Output Power Smoothing Strategy Research Of Photovoltaic-energy Storage Power Generation System

In order to alleviate the energy shortage and environmental pollution,the new energy generation technology represented by PV has been developed rapidly.Although photovoltaic technology has been relatively mature,but due to the temperature and light intensity changes,PV power still has some volatility and randomness.In order to solve the fluctuation problem of the output power of PV power station,this paper studies the output power smoothing strategy of the combined power generation system from the angle of photovoltaic power curtailment,and the specific research contents are as follows:Firstly,on the basis of analyzing the principle of PV power generation,the method of establishing photovoltaic cell model under different illumination intensity and temperature is given from the two angles of circuit model and engineering model.Based on the operation history data of PV power station,the output power fluctuation analysis of PV power station is carried out.Aiming at the output power fluctuation index of PV power station,the output power fluctuation distribution of PV power station is studied,and the reason of photovoltaic power curtailment station is analyzed.Secondly,based on the analysis of electrochemical energy storage,pumped storage,super capacitor charging and discharging principle and internal composition of energy storage power station,the most widely used lithium-ion batteries are researched,and the internal impedance model,Thevenin model and PNGV model are studied.Considering the parameters of charge state,charging and discharging power and capacity of energy storage system in energy storage system,the model of simulation application of energy storage system is put forward,and the corresponding constraint conditions are established for this model.From the perspective of new energy generation,safe operation of power grids,distributed generation and micro-network,the performance index of the energy storage system is obtained,as the basis for the smoothing strategy of output power of the combined power generation system.Thirdly,the research on the station control of energy storage power station is carried out,and the Power coordination control strategy considering the regional autonomy is proposed.A partitioning method of energy storage power station is proposed,and an agent model of energy storage sub station is designed.A method of power control for an autonomic storage battery station is proposed,which provides theoretical support for the output smoothing strategy of an optical energy storage system.Finally,in order to solve the output power fluctuation of PV power station and abandon thetwo problems,the output power smoothing strategy of the combined power generation system considering photovoltaic power curtailment is established.The target function of output power control of the combined power station with photovoltaic power curtailment is established by reference national standard.According to the historical light storage combined output power of the previous time period,the current PV output power forecasting value is divided,and the output power range of the PV system is determined by the normal power generation interval and the photovoltaic power curtailment interval.Based on the established objective function,the output power of the energy storage system is optimized by genetic algorithm,and the output power of the energy storage system is determined.The simulation results show that the output power of the optimized storage system is matched with the current time of PV output power,not only can the output power of the combined power plant be smoothed,but also more effective than the original control strategy in photovoltaic power curtailment.