Design And Implementation Of Overvoltage Online Monitoring System For Power Network

With the development of the society, the request for power grid’s safe motion is higher and higher, with long-term improvement, operation failure rate of power grid has been reduced. However, the accident rates caused by over-voltage do not reduce. Over-voltage is the main factor to induce power equipment insulation accident according to nowadays’ power system. Over-voltage often causes power outages and large power equipment’s damage, this problem is attracting wide attention in the power system.Now in the market there have been many over-voltage monitoring equipments, and record voltage waves, but rarely gets accurate over-voltage records. Now the study on over-voltage is only based on the models. Getting protean over-voltage datas can provide valuable first-hand over-voltage material for the research.This text introduced a kind of on-line monitoring device for research in power system over-voltage, batch input to the power stsyem, we can get perfect over-voltage data records, and get accurate and detailed understanding of over-voltage occurrence process. The main research contents for:Over-voltage has a wide spectrum, analyzes the influence of sensor response characteristics of different forms of factors. In different frequencies, analyses the ratio of transformation, make high voltage divider have the same ratio of transformation in different frequencies, and take the high over-voltage step-down without distortion. Through the simulation, the voltage divider is analyzed theoretically; the parameters can confirm the correctness of the design.Use voltage divider safety. To test the voltage divider, confirm the divider can be used for power system use.Analysis the cable transmission characteristics when transmit in different frequencies the response different of signal in different frequencies will cause signal transmission distortion, through improving matching circuit, making the output voltage sent to the sampling circuit without distortion, which makes it possible to sample real over-voltage signals.Developed a set of over-voltage online monitoring systems, the device overall structure and working principle of each part and the process of the working together of each partOver-voltage online monitoring system have worked in field, and collected back a large number of original datas, this text give wave forms, and compared with RTU, They are the accordance. This waveform gives first-hand data of over-voltage state for further research.