FPGA-based broadband current control of a linear motor with Class-G power amplifiers

In this paper, a broadband current control system using a FPGA and Class-G power amplifiers is realized. The current controllers with general PWM inverter, which is classified as Class-D power amplifier, does not operate in case that bandwidth of current controllers is enlarged due to PWM switching operations. On the contrary, the current control system using Class-G power amplifiers is able to be operated normally, even where the bandwidth is set as 25100 rad/s (≃ 4kHz). By the numerical simulations and the experiment, validity of the current controllers with Class-G power amplifiers is verified. The broadband current control realized in this paper is useful for servo systems in the field of fast motion control and real-world haptics.