| With the applications of more and more power electronics equipments, the power quality issues become more and more severe.. Harmonics, reactive power, voltage flicker and negative-sequence current of power grids can affect the power quality and harm the power equipment badly. Traditional methods only can settle power quality problems partially. As the electronics and control technique develop rapidly, unified power quality management equipments included unified power quality conditioner and unified power flow conditioner become more mature and available, which are expected to improve power quality generally. The unified conditioning technology of power quality, based on power electronic technology, is one of all important branches of custom power. Unified Power Quality Conditioner(UPQC),composed of a parallel and series conversion system is of the general ability to adjust power energy. It can not only improve the network current quality but also the load voltage quality. Traditionally, the device for power quality conditioner can compensate distorted voltage wave form and current wave form respectively. However, UPQC, which has capacity of simultaneously coordinating voltage and current wave form compensation and satisfy the demand of the power consumer and supply system, must have a prospective future. This paper, based on practice of improvement of power quality, deals with the theory, topology, real-time algorithm for distorted wave form, compensation strategy, control strategy for loop system.This paper, at first, introduces the development actuality and present problem existed. On the base of analysing the principle of the active power filter, introduces the topological configuration and principle of UPQC; the following studies on real-time detection of distorted component of current and voltage wave form, and the compensation control strategy and simulation of UPQC. The result shows that the control strategy which referred in the paper has better effect. |
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