A current-control mode three-level PWM switching power amplifier for active magnetic bearings

A current-control mode three-level pulse width modulation (PWM) switching power amplifier for active magnetic bearings was proposed in this paper. The basic structure of this power amplifier is introduced. The basic characteristics of this power amplifier are simulated in PSPICE, measured and compared with that of a standard two-level PWM switching power amplifier. It is shown that the current ripple of the three-level PWM switching power amplifier is independent with the DC supply voltage and much smaller than the two-level PWM switching power amplifier, which can improve the dynamic characteristic of power amplifier by boosting the DC supply voltage without enlarging current ripple.