Research On Evaluation Method And Guarantee Mechanism Of Generation Capacity Adequacy In Multi-source Electricity Market

Generation capacity adequacy is a constant theme in the operation of power industry,and it is very important to keep it at a reasonable level.With the continuous deepening of power system reform and the rapid development of new energy,generation capacity adequacy is facing new situations and new challenges,new methods and mechanisms are urgently needed to deal with new risks and new problems.In this paper,the evaluation method and guarantee mechanism of generation capacity adequacy are studied,which is based on the market-oriented and multi-sourced power system in China.It is expected to provide a theoretical basis for ensuring the reliable supply of the power system,promoting the coordinated construction of the power market and promoting the fair competition of the market members.Firstly,the theory and practice of guaranteeing the generation capacity adequacy are summarized.This paper introduces the theory of generation cost and the principle of marginal cost pricing as the economic basis.This paper summarizes five basic methods commonly used internationally to ensure generation capacity adequacy,including scarcity price mechanism,capacity market mechanism,capacity compensation mechanism,capacity option mechanism and administrative compensation mechanism.The practice of these methods in the Americas,Europe and Australia have been investigated,and the applicability of scarcity price mechanism,capacity market mechanism and capacity compensation mechanism are analyzed.Secondly,drawing on the concept of sufficient capacity in Chile’s compensation mechanism,a quantitative evaluation model for generation capacity adequacy of multi-source power system is proposed.Above all,considering the technical characteristics of the generator and the characteristics and reserves of the primary energy,the initial capacity of the generator is calculated by using the historical data statistics method.The initial capacity evaluation results of the conventional power are nested into the evaluation process of the new energy generation by using the idea of equal reliability substitution benefit.Then,considering factors such as planned maintenance,plant load and forced outage,the Monte Carlo stochastic simulation method is used to calculate its sufficient capacity.Finally,the sufficient capacity is compared with the peak load in the power system,and the index of generation capacity adequacy is obtained.The example analysis results show that the evaluation method is effective and sensitive,and its rationality has been verified by comparing with the traditional indexes.Finally,after comparing the schemes,the generation capacity adequacy evaluation model is applied to propose a generation capacity adequacy guarantee mechanism that is in line with the reality of China’s electricity market.The organization of capacity compensation mechanism can be divided into four steps:capacity pricing,capacity quota,fee payment and settlement.The capacity price is determined based on the investment cost of the marginal generator operating during the peak load period,and compensated capacity is assessed based on load demand and grid congestion.The analysis results of numerical examples show that the proposed mechanism meets the requirements of reliability,economy,fairness and flexibility.