Study Of Fault Line Detection Device Based On DSP And Wavelet Packets Reconstruction Algorithm In Distribution Networks

Fault detection in distribution network is being a worldwide knotty point for along time. In this paper, a new method of fault detection is presented based on thedeeply studying of phase-to-ground fault transient conditions and the wavelet packetsreconstruction technology. a comprehensive intelligent method to detect the faulty lineis proposed. In this faulty line detection method, first the zero-sequence current isdecomposed by wavelet package with the advantage of time-frequency zoom , andthen the signs of the reconstructed instantaneous current values are comprehensivelycompared in the characteristic band that is chosen based on the principle of maximumenergy. A lot of simulation results by alternative transient program show that theproposed method can realize the faulty line detection when the phase voltage is closeto its peak value as well as the phase voltage is close to its crossover point.According to the requisition of wavelet algorithm, a hardware platform forgrounding line detection of distribution network based on digital signal processor(DSP) is constructed .The hardware architecture and its operation results areintroduced.and on this platform the proposed comprehensive intelligent faulty linedetection method is verified. The simulation and dynamic analogy experimentationtest results show that the presented software and hardware possess followingadvantages, such as high calculation speed, high anti-interference ability, highperformance to cost ratio and stable operation. The developed fault line detectiondevice on distribution line is based on the algorithm of dsp and the wavletreconstruction. and the device has hign successful possibilities on the flaut linedetection. So it has a broad future in the application field .