Abstract:Quench protection system plays an important role in the operation of superconducting tokamak. When quench occurs, it quickly transfers the magnetic field energy stored in the coil to protect the superconducting magnet. Due to the high power of quench protection system, multiple solid-state switch modules must be connected in parallel, so the current sharing problem needs to be further solved. After selecting IGBT as the solid-state switch in the quench protection system, this paper analyzes the factors affecting its current sharing. The dynamic current sharing when IGBT is turned off is carried out by adjusting the grid resistance, and the static current sharing is realized by PI control of the grid voltage. The simulation and experimental results show the effectiveness of the control scheme at 220A current. Compared with the current sharing method of traditional branch series impedance, this scheme does not need to change the main circuit, with simple control mode and better flexibility. At the same time, it can effectively resist the influence of interference, and further promote the practical application of solid-state switch in quench protection system.