A boost inverter includes a first capacitor for connection in parallel with a dc supply voltage; a second capacitor connected in series with the first capacitor; an energy transfer path including a transfer capacitor and switches connected to the transfer capacitor for cyclically transferring energy from the first capacitor to the transfer capacitor and then from the transfer capacitor to the second capacitor; a multilevel inverter circuit connected in parallel with the series combination of the first and second capacitors, the inverter having at least one phase output for connection to an electric motor; and a PWM controller that activates the energy transfer path when a desired peak-to-peak output voltage exceeds the dc supply voltage and deactivates the energy transfer means when the desired peak-to-peak output voltage is less than the dc supply voltage.