Improved current control dynamics at the point of inflection in tokamak coil power supply

Tokamak coil power supply for superconductivity coil of ITER(International Thermonuclear Experimental Reactor) requires fast dynamic performance of di/dt and smooth changeover of current direction. To meet the specification high performance this power supply is designed for 12-pulse thyristor dual converter with interphase reactor(IPR). The study about improving current control transient response had been progressed in the ac-dc thyristor converter when the sign of current reference changes from positive to negative or vice versa. When the gradient of the current reference changes, an additional feedforward compensator is proposed in this paper to supply the voltage change in the load inductance. For practical implementation of the derivative of current reference, a low pass filter is designed and tested in case of the reference signal contains noise.