A Partial Discharge Testing System Based on A 5-Level Converter with Different Control Signals

In this paper, analyses of a partial discharge (PD) testing systems using a voltage source from a 5-level converter with different control signals are presented. The low voltage source with 200 Hz of the test system is generated using the 5-level converter. The converter connected to a high voltage transformer, a partial discharge detection. The LC-filter type is set for the test system. The efficiency of voltage source from the 5-level converter with different control signal topologies, i.e. 5-level square wave, 5-level quasi-square wave, and 5-level sinusoidal pulse width modulation (SPWM) with modulation index (m
_a
) of 1.0. The effect of the topologies to partial discharge test system is presented and compared in cases of the voltage difference, total harmonic distortion (THD
_v
) of the output voltage, and the background noises in the partial discharge testing system with no-load and load test with a potential transformer (PT). It is found that the 5-level sinusoidal pulse width modulation (SPWM) with modulation index 1.0 provides the best performance in cases of the voltage difference and THD
_v
of below 5%, and the background noise of below 2.5 pC.