New Switching Patterns Based on Current Space-Vector Diagram Viewpoint to Reduce Input Current Ripple for Three-Level Inverters

From the current space-vector diagram viewpoint, this paper proposes new switching patterns which reduce the input current ripple in DC link capacitors by considering the three-level inverter as a special case of a matrix converter. Several modulation concepts of the matrix converter are applied to the three-level inverter. Comparison among several modulation methods reveals that the lowest input current ripple can be achieved by the proposed PWM method without loss of neutral-point voltage balancing and limitation on the modulation index.