TFTR-MG uprate, analysis and performance

The energy requirement for TFTR operation at 5.2 Tesla is 4.5 GJ, 950 MVA provided by two 13.8 kV flywheel generators. To achieve tokamak fields beyond 5.2 Tesla (up to 6.0 Tesla), the MG system must be uprated to 1300 MVA, 15.0 kV and store 4.8 GJ of energy. The uprate is attainable by exploiting existing excess capacity and accepting reduced life. Considerations for the MG uprate include the number, level, duration, repetition rate of uprated pulses, and the expected life reduction. The mechanical degradation of the equipment due to speed overcurrent and over voltage was analyzed, as well as the deterioration of insulation due to thermal and mechanical stresses. This paper describes the requirements, and analysis and includes data of MG performance above rating.