# EEE8159 : Electrical Machines and their applications

• Offered for Year: 2021/22
• Module Leader(s): Dr Glynn Atkinson
• Owning School: Engineering
• Teaching Location: Newcastle City Campus
##### Semesters
 Semester 1 Credit Value: 20 ECTS Credits: 10

#### Aims

To provide a thorough basis for electrical machines study at advanced level.

#### Outline Of Syllabus

Salient pole Synchronous Machine -dq approach: -
*DQ axis reactance models, salient pole phasor diagrams, torque and power calculations, reluctance and excitation torque, voltage and current fed performance, wound rotor and PM types.

Circuit analysis of electrical machines: -
*Development of circuit models from dc machine and synchronous machine routs. Impedance matrix; instantaneous and phasor variables; real-coil and pseudostationary coil machines; expressions for torque and power, transformation of variables with power invariance, examples; general two-axis machine. Extension of two axis models to induction motors and links to the steady state per phase model.

Steady state models for ac commutator motors.

Parks equations and two-axis equivalent circuits
Derivation of Parks equation and dq equivalent circuits for a general two-axis machine.

Single Phase Induction Motor:
*Analysis of simple single phase salient pole induction motor; derivation of equivalent circuit showing forward and backward wave effects; torque characteristics, f and b components; practical methods of improving starting characteristics: capacitor motor, shaded pole motor, split phase motor.

Transient behaviour of machine
*Transients in dc machine, time constants, distinction between electromechanical and electrical transients, linearization concepts, numerical methods.
Electrical transients effects in ac machines using a sudden symmetrical short circuit in a synchronous machine as an example; transient and sub-transient reactances and time constants, engineering importance; discussion of behaviour in physical terms, with reference to equivalent circuits.

Electromechanical transients in ac machines, natural oscillation frequencies.

Reluctance Machines
Synchronous reactance, stepping motors and switched reluctance machines, principles of operation and models for operating characteristics.

Models and reference frames: -
An understanding of alternative reference frames, dq, alpha/beta, space vector, forward/backward, rotor/stator/air gap and their transformations for each machine type. An explanation of the merit of each derived machine model.

Synchronous Machines
Models for saturations; field oriented control of damperless machine; role of damper circuits, field oriented control of dampered machine.

Permanent magnet Synchronous machines:-
Performance under vector control; field weakening.

Synchronous Reluctance Motors
Operation for peak torque per unit current; power factor; current angle for max power-factor; field oriented control, field weakening, comparison with induction machines.

Induction motors
Induction machine models for control purpose; relationship of induction motor models to synchronous and dc. Harmonics in spatial mmf, reasons for their existence and explanation of the effects they cause -zero sequence, asynchronous crawling, cogging, harmonic torques.

Brushless DC machines:
Armature reaction, compensating windings, commutation, interpoles.

Brushless dc drives.
Principles of operation: sinusoidal and trapezoidal drives. Relationship to brushless dc machine.

Stepping and Switched Reluctance Machines
Models,reasons for difference with other machines; relationship to other machine types through flux linkage/current.

#### Teaching Methods

##### Teaching Activities
Category Activity Number Length Student Hours Comment
Structured Guided LearningLecture materials250:3012:30Twenty five Non-synchronous pre-recorded lectures covering course material and worked examples.
Scheduled Learning And Teaching ActivitiesLecture21:002:00Two synchronous guest lectures from industry
Guided Independent StudyAssessment preparation and completion51:005:00Formative online test summarizing each unit and laboratory work
Guided Independent StudyAssessment preparation and completion110:0010:00Preparation and completion of summative individual assignment
Guided Independent StudyAssessment preparation and completion241:0024:00Revision for final exam
Guided Independent StudyAssessment preparation and completion13:003:00Completion of summative individual assessment during normal assessment period
Scheduled Learning And Teaching ActivitiesPractical13:003:00One three-hour present-in-person (PiP) practical lab session.
Structured Guided LearningStructured research and reading activities42:008:00Reading activity to supplement knowledge of material taught in each week.
Scheduled Learning And Teaching ActivitiesSmall group teaching22:004:00Three two-hour group activities exploring Electrical machine applications and manufacturing culminat
Scheduled Learning And Teaching ActivitiesWorkshops121:0012:00Three one hour timetabled PiP workshops per week covering tutorials, simulation activities and appli
Scheduled Learning And Teaching ActivitiesWorkshops12:002:00Initial 2-hour software training session PiP/online
Scheduled Learning And Teaching ActivitiesDrop-in/surgery41:004:00One one-hour zoom surgery session per week (online)
Guided Independent StudyIndependent study250:3012:30Student study time of non-synchronous pre-recorded material
Guided Independent StudyIndependent study250:3012:30Student led study and completion of set activities
Guided Independent StudyIndependent study198:0098:00Reviewing lecture notes; general reading
Total212:30
##### Teaching Rationale And Relationship

Online sessions provide the core material and guidance for further reading, problem solving and practice are integrated into the lecture structure.
Computer based simulation problems will allow the students to gain a deeper understanding of the characteristics and principles of the electrical machines being studied, and an ability to link the mathematical models developed to the electrical machine operation.
The online unit assessments will help the students to reflect on what has been learnt so far and give feedback throughout the course.

Alternatives will be offered to students unable to be present-in-person due to the prevailing C-19 circumstances.
Student’s should consult their individual timetable for up-to-date delivery information.

#### Assessment Methods

The format of resits will be determined by the Board of Examiners

##### Other Assessment
Description Semester When Set Percentage Comment
Practical/lab report1M25Laboratory Assignment
Written exercise1M75Individual Coursework
##### Formative Assessments
Description Semester When Set Comment
Computer assessment1MNUMBAS based assessment
##### Assessment Rationale And Relationship

The formative assessment will allow the students to demonstrate their knowledge on a single teaching unit; Background and mechanical modelling, Induction machines, DC machines, Synchronous machines.
The summative assessments will allow the students to demonstrate a deeper understanding in a problem based setting. Feedback will be given prior to the end of the autumn term to allow the students to reflect.