> Power Electronics: Devices, Circuits, and Applications, by M. H. Rashid, 2013 (plenty of worked examples, ebook in QMUL library, free online version). This is the most important textbook I recommend for the module ECS643U/ECS720P Power electronics.
> Principles of Power Electronics by J. G. Kassakian, M. F. Schlecht, and G. C. Verghese, Addison-Wesley, 1991 (MIT source and paperback version in QMUL library).
> Chapter: Introduction to Power Electronics in Electric Machinery Fundamentals by S. J. Chapman, McGraw-Hill, 5th Edition, 2011 (short but very easy to read, paperback version in QMUL library)
Online Power Electronic course by Dr Firuz Zare.