  This paper proposes a new DC-AC converter with a less number of semiconductor
switches and therefore gate drive and control circuit components. A salient
feature of this inverter is its pure sinusoidal line-to-line voltages with no
need for output filter. Also, the proposed inverter improves the voltage
utilization factor of the input dc supply compared to four-switch three-phase
inverter (first best topology in the literature from the number of switches
point of view) and standard six-switch inverter with sine PWM. The proposed
inverter is capable of operating with a wide range of output voltages from zero
to the full value of the dc input voltage by appropriately altering
instantaneous duty-cycle. For the first time to our knowledge, in this paper, a
three-phase universal inverter with only three power-switch has been proposed.
For the purpose of providing a good compromise between fast transient response
and stability, a model predictive controller is proposed. All the design
expressions have been derived. A comparison with other DC-AC converters is
given to show the merits of the proposed converter. Finally, satisfactory
circuit operation is confirmed by experimental results from a laboratory
prototype.
