An Application of Two-Phase Resonant Inverter System to Generate Rotating Magnetic Field for Plasma Instability Control in a Tokamak

Rotating magnetic field (RMF), which interacts with plasma through electromagnetic force, is increasingly used for plasma instability control in magnetic confinement fusion experiment devices. In general, energizing magnetic field coils to obtain the desired RMF requires multiphase currents with an amplitude of up to several kiloamperes at a frequency ranging from a hundred hertz to several kilohertz. In this paper, we propose a two-phase ac power supply (ACPS) system based on full-bridge resonant inverters as an extension of the application of multiphase resonant converters. A novel phase control scheme for the two-phase resonant inverter system using a digital phase-locked loop is also proposed to synthesize RMF with enough spectral purity. The completed power system consists of two units. Each unit can supply a load with a rated output power of 1200 kW and a sinusoidal current in the frequency range of 1-5 kHz. The proposed ACPS can effectively cope with the physical requirements.