Research On Control Method Of Complex Current Compensator Based On RTDS

Presently, with the development of power system and widespread use of non-linear loads, the pollution of reactive power, harmonic current and negative sequence current in power quality has become increasingly prominent, and different kinds of compensating device used to enhance the power quality developed rapidly. The control method, simulation analysis and experimental research were carried out in the paper.The paper presented detail introduction on the structure of complex current compensator and operation principle, deduced the formula of inverter side of compensator, studied on the detecting method and control methods of DC voltage and output current loop. By comparing of the existing harmonic detection methods, the d-q algorithm based on the instantaneous power theory was introduced. Single-phase PWM rectifier was designed as a DC capacitor voltage control method to ensure capacitor voltage balance. The paper researched on the control strategy of the current compensator and designed fuzzy self-adapted PI control with strong robustness, which did not depend on the system model in output current loop and realized the self-adjust of PI parameters. Besides, based on the fuzzy self-adapted PI control and according to the periodic character of the reference signal of current compensator, repetitive control was introduced to improve the performance of system steady state and analyzed in detail.Simulation model was built up based on RTDS and external digital controller was connected to RTDS to test the detecting method and control algorithm. At last, the experimental results of low-voltage compensator verified the correctness and effectiveness of this compensator as well.