An Inductive Hybrid UPQC for Power Quality Management in Premium-Power-Supply- Required Applications

In this project, an Inductive Hybrid Unified Power Quality Conditioner (IH-UPQC), which is characterized as high integration, reduced DC-link voltage and satisfactory harmonic isolation of transformer, is presented to realize the bi-directional power quality improvement for medium-voltage premium-power-supply-required park. 

First, the three-phase equivalent circuit and mathematical model are established to reveal the mechanism of harmonic suppression and voltage regulation. Based on the theoretical analysis, the compound control strategy of series and shunt Hybrid Active Power Filter (HAPF) as well as the synchronous method sliding Goertzel discrete Fourier transformation-pre-filtering Phase Lock Loop (PLL) are designed. 

Then, the main circuit components design including Double Resonant Passive Filter (DRPF), L-C-R low pass filter and the special designed filtering winding for implementing inductive filtering method are described. Finally, the performance of IHUPQC is validated in 10kV distribution network by MATLAB/Simulink. The simulation results demonstrate that the IH-UPQC is effective to perform grid voltage regulation, load harmonic current suppression and reactive power compensation.

Keywords: Inductive filtering method, Unified Power Quality Conditioner (UPQC), Double Resonant Passive Filter (DRPF), Neutral Point Converter (NPC), Synchronous Reference Frame (SRF), Hybrid Active Power Filter (HAPF), Power Quality (PQ), Phase Lock Loop (PLL).