PLL with PI, PID and Fuzzy Logic Controllers based shunt Active Power Line Conditioners

This paper presents a novel Phase Locked Loop (PLL) circuit in conjunction with Proportional Integral (PI) or Proportional Integral Derivative (PID) or Fuzzy Logic Controller (FLC) based shunt Active Power Line Conditioners (APLC) for the power-quality improvement such as current harmonics and reactive power compensation due to the non-linear/unbalanced loads. The shunt APLC system is implemented with three phase current controlled Voltage Source Inverter (VSI) and is connected at the point of common coupling for compensating the current harmonics by injecting equal but opposite filter currents. The compensation process is based on PLL synchronization with PI or PID or fuzzy logic controller. These controllers are capable of controlling dc-side capacitor voltage and estimating reference currents. Hysteresis Current Controller (HCC) is used to generate switching signals for the voltage source inverter. Extensive simulation studies under different non-linear and unbalanced load conditions are conducted, this simulation results analysis reveals that the APLC system performs perfectly with PI, PID and fuzzy logic control strategy. A comparative assessment of the three different controllers has been disclosed.