Development and Implementation of Innovative Insulating Materials for High-Voltage Direct Current (HVDC) Power Transmission Cables: Analysis and Characterization of the Electrical Properties of Vitrimers

Historically, High Voltage Alternating Current (HVAC) has dominated global power grids due to the high efficiency of static transformers in stepping voltages up and down to minimize transmission losses. HVAC systems also offer simpler architectures, straightforward switchgear, and low maintenance costs. However, advancements in power electronics—specifically Insulated Gate Bipolar Transistors (IGBTs) and Voltage Source Converters (VSCs)—have unlocked the potential of High Voltage Direct Current (HVDC) for bulk energy transport. HVDC operates without voltage oscillations, eliminating capacitive charging currents, reactive power compensation needs, skin/proximity effects, and dielectric hysteresis losses. Beyond an economic break-even distance, HVDC becomes more cost-effective than HVAC, making it the industry standard for long-distance, deep-water subsea interconnections required by remote offshore wind farms and renewable grid integration. To enhance the performance and sustainability of modern HVDC extruded cable insulation, recent research focuses on advanced polymeric materials. Traditional thermosetting insulators present end-of-life recycling challenges and require an energy-intensive degassing process to remove cross-linking by-products. To resolve these limitations, this study investigates vitrimers, a novel class of covalent adaptable networks (CANs) provided by the University of Parma. Featuring dynamic exchangeable covalent bonds, these vitrimer formulations combine excellent dielectric properties with unique thermal reprocessability, offering a sustainable alternative to conventional cross-linked polyethylene (XLPE) for next-generation high-voltage insulation systems.