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

Voltage sag and harmonic pollution have a serious impact on the medium-voltage premium-power-supply-required park represented by optical semiconductors, data storage, precision instruments and biopharmaceuticals. Which makes existing equipment require higher voltage capacity of power electronics, higher economic cost and compensation performance. In this paper, 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 IH-UPQC 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.