BEng Electrical and Electronic Engineering

This unit will cover the following:

(1) Single-Phase Transformers. Principles of operation. Equivalent circuit. Load calculations. Open- and short-circuit. Tests. Regulation. Loss mechanisms. Uses of transformers. Construction (including high-frequency). Basic design principles and examples.

(2) Induction Machines. Production of a rotating field. Induced emf in the rotor, the concept of slip. Equivalent circuit. Performance calculations. Loss mechanisms. Efficiency. Torque/speed characteristics. Load curves and speed of operation. Speed control by classical means. The need for variable frequency.

(3) Synchronous Machines. Machine topologies and construction. Equivalent circuit. Performance. Phasor diagrams. Permanent-magnet machines, BLDC motor equivalent circuit and torque/speed characteristics.

(4) DC-DC converters. Principle of switched-mode power conversion. Power MOSFET device. Step-up and step-down DC-DC converters. Bi-directional step-down / step-up DC-DC converter. High-frequency transformer isolation and the the two-transistor forward converter. Inductive switching waveforms and switching losses.

(5) AC-DC Converters. Single-phase diode rectifier circuit with inductor or capacitor DC filter. Calculation of active power, apparent power and power factor. Power transfer in AC circuits to non-linear loads, harmonics and power factor.

The course unit aims to: Introduce the methods by which electrical energy is converted from one voltage level to another using transformers or solid-state techniques, and converted to mechanical energy, using electrical machines and appropriate control techniques.

On the successful completion of the course, students will be able to:

ILO 1: Describe using sketched waveforms the operation of DC-DC converters and single-phase rectifiers.

ILO 2: Formulate equivalent circuits of transformers, induction, synchronous and BLDC machines.

ILO 3: Model transformer and machine behaviour using per-phase equivalent circuits.

ILO 4: Analyse DC-DC and AC-DC converter waveforms, calculate operating conditions, component values and switching losses.

ILO 5: Measure transformers and DC-DC converter waveforms and critically evaluate the results.

ILO 6: Evaluate the technical, environmental and sustainability impacts of electrical drive and power electronic technologies.

Coursework:
Machines Lab (10%)
Power electronics Lab (10%)
The coursework forms 20% of the unit assessment

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D. O’Kelly:’Performance and control of electrical drives’, McGraw-Hill
G.R. Slemon: ‘Electrical Machines and Drives’, Addison Wesley
Mohan, Undeland and Robbins, ‘Power Electronics: Converters, Applications and Design’, Wiley.