Electrical Machines


This self-contained module follows on from the compulsory year 1 module Electrical Science and the year 3 Electrical Energy Technologies. All required theory is revised to accommodate students who may not have taken this second module. The module aims to give a comprehensive introduction to rotating electrical AC and DC machines. The concept of the magnetic fields is introduced first, and simple magnetic circuits which arise for example in transformers are analysed. Faraday's and Lenz's law are revised and the equations for torque and power for a current carrying coil are derived. DC motors are introduced next, along with the requirements for safely starting them. Some basic AC theory is reviewed which allows for the analysis of synchronous generators which are used on the national grid. Finally, induction motors are examined. Laboratory work concentrates on finite element analysis of simple magnetic circuits and a demonstration of the testing of AC and DC machines.  

Learning Outcomes

  1. Explain the operation of single and three-phase AC machines and DC motors.

  2. Calculate from first principles the torque, speed and efficiency characteristics. 

  3. To be fully aware of the safety implications of working in a magnetic field.

  4. To create a finite element model of simple magnetic circuits such as in a transformer core.

  5. To determine the performance characteristics for different electrical machines using measured data.

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