Harmonic analysis of arc suppression coil based on transformer with high short circuit impedance

This paper analysis harmonic characteristic of an arc suppression coil based on transformer with high short circuit impedance. While using thyristors to adjust the impedance of arc suppression coil, the current wave is periodic nonsinusoidal, only containing odd order harmonic components. The analysis indicates that the fundamental current varies continuously with the triggering angle α and when triggering angle α is fixed, the harmonic current decreases gradually with the increasing of harmonic order, and the third harmonic current component is the largest which can reach about 30% of the rating current and about 50% of the fundamental harmonic current. While the capacitive current at single-phase earth fault is compensated, decreasing of the residual current and restraining of the arc overvoltage isn´t realized until harmonic currents are restrained effectively.