Research On Detection And Identification Of Transient Power Quality Disturbance For Power System With Wind Energy Generation

Wind power generation has become the world’s fastest growing, green and cleanenergy. As the increasing proportion of wind power in power grid, the power qualityproblems in system which connected with wind power generation are also growing.Therefore, the detection and identification of power quality in grid which connected withwind power genetation has become the research focus. In this paper, transient powerquality problems caused by wind power integration are analyzed, and have researcheddetection and identification of transient power quality.Wavelet denoising method is carried out the research because of the existence ofcertain noise in transient power quality disturbances of wind power integration. Aftermulti-resolution signal decomposition of disturbancs, multi-scales information infrequency donation is denoised by sqtwolog threshold and the soft and hard thresholdcompromised method. Simulation results show the better denoising effect.Lifting complex wavelet is used to detect transient power quality disturbances bywind power integration. Lifting scheme algorithm is introduced to complex wavelettansform, and the Euclidean decomposition principle is used to design the lifting schemeof db4complex wavelet. Simulation results show that the proposed method locates thedisturbance singularity more precise and accurate by the phase information, and therealization process is simple to improve the computing speed, shorten the detection time.Finally, this dissertation carried out the research on identification of transient powerquality disturbances based on wavelet transform and RBF network. After multi-resolutionsignal decomposition of disturbance and standard voltage signal, multi-scales energyinformation in frequency donation can be extracted. The difference of the two energyinformation is normalized and input to the RBF network classifier as the feature vector toachieve the identification of a variety of transient power quality disturbances.