A novel multi-level CSI based topology with inter-cell magnetic couplings for minimum DC storage components

Progress and developments in technology have meant that every year an increasing number of industrial applications have higher power rates in large electrical motors where power quality is an important issue. These developments, together with the cost of medium voltage semiconductors, have given rise to multilevel topologies based on an array of power cells conveniently connected. These topologies have features that do not have conventional topologies, such as high voltage operation ranges using conventional low-voltage semiconductors, reduced dv/dt, and high quality in the supply currents, helping to fulfill the recommendations and standards currently in force. However, it is still necessary to use large energy accumulators in the DC-link of the power cells in order to properly operate. This paper proposes a new multilevel topology based on current source power cells. The resulting topology has similar and improved features compared to their counterparts voltage sources, among which is the possibility of using conventional low-voltage semiconductors, null dv/dt, and more importantly, small DC-link inductors. Also, it includes the ability to regenerate without any additional control scheme.