Calculating the Starting Currents of Electric Motors in 0.4 kV Auxiliary Networks of Nuclear Power Plants

Abstract

Consideration is given to the effect of the resistance of the cable supplying power to the electric motor in the 0.4 kV auxiliary network of a nuclear (thermal) power plant on the starting current and, hence, on the current setpoint for the circuit breaker, on its sensitivity to short-circuit current, and on the cable size. It is shown that accounting for the resistance of the power cable of the motor that is commensurable with the starting resistance of the latter allows using a cable of smaller size compared with that determined regardless of its resistance.