In recent days, the quality of power has become more important to the most of the customer load. The unified power quality conditioner (UPQC) is the ultimate solution to provide the quality of power irrespective of the type of power quality problems. The UPQC can improve the quality of power for all end users, but it will not provide the power quality at different demand levels. Another topology Open UPQC being more flexible for field application as the power quality is determined by the electricity bills of the users. In this paper, the both the topologies are developed in the MATLAB Simulink environment and analysed the performance with non-linear loads and different types of voltage sags in the system.