Course detail
Electrical Drives
FSI-RRYAcad. year: 2021/2022
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
Number of ECTS credits
Mode of study
Guarantor
Learning outcomes of the course unit
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
Prerequisites
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.
Co-requisites
Planned learning activities and teaching methods
Assesment methods and criteria linked to learning outcomes
Students submit 4 protocols from laboratory exercises (4 * 4 points), 14 points for two tests during semester and 70 points for the final exam. The final exam consists of a test on the topic of laboratory tasks (10 points) and a computational part (60 points). Detailed conditions for successful completion of the course and also the time schedule of numerical, computer and laboratory exercises are set by the annually updated decree of the course guarantor.
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.
Course curriculum
1. Types of control drives, its structure, working quadrants, concepts of control and regulation.
2. Mechanical characteristics of driving and loading torque
3. Methods of reduction of static and dynamic forces and torques
4. Mechanics of drives, motion equation
5. DC motor, types, static characteristics, dynamic mathematical model
6. Transistor converter as a dynamic element from the control theory point of view
7. Sensors of electrical and non-electrical quantities in electric drives
8. Cascade control in electric drives, principle, structure, stability
9. Methods of current and speed control loops design, their comparison.
10. Drive losses, dimensioning, equivalent methods
11. Drives with asynchronous machines, equivalent scheme, static characteristic
12. Speed control of AM, frequency converters, soft starts
13. Drives with PMSM, types of motors and its control algorithms
Work placements
Aims
Introduction to the concepts and basics of electric drives in the theoretical and practical level in connection with the requirements of the bachelor profile.
Specification of controlled education, way of implementation and compensation for absences
Recommended optional programme components
Prerequisites and corequisites
Basic literature
Caha, Z., Černý, M.: Elektrické pohony SNTL Praha, 1990
Kubík, Z. a kol. : Teorie automatického řízení I., , 0
O. Kelly: Performance and Control of Electrical Machines, , 0
Pavelka, J., Čeřovský, Z., Javůrek, J.: Elektrické pohony, skripta ČVUT Praha, 1996
Recommended reading
Stemme,O.,Wolf,.: Principles and properties of Highly Dynamic DC Miniature Motors. Interelectric AG,1994.
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.
W.H.Yeadon,A.W.Yeadon.:Handbook of Small Electric Motors. McGraw Hill, 2004
www.maxonmotor.com
www.minimotor.ch
Elearning
Classification of course in study plans
Type of course unit
Lecture
Teacher / Lecturer
Syllabus
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
Teacher / Lecturer
Syllabus
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
11. Fan load characteristic
12. Submission of protocols, task assessment
Elearning