An Alternative Voltage Ripple Control Strategy for the AGPS of the ITER Neutral Beam Injector

To construct a high power negative neutral beam injector, an ultra-high voltage power supply for acceleration grid is required. The acceleration grid power supply (AGPS) has been designed for ITER, based on neutral point clamped three phase three level inverter, step-up transformer and rectifier. The output voltage ripple is an important parameters for the AGPS, influencing the heating efficiency. This paper proposes an alternative voltage ripple control strategy. The new control strategy is illustrated and the design principles of the controller is discussed, based on the detail analyzing of operation processes and output characteristics of the AGPS circuit. Finally, simulations results are shown to verify the control system.