High-frequency switching-mode power amplifier for shaker armature excitation

The paper presents the design and implementation of a switching-mode power amplifier for shaker armature excitation. First, the dynamic model of a current-source-driven shaker system is derived. Then a novel currentcontrolled PWM scheme is proposed for performing the switching control of inverter. To obtain good reference-current tracking-control characteristics over a wide frequency range, the feedback-current controller is augmented with a command-feedforward controller and a robust disturbance-feedforward controller. In the design of the disturbance-feedforward controller, the disturbance observer and robust-control technique are developed to make it practically feasible and have robust control performance. The design of the proposed controller is described in detail and practical limitations and the implementation of the current controller are discussed. Some measured results are provided to demonstrate the performance of the developed switching-mode power amplifier.