Design And Optimization Control Of Power Converter In Wind Compressing Air Energy Storage System

As an inexhaustible clean energy,wind power has developed quickly in recent years.However,intermittency and volatility features severely limit its development.Energy storage system can stabilize energy fluctuations,which can effectively compensate for shortcomings of wind power.Compressing air energy storage system,which has low cost,low pollution and high energy conversion efficiency,is ideally suited for wind power systems.The paper mainly studies in power converter in wind compressing air energy storage system,including research,design and optimization control.Topology,working principle and operation model are the basis of power converter.The paper analyzes the effect of the power converter in the system,and to determine the topology of power converter connecting wind turbine,DC micro-grid and vortex machines.The paper also analyzes operating mode of power converter on the basis of the topology.According to the energy flow,operating mode is divided into five categories:no-load mode,single PWM rectifier mode,dual PWM rectifier mode,PWM rectifier inverter mode,protected unloading mode.For different operating modes,this paper proposes the corresponding optimal control strategy.As for wind turbine,the paper uses maximum power point tracking power(MPPT)control to ensure the capture of maximum wind energy in current wind speed.As for the vortex machine,the paper uses maximum efficiency tracking(MEPT)control to ensure vortex machine work in the high efficiency zone,thus improving overall system efficiency.When the system needs unloading protection,dual control of DC bus voltage and power cannot only quickly realize unloading excess wind energy,but also avoid unloading device frequent pitching in and out.Modeling and control strategy of the power converter is the key to ensure the efficient operation of the system.The paper applies the theory of hybrid switching in the unified modeling of power converter and its load(PMSM).On the basis of the hybrid switching model,the paper designs optimal switching rule,taking the cost function as an assess target.When the cost function reaches minimum,the system can reach the desired state with a quick speed.By means of hybrid switching control,permanent magnet synchronous motor(PMSM)has a very fast current and torque response.Simulation is an effective means for validation of the entire system and control strategy.As can be seen from the simulation results,the power converter system can achieve MPPT control for wind motor,and MEPT control for scroll.Viewing from the results of hybrid switching control,permanent magnet synchronous motor can operate steadily and respond quickly to load mutation.The stability and dynamics of the PMSM in simulation are consistent with analysis.Simulation results laid the foundation for the subsequent experiments.Finally,the paper introduces the hardware platform,on which the operation mode of power converter is verified.In this system,dSPACE control system is used to realize the hardware debugging in the ring.In this paper,design of power converter in wind compressing air energy storage system is completed and some of the functions have been verified according to the experiment results.