Research on three‐phase VSR segmented PI synergetic control strategy based on LCL filter

Abstract

In view of the resonance phenomenon caused by LCL filter introduced by voltage pulse width modulation (PWM) rectifier as well as the inability of traditional PI adjustment to meet the needs of different load changes, this article proposed a segmented PI synergetic control strategy for the LCL filter rectifier based on the proportional-integral manifold form synergetic control strategy. First of all, a synergetic controller based on the proportional-integral manifold was constructed; secondly, particle swarm optimization was used to optimize PI parameters under different load conditions; thirdly, the optimized PI parameters were used to establish a segmented trigger database, taking load impedance as the trigger condition. The control strategy made full use of the LCL filter's ability to suppress higher harmonics and the PI adjustment is simple and fast under specific loads. The synergetic control theory has a lot of advantages, including chatter-free, simple control ideas, easy implementation, etc. Simulation experiments verified that the control strategy could effectively reduce the harmonic content, avoid resonance phenomena and improve system stability, and it was characterized by high control accuracy and simple structure.