| The large amounts of power distribution systems take on the basic task of mains power supply to the widespread consumers. Along with the development of society and economy, the demand for power supply and its quality has increased rapidly in recent years. Consequently, it is necessary to analyze the abnormal state and find out the insulation hidden trouble of distribution networks. Besides, faults should be detected rapidly and effectively in order to guarantee the operation of the distribution systems safely and reliably.The small current grounding power system is a popular neutral grounding mode around the world and is widely used in our country. However, the faulty line identification and fault location in such system are acknowledged two difficult problems, which have not solved successfully for many years.Firstly, a new method of faulty line selection in distribution system is proposed in this paper, in which the signal of zero-sequence transient current is dealt with the way of the wavelet package based on analyzing the characteristics of the single-phase earth fault in distribution system. The method just mentioned is validated by a great number of simulation experiments in Matlab accurately and reliably for various distribution systems with different neutral grounding modes. Then, a new way to identify the faulty line in the distribution systems, two current transformers only installed in phase A and C, has been presented. Finally, the fault location algorithm has been presented, combining the Wavelet Package Transform and the Neutral Network.Theoretical analysis and a variety of simulation results show that the proposed methods are accurate and reliable. They are suited for various small current grounding systems, furthermore, the robustness and feasibility of there schemes are also testified. And the method of fault location in distribution systems proposed in this paper has also been validated by many simulation results.
|
PDF Full Text Request