A new bilateral equivalent pay as bid(PAB)clearing mechanism and a unified clearing mechanism in the electricity market are compared and analyzed based on the co-evolutionary algorithm. As a kind of artificial intelligence algorithm

the co-evolutionary algorithm has gradually become the focus of theoretical analysis and engineering practice in recent years. Because it meets the concept of evolutionary game and can fully reflect the market dynamics

this algorithm has been widely used in the research of electricity market. Based on the PAB clearing method and the clearing method used in Guangdong electricity market in 2016

a bilateral equivalent PAB clearing mechanism under the step-wise bidding is proposed. The co-evolutionary algorithm is used to compare and verify the unified clearing mechanism and the bilateral equivalent PAB clearing mechanism. The simulation results show that compared with the unified clearing mechanism

the market using bilateral equivalent PAB clearing mechanism is more stable

and the market clearing results are closer to the intersection of market actual supply and demand curve

thus can reflect the real situation of electricity market better.