Development of a Digital Quench Detection and Dumping Circuit With Constant Voltage System for SMES

A digital quench detection and protection system has been developed for a micro-sized superconducting magnetic energy storage system (SMES). The digital quench detection system based on a high-performance NI-6224 digital acquisition card accepts a standard set of input signal such as magnet induced voltage, current, pressure of cryostat. It also provides improved signal processing for sensitive and exact quench detection and data logging function. Once the superconducting magnet quenches, the quench detection system activates immediately the protection circuit. Some novel protection circuits are developed to dump the electromagnetic energy stored in the magnet; these greatly enhance the dump efficiency by maintaining the magnet terminal voltage constant during the dumping energy process. This paper detailedly describes the system and presents results.