Compensation strategies based on SPLL for dynamic voltage restorer

According to the sensitivity of load to voltage amplitude or phase jump, UDVR (Uninterrupted Dynamic Voltage Restorer) adopts different compensation strategies, such as pre-sag compensation strategy and in-phase compensation strategy, which are introduced with phasor diagram. An improved integrated compensation strategy is proposed. Three strategies mentioned above are respectively implemented by adjusting the settings of SPLL(Soft Phase Locked Loop) and the parameters of PI controller. Matlab/Simulink based experiments for single-phase voltage sag compensation verify that, compared with the in-phase compensation strategy, the improved integrated strategy mitigates the phase jump, and compared with the pre-sag compensation strategy, it decreases the injecting voltage amplitude of UDVR.