Simulation of 3-wires and 4-wires UPQC to improve the quality of power under balanced and unbalanced nonlinear load conditions

Power electronics has the ability to control electric power in the most effective and economical way and it plays a leading role in the transmission, distribution and application of electrical power, However, the non-linear properties of power electronic devices add harmonics which greatly reduces the power efficiency and hence the Power quality has become the severe issue for both customers and utility. Many devices are designed to increase the efficiency of electricity at the customer end. Now a days, UPQC has proven to be an effective device used to alleviate power quality issues in the distribution network. It has the ability to eliminate both voltage and current based problems simultaneously. This paper presents, 3-phase 3-wires UPQC system and 3-phase 4-wires UPQC system modelled using MATLAB which is used to eliminate the power quality issues. The shunt APF of UPQC uses PQ-theory based control technique and nonlinear adaptive filter is used in the series APF of UPQC. The THD analysis is used to determine the efficiency of UPQC. On comparing the results, it can be seen that the THD value with UPQC is less, suggesting an increase in power efficiency.