The effect of the stray cable parameters on the HF interrupting capacity of VCB

HF interruption behaviour of vacuum circuit breakers (VCB) is very important for analysis of switching surges induced at interruption of inductive load by VCB. In an actual network, HF current is produced when a power cable is discharged through VCB separating contacts. Many researchers dealt with this problem by simulating an actual cable by LC circuit with lumped elements. We have conducted experimental research concerning HF interruption behaviour of VCB with CuCr contacts at interruption of the "artificial" cable and equivalent single-frequency LC circuit. The experimental results revealed a strong effect of cable stray parameters on the VCB HF interruption behaviour.