6 ~ 35 kV non-ground neutral assolenoid style in the grid voltage transformer (hereinafter referred to as the PT), when the bus is fewer no-load or outlet, feeder for charging or at run time ground fault eliminate such reasons as the stimulating, will make voltage transformer supersaturated, it may produce ferroresonance overvoltage. Appear relatively voltage instability, grounding instructions misoperation, PT abnormal high pressure fuse fusing phenomenon, will cause serious PT burned, leading to other accidents.

     LXQ Ⅱ type, a away the harmony, is installed in 6 ~ 35 kV PT a winding Y0 connection between earth and neutral high capacity nonlinear resistors, damping and the current limit role. The away harmonic resistor full compliance with all electrical standard DL/T 620-1997 "ac electric device overvoltage protection and insulation coordination" the first article 4.1.5 of the rules, can have good limit voltage transformer ferroresonance effect.

   If 6 ~ 35 kV power grid non-ground neutral, on the bus Y0 wiring the PT a winding will become the power grid of the only gold attribute channel. Single-phase grounding or disappeared, the power grid of capacitance through the PT a winding a charging and discharging the transition process. The test this time often has the highest number of amplitude of ampere half wave power frequency current through the PT, this current likely will melt PT high pressure wire (0.5 A) fusing. And installed LXQ Ⅱ series away after the harmony, the current will be effectively controlled, high pressure because the current melt silk no longer and fusing (note: installed in PT secondary side electronic away harmonic currents generally cannot eliminate the device).