Research On Operation Control Strategy Of Hydro-Photovoltaic-Pumped Storage Complementary Generation System

With the development of renewable energy,improving the energy structure and increasing the utilization rate of renewable energy has become an important trend in the development of the power system.Due to the fluctuation,intermittency,and randomness of wind power and photovoltaic power,how to use multiple energy complementary power generation technologies to smooth the fluctuation of renewable energy has become an important research topic.Therefore,it has important application significance for the research related to smoothing the power fluctuation of wind power and photovoltaic power.In this thesis,the optimal operation strategy and real-time coordinated control strategies of the hydro-photovoltaic-pumped storage complementary generation system consisting of the hydropower,photovoltaic and pumped storage,as well as photovoltaic and load power prediction methods are studied in depth.The specific research work is as follows:The models of the hydroelectric unit,photovoltaic power generation system,and full size converter based variable speed constant frequency pumped storage unit are established.The full size converter based variable speed constant frequency pumped storage unit connects the generating motor to the power systems through a full size converter,which can realize variable speed and constant frequency operation and has greater flexibility.Also,the structure of the hydro-photovoltaic-pumped storage complementary generation system and its control architecture are established.Photovoltaic and load power prediction methods are studied.The short-term photovoltaic and load power prediction models based on the light grandient boosting machine prediction algorithm are established,and the established models have high efficiencies and strong scalabilities on the basis of the guaranteed accuracy.An ultra-short-term photovoltaic power prediction model based on improved the moving average algorithm is developed,which has strong real-time capabilities.The validity of the established model is verified by simulations based on actual cases.On the basis of considering the characteristics of the hydro-photovoltaic complementary power generation system and the characteristics of centralized hydro-photovoltaic-pumped storage complementary generation system,the optimal operation strategy of the hydro-photovoltaic-pumped storage complementary generation system is studied.The system optimization models are established with the objectives of minimizing the fluctuation of the total output power of the complementary power generation system and maximizing the power generation revenue of the complementary power generation system,including the constraints of the output power of the hydropower station,the output power of the pumped storage power station,the reservoir capacity,and the water level.The established models are solved by the genetic algorithm.The practicality of the algorithm is verified by performing simulations based on actual examples.A real-time coordinated control strategy for the hydro-photovoltaic-pumped storage complementary generation system is proposed for smoothing photovoltaic power fluctuations.Based on the empirical modal decomposition method,this strategy calculates the compensation power of the full size converter based variable speed constant frequency pumped storage unit and the small hydropower,when using them to smooth photovoltaic power fluctuations.This thesis controls the fast response of the full size converter based variable speed constant frequency pumped storage unit and the hydropower unit to provide compensation power when PV power fluctuations occur.In addition,a smoothing strategy based on the photovoltaic output power increasing rate control is proposed,which can reduce the number of rapid adjustments of the output power of pumped storage units.Simulations are performed using actual examples to verify the effectiveness and feasibility of the proposed strategy.