Improving the dynamic response of shunt active power filter using modified Synchronous Reference Frame PLL

This paper evaluates an algorithm for three-phase active shunt power filter using a digital PLL based on Modified Synchronous Reference Frame (MSRF). The Modified Synchronous Reference Frame PLL (MSRF_PLL) algorithm guaranty fast transient response, robust operation under grid disturbance, noise tolerance and does not use PI controller. Therefore, it improves the transient response and accuracy of compensating harmonic currents. The PLL algorithm is applied to a Three Phase Shunt Active Power Filter and the system behavior is described in details and the practical results, under load variation and steady stated harmonic compensation, are presented and discussed.