Xiangtan Grid Transmission Lines AC De-Icing Methods And Its Application

Hunan belongs to the central region, to the end of each year season, the ice will become the biggest threat to the grid, South and North cool dry air warm air, above the intersection, the unique topography makes the sudden drop in temperature, humidity is very easy to form here, freezing rain, if maintained for a long time, it will cause transmission line icing, in at the beginning of 2008 Chinese Southern ice disaster, one hundred million population live without electricity and water, many people have painful memories, this is from the national grid in the history of the most serious one ice disaster, which lasted 27 days, most of the grid icing 30-60 mm, the most severe icing reached 100 mm, transmission line flashover the trip, part of the line has overwhelmed, break down the tower. The relevant research shows that the transmission line icing to a certain extent, the choice of the correct way of melting ice is to ensure the safety of the power grid, to prevent transmission line fault trip accident, improve the reliability of power supply system, an effective way. In view of the melting ice of transmission lines in regional power grid, the following work is carried out in this paper:(1) the icing on the transmission line and the prevention and control of the transmission line is analyzed. The icing condition of power system transmission line is analyzed, and the control method is described. This paper expounds the problems existing in the melting ice of traditional transmission lines.(2) the different voltage levels are applied to calculate the length of different lines.Different types of lines due to maximum allowed to thaw ice current and ice melting required minimum current limit, different grades of melting ice voltage for different types of line ice melting has its maximum and minimum effective length, this paper in accordance with the relevant conditions were calculated by summing the.(3) analysis of the application of Xiangtan power grid transmission line icing power rating. According to the type and length of transmission line in Xiangtan power grid, the applicable voltage level of melting ice is analyzed, and the reasonable solution of melting ice is determined.(4) the idea of melting ice distribution transformerAccording to the application of power transmission line, an adjustable voltage distribution transformer is proposed, which can increase the voltage level and satisfy the need of melting ice.In of 220 kV and below transmission line ice melting, AC de- icing in the aspects of scope of application, the influence on the system, operation difficulty compared with DC de-icing melting has more advantages, and can obtain good effect, so is the best choice for regional power grid of high voltage transmission line ice melting.