Identification Method And Its Application Of Lightning Wave Invading Grid

Almost all high voltage transmission lines use overhead lines, it is inevitable that the possibility of being struck by lightning. The number of data and the actual operating experience of the grid shows that among the power grid transmission line fault tripping, more than40%is caused by lightning. Lightning strike is harmful to security and stability of the power system. According to whether the lightning strike causes fault, it can be divided into lightning with fault and lightning without fault. Lightning with fault will leads to the operation of the protection, in order to quickly restore power supply, according to the power system field operating procedures for re-closing successful line artificial coincidence, for the lightning fault no problem, but for the external cause failure, artificial coincidence could endanger the lives of others; not cause a malfunction lightning may cause malfunction of EHV line transient protection, recognition of this lightning interference is a difficult problem to practical transient protection must be addressed. In actual operation, the need for power system disturbance classification to distinguish accurately the fault, to improve the security of electricity supplyChapter II of this paper specifically describes the disturbance identification method, a particular substation according to the Shandong power grid using PSCAD/EMTDC to build a simulation model to simulate the different disturbances, followed by the different disturbance waveform analysis presented S transform to extract the waveform characteristics to construct the idea of the identification criterion, and use the MATLAB identification procedures to conduct a detailed analysis of the PSCAD/EMTDC simulation data to verify the feasibility of the identification method. The third chapter describes the composition of the hardware system and various technical indicators. The fourth chapter describes the back-end application software development and system implementation plan. Finally, the research and inadequacies are summarized, and directions for future research are prospected.This paper use high-speed data acquisition technology, network communication technology, data mining and signal processing techniques, and fault identification theory, develop a set of real-time monitoring atmospheric over voltage invasive wave disturbances on the grid monitoring applications. The system uses a master-slave structure, constituted by the high-speed data acquisition and communication sub-station and data analysis and processing master. Temporary steady state signal of the underlying collection terminal based on the high-speed DSP data bus, and GPS technology, on-line real-time high-speed acquisition of substation bus voltage and the wire current, and real-time through the mass storage and communications module to upload the recorded data; master analysis software using data processing, classification, fusion, and intelligent analysis capabilities, waveform display and features a variety of transient process caused by grid disturbances extraction, disturbed nature of the discrimination, the precise positioning of the on-line characterization of the lightning amplitude and steepness parameters and fault provide technical support for lightning monitoring, mine design, power transmission equipment, state of maintenance and dispatcher on the trip because discrimination.Disturbance recognition system by installing tired strike of lightning monitoring to collect the information of operation of electrical equipment, in-depth analysis of the lines, substations different location, different forms of wiring, equipment and lightning fault and its impact can guide the construction of smart grid unreasonable grid and device structures to be refined and continuously improve the reliability of power supply and grid security and stability.