南阳特高压断路器失灵保护的研究

Study on Nanyang substation of UHV circuit breaker failure protection

晋东南-南阳-荆门特高压示范工程的正式投运标识着特高压电网的建设已进入快速发展阶段,但是特高压二次系统时间常数的增大使得CT拖尾现象变得不可忽视。一方面,对特高压断路器CT电流互感器的选型提出了新的问题,只选择TPY次级则会进一步恶化CT拖尾现象,选择P次级则增加成本。另一方面,CT拖尾对断路器失灵保护的正确动作造成了负面的影响。针对该情况,对特高压3/2断路器接线方式下断路器的失灵保护进行了研究,并提出一种针对性的改进方案。通过对比分析、仿真实验以及数模实验结果,证明该修改方案是切实可行的。既能有效地解决特高压断路器CT电流互感器的选型问题,也能有效地解决CT拖尾对失灵保护的危害问题。

The formal commissioning Jindongnan-Nanyang-Jingmen UHV demonstration project identifies that the construction of special high-voltage power grid has entered a rapid development stage, but the increase of UHV two system time constant makes the CT become tailing phenomenon can not be ignored. On the one hand, it puts forward a new problem for the selection of UHV circuit breaker CT current transformer, namely selecting only the TPY secondary will deteriorate further CT tailing phenomenon and selecting the P secondary will increase the cost. On the other hand, CT trailing influences breaker failure protection, making it unable to right action. In view of this situation, it studies the failure protection under the wiring mode of 3/2 breaker in UHV and proposes an improved scheme. The contrast analysis, simulation and RTDS experimental results prove that the modified scheme is feasible, which can both effectively solve the problems of the selection of UHV circuit breaker CT current transformer and CT tailing hazard failure protection.