Development of HTS current leads for 1 kWh/1 MW module type SMES system. II. Manufacturing and testing of prototype leads

For pt.I see ibid., vol.7, no.2, p.684-7 (1997). We have been developing HTS current leads for a 1 kWh/1 MW module type SMES system (which we call "ESK" for Experimental SMES of Kyushu Electric Power Co., Inc.). Each module of a module type SMES system has a pair of current leads. For the purpose of reducing the heat load from the current leads, we have employed a bulk HTS. As a step in the preparation of HTS current leads for ESK, we trial produced HTS current leads and tested them to evaluate their characteristics. Our test results indicated that the heat load in a steady state at a rated current of 1 kA and with a rated flow rate of 0.05 g/s was 0.035 W, well below the specified value of 0.1 W. Also, our results indicated that the HTS current leads can be satisfactorily energized for pulsing operation at a rated current for ESK of 500 A-1 kA. The heat load under such conditions was 0.025 W, approximately 80% of that under normal 1 kA operating conditions. It was also verified that operation could be continued for 15 minutes even when the coolant flow was stopped.