Research On Active Disturbance Rejection Control Strategy Of Hybrid Energy Storage

In order to ensure the safe and stable operation of the photovoltaic microgrid,this paper takes the hybrid energy storage system as the main research object,absorbing in how to suppress the instability of the system due to the light intensity,load changes and grid-side fluctuations.In this paper,the following research work is carried out around the control strategy and parameter identification method of hybrid energy storage.This article first analyzes and compares the different circuit models of batteries and supercapacitors,builds mathematical models of different energy storage units in the hybrid energy storage system in the two-way DC-DC state,and determines the dual DC-DC parallel structure to realize the hybrid energy storage system Flexible control.Aiming at the problems of poor power frequency division response between energy storage devices and weak disturbance rejection ability in photovoltaic microgrid,This thesis puts forward a hybrid energy storage control strategy for photovoltaic microgrid based on feedforward active disturbance rejection(FK-LADRC).By introducing feedforward active disturbance rejection control in the voltage loop control,the dynamic response speed and anti-interference performance of the hybrid energy storage system are improved,and low-pass filtering is set to realize the power frequency division response between different energy storage devices.At the same time,linear active disturbance rejection control is introduced into battery current loop control and super capacitor current loop control respectively to achieve coordinated control between different energy storage devices,thereby improving the power stability on the grid-connected side.The results of frequency domain analysis prove the effectiveness and stability of the proposed control strategy.The simulation results show that the proposed control strategy can quickly carry out power division frequency distribution,and at the same time coordinate the effective operation of the photovoltaic microgrid.Aiming at the problems of active disturbance rejection controllers such as difficult selection of parameters and coupling between parameters,In this paper,an adaptive parameter identification strategy of ADRC based on chaotic particle swarm optimization(NCPSO-ADRC)is proposed.Based on the research of traditional parameter identification,this paper takes the objective function of the controller parameter identification as the controlled target,adopts the iterative optimization calculation of the chaotic particle swarm algorithm,and adapts the inertia weight factor to achieve the local optimum.Particles trapped in the local optimum can be re-searched globally.At the same time,In order to realize the parameter identification and optimization of the controller,The external archive function is used to select the optimal objective function value.The results of the simulation show that the parameter identification efficiency and identification accuracy of the active disturbance rejection controller can be improved by the proposed control strategy,and maintain the stability of the hybrid energy storage system.