An AC converter with a small DC link capacitor for a 15 kW permanent magnet synchronous integral motor

An AC/AC power converter designed to feed a permanent magnet synchronous motor with a rated power of 15 kW is investigated in this paper. The converter consists of a diode rectifier, a small DC link capacitor and an inverter, which is controlled by an open loop pulse width modulation system (PWM). The circuit is simulated and the simulation results are analyzed and verified by measurements. Due to the small capacitor, special emphasis is put on the analysis of the DC link voltage. The paper also includes an analytical expression of the ripple of the DC link voltage.