灵州换流站换流变压器非电量保护问题分析

Non-electric protection analysis of converter transformer in Lingzhou Converter Substation

针对灵州换流站换流变压器非电量保护所存在影响直流系统运行可靠性的问题,通过对阀侧套管压力继电器一级报警接点、网侧套管升高座瓦斯继电器和阀侧套管末屏电压回路存在问题进行分析,提出相应的改进方案。应用结果表明:改进方案可以快速测定SF6漏气率,使值班运维人员更易于掌控阀侧套管泄漏情况,有利于开展事故应急处置;网侧套管升高座瓦斯继电器由跳闸逻辑改投报警,避免了储油柜油位下降或升高座瓦斯继电器误动作导致直流跳闸的问题,提高了直流系统的运行可靠性。

For the problems of non-electric protection of converter transformer affecting the reliability of DC system operation in Lingzhou Converter Substation,analyzes the existing problems such as the primary alarm contact of valve side bushing pressure relay without access to the workstation,the elevated gas relay of net side bushing higher than the lowest position of the oil conservator and the end of the screen voltage circuit of valve side bushing with two-point grounding,puts forward the improvement schemes.The application results show that the improvement schemes can fast determine SF6leakage gas rate,make the duty operators more liable to master the situation of the valve side bushing leakage,which are beneficial to make accident emergent treatment.The elevated gas relay of net side bushing is changed from trip logic to alarm,avoid DC trip problem resulted from the oil level dropped in oil-storage cabinet or the misoperation of the elevated gas relay,so the scheme improves the reliability of the DC system operation.