China International Youth Conference on Electrical Engineering (CIYCEE 2026)

To address the problem that racetrack excitation coils of large-capacity high-temperature superconducting synchronous condensers are susceptible to quench under fault shocks and that the quench evolution rules remain unclear, this work investigates triple-stacked racetrack double-pancake coils for a 15 Mvar superconducting synchronous condensers by establishing a multi-physics simulation model. Two types of characteristic inter-turn resistances, i.e., high specific contact resistance (4000 μΩ·cm²) and low specific contact resistance (100 μΩ·cm²), are adopted to simulate and investigate the effects of radially non-uniform inter-turn resistance configurations on coil quench behavior under fault shocks, with emphasis placed on electromagnetic response and temperature evolution characteristics. The results demonstrate that quench propagation is dominated by electromagnetic coupling. Although low-resistance layers sustain higher current and thermal loads, they mitigate magnetic flux decay and current surges in high-resistance layers. Under the uniform high-resistance configuration, simultaneous quenching occurs across the entire coil with evenly distributed shocks, whereas non-uniform configurations produce pronounced heterogeneous load distributions, rendering it impossible for all coil layers to simultaneously achieve flux buffering while maintaining low thermo-mechanical loads. This study reveals the mechanism by which the inter-turn resistance gradient, through regulating electromagnetic induction pathways, shapes the spatiotemporal distribution of current and temperature during quench, thereby providing a theoretical basis for quench characteristics analysis and rotor coil design in large-capacity superconducting synchronous condensers.
 

high-temperature superconducting, superconducting synchronous condenser, quench, racetrack coil, specific contact resistance