Abstract：The electricity power price setting mechanism will be fundamentally reformed with the continuous

advancement of a new round of electricity market-oriented reform. Presently，some provincial and regional power

grid enterprises are facing the problem of large fluctuations in electricity prices，which is not conducive to the indepth promotion of electricity marketization reform. Firstly，based on the partial least squares method，the agency power purchase price formation model was established. Then，the main factors affecting the fluctuation of power purchase price were analyzed，and the mechanism of the influence of power supply and consumption balance on the price change of different types of electricity consumption was clarified. In order to reduce the fluctuation of electricity purchase price，a multi-objective optimization model of agent electricity purchase was established with the constraint of power supply and consumption balance. The actual example results show that the model can realize the reasonable distribution of power consumption among different types of power sources in the process of agent power purchase，and effectively reduce the fluctuation of agent power purchase price.

      Key words：fluctuation of electricity purchase price；agent power purchase；partial least squares；next

generation power system；flattening fluctuations in electricity purchase prices