An Improved Current Control Strategy Based On Particle Swarm Optimization (pso) And Steady State Error Correction For Sapf

Shunt active power filter is widely used for compensating harmonic current produced by nonlinear loads. As one of the critical technologies, the current control strategy has an important influence on the compensation precision and dynamic response performance. In this paper, the essential of the current-limiting demands for the comprehensive protection of SAPF are revealed, namely the limiting control objects: 1) RMS of the compensation current (mainly for the overheat protection of IGBTs and inductors); 2) the instantaneous wave of compensating current (mainly for the accurate current control and IGBT Icnom specification) and 3) the instantaneous wave of PWM-VSC modulation voltage (for the need of liner close-loop control). To avoid the over-current fault and over-modulation fault of SAPF, this paper proposes an improved current-limiting scheme based on particle swarm optimization (PSO) to achieve the two optimization targets: 1) the minimization THD for the grid-side current; 2) the maximization utilization ratio for the capacity of SAPF. Finally, simulation results verify the effectiveness of the proposed strategy.