Research On Market Mechanism Design For Flexible Operation Of High Share Of Renewable Energy Integrated Power System

In view of“30·60”Carbon-neutral Target,constructing the new power system with renewable energy as the main body has become the future development pattern.The high proportion of renewable energy integration makes the net load curve of the system more volatile and uncertain,which puts forward higher requirements for the flexibility of the power system.Currently,China has invested a lot of money to improve the flexibility from the technical level,but it is difficult to fundamentally solve the problem of flexibility improvement only from the technical level,and a reasonable market mechanism is needed to activate the flexibility potential of the system.However,the electricity market did not take into account the integration of large-scale renewable energy and the urgent demand for flexibility at the beginning of the design,and the existing market design lacks a reasonable quantitative evaluation method for the value of flexibility,which makes it difficult to play an effective incentive role.On the other hand,different from the mature electricity market abroad,China is in the early stage of the spot market construction,the market development has certain particularity,and it will be in the dual-track system of "plan-market" for a long time in the future.Therefore,this paper studies the design of market mechanism to improve the flexibility of power system,and preliminarily constructs the theoretical framework of market mechanism design to adapt to the flexible operation of high proportion of renewable energy power system,including the evaluation of the value of flexible resources,balancing market settlement mechanism adapting flexible operation of the renewable energy power system,the capacity renumeration mechanism guarantee the abundant of flexibility resources and the allocation mechanism promoting the optimal allocation of flexible resources across regions,to explore a market mechanism suitable for the flexible operation of the new power system in China.Aiming at the problem that the flexibility value provided by flexibility resources with different characteristics is difficult to be quantified uniformly,this paper defines the flexibility value of a market member as the substitution benefit of the other members from the perspective of the system balance cost,that is,the change of the corresponding balance cost before and after the market member joins the system or the alliance.On this basis,concentrating solar power with flexible regulation ability and wind power with uncertain and fluctuating output are selected as the research objects,and a joint operation strategy suitable for market members with different characteristics and the corresponding profit sharing mechanism considering flexibility value are proposed.It is further proved that the proposed profit sharing mechanism satisfies a series of properties,such as individual rationality,balance of income and expenditure,maximization of social welfare,etc.,can motivate market members to provide flexibility,and fully tap the flexibility potential of each link of the system.Aiming at the design of balancing market mechanism which embodies the flexibility value of flexible resources to fluctuating renewable energy sources,the agent-based modeling method is used to construct a balancing market simulation model which considers the interaction between individual behavior and market mechanism.A link between the "bounded rationality" behavior of heterogeneous market participants and the effect of balancing market mechanism is established.Then,an evaluation criteria system of market operation from two dimensions of individual level and system level is set up,and a comprehensive evaluation method of balancing market mechanism based on multi-attribute decision-making are constructed.Based on the simulation analysis of typical market parameters in China,the results show that the proposed balancing market settlement mechanism can effectively regulate the behaviors of market members and reveal the real balance cost of the system.In view of the capacity renumeration mechanism to ensure the medium and long term adequacy of flexible resources,considering that in the power system with high proportion of renewable energy,thermal power units will gradually be converted from the main body of power generation to the regulatory power source,which is more reflected in the value of capacity,this paper takes thermal power as the research object,and puts forward a two-layer model which can accurately reflect the interaction of capacity compensation mechanism,thermal power unit decision-making behavior and spot market operation.The proposed model quantifies the flexibility value of thermal power units to the system operation through high-precision hour-level power system operation simulation.A capacity payment mechanism to motivate thermal power units to provide flexibility is put forward,which is able to provide accurate price signals for the future investment and construction of flexible resources.Aiming at the cross-regional optimal allocation of flexible resources in spatial dimension,this paper analyzes the benefit sources under different modes of cross-regional balancing market and their influences on social welfare distribution,and then puts forward the cross-regional balancing market cooperation surplus return mechanism by clarifying the property right of flexible resources.The proposed distribution mechanism ensures the realization of cross-regional balance and benefits,and does not change the original distribution pattern of benefits as far as possible,which is conducive to the formation of flexible resource-sharing and mutually beneficial pattern among multi-regional markets.In this paper,a quantitative method to evaluate the value of flexibility resources is proposed for the flexible operation of renewable energy power system.Based on the current situation of electric power reform in China,the methodology system of market mechanism design to improve the flexibility of power system is constructed from two dimensions of time and space,which provides a research framework for the quantitative evaluation method of the flexibility value of market members and the interactive simulation of individual decision-making and market mechanism.It is expected that the work of this paper can provide a useful reference for the development of China's electricity market and provide new ideas for the research field of market mechanism design to enhance the flexibility of power system.