旧变电站实现双母差、开关失灵保护改造中存在的问题

由于电网安全稳定运行的需要，部分220kV变电站必需装设两套母差、开关失灵保护，以解决仅一套母差、开关失灵保护时存在保护装置检修及故障时母线或开关失灵保护，及一套保护装置因功能错判或元器件失效造成拒动的情况，因此，解决实现双母差、开关失灵保护改造中存在的诸如旧变电站二次电流互感器（TA）不够等问题已经成为当务之急。设计了母差、开关失灵保护电路切换屏，有效地解决了改造后双母差、开关失灵保护在运行、检修中存在的问题。

Problems in realizing dual bus differential and breaker failure protection during substation retrofitting

For the safe and stable operation of power network,it is necessary for some 220kV to install two sets of bus differential and breaker failure protection.Otherwise there will be no bus differential and breaker failure protection when the only protection is out of operation because of repair or failure.It is also useful when one set rejects protective action because of functional error or component defect.Therefore,the problems existing in the substation retrofitting for realiz ing dual bus differential and breaker failure protection should be resolved,such as insufficient secondary windings of circuit transformer.The circuit-switching panel designed for dual bus differential and breaker failure protection can effectively solve these problems.