of a photovoltaic power station facing a receiving-end weak network according to any one of claims 1 to 8.

Description

Photovoltaic power station super capacitor energy storage configuration method and system for receiving end weak network Technical Field The invention belongs to the technical field of stable control and energy storage optimal configuration of an electric power system, and relates to a photovoltaic power station active supporting capacity improving method and system based on super capacitor energy storage. Background The receiving grid is usually far from the large synchronous power supply and has limited short-circuit capacity. When new energy installation such as photovoltaic increases rapidly, the system presents the problems of short circuit ratio decline, voltage response retardation and inertia deficiency. Voltage drop is difficult to recover in time during faults, the frequency change rate is easy to overrun, and the traditional configuration scheme mainly comprising battery energy storage or single peak regulation index cannot simultaneously meet multiple constraints of small interference, transient state and frequency stability. In addition, the lack of modeling the dynamic coupling between the millisecond-level high-power output and the energy consumption of the super capacitor leads to unmatched capacity and actual support requirements, and the multi-index decision also lacks objective and consistent weight basis, thus easily causing scheme deviation. Therefore, an integrated configuration method integrating generalized short-circuit ratio, transient criteria, virtual inertia and dynamic energy constraint is urgently needed, so that the photovoltaic power station has verifiable active supporting capability in the receiving-end weak network. Disclosure of Invention The invention aims to solve the technical problems of ensuring small interference stability, transient voltage support, frequency support and energy safety margin in the process of energy storage configuration of the super capacitor of the photovoltaic power station facing the receiving end weak network, and simultaneously considering economical efficiency and control feasibility. The principle of the invention is that a mixed super capacitor model containing GFM and GFL is constructed, a generalized short-circuit ratio is utilized to evaluate static indexes, a multi-threshold transient criterion and a virtual inertia model are utilized to evaluate dynamic indexes, energy constraint based on time domain integration is introduced, and an optimal scheme is output through a decision flow combining two-stage five-dimensional target NSGA-II optimization and improved AHP+ CRITIC with relative entropy TOPSIS. In order to solve the technical problems, the invention adopts the following technical scheme: a photovoltaic power station super capacitor energy storage configuration method facing a receiving end weak network comprises the following steps: step 1, collecting parameter data of a receiving end power grid, a photovoltaic power station and a super capacitor energy storage system, wherein the parameter data comprises equivalent short circuit capacity of the receiving end power grid Rated active power of photovoltaic power stationThe topology and control parameters of the super capacitor energy storage system comprise the number of super capacitor modules connected in series and parallel and the filter inductance of the DC/DC converterAnd capacitorPI control coefficient of parameter, inner loop current and outer loop voltage、; Step 2, based on parameter data of a receiving end power grid, a photovoltaic power station and a super capacitor energy storage system, establishing a hybrid super capacitor energy storage equivalent model simultaneously comprising a power grid shaping type converter unit GFM and a power grid following type converter unit GFL, wherein the power grid shaping type converter unit GFM is equivalent to a controlled voltage source in a small signal model, and the power grid following type converter unit GFL is equivalent to a controlled current source; Step 3, aiming at preset multiple fault conditions, performing time domain simulation on the combined active power response of the GFM and the GFL, and enabling investment cost to be increased under the condition that all parameter setting conditions are simultaneously met Minimizing and small interference stability marginMaximizing goal, solving for GFM capacityAnd GFL capacityA kind of electronic deviceAn optimal solution set; Step 4, for And evaluating the supporting capability of all the alternatives in the optimal solution set, and selecting a final configuration result. In the foregoing method for configuring the super capacitor energy storage of the photovoltaic power station facing the receiving end weak network, in step 2, the generalized short-circuit ratio is calculated according to the following method: Wherein the method comprises the steps ofEquivalent contribution coefficient of GFM to short circuit ratio; Calculating critical generalized short-circuit ratio ba