Performance Enhancement of Unified Power Quality Conditioner with PID Controllers

Power quality should be maintained in distribution system to operate various loads effectively. Generally unbalanced loads are operating in three phase distribution system due to single phase loads. Along with these, nonlinear and reactive power loads are also connected to three phase load bus system. These all loads cause poor power quality by supplying unbalanced and harmonic voltage at load bus. Hence, voltage should be maintained constant as well as harmonic free supply. The voltage can be restored by connecting dynamic voltage regulator (DVR) at load bus. Similarly a DSTATCOM is required to inject currents into load bus as well as to compensate reactive power. Therefore the combination of DVR and DSTATCOM can able to supply quality power at load bus. This system is generally calling as unified power quality condenser (UPQC) in a distribution system. A novel control method is developed on UPQC in this research work to improve the power quality under various operating conditions. In order to present various results, hardware – in the – loop (HIL) is established by connecting two OPAL-RT modules in a loop.