Electrical Machines and Drives

Learning Outcomes

Subject Specific Practical Skills

Having successfully completed this module you will be able to:

• Undertake virtual prototyping of electromagnetic devices, by setting up models and solving them via FE software
• Conduct simple experiments on rotating electrical machines and transformers
• Analyse a specific application and produce the drive requirements that will result in the selection of sizing of a suitable drive system.

Knowledge and Understanding

Having successfully completed this module, you will be able to demonstrate knowledge and understanding of:

• Fundamentals of modelling, simulation techniques and components of CAD systems for Electromagnetics and Electrical Machines.
• Construction and design issues associated with electrical machines
• The principles of operation of electrical generators and motors; fundamental characteristics of various types of machines

Subject Specific Intellectual and Research Skills

Having successfully completed this module you will be able to:

• Describe the characteristics of various types of electrical machines; advantages and disadvantages that different motors drives will bring to an application
• Apply equivalent circuits to performance prediction, interpret results and correlate them with theoretical predictions, perform design calculations for drives.
• Understand the operation of modern drive systems applied to industrial applications including robotics and advanced machine tools.
• Solve problems related to the analysis of performance and characteristics of electrical machines.

Transferable and Generic Skills

Having successfully completed this module you will be able to:

• Transfer understanding and theories from one discipline to another, in particular from the mechanical design to the electrical power domain.
• Discuss the wide range of issues that impact on the use of drive system in the industrial context, including safety, efficiency, sustainability and costs.
• Use CAD packages.

Principles of electric machines and transformers.

• Function of transformers, construction, equivalent circuit and operation; regulation, single- and three-phase connections, parallel operation; Auto-transformers.
• Underlying concepts and features of rotating machines, fundamental torque equation, rotating field principle, generated EMF, air-gap mmf and permeance;
• Concepts and features of linear machines, compare and contrast with rotating machines
• Construction of different types of electrical machines windings and winding factors, conductors and insulation systems.

Introduction to CAD and the CAD environment.

• Hierarchical design
• Pre- and post-processing, automatic and adaptive meshing.
• Design Environment, optimisation, future trends.

Numerical solution of large systems of equations.

• The finite element method for virtual prototyping
• Analysis of errors, matrix and vector norms, condition numbers.

Alternating current machines

• Synchronous machines: output equation, armature reaction, phasor diagram, synchronous reactance, equivalent circuit, load angle
• Induction motors: equivalent circuit, analysis of machine equations, speed/torque curves, starting performance
• Single-phase AC motors: single phase induction motors, universal motors, permanent magnet and reluctance machines, and vector-controlled AC motor drives.

Direct current machines.

• Basic equations and steady-state characteristics, field form and armature reaction, commutation; brushless DC motors

The Drive Environment:

• Robotic and machine tool applications
• Introduction to position and speed control systems for AC and DC machines
• Dynamics and load characteristics, power transmission, environmental factors
• Determination of speed and torque requirements, motion profiles, installation considerations.

Design of electric machines and specification of Drive Systems:

• Main steps of electrical machine design, considering electrical, mechanical and thermal limitations
• Mechanical transmission elements, gears, leadscrews, belts etc.
• Sizing algorithms.
• Integration of controllers into the drive package.

Operation of electric machines

• Synchronous machine on infinite busbars, generators and motor operation, power factor correction.
• Consideration of specific drives and their operating characteristics.

Testing of electric machines.

• Measurement of equivalent circuit parameters.

The content of this module is delivered through lectures, module website, directed reading and tutorials.

Students work on their understanding through a combination of independent study, preparation for timetabled activities, tutorials and problem classes, along with formative assessments in the form of coursework assignments and problem sheets.

Students work on their practical skills and technical understanding in technical laboratories.

Summative

This is how we’ll formally assess what you have learned in this module.

Referral

This is how we’ll assess you if you don’t meet the criteria to pass this module.

Repeat

An internal repeat is where you take all of your modules again, including any you passed. An external repeat is where you only re-take the modules you failed.