Partial Discharge Characteristics of High-voltage Power Module Packaging Insulation Under High dV/dt Square Pulse Voltage
The partial discharge(PD)occurring in packaging insulation under high dV/dt square pulse voltage is one of the major causes of high-voltage power module failure.However,the electromagnetic interference and displacement current generated during the rising and falling edges of the square pulse bring serious interference to PD detection.Additionally,the testing result under the sinusoidal voltage required by the current testing standard of the power module PD is different from that under square pulse.To solve the above problems,this paper proposes a PD detection method under high d V/dt square pulse based on the down-mixing principle and investigates the PD characteristics of the packaging insulation under different frequencies of unipolar square pulse and power frequency sinusoidal voltage.The model of the packaging insulation solid-solid structure is built,and the dynamic simulation calculations of the electric field distribution are carried out considering the charge relaxation characteristics of composite insulation.The results show that due to the difference in local electric field caused by interfacial charge relaxation,the partial discharge inception voltage(PDIV)under the unipolar square pulse is higher than that under the sinusoidal voltage,and the PDIV under the unipolar square pulse slightly increases with the increase of frequency.The average magnitude of PD under unipolar square pulse is higher than that under sinusoidal voltage for the same applied voltage magnitude.As the frequency increases,the distribution of the amplitude of the PD at the rising edge of the unipolar square pulse is similar,while the average amplitude of the PD at the falling edge decreases,and both phase distributions show a lagging trend.This study analyzes the PD characteristics of packaging insulation under high dV/dt square pulse and their differences from that under sinusoidal,which provides a reference for the reliability testing and evaluation of power modules.
high dV/dt square pulsepower modulepackaging insulationpartial dischargeelectric field dynamic simulation
万方数据
维普
