Evaluating Space Charge Behavior of Polypropylene Blends Using TSDC Measurements

Thermoplastic polypropylene (PP) -based materials have gained increasing interest as potential alternatives to conventional cross-linked polyethylene (XLPE) for high-voltage direct current (HVDC) cable insulation due to their recyclability, good electrical and thermal properties, and simplified processing. Under HVDC conditions, space charge has a significant impact on the dielectric behavior of insulating materials. In this work, the dielectric characteristics of binary and ternary PP blends are investigated using thermally stimulated depolarization current (TSDC), pulsed electro acoustic (PEA) and DC dielectric breakdown strength measurements. The combined TSDC and PEA results demonstrate a reduced accumulation of space charge in the additive-containing samples. Furthermore, optimization of the PP component ratios enables control of the space charge behavior, while maintaining good dielectric breakdown performance of the PP blends.