A Novel UPQC based on variable impedance

A unified power quality controller based on a magnetic flux control tunable reactor is proposed. The magnetic flux control tunable reactor is composed of a voltage source inverter (VSI) and a transformer with an air gap. The power quality controller is divided into two parts: the harmonic open circuit part is connected in series in the system, and the harmonic short circuit part is connected in parallel in the system. Among them, the series part detects the fundamental wave component of the primary side current of the transformer, generates a reference signal, and controls the VSI to generate a fundamental wave controllable current, after the filter is applied to the secondary side of the transformer, the primary side of the transformer will show variable impedance and open circuit to the fundamental wave and harmonic current respectively; The parallel part detects the fundamental wave component of the primary side current, generates a reference signal, and controls the VSI to generate a fundamental controllable voltage, After the filter is applied to the secondary side of the transformer, the primary side of the transformer presents controllable impedance and short circuit to the fundamental wave and harmonic current respectively.By building a MATLAB simulation model, the effectiveness of the proposed unified power quality controller is verified.