A novel detection and control strategy of power quality

To overcome traditional methods' shortcomings of inherent time lag and sensitive to system parameters, a strategy based on gray system theory was proposed. GM(1,1) was constructed repeatedly by gray data sequence of distortion components. It could forecast distortion signals of next period and select the optimal control strategy to produce compensation signals. Before new predicting the oldest data was eliminated and the latest data was added to data sequence. GM(1,1) can always reflect the latest system action and not increase calculation quantity. The deadbeat track control strategy makes unified power quality controller(UPQC) compensate distortion components without delay. Simulation results show that it can effectively improve power quality and is characterized by less calculation, high accuracy, fast speed and good flexibility. (6 pages)