Power Quality Enhancement by Shunt Active Power Filter With Improved Transient Response

This manuscript proposes the mitigation of current dependent power quality issues in distribution systems to improve the power quality. For that, Synchronous Reference Frame (SRF) theory and Instantaneous Symmetrical Component Theory (ISCT) control algorithms are implemented for Shunt Active Power Filter (SAPF). In the SRF theory control algorithm, real power flow control is delayed by 0.04 seconds when the load suddenly varies in the distribution system. This delay happens because of the presence of Phased Locked Loop (PLL)in the SRF control algorithm. As a result, the transient response is degraded in the system. To overcome this problem, a modified instantaneous symmetrical component technique (M-ISCT) is implemented in this paper. The M-ISCT control algorithm of SAPF also provides delay compensation, but it is 0.02 seconds, which is less than the delay in the SRF control method. The proposed one is validated by using MATLAB simulation, and the results shows an improved transient response.