Design of the Electricity Spot Market Model Based on Renewable Energy Quality Quantificationn

In order to solve the problem that the traditional electricity market mechanism can’t fully reflect the characteristics differences between renewable energy generations and conventional generations, a spot market trading model of the electricity market with high renewable energy proportion was proposed in this paper. Firstly, the renewable energy generation attributes were divided into resource attributes and load attributes, and the difference of the settlement between the real-time market and the day-ahead market caused by renewable energy generations was defined as the system balance cost. By analyzing the impact mechanism of renewable energy attributes on the system balance cost, the accuracy index and correlation index were used to describe those attributes. The renewable energy power quality index was further presented using the improved cross-entropy method. Combining this index and the system balance cost, the renewable energy power quality price was obtained for quantifying the power quality of the renewable energy. Secondly, the clearing model of the PJM market in the U.S. was improved. Renewable energy generations were added with the power quality price and cleared together with conventional generations. A market trading environment with competition on the same platform was established and the incentive-compatible settlement rule was proposed. Finally, an improved IEEE 30-nodes system example was used to verify the effectiveness of the proposed model. The case results showed that the proposed clearing method can achieve a priority consumption of high-quality renewable energy, reduce amounts of power deviation between the day-ahead market and the real-time market, decrease the system balance cost and the market average electricity price. Moreover, conventional generations can get extra income during the peak load period and the strategic bidding of renewable energy will increase its loss by an average of 9%. The research reflected that the proposed model is in favor of the improvement of renewable energy quality and fair competitions. The proposed model provides a solution to the fixed cost recovery of long-term marginal units, guides future capacity investment of conventional units and provides capacity guarantee for the construction of new power systems. © 2023 Editorial Department of Journal of Sichuan University. All rights reserved.