Talk: “Electric Motors for Traction Applications” by Bob Walker

The presentation will cover the general topic of electric motors, their operating principles and the different types, illustrating both their underlying similarities and their functional differences. The focus will be on the special requirements for traction applications, with particular emphasis on applications for model electric locomotives, i.e. up to a few hundreds of watts or a couple of kW output. In passing, calculations for the power requirements for a 7¼” or 5″ passenger-carrying train will be used to illustrate the design and/or selection of a motor and transmission system.  Photographs and demonstration of an experimental motor using a surplus car alternator will also be included, together with pictures of electrical waveforms and estimated performance data.  It will also be noted that modern integrated systems based on the principles of “brushless DC” motors are now available. The talk and the demonstration models are primarily intended to be illustrative and do not necessarily represent a practical system.