Course detail

# Electrical Drives

Content annotation :
This new course link to courses of mechanic, theory of Electric machines and Power Electronics. Explain the principles and methods dimensioning of power parts structure of Electric drives. Electric drives play an important role as electromechanical energy converters in most production processes. Explain problems : Dynamics of a Mechanical Drive, Integration of the simplified Equation of Motion, Thermal effects in Electrical machines,structures with Separately Excited and Series DC machines, Control of Converter-supplied this type, Induction Motor + frequency converter,Variable Frequency Synchronous Motor Drives and Some Applications of Controlled Drives.

Language of instruction

Czech

Number of ECTS credits

5

Mode of study

Not applicable.

Entry knowledge

The subject knowledge on the secondary school level is required.
Student has to able to:
- explain general principles of the electric machines.
- compute in complex domain.
- apply differential equations of the electromechanical systems in time and Laplace domain.
- handle the software MATLAB SIMULINK on basic level
- prove that he is qualified to handle with electrical equipment according to defined rules.

Rules for evaluation and completion of the course

Requirement for credit award, exam form and way and rules of final course classification:
Running evaluation of work in laboratory and numerical exercises.The exam has a written and an oral part.
Detail requirements for completion of a course are specified by a regulation issued by the lecturer responsible for the course and updated for every academic year.
Attendance at practical training is obligatory.

Aims

New conception and essential information of Electric Drives
/ theoretical and practice /.
Learning outcomes BEPB
Student:
- He is able describe mathematical background of the common torque – velocity characteristics of the drivetrain systems in dependence on absolute value of the velocity and also in dependence on operational quadrant.
- He can recalculate drivetrain inertia on the side of the motor shaft.
- He is able to create frequency characteristic from voltage and Newton´s second law equations. He is able to build a model of DC motor according to mentioned equations.
- He is able to draw and explain principles of all possible variations of the power parts of the DC/DC inverter intended for motor supply.
- He knows how to build mathematical models of the DC/DC inverters and all related sensors.
- He perfectly understands the principles of cascade regulation structure of the DC drivetrain and he is able to describe all inner loops.
- He can calculate current and velocity regulators for DC drivetrain according to specialized “Optimal module methods”.
- He knows how to calculate “bode characteristics” of the desired value and fault signal.
- He is able to describe principles of the drivetrain with asynchronous motors from user point of view. He is able to describe principle of velocity control of the asynchronous motor.
- He is able to draw power diagram of pules inerter for asynchronous motor. He is able to explain principles of scalar velocity control.
- He knows phenomena of the asynchronous motor de-excitations. He is able to explain areas of the constant torque and power of the motor.
- He is able to identified dissipations presented in electrical drivetrain. He is able to design the electrical drivetrain with help of methods assuming effective values of torques (currents) or average values of dissipations.
- He is able to choose suitable type of motor and inverter for typical industrial and traction applications.
Computer and laboratory lessons outcomes
- Student can create project in program Matlab/Simulink and he is able to handle its basic library functions and functional blocs.
- He is able to simulate Newton´s second law principles of the mechanical system
- He is able to create Simulink model of the DC motor with external field excitation of with permanent magnet.
- He is able to create Simulink model of current loop of the DC motor with inverter
- He is able to create model of the velocity closed loop with inner current loop.
- He is able to create simplified model of the position loop.
- According to simulations result of the electric drive operation cycle he is able to defined dissipation and design the main power parts of the drivetrain (motor + inverter) according to these dissipations.
- He is able to realize current and velocity regulators (designed via “Optimal module methods”) via analog circuits (operational amplifiers).
- He is able to analyze dissipations presented in drivetrain with synch

Study aids

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

O. Kelly: Performance and Control of Electrical Machines, , 0
Pavelka, J., Čeřovský, Z., Javůrek, J.: Elektrické pohony, skripta ČVUT Praha, 1996
Bose, B.,K a j.: Power Electronics and Variable Frequency Drives, , 0
Kubík, Z. a kol. : Teorie automatického řízení I., , 0
Caha, Z., Černý, M.: Elektrické pohony SNTL Praha, 1990

Stemme,O.,Wolf,.: Principles and properties of Highly Dynamic DC Miniature Motors. Interelectric AG,1994.
Accarnley,P.: Stepping Motors -a quide to modern theory and practice . IEE Control Engineering Series 19,1984.
T.Kenjo.,A.Sugawara .: Stepping motors and their microprocessor controls. Second edition.Clarendon press,Oxford 2000.
Ueha,Tomikawa, Kurosawa,Nakamura.:Ultrasonic motors - Theory and Applications.
www.maxonmotor.com
www.minimotor.ch

eLearning

Classification of course in study plans

• Programme B-MET-P Bachelor's, 3. year of study, summer semester, compulsory

#### Type of course unit

Lecture

26 hours, optionally

Teacher / Lecturer

Syllabus

Teaching methods :
Lectures: 13 x 2 hrs.
Seminars in computer labs: 13 x 2 hrs.
Lectures:
1. Block diagram of electric drive
2. Summary of electric drives, control, regulation.
3. Mechanics of electric drive, equation of motion
4. The main types of electric machines, used in electric drives
5. DC machine, matematic model
6. Transistor inverter as a dynamic element in control theory
7. Cascade control loops regulation of electric drives
8. SO, OM, transient characteristics, regulator design
9. Mechanic charakteristic of mechanism and industrial machines
10. Loses in drive, dimensioning, equivalent methods
11. Drives with serial excitacion, deexcitacion, DC machine in electric traction
12. Drives with asynchronous machines, frequency inverters, softstarts.
13. Drives with synchronous machines, EC motor.

Computer-assisted exercise

13 hours, compulsory

Teacher / Lecturer

Syllabus

Numerical and computer exercises:
1. Electric drive kinematics, load characteristics
2. Methods for reduction of the load and moment of inertia
3. Electric drive dynamics, motion equation
4. DC machine model
5. Synthesis of current control loop
6. Synthesis of speed control loop
Laboratory exercises:
7. Introductory lesson, introduction to laboratory safety regulations, operation with laboratory instruments.
8. Measurement on induction motor
9. DC motor speed control
10. Measurement on BLDC motor