Unified series-shunt compensator: modeling and simulation

This paper presents the model and simulation of a unified series-shunt compensator (USSC). An accurate model of the USSC is developed aimed at examining its capability in mitigating power quality problems in a power distribution network. The USSC simulation model comprises of two 12-pulse inverters which are connected in series and in shunt to the system. A generalized sinusoidal pulse width modulation (SPVVM) switching technique is developed in the proposed controller design for fast control action of the USSC. Simulations were carried out using the PSCAD/EMTDC electromagnetic transient program to validate the performance of the USSC model. Simulation results verify the capabilities of the USSC in performing voltage sag compensation, flicker reduction, voltage unbalance mitigation, power flow control and harmonics elimination.