Double-layer energy storage operation strategy that takes into account PV output error and smooths out fluctuations

Abstract

In order to meet the grid connection requirements of new energy power generation and ensure the stable operation of the power system, in view of the security problems brought by the uncertainty and volatility of intermittent new energy power generation to the stable operation of power grid equipment, a bilevel programming model aimed at compensating the output error and stabilizing the grid connection power fluctuation is proposed. First of all, the capacity and error satisfaction rate characteristic curve is constructed to obtain the optimal energy storage capacity to improve the economy of the energy storage system. Then, the upper planning model takes the minimum output error as the goal. The charging and discharging power distribution strategy of the energy storage system is established, the cycle life of the energy storage battery is considered and unnecessary compensation values is set to avoid its overcharge and overdischarge. The lower planning model takes the minimum grid connection fluctuation rate as the objective function, and the model predictive control algorithm is adopted to carry out the advanced rolling optimization control for the compensated photovoltaic output, so as to achieve the smooth fluctuation of photovoltaic output. Finally, based on the above model, the model evaluation index function is established, and a 21 MW photovoltaic power station in Xinjiang is taken as an example to verify the feasibility of the strategy.

Keywords

• new energy power generation
• compensate the prediction error
• stabilize power fluctuation
• bilevel programming model
• model predictive control
• evaluation index function