Current chopping

Current chopping is actually breaking of fault current before it passes through the neutral zero. Whenever the low-inductive current is interrupted, current chopping occurs in the circuit. One example is current due to no load magnetizing current of a transformer. Another one is current passing through a circuit-breaker producing different degree deionizing force. Here arc current is always decreases to zero in normal fashion, since the increase in temperature increases the arc resistance. At a certain value of arc current, there is a chance for disproportionate high deionizing force which destabilizes arc and arc current attains zero before the natural zero. Low inductance and capacitance introduced in the circuit causes frequent current chopping. This results in resonance conditions which are very much dangerous and undesirable and may cause harmful overvoltages.