微机型变压器保护的缺陷及改进

目前的微机型变压器保护,在用旁路开关带主变开关运行,或者由旁路开关恢复到主变开关运行时,保护的电流、电压回路切换,保护出口压板的切换,全部由运行人员手动操作.切换过程中易造成电流回路开路,危及运行人员及设备的安全.在进行电流、电压回路切换时必须先退保护,切换完毕后再投入保护,操作步骤烦琐,容易造成差动保护的误动.采用数字量切换方式对电压、电流进行切换,使得电流回路切换没有开路的可能,防止了电流回路开路对人身及设备造成的危害.在电流、电压回路切换时自动闭锁差动保护,减少了保护误动的机率.此方案还能实现远方操作,满足变电站无人值班的要求.

A Drawback and Its Solutions of Microprocessor-based Transformer Protection

When using the bypass circuit breaker as transformer′s and the reverse,the current,voltage circuit switch and protection trip switch of the microprocessor-based transformer protection are manual.It is easy to cause the current circuit broken when switching,and this is dangerous to the operator and device.The protection must be disabled before switch and be enabled after switch and it is easy to cause the differential protection misoperation.This solution uses digital switch to switching the current and voltage, the current circuit can not be broken when switching,and it is safety to the operator and device.The differential protection is locked when switching the current and voltage,and the misoperation of differential protection is reduced.And this solution makes the remote operations and the man-free substations possible.