PWM based modulation strategy with variable switching frequency for an active rectifier stage with flexible DC-voltage output

A modulation strategy for an active rectifier is discussed in this paper. It is designed for an inverter which is structurally based on the topology of the rectifier stage in an indirect matrix converter. This modulation strategy is based on a carrier signal whilst the switching frequency remains variable within a certain range. The switching frequency is dependent on the input value for the inverter output voltage. This modulation strategy allows easy set-up of the output voltage within a wide range and with that allows the use of energy storage systems which demand high flexibility. This Modulation scheme allows a reduction of switching processes depending on the working point while it remains based on the underlying PWM signal. The implementation of this strategy is illustrated in this paper as well as simulation results which demonstrate the variance in the switching frequency.