Design and implementation of a versatile H-bridge power supply for experiments on the STOR-M Tokamak

Abstract

An H-bridge power supply has been developed for different experiments on the STOR-M tokamak. Four insulated-gate bipolar transistors (IGBTs) are used to guide the current to the load from a capacitor bank discharge. The timing signal to the gates of the IGBTs is controlled by a field programmable gate array (FPGA). The power supply can be programmed to drive either a sinusoidal current waveform to an inductive load or a bipolar rectangular current waveform to a resistive load. The maximum frequency and current tested for the sinusoidal current waveform are 25 kHz and 2200 A, respectively. For bipolar current waveforms, the maximum current tested is 1500 A at 3 kHz. The sinusoidal current to a set of helical coils was used for the Resonant Magnetic Perturbation (RMP) experiments and the bipolar rectangular current waveform was used for both the electrode biasing experiments and the RMP experiments on the STOR-M tokamak.