Designing Electrical Machines

Lectures:
- Design and construction, basic description of the activity. Product life cycle, stages of a designer’s work, methods of designing electrical machines.
- Standards and specifications for electrical machines. Operation of electrical machines, overload capacity, mass inertia, vibration and noise. Effects of supply frequency, voltage, temperature, and cooling; load type; working environment; and machine configurations.
- Basic steps in transformer design. Determination of the main dimensions of the transformer’s magnetic and electrical circuits. Materials used in the construction of the transformer’s magnetic and electrical circuits. No-load current, short-circuit voltage, calculation of losses, and overall efficiency of the transformer.
- Basic steps in the design of an asynchronous machine. Determination of the main dimensions of the magnetic and electrical circuits. Design of the stator windings, slot fill factor, winding factor, pitch factor, and step factor. Shape of the asynchronous machine’s rotor, rotor windings, and the effect of slot skew.
- Basic steps in the design of a synchronous machine. Determination of the main dimensions of the magnetic and electrical circuits. Design of the stator windings, fractional windings. The shape of the synchronous machine’s rotor, windings of machines with a smooth rotor and salient poles. No-load and short-circuit characteristics, determination of excitation for the machine’s rated operating conditions.
- Basic steps in the design of a DC machine. Determination of the main dimensions of the magnetic and electrical circuits. Design of the field windings and field poles of the machine. Design of the auxiliary poles and commutator. Design of the rotor windings: loop windings and wave-shaped windings.
- Basic steps in the design of reluctance machines and permanent magnet machines. Determination of the main dimensions of the magnetic and electrical circuit. Design of the stator windings. Basic rotor configurations for reluctance machines and synchronous permanent magnet machines. Demagnetization characteristics of permanent magnets, the effect of temperature, and the operating point of the magnet.
- Heating and cooling of electric machines. Methods of heat transfer, equivalent thermal circuits, calculation of thermal resistances, ventilation systems for electric machines. Calculation of the required quantity of coolant.

Exercises:
Exercise schedule, requirements for credit, study materials, assignment instructions

Projects:
Students are assigned an independent project to be completed outside of class time. The project consists of calculations, drawings, and reports.

1.Electromagnetic design of an induction motor, calculation of the machine’s basic design dimensions and fundamental characteristics.
2.Modification of the designed dimensions and parameters of the induction motor (stator and rotor slots, number of slots, slot depth and shape, rotor winding material), numerical analysis of the impact on the basic parameters of the induction motor.
3.Optimization of the basic machine design; analysis of the impact on overall efficiency, changes in the machine’s power factor, and the effect of optimization on the machine’s torque characteristics.
4.Testing, verification, and completion of projects.