Open-Phase Voltage at Suddenly Line-to-Line Short Circuit of Synchronous Machine

Abstract

Synchronous machine generates the sinusoidal voltage on the balanced load operation. In case of the line-to-line short circuit, it generates the harmonic voltage on the open-phase of synchronous machine, if the direct and quadrature subtransient reactance are not equal as the machine without conection of the damper windings between poles. The harmonic orders of the voltage waveform on the open-phase winding consist of not only odd numbers, but also even numbers.
When this harmonic voltage is resonant with network with capacitor, the overvoltage arise on the network.
This paper shows the voltage waveform and the harmonic contents of the open-phase voltage by the analytical voltage equation without decay of the magnetic flux.