Proportional-resonant based high-performance control strategy for voltage-quality in dynamic voltage restorer system

Dynamic voltage restorer (DVR) has been demonstrated to be a very effective mechanism to deal with key voltage-quality disturbances. Although the dynamic response requirement could be satisfied by a feedforward control strategy, the high-quality voltage requirement and zero-error tracking need an advanced feedback control strategy. This paper proposes a multi-proportional-resonant based feedback control strategy for DVR system. The multi-proportional-resonant controller contains fundamental resonant control loop and harmonic resonant control loops. The fundamental resonant loop could realize zero-error tracking for voltage sag; the 6k±1^th harmonic resonant control loops could compensate the harmonic components and improve the voltage quality. Frequency-domain analysis analyzes the system characteristics and provides a way for control parameters design. The simulations on MATLAB/ Simulink demonstrate the validity and superiority of proposed control strategy.