Power amplifier design in magnetic suspension system

Magnetic suspension system is a typical nonlinear system, so the complexity of its control system design can be directly affected by the linearity and response time of every unit in the system, so as the power unit. A method of forming a linear current source controlled by voltage is presented in this paper, with an H-type bridge chopper as its major circuit. It makes use of the pulse width modulation characteristic of voltage-drive modulator TL494, and the bootstrap function of IR2110, generates MOSFET drive pulse signals whose duty cycle can be adjusted, so that the output current value can be changed. Frequency band is broadened and response speed is improved by improving the compensation part of the system. The experiments have indicated that this power circuit has a good linearity. It has not only the simple and stable characteristics but also good performances and practical characteristics