Partial discharges in twisted-pair magnet wires subject to multilevel PWM pulses

Analysis of Partial Discharge Behaviour under Staircase-based Sinusoidal Voltage Waveforms

“…[6,7] suggested that the higher the number of levels in the PWM waveform, the lesser is the PD magnitude and inception voltage. Also, it is concluded in [6] that the multilevel PWM applies a new type of stress, which is a combination of AC, DC, and chopped waveforms. For a better understanding of different wave shapes mentioned above, the typical voltages generated by power electronic systems operating with 3-, and 9-levels are shown in Fig.…”

Partial Discharge Behavior of Typical Defects in Power Equipment Under Multilevel Staircase Voltage

“…The phase distribution range of PD is also reduced from 81.8° (5-level) to 60.7° (9-level), and then gradually expands to about 69.8° (39-level), which is almost similar to a sinusoidal waveform. This phenomenon is different from the PD at multilevel inverter voltage [4,15]. Each level of the staircase voltage is a DC component, while each level in the multilevel inverter voltage is composed of some square waveforms.…”

“…However, the switching operation of power electronic devices introduce new electrical stresses to power equipment, such as multilevel staircase waveform voltage [3]. The appearance of the multilevel staircase waveform voltage will pose a new challenge to the insulation state evaluation, which are typically assessed through the analysis of partial discharge (PD) [4].…”

Effect of Magnetic Field on Partial Discharge Dynamics in Insulation Systems of Transportation Power Devices

“…[44]. A reduction of PD intensity may be also achieved by going toward a higher number of converter levels as a tradeoff with cost [45]. The new generation of wideband gap semiconductors imposes the challenges for designing the electrical insulating systems of power converters.…”