Power quality enhancement in distribution line using series compensator

This paper describes the novel control techniques of VSC (voltage sag corrector) for the purpose of power quality enhancement. A fast detecting technique of voltage sag is implemented through the detection of instantaneous value on the synchronous rotating dq-reference frame. The first order digital filter is added in the detection algorithm to protect the insensitive characteristics against the noise. The relationship between the total detection time and cut-off frequency of the filter is described. The size of the capacitor bank used as the energy storage element is designed from the point of view of input/output energy with circuit analysis. Finally, the validity of the proposed scheme is proven through simulation results