Modeling and Control Analysis of a Hybrid Unified Power Quality Conditioner

Abstract

With the widespread use of large-capacity power electronic devices, there are too much harmonic current and harmonic voltage in power system at the same time. The active power filter (APF) or hybrid active power filter (HAPF) can only eliminate harmonic current or harmonic voltage, and possibility resonance. To eliminate harmonic current and harmonic voltage in power system simultaneously and enhance the capacity, the paper presents a hybrid unified power quality conditioner (HUPQC). Compared with UPQC, the HUPQC is made up of a hybrid series active power filter (the series device) and a shunt active power filter (the shunt device). The shunt device employs an injection circuit to lower the capacity of the active part to fit high-voltage power system. Designed reasonably, and controlled with composite control method, the HUPQC can filter the harmonic current and harmonic voltage effectively at the same time. At the end of this paper, the simulation and experiment results improve that the HUPQC can prove the power quality greatly and achieve satisfactory effect. Keywords-harmonic current; harmonic voltage; UPQC;HUPQC; active power filter; power quality I.

Voltage Dip/Swell Mitigation and Imaginary Power Compensation in Low Voltage Distribution Utilizing Improved Unified Power Quality Conditioner (I-UPQC)

“…Schematic UPQC System configuration [26] Out of all the recently used PQ improvement approaches, the unified power quality conditioner has a comparative advantage for sag and swell compensation capability. The sags on distribution system can be controlled with three major approaches in UPQC: i) the real power control (UPQC-P) [27,28]; ii) controlling imaginary power UPQC-Q [29,30]; and iii) a lowest apparent power loading approach by injecting series voltage at a specific angle [23,24,31], which is known as UPQC_VAmin. The work outcome in [24,31] concentrated on the optimal VA load of the series inverter of UPQC, most importantly during sag condition.…”

Improve Power Quality with High Power UPQC

“…Series device of UPQC is mainly to filter utility voltage and adjust voltage exerted on load so as to eliminate harmonic current produced by utility harmonic voltage and provide load a good sinusoidal voltage (Brenna et al 2009;Zhou et al 2009). Series device of high power UPQC has the same topology as series APF whose Configuration is shown in Fig.1.…”