Redundant and Self-Healing Drive System for Pure EV Based on Low Voltage Building Blocks

An ideal interface between the energy tank on board of an EV and the electric motor used for propulsion should have a number of desirable characteristics: it should be efficient, reliable, safe, cheap, light and small, just to mention a few. Priority and relevance of each item may vary widely with the particular application. In this paper, the cascaded multilevel topology is proposed, mainly for those applications where reliability and availability is a major concern. It is shown that the proposed topology is inherently redundant, and that a self-healing system can be built around the cascaded converter with relatively little effort. Theoretical and practical aspects like voltage generation and optimal energy extraction within the system are discussed, and main concepts are proven by experimental results.