Cyber Physical System Control And Hardware-in-the-loop Realization Of Wind-solar-storage Microgrid

With the intensification of energy crisis and ecological environment problems in various countries in the world,it is urgent to develop renewable energy.However,the power generation capacity of intermittent energy represented by wind power and photovoltaic is limited by natural factors.There are problems that it cannot be directly used by the distribution network and the output power is unstable.In view of these shortcomings,microgrid technology can not only deal with the grid-connected inverter problem of renewable energy power generation,but also balance the energy buffer of wind and photovoltaic power generation to make the system run more stably.In recent years,the traditional power network has been gradually improved,and the microgrid system has also become more and more complex.Information and energy frequently interact and influence each other in this huge system,thus forming a microgrid cyber physical system（CPS）.The research of microgrid CPS plays a vital role in the development of the current microgrid system.Based on the modeling and analysis of wind,solar and storage systems,this paper uses the idea of layered control to design control strategies in the bottom and top control of the system to enhance the stability and economy of the microgrid CPS.The main research contents of this paper are as follows:Firstly,the wind power generation system,photovoltaic power generation system and energy storage system in the microgrid CPS are modeled.Their operation mode,working characteristics and control method are studied.Aiming at the problem of low power generation efficiency of wind power system and photovoltaic system,the variable-step disturbance method is used to achieve maximum power tracking.Simulink simulation method is used to prove the superiority of this method.Secondly,in the underlying control of microgrid CPS,the control algorithms of wind and solar system inverters are studied and simulated,and a three-loop control algorithm based on droop control is proposed for energy storage system inverters.The results of offline simulation of the entire underlying system further prove that the control strategy and control algorithm in this paper meet the expected goals,briefly describe the functions and goals of the upper-level control,and lead to the research content in the next section.Then,aiming at the optimization problem of microgrid CPS,a new optimization scheduling strategy based on improved particle swarm optimization is designed.The strategy aims to minimize the comprehensive cost including the initial investment cost,maintenance cost and power exchange cost of the system,considers every constraint condition of the system,and uses offline simulation to prove the feasibility of the optimization algorithm designed in this section.Finally,the CPS hardware-in-the-loop simulation verification method of wind-solar storage microgrid is studied,and a hardware-in-the-loop simulation system based on Star Sim and PXI is built.The system structure and workflow of the hardware-in-the-loop simulation are expounded,and the feasibility of the microgrid CPS modeling method,control strategy and optimal scheduling strategy is further verified through the hardware-in-the-loop simulation system.