H∞ repetitive control strategy based on state-feedbackfor PWM inverters
CHEN Li-gong，HONG Xiao-xiao，HU Ke-yong，XV Fang
（Key Laboratory of E&M，Ministry of Education & Zhejiang Province，Zhejiang University of Technology，
Hangzhou 310014，China）
Abstract：In order to improve PWM inverters' dynamic performance and tracking accuracy，a new control strategy incorporating H∞control，repetitive control and state-feedback control was proposed for PWM inverters. In this strategy，the inductor current state-feedbackwas introduced firstly，which can effectively increase damping ratio of the inverter system and improve its dynamic performance，and thenrepetitive control was added，which can improve the system's tracking accuracy，and finally repetitive controller by solving a standard H∞
problem was achieved，which reduces repeated process of adjusting the parameters and takes the system's stability and tracking accuracyinto account. Simulation results show that the strategy can guarantee inverter system with satisfying dynamic performance and high steadystateaccuracy，overcoming the "transient" voltage drop problem because of sudden load，even after joining the rectifier load invertersystem can output sinusoidal voltage waveform of high quality.
Key words：H∞ control；repetitive control；state-feedback control；dynamic performance；tracking accuracy