Deadline: Applications will be accepted at any time until the position is filled.

As an increasing number of high-power applications are emerging, e.g. high-voltage DC transmission, flexible AC transmission, and large electric drives, using multilevel converters has received great attention in recent years. A significant advantage of multilevel converters lies in the fact that high power can be generated with mature medium-power semiconductors. In addition, as the number of levels increase, the total harmonic distortion of the output can be reduced, thus improving the quality of the output and reducing filter size. Due to these advantages, multilevel converters have been regarded as an effective solution to current and future high-power applications.

However, due to the large number of power semiconductors and circuit components involved in these converters, the possibility of a fault is much higher compared with conventional two-level or three-level converters. A fault in multilevel converters can result in very serious problems and in some cases leads to catastrophic consequences. For instance, faults of electric propulsion systems in large electric vehicles may result in an accident. Uncontrolled torque due to faults in converters can have an adverse influence on vehicle stability, thus ultimately threatening passenger safety. In renewable energy systems such as wind power systems with multi-MW wind turbines, an unexpected shutdown resulting from faults in inverters may cause significant energy production loss and cost increase. This could also result in the extension of cost recovery period. Therefore, managing faults in multilevel converters effectively is of vital importance to reliable operation of related systems.

In this project, through the incorporation of a variety of theories and techniques recently developed for hybrid systems and fault-tolerant control, we plan to develop advanced fault diagnosis algorithms and fault-tolerant operation strategies for multilevel converters. Experimental work will be included to verify the efficiency and efficacy of the proposed approaches.

If you wish to discuss any details of the project informally, please contact Dr. Zhan SHU, Electro-Mechanical Engineering research group, Email: z.shu<στο>soton.ac.uk, Tel: +44 (0) 2380 59 3687.