Design and simulation of six-phase UPFC power quality enhancement with improved GWO based decoupled power control strategy

The unified power flow controller (UPFC) is a device used in power systems to control and optimize the flow of electric power. It is a flexible AC transmission system device that combines several power electronic components to provide comprehensive control over voltage, active power, and reactive power in transmission lines. This research offers an improved gray wolf optimization (IGWO)-based decoupled power control strategy (DPCS) for a six-phase UPFC (6P-UPFC) to enhance power quality. The proposed 6P-UPFC-DPCS divides its control efforts between reactive power control and active power control. This is because the UPFC can independently regulate the transmission line’s voltage and phase angle by decoupling the active and reactive power flows. A fault isolation technique is provided for isolating the damaged part of the transmission line, which would increase system efficiency and dependability. By analyzing the voltage and current signals at the UPFC terminals, as well as the line impedance, it is possible to ascertain whether a problem exists. After the trouble spot has been identified, the 6P-UPFC must be adjusted to compensate for the predicted impedance of the damaged line to restore power to the system. After that, the coordinated voltage and current are managed through the virtual impedance. The PI controller’s proportional and integral gains, as well as the inverter’s voltage phase angle and magnitude, are optimized using the IGWO method. The performance and dependability of the control strategy are further enhanced by tuning the controller parameters for the 6P-UPFC-DPCS controller using an IGWO approach. The simulation results show that the proposed 6P-UPFC-DPCS might reduce the false setting time to 0.01 s, boost the power factor to 0.98, and lower the total harmonic distortion to 1.40%.