A joint bidding mode for charging stations approaching social welfare maximization

Abstract

Megawatt supercharger stations will act as price-makers due to their large charging capacity. However, charging station operators (CSOs) have different accuracy in forecasting clearing price. Disordered bidding caused by asymmetry information will cause unnecessary social welfare loss. For this, a joint bidding mode that is easy to apply and approaches social welfare maximization is proposed. A third-party operator (TPO) is introduced as an assistant of the market operator to joint and coordinate CSOs, while retaining the local checking role of the distribution system operator (DSO). Little private information is exchanged to coordinate a large number of multi-region CSOs to bid on the premise of considering the interests of all players and the operation of both transmission and distribution systems. Graphical method is used to prove that the TPO can adjust the lower bound of bid/offer price of CSOs to approach the social welfare maximum. Taking the three-month load data of the UK power grid as a case, the deviation is concentrated in the interval [6.2%, 13.5%], with a minimum deviation of only 2.1%.