Research And Design Of High-Impedance-Irounded Fault Detecting Device In Transmation Line

Transmission line trip accident is one of the most frequent accidents in power system, it not only treatens the stability of power system operation but also brings great impact on power system reliability. At present, with the construction and development of smart grid, according to the characteristics of the transmission line fault traveling wave current and based on traveling wave theory, the diagnosis results of fault location and fault reasons have important significance on operation maintenance and make effective emergency measures for power systems.When the transmission line high-impedance-grounded fault occurs, because of the large flashover channel transition resistance, the amplitude of travelling wave current decays quickly, it is difficult for the substation fault recorder to record the traveling wave current waveform, bring great difficult to fault diagnosis. Based on this, on the basis of the current domestic research results, this paper carries out the research on little travelling wave recorder for high-impedance-grounded fault, it is applied to the fault location and fault diagnosis of transmission line traveling wave, it can use the intelligent recognition technology to analysis the waveform characteristics of fault to determine the location of the accident and the reason, it will effectively reduce the smart grid trip rate, improve power supply reliability and reduce maintenance costs.The work of this paper mainly includes the following several aspects:First of all, it carries out theoretical research about transmission line high-impedance-grounded fault, and analyses the vegetation type wave process of transmission line high-impedance-grounded fault flashover.Secondly, it analyses the working principle of Rogowski coil and design a have integral compensation correction function modulation circuit according to the spectrum characteristics analysis, it uses to correct the integral type travelling-wave Rogowski coil current measurement of low frequency distortion.Then, according to the working principle of the transmission line coupling power, it discusses the methods to enhance power system reliability and reduce the minimum starting current. According to the characteristics of the traveling wave always is large amount of data, this paper proposes a high reliability of data communication redundancy design, which can effectively solve the problem of traveling wave data in the process of transmission loss.Finally, it completes the hardware circuit design and debugging and makes further application analysis about the vegetation type travelling current wave recorded by this device.