We use cookies to ensure that we give you the best experience on our website. You can change your cookie settings at any time. Otherwise, we'll assume you're OK to continue.

Durham University

Research & business

View Profile

Publication details for Dr Christopher Donaghy-Spargo

Donaghy-Spargo, C. M. (2017). Rotating Electrical Machines: Poynting Flow. European Journal of Physics 38(5): 055204.

Author(s) from Durham


This paper presents a complementary approach to the traditional Lorentz and Faraday approaches that are typically adopted in the classroom when teaching the fundamentals of electrical machines - motors and generators. The approach adopted is based upon the Poynting Vector which illustrates the 'flow' of electromagnetic energy. It is shown through simple vector analysis that the energy-flux density flow approach can provide insight into the operation of electrical machines and it is also shown that the results are in agreement with conventional Maxwell Stress based theory. The advantage of this approach is its complementary completion of the physical picture regarding the electromechanical energy conversion process - it is also a means of maintaining student interest in this subject and as an unconventional application of the Poynting vector during normal study of electromagnetism.