Design and Analysis of Cascaded Generalized Integrators for Mitigation of Power Quality Problems

This paper presents a detailed analysis of the effect of using cascaded generalized integrator (GI) blocks for power quality improvement in the single-phase distribution system. Second order Generalized Integrator (SOGI) is a conventional algorithm which generates filtered in-phase and quadrature component of the input voltage or current signal. The paper explores multiple cascaded SOGI blocks for mitigation of power quality problems. The paper aims to determine the optimum number of cascaded GI blocks and considers analysis of several SOGI blocks upto 10
^th
order. The SOGI algorithm has been realized for synchronization as well as estimation of fundamental load component in this paper. Studies on the basis of filtering capability, response time, mathematical complexity and other factors are presented by connecting several cascaded SOGI stages together. Open and closed loop working of proposed algorithm have been investigated. Closed loop analysis has been demonstrated for control of shunt compensator and verified by simulation and experimental results.