Chopped wave lightning impulses are not a concern in substations equipped with line surge arresters, which effectively divert overvoltage surges to ground without causing outages. The IEC 60071 standard does not recognize chopped wave impulse voltage as a relevant factor for insulation coordination. Surge arresters are globally acknowledged as the best protection for substation equipment. While closed circuit breakers (CBs) should be tested for chopped wave withstand capability, open vacuum circuit breakers (VCBs) inherently protect against impulse flashover. In modern substations, MOV arresters mitigate the need for chopped wave testing, aligning with industry standards.
