Research On Comprehensive Evaluation Of Virtual Power Plants Participating In Optimal Active Power Dispatching

With vigorous promotion of the energy reform,large-scale renewable energy paralleling in the grid has become imperative.In order to eliminate the impact on power system caused by renewable energy paralleling in,virtual power plants(VPPs)can be constructed to participate in grid dispatching.Different internal dispatching strategies of virtual power plants will result in different control effects.In order to help dispatchers formulate reasonable and effective control strategies,it is necessary to provide a comprehensive evaluation technology to evaluate the control effects of VPPs participating in active power dispatching of power grids.Based on the research of active power dispatching in VPPs,this paper presents a target comprehensive evaluation technology,which includes index system and evaluation method.The proposed index system contains seven indicators,which evaluate the effectiveness of active power dispatching in VPPs from three aspects:reliability,economy and schedulability.This index system conforms to the general principle of evaluation system construction,and can meet the requirements of power plant and dispatcher at the same time.It is different from the traditional power plant index system.In terms of reliability,this paper considers the uncertainties of virtual power plant output,and introduces the degree of response,constructing a three-state model.Calculation of the reliability index under the new model is finished by using the state duration sampling method.In terms of economy and schedulability,this paper combines the basic functions and dispatching characteristics of VPPs to propose new indicators.Calculation of the economic and schedulability indicators is finished according to the definition formulas.Taking the analytic hierarchy process(AHP)and the entropy weight method as representatives,this paper analyses the differences between subjective and objective weights.Definitions the ranking and intensity relations are given.Then the weight information decomposed and a comprehensive evaluation method considering the difference of weight information is proposed.This evaluation method takes the accuracy of objective weighting method and the stability and inheritance of subjective weighting method into account.In this paper.particle swarm optimization(PSO)is used to solve the comprehensive weighting model,and variable weight theory is used to improve the weights,so as to avoid the evaluation distortion caused by poor single index.The synthetical evaluation technology is suitable for evaluating the effect of virtual power plant participating in active power dispatching of power grid.In this paper,a VPP is constructed under the background of a certain power grid in Henan Province.The feasibility and effectiveness of the results are verified by using the evaluation index system and methods under different dispatching strategies.The evaluation results have guiding significance for the dispatchers to evaluate the dispatching quality of virtual power plants.