Method for simulating lightning trip-out rates of 500kV transmission line with four circuits on same tower

Abstract

The invention discloses a method for simulating lightning trip-out rates of a 500kV transmission line with four circuits on the same tower. The method comprises the following steps of: getting information of the tower, wherein the information of the tower comprises the height of a cross arm, an equivalent radius of a tower body and the width of the cross arm; establishing a multi-wave impedance model according to the information of the tower; establishing an insulator flashover criterion model based on an EPRI (Electric Power Research Institute) pilot model; establishing a horizontal lighting-resistant simulation model of the transmission line according to the multi-wave impedance model of the tower and the insulator flashover criterion model; adjusting a phase angle of a power supply and a simulated lighting current amplitude in the horizontal lighting-resistant simulation model of the transmission line, and then obtaining the lighting trip-out rate of each circuit of the transmission line, wherein the lighting trip-out rates comprise back flashover trip-out rates and shielding failure trip-out rates. By adopting the method for simulating lightning trip-out rates of the 500kV transmission line with four circuits on the same tower disclosed by the invention, lighting trip-out rates of the transmission line can be calculated accurately, so that security and power supply reliability of power grids are improved.

Description

technical field [0001] The invention relates to the field of design of power grid transmission lines, in particular to a method for simulating the lightning tripping rate of a 500kV four-circuit transmission line on the same tower. Background technique [0002] With the development of economy and society, the society's demand for electric energy is increasing day by day, but the continuous development of land resources has led to the increasingly scarce transmission corridors available for grid construction. For this reason, erecting four 500kV transmission lines on the same tower to save precious land resources has become an inevitable trend in power grid construction. At the same time, it has also brought some new problems to be solved urgently, one of which is the accurate prediction of lightning tripping rate. estimate. [0003] Taking the 500kV four-circuit transmission line on the same tower as an example, if the insulation configuration is too high, the tower head ga...

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Problems solved by technology

[0003] Taking the 500kV four-circuit transmission line on the same tower as an example, if the insulation configuration is too high, the tower head gap will be too large, which will increase the cost of the line (if one more insulator is installed, the overall cost of the line will increase by about 88,000 yuan / km); if If the insulation configuration is too low, the trip rate after the line is put into operation is high, which is not conducive to the safe operation of the line and the safety and stability of the entire power grid.

[0004] Currently, the electricity industry standard DL / T 620-1997 "Overvoltage Protection and Insulation Coordination of AC Electrical Installations" is commonly used to calculate the lightning tripping rate of transmission lines. The calculation method is mainly based on the operation of single-circuit lines with relatively short towers. The empirical formula summed up is difficult to ensure the accuracy of the calculation of the lightning trip rate of the transmission line, which affects the safety of the power grid and the reliability of power supply

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