Unit 21 – Electrical Machines

Electrical machines can be found in manufacturing, transport, consumer appliances and hospitals. People will come across them every day in their home and at work.
They convert energy in three ways: transformers which change the voltage level of an alternating current; motors which convert electrical energy to mechanical energy; and generators which convert mechanical energy to electrical energy. Transducers and actuators are also energy converters, and can be found in a wide range of industrial and domestic applications.

This Module includes:

  • 3 Workbooks
  • 3 Assignments
  • 14 Video Tutorials

Description

This unit introduces students to the characteristics and operational parameters of a range of electromagnetic powered machines that are used in a variety of applications. Among the topics included in this unit are: principles underlying the operation and construction of transformers, induction motors, synchronous machines, electromagnetic transducers, actuators, and generators; and operating characteristics of electrical machines such as voltage, current, speed of operation, power rating, electromagnetic interference (EMI) and efficiency.

On successful completion of this unit students will be able to identify the constructional features and applications of transformers; investigate the starting methods and applications of three-phase induction motors and synchronous machines; investigate the types of generator available in the industry by assessing their practical application; and analyse the operating characteristics of electromagnetic transducers and actuators.


Learning Outcomes

By the end of this unit students will be able to:

1. Assess the constructional features and applications of transformers.

Constructional features:
Construction, application, characteristics and testing of transformer types such as: step up, step down, and isolating
Shell and core, windings, connections, efficiency, short circuit and no-load testing, and equivalent circuit

2. Analyse the starting methods and applications of three-phase induction motors and synchronous machines.

Methods and applications:
Construction, application, characteristics and testing of induction and synchronous motors
Types of electric motors and their practical applications
Starting methods
Voltages, power, speed, torque, inertia, EMI, and efficiency
Cooling and protection devices

3. Investigate the types of generator available in industry by assessing their practical applications.

Types of generators available:
Construction, application, characteristics and testing of generators
Types (direct current, alternating current and self-excitation)
Practical applications
Generation methods
Voltages, power, speed, torque, inertia, EMI, efficiency
Cooling and protection devices

4. Analyse the operating characteristics of electromagnetic transducers and actuators.

Operating characteristics:
Construction, application, characteristics and testing of electromagnetic transducers and actuators
Transducer types (active, passive, sensor), actuator types (solenoids, linear, rotary)
Practical applications.
Voltage and current requirements, hysteresis and speed of operation
Torque
Insulation Protection (IP) rating
Contact types
Back Electromotive Force (EMF), EMI and efficiency

Additional information

Workbooks

3

Assignments

3

Tutorial Videos

14 Tutorial Videos included in the module price.

Casio Scientific Calculator Demo (37:24)
Electromagnetic Induction (26:18)
Graph Simulator – Advanced (12:46)
Graph Simulator – Beginner (23:17)
Graph Simulator – Intermediate (15:12)
Magnetic Fields (21:34)
SI Base Units (10:00)
SI Derived Units (10:23)
SI Prefixes (13:06)
Sinusoids and Radian Measure (13:03)
The Mysterious Root 3 and 3 Phase Systems Analysis (22:27)
Transformers (13:40)
Transposition of Formulae (14:53)
Vector (Cross) Product and Scalar(Dot) Product (31:08)

Workbook Sample

Tutorial Video Sample