跟踪式二次谐波涌流制动改进方法

针对二次谐波制动原理存在的问题，提出一种新的二次谐波制动原理。通过判断变压器的开关位置和差流大小来改变涌流闭锁二次谐波门槛值，在空载合闸和故障切除恢复电压的过程中监视变压器内部故障和励磁涌流，达到在不会拒动的情况下更准确地判断励磁涌流、防止保护误动的目的。该方法具有实时跟踪的功能，克服了单一定值不能实现可靠制动的缺点。验证表明新方法具有较高的可靠性和灵敏性，可以克服传统制动方法的缺点，实现对励磁涌流现象的可靠制动。

An Improved Second-order Harmonics Restraint Method for Inrush Currents with Tracking Ability

A new second-order harmonics restraint principle is proposed to solve the problems in the existing methods.The threshold values of second-order harmonic blocking inrush current are adjusted according to the breaker positions of transformer and the differential currents.By monitoring internal faults and magnetizing inrush currents during the process of no-load switching and voltage restoring after fault clearances,the magnetizing inrush current can be judged more precisely without causing resistive operations and maloperations of protection.The new method has the function of real-time tracking and overcomes the shortage of single setting point that cannot realize reliable restraints.The reliability and sensibility of the new method are demonstrated by testing results.