Investigation on reduced DC link voltage based UPQC for harmonic compensation under unbalanced load

摘要

The unified power quality conditioner (UPQC) is one of the major solutions for harmonics in the power distribution network. This paper presents reduced DC link voltage based UPQC for mitigating current harmonics and voltage harmonics due to the load and source in the distributed network. In the modified UPQC, introduce a small capacitor in series with the coupling inductor of the shunt filter. In this paper reducing the rating UPQC, by reducing the DC link voltage, hence the switches rating of the system. The modified UPQC provides effective suppression of the voltage harmonics and current harmonics under varying load conditions. Also, it simultaneously balances the current and voltage in the system under unbalanced load conditions. Here the analysis done by using the three phase three wire system with UPQC for mitigating the power quality issues. The parameters of UPQC are calculated from the state space time average modal. Also, the stability of the system is verified by using state space analysis with Lyapunov theorem.