Experimental Investigations into the Enhanced Dielectric Breakdown Performances of Propylene Carbonate Modified by TiO2 Nano-particles

Water is frequently used as energy storage medium in the compact pulsed power system because of its great dielectric constant and high breakdown strength. As an alternative to water, propylene carbonate (PC) has relatively low freezing temperature and large resistivity. In this study, TiO2 nano-particles with different volume concentrations have been suspended into PC to enhance the dielectric strength. Breakdown voltage and the time lag to breakdown with several tens microseconds' duration have been investigated for PC and PC-based nano-fluids. The waveforms of breakdown voltages were measured by a calibrated voltage divider. Experimental results show that, with increasing the value of high-voltage electrode potential increasing rate, the breakdown strength increases and the time lag to breakdown decreases. Experimental results also show that, the dielectric properties of nano-fluids are strongly influenced by the volume percents of the nano-particles. In general, the addition of nano-particles is favorable for the overall dielectric performance of PC. For a large high-voltage electrode potential increasing rate, the mean breakdown voltage of nano-fluids is largely increased compared with that of PC; for a low high-voltage electrode potential increasing rate, the breakdown voltage increases and the scatter of breakdown data decreases, which shows a great potential to increase the reliability of the pulsed power system.