Research On Passivity Based Control And Performance Of Energy Storage Inverter

With the increasing penetration of new energy power generation and the proposal of carbon peak and carbon neutralization strategy,renewable energy has been vigorously developed and energy storage has ushered in development opportunities.As the key equipment connecting the energy storage system and the power grid,the steady-state and dynamic performance indexes of the energy storage inverter are particularly important from the perspective of operation.Therefore,the research on the control strategy of the inverter is an important way to improve the performance indexes of the inverter.Due to the strong coupling,high-order and nonlinear characteristics of the inverter model structure,the traditional control is difficult to ensure the good dynamic performance of the inverter.As a nonlinear control strategy,passive control improves the dynamic performance and anti-interference ability of the system.This paper studies the energy storage inverter running in grid connected mode.Based on the traditional active damping control and Euler-Lagrange(EL)passivity-based control strategy,the mathematical model and EL model of LCL inverter are established,the PI controller parameters and active damping coefficient are designed in detail,and the passivity-based controller is designed through damping injection,It is verified that the passivity-based control of EL model can’t effectively improve the dynamic performance index and anti-interference ability of the system.Aiming at the problems of large steady-state error,slow response speed and weak anti-disturbance performance in the passivity-based control of EL model,this paper adopts the interconnection and damping assignment passivity-based control(IDA-PBC)method;Aiming at the problems of multi-variable mutual coupling of the control model and the complex control structure,and the decoupling equivalent control model of IDA-PBC is established.Based on this model,an injection damping parameter design method is proposed.Through closed-loop characteristic analysis and simulation,it is verified that IDA-PBC can reduce dynamic overshoot,accelerate dynamic response speed and improve the anti-disturbance ability of the system,but there are still steady-state errors.In order to eliminate the steady-state error,an integral IDA-PBC control strategy and parameter design method are proposed.In the dynamic process of power switching,the grid connected current adopts damping control,which has good dynamic anti-interference performance of IDA-PBC.In the steady-state,the grid connected current adopts integral controller,which has good steady-state performance,greatly reduces the steady-state error and improves the global stability of the system.Finally,the MATLAB/Simulink simulation model and experimental platform are used to verify the control strategy studied in this paper,and the software and hardware of the platform are introduced.Based on the platform,experiments of traditional active damping control,IDA-PBC and integral IDA-PBC control were carried out.The simulation and experimental results verify the correctness and effectiveness of the theoretical analysis and research results.