采用均压电容对500 kV氧化物避雷器电压分布的影响

The Influence on Potential Distribution of 500kV MOA by Employing the Grading Shunt Capacitors

由于500 kV氧化锌避雷器是由3节构成,在持续运行电压下,因其杂散电容的存在将引起电阻片电压分布极不均匀的现象,使部分电阻片因电压过高而加速老化和热崩溃,最终导致避雷器的损坏,大大缩短了它的运行寿命。通过改善避雷器的电位分布,进而有效地提高其运行可靠性,一般采用在避雷器上端装设均压环、避雷器元件并联均压电容棒的方式进行均压。针对500 kV氧化锌避雷器,在给定的均压环配置下,采用光纤—电流法来研究并联不同的均压电容棒对避雷器电位分布的影响。

The 500 kV MOA in service is made up of three sections. Its service life is probably cut down seriously and even damage ultimately because of the aging acceleration and thermal run away of part of resistor discs led by the overvoltage that is caused by the non-uniform potential distribution in the axial direction of arrester with the stray capacitance when the arrester services in the continuous operation voltage. To improve MOA potential distribution and enhance its operational reliability,the grading rings are usually installed in the high-voltage side and the grading capacitors are paralleled on the arrester elements. Based on the given grading rings configuration of 500 kV MOA,the fiber-current method was utilized to research the influence on the arrester's potential distribution with different grading capacitor configuration.