Performance assessment of current source converter based UPQC for power quality improvement with simple control strategies

Abstract

The unified power quality conditioner (UPQC) is predominantly designed and implemented by utilizing the voltage source converter (VSC) topology with proportional - integral (PI), Fuzzy logic and Artificial Neural Network (ANN) based controllers, etc. for mitigating electric power quality (PQ) problems in distribution systems. The availability of very few literature on the application of current source converter (CSC) topology in custom power device (CPD) suggests that there are still significant research scopes in this area. This paper proposes a right shunt configured UPQC model based on the much overlooked CSC topology. The proposed model is controlled by two simple controllers viz. PI and Hysteresis band controllers acting in a coordinated manner eliminating the interference between the shunt converter and passive filter, requirement of the pre-charged capacitor on the DC link section and works with greater reliability, fault-tolerant, and efficiency. The performance assessment of the proposed model has been carried out through simulation with the help of Matlab©-Simulink. The results of the simulation study reveal that the proposed model can alleviate both the problems of voltage sag and harmonics simultaneously in a secondary power distribution system feeding a nonlinear load thereby improving power quality to the levels prescribed by the IEEE Standards.