Microgrid Wind And Solar Storage Collaborative Control Strategy

With the continuous development of society,people's demand for electricity is getting higher and higher,and it plays a very important role in our daily life.Therefore,the requirements for electrical energy are also more stringent.Wind power and photovoltaic power generation have attracted worldwide attention due to their own advantages: renewable,low cost,and flexible power generation.However,since the output of wind power and photovoltaics is related to natural conditions and climate,it is difficult to provide stable voltage and current to the grid,so the control problems for them need to be studied.The voltage and frequency in the power grid will affect the power quality and operational safety of the power grid,which will cause unnecessary impact on human production and life,and bring serious economic losses to the enterprise,which will seriously lead to power accidents.In order to solve this problem,the micro-grid concept is proposed to connect the micro-grid to a large power grid through a common connection point.It can operate in an island mode and a grid-connected mode,which solves the shortcomings of unstable power supply of a single power unit.Firstly,the basic principles and mathematical models of photovoltaic power generation system,wind power generation system and storage battery are analyzed.Three kinds of micro power supply simulation models are built in MATLAB/Simulink,and the effects of power,current and voltage are simulated from various factors verification.The simulation results show that the output power of photovoltaic power generation system and wind power generation system is affected by environmental factors,and the maximum power tracking control can be realized.At the same time,the battery can maintain the DC voltage constant.Secondly,the micro-grid simulation system model with wind and light storage is established.The simulation of the system's network mode and island mode is carried out.The simulation results show that the micro-grid can operate safely and stably,and achieve good grid-connected conditions.Finally,for the power sharing control of the independent microgrid,this paper analyzes the principle of the traditional droop control power sharing in detail.Since the frequency in the system remains stable,the active power can achieve good power sharing,but the micro power output the voltage is difficult to achieve equalization due to the existence of the line impedance voltage drop.For this reason,we propose an improved droop control method.By improving the droop coefficient,even if the voltages output across the micro power supply are not equal,it can meet the equalization of reactive power,so that the micro power supply evenly distributes the load charge to ensure stable and safe operation of the system.The simulation model of two parallel micro-power supplies is built by MATLAB/Simulink.The simulation results show that the improved droop control method can achieve equalization of reactive power and ensure safe and stable operation of the system.