The Supplementary Design Method of HTS SMES System Considering Voltage Distribution Characteristic

In the latest design studies of superconducting magnetic energy storage (SMES) systems, the emphasis was put on the electromagnetic design of SMES magnets without giving due attention to the electrical design with a view to eliminating the overvoltage problem. The power conditioning system (PCS) interfaces with the superconducting magnet and the ac system through an electrical connection. With a pulse-width modulation converter usually adopted in the PCS, the high-frequency overvoltage problem is even more serious. Therefore, electrical design based on voltage distribution analysis and protection measures should be taken into account during the SMES design. This paper first gives transient models of PCS, SMES, and the connecting cable in a systematic view. Later on, a design flow path containing both the electromagnetic design and the electrical design is presented. Adopting the proposed design method, one design plan of a 1 MJ HTS SMES is chosen and conclusions are drawn on its optimal comprehensive design plan.