Design and Test of Quench Protection for Superconducting Generator Field Coils

The quench protection for an LTS superconducting field winding within a 15+ MW direct-drive superconducting wind generator is presented. The quench protection circuit comprises multiple superconducting field coils, one quench protection switch (QPS), a set of trigger heaters thermally attached to the QPS, and a set of quench protection heaters in thermal contact with each field coil. Trigger heaters are electrically connected across each field coil. All quench protection heaters are electrically connected across the QPS. The quench of any field coil will power at least one trigger heater and heat the QPS to quench. Consequently, the QPS voltage will power all the quench protection heaters and trigger all field coils to quench nearly simultaneously. This QPS-based quench protection circuit has been successfully validated by experiments. Alternatively, one of the field coils, designated as trigger-coil, can also function as the QPS. Simulation results of the two quench circuits are compared.