Effect of Temperature on Breakdown Characteristics of Propylene Carbonate in Nonuniform Fields Under Microsecond Pulse

Propylene carbonate (PC), due to its great dielectric constant, high breakdown stress, and strong adaption to the environment, will have great potential in the application of the pulsed power system as a liquid dielectric with high energy storage density. Therefore, it is of great practical significance and academic value to study the effect of external temperature variation on the breakdown characteristics of PC. Based on a pulsed power generator with a compact Tesla transformer as a high-voltage source and needle-plate electrode as a test specimen, the effect of external temperature ranging from −45 °C to 45 °C on the polarity of PC was experimentally investigated under microsecond pulse in this article. The breakdown voltage waveform is captured by the test probe using the capacitor voltage divider and the breakdown process of the specimen gap is recorded by the ultrahigh-speed camera. Experimental results show that the breakdown strength of PC increases with the rise of temperature in the different polarity, with an exceptive point at 0 °C. Meanwhile, the positive breakdown voltage of PC is greater than the negative one under this experimental condition, and the difference between them is the smallest at 18 °C. The analysis shows that microbubbles and water in PC are the main reasons for this phenomenon.