Transient analysis of PWM-excited electromagnetic actuators

In order to increase the initial force of a DC electromagnetic actuator and improve its dynamic characteristic, at the beginning of the operation the supply voltage is temporary enhanced. After the dynamic operation is completed the voltage is decreased to the rated value. The voltage control may be realised by pulse width modulation (PWM). In such a case, the current and magnetic flux contain periodic components. Therefore, the eddy currents and losses in conducting parts of the core are generated. In the paper, an analysis of transients in the converter and in semiconductors of the feed system is presented.