Fundamentals of AC machines

Fundamentals of AC machines Workbook With CD-ROM L1 N PE CB CA U1 U2 Z1 n = f [M] n I 1500 P2 M n Z2 1/min 1300 1200 220 2.2 1100 W A 1000 180 1.8 900 160 1.6 800 140 1.4 700 120 1.2 600 100 1.0 500 80 0.8 400 60 0.6 300 40 0.4 200 20 0.2 100 P2 = f [M] I = f [M] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Nm 1.2 M Festo Didactic 571791 en Order no Revision level: Author: Editor: Graphics: Layout: 571791 06/2011 Jürgen Stumpp Frank Ebel Jürgen Stumpp, Thomas Ocker 11/2011, Frank Ebel, Sophia Härer © Festo Didactic GmbH & Co KG, D-73770 Denkendorf, Germany, 2011 Internet: www.festo-didactic.com e-mail: did@de.festo.com Reproduction, distribution and utilisation of this document, as well as the communication of its contents to others without explicit authorisation, is prohibited Offenders shall be held liable for payment of damages All rights reserved, in particular the right to file patent, utility model and registered design applications Contents Intended use V Preface VI Introduction VIII Work and safety instructions _ IX Training package, “basic principles of AC machines” X Learning objectives _ XI Allocation of learning goals to exercises XIII Components XV Notes for the teacher/trainer XVII Structure of the exercises XVIII Component designations _ XVIII CD ROM contents XIX Exercises and solutions Overview of alternating current machines Exercise 1: Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) _5 Exercise 2: Single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads _ 13 Exercise 3: Single-phase AC motor with squirrel-cage rotor: measurements with DriveLab software 23 Overview of direct current machines, single-phase AC machines 37 Exercise 4: Basic principles of the universal motor 39 Exercise 5: Universal motor with different loads 45 Exercise 6: Universal motor with different loads: measurements with DriveLab software _ 53 © Festo Didactic GmbH & Co KG 571791 III Exercises and worksheets Overview of alternating current machines Exercise 1: Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) _5 Exercise 2: Single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads _ 13 Exercise 3: Single-phase AC motor with squirrel-cage rotor: measurements with DriveLab software 23 Overview of direct current machines, single-phase AC machines 37 Exercise 4: Basic principles of the universal motor 39 Exercise 5: Universal motor with different loads 45 Exercise 6: Universal motor with different loads: measurements with DriveLab software _ 53 IV © Festo Didactic GmbH & Co KG 571791 Use for intended purpose The training package for “basic principles of alternating current machines” may only be used: • For its intended purpose in teaching and training applications • When its safety functions are in flawless condition The components included in the training package are designed in accordance with the latest technology as well as recognised safety rules However, life and limb of the user and third parties may be endangered, and the components may be impaired, if they are used incorrectly The training system from Festo Didactic has been developed and produced exclusively for training and further education in the field of automation technology The training companies and/or trainers must ensure that all trainees observe the safety instructions described in this workbook Festo Didactic hereby excludes any and all liability for damages suffered by trainees, the training company and/or any third parties, which occur during use of the equipment sets in situations which serve any purpose other than training and/or vocational education, unless such damages have been caused by Festo Didactic due to malicious intent or gross negligence © Festo Didactic GmbH & Co KG 571791 V Preface Festo Didactic’s training system for automation and technology is geared towards various educational backgrounds and vocational requirements The training system is therefore broken down as follows: • Technology-oriented training packages • Mechatronics and factory automation • Process automation and control technology • Mobile robotics • Hybrid learning factories The training system for automation and technology is continuously updated and expanded in accordance with developments in the field of education, as well as actual professional practice The technology packages deal with various technologies including pneumatics, electro-pneumatics, hydraulics, electro-hydraulics, proportional hydraulics, programmable logic controllers, sensor technology, electrical engineering, electronics and electric drives The modular design of the training system allows for applications which go above and beyond the limitations of the individual training packages For example, PLC actuation of pneumatic, hydraulic and electric drives is possible VI © Festo Didactic GmbH & Co KG 571791 All training packages feature the following elements: • Hardware • Media • Seminars Hardware The hardware in the training packages is comprised of industrial components and systems that are specially designed for training purposes The components contained in the training packages are specifically designed and selected for the projects in the accompanying media Media The media provided for the individual topics consist of a mixture of teachware and software The teachware includes: • Technical literature and textbooks (standard works for teaching basic knowledge) • Workbooks (practical exercises with supplementary instructions and sample solutions) • Lexicons, manuals and technical books (which provide technical information on groups of topics for further exploration) • Transparencies and videos (for easy-to-follow, dynamic instruction) • Posters (for presenting information in a clear-cut way) Within the software, the following programmes are available: • Digital training programmes (learning content specifically designed for virtual training) • Simulation software • Visualisation software • Software for acquiring measurement data • Project engineering and design engineering software • Programming software for programmable logic controllers The teaching and learning media are available in several languages They are intended for use in classroom instruction, but are also suitable for self-study Seminars A wide range of seminars covering the contents of the training packages round off the system for training and vocational education Do you have suggestions or criticism regarding this manual? If so, send us an e-mail at did@de.festo.com The authors and Festo Didactic look forward to your comments © Festo Didactic GmbH & Co KG 571791 VII Introduction This workbook is part of the learning system for automation and technology from Festo Didactic GmbH & Co KG The system provides a solid basis for practice-oriented basic and further training Training package TP 1410, “Servo brake and drive system”, deals with the following topics: • Basic principles of DC machines • Basic principles of AC machines • Basic principles of 3-phase machines The workbook entitled “Basic principles of alternating current machines” provides an introduction to the topic of electric machines with AC connection We come into contact with AC drives every day, as these motors are commonly used in household appliances, and above all in handheld electrical tools Knowledge regarding layout, connection and applications ranges is imparted In doing so, the machines are exposed to a wide range of simulated load situations in order to ascertain their capabilities Technical prerequisites for setting up the circuits include: • A laboratory workbench equipped with an A4 frame • Servo brake and drive system equipment set TP 1410 • 230 V AC mains outlet • Universal motor • Capacitor motor • Components for controlling the electric machines • Laboratory safety cables The circuits for all exercises are set up using the TP 1410 equipment set and the AC drives Data sheets for the individual components are also available (universal motor, capacitor motor etc.) VIII © Festo Didactic GmbH & Co KG 571791 Work and safety instructions General information • Trainees should only work with the circuits under the supervision of a trainer • Observe specifications included in the technical data for the individual components, and in particular all safety instructions! • Malfunctions which may impair safety must not be generated in the training environment and must be eliminated immediately Mechanical components • Attach all components intended for mounting of this sort to the A4 frame • Adhere to the instructions regarding positioning of the components Electrical components • The servo brake and drive system (motor test bench) may only be placed into service with an additional protective earth conductor Output L1 DC+ L2 L3/N DC- Input PE PE • • • • Always connect the motor’s thermo-switch to the “Motor ϑ” input at the motor test bench Establish or interrupt electrical connections only in the absence of voltage! Use only connecting cables with safety plugs for electrical connections Always pull the safety plug when disconnecting connecting cables – never pull the cable © Festo Didactic GmbH & Co KG 571791 IX Training package, “basic principles of AC machines” The subject matter of this section of the TP 1410 training package is basic principles of AC machines Individual components from training package TP 1410 may also be included in other packages Important TP 1410 components • Permanently installed workstation with A4 frame • Equipment set or individual components (universal motor, capacitor motor) • Laboratory safety cables • Set of laboratory equipment Media The teachware for training package TP 1410 consists of three workbooks The workbooks contain worksheets for each exercise, the solutions for each individual worksheet and a CD-ROM A set of ready-touse exercises and worksheets is included for each exercise Data sheets for the hardware components are made available along with the training package Media Workbook Basic principles of DC machines Basic principles of AC machines Basic principles of 3-phase machines Digital training programmes WBT, “Electric drives 1” WBT, “Electric drives 2” Overview of media for training package TP 1410 Software available for training package TP 1410 includes digital learning programmes entitled “Electric drives 1” and “Electric drives 2” These programmes explore the basic principles of electric drive technology in detail Training content is elucidated on the basis of practical case studies in a systematic, applicationsoriented fashion Further training materials can be found in our catalogue and on the Internet The learning system for automation and technology is continuously updated and expanded Transparency sets, videos, CD-ROMs, DVDs and training programmes as well as additional teachware are offered in several languages X © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Measuring circuit for checking the specifications in the rating plate a) Complete the measuring circuit for checking the specifications in the rating plate Set up the circuit and start up the motor L1 N PE -P1 V -P2 A -P3 W CB CA U1 U2 -A1.1 n> -M1 M n Z2 Z1 Quantity Identification Designation -M1 Capacitor motor -P1, -P2 Digital multimeter -P3 Single-phase power meter -A1.1 Motor test bench, servo brake and drive system Equipment list 10 © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) b) Set up the circuit – Use the 230 V capacitor motor (order no 571872) Checking the specifications in the rating plate by means of measurement and calculation a) The motor is connected to the motor test bench in order to perform measurement The motor test bench is switched on but it is not connected to the PC The motor is switched on b) Measurement is performed first of all during no-load operation Enter the measured values to the “Noload” column in the table c) For measurement at nominal load, the motor is loaded by the test bench up to nominal current (see rating plate), and the measurements are documented Enter the measured values to the “Nominal load” column the table No-load Nominal load V [V] 228 228 I [A] 1.2 1.86 P [W] 216 352 n [rpm] 1480 1400 d) Calculate values for apparent power, power factor and reactive power on the basis of the measured values in the table for no-load and nominal load operation No-load Apparent power S: S = U ⋅ I = 228 V ⋅ 1,2 A = 274 VA Power factor cos φ: cos ϕ = Reactive power Q: Q = S ⋅ sin ϕ = 274 VA ⋅ 0,63 = 173 var © Festo Didactic GmbH & Co KG 571791 P 216 W = = 0,78 S 274 VA 11 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Nominal load Apparent power S: S = U ⋅ I = 228 V ⋅ 1,86 A = 424 VA Power factor cos φ: cos ϕ = Reactive power Q: Q = S ⋅ sin ϕ = 424 VA ⋅ 0,56 = 237 var P 352 W = 0,83 = S 424 VA Monitoring capacitance of CA Measured values: U = 230 V I = 1.75 A Reactance XC: XC = Capacitance C: C= UC 230 V = = 131,42 Ω IC 1,75 A 1 = = 24,2 μF ⋅ π ⋅ f ⋅ X C ⋅ π ⋅ 50 s-1 ⋅ 131,42 Ω Monitoring capacitance of CB 12 Measured values: U = 220 V I = 0.7 A Reactance XC: XC = Capacitance C: C= U C 220 V = 314,28 Ω = 0,7 A IC 1 = = 10,13 μF -1 ⋅ π ⋅ f ⋅ X C ⋅ π ⋅ 50 s ⋅ 314,28 Ω © Festo Didactic GmbH & Co KG 571791 Contents Exercises and worksheets Overview of alternating current machines Exercise 1: Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) _5 Exercise 2: Single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads _ 13 Exercise 3: Single-phase AC motor with squirrel-cage rotor: measurements with DriveLab software 23 Overview of direct current machines, single-phase AC machines 37 Exercise 4: Basic principles of the universal motor 39 Exercise 5: Universal motor with different loads 45 Exercise 6: Universal motor with different loads: measurements with DriveLab software _ 53 © Festo Didactic GmbH & Co KG 571791 © Festo Didactic GmbH & Co KG 571791 Overview of alternating current machines AC machines Transformers Single-phase transformer Rotating machines Three-phase transformer Special transformers e.g leak and auto transformers Motors Synchronous machines Generators Asynchronous machines Single-phase machines Three-phase machines Motors with auxiliary winding or capacitor Motors with squirrel-cage rotor Special machines e.g pole switching and repulsion motors Motors with slip-ring rotor Special machines e.g linear and collector motors © Festo Didactic GmbH & Co KG 571791 © Festo Didactic GmbH & Co KG 571791 Exercise Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Learning objectives After completing this exercise: • You will be familiar with the basic function of the capacitor motor • You will be familiar with the connection plate on the motor with all of its designations • You will be familiar with the motor’s circuitry including main and auxiliary windings, as well as the starter and operating capacitors • You will be familiar with terminal board wiring for clockwise and anti-clockwise motor operation • You will be familiar with the measuring circuit for checking the specifications in the rating plate • You will be familiar with checking the specifications in the rating plate by performing measurements while the motor is idling, and while running at nominal load Problem description 230 V single-phase alternating voltage (L1 and N) is the only option available for operating an air compressor Due to the fact that high-inertia starting conditions can be expected with the compressor, a capacitor motor with starter and operating capacitors will be used as a drive The motor needs to be tested for suitability in the training workshop The examination results will need to be documented in a report Air compressor © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) • • • • • • Project assignments Describe the basic function of a single-phase AC motor with squirrel-cage rotor (capacitor motor) Complete the specifications for the motor’s connection plate Complete the motor circuit with main and auxiliary windings, as well as the starter and operating capacitors Complete the specifications for clockwise and anti-clockwise motor operation Complete the measuring circuit for checking the specifications in the rating plate Check the specifications on the motor’s rating plate for no-load operation and operation at nominal load by means of measurement and calculation Work aids Textbooks, books of tables Excerpts from manufacturers’ catalogues Data sheets Servo brake and drive system manual Internet WBT, “Electric drives 1” Name: Date: © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Basic function of the capacitor motor a) Describe the layout of a capacitor motor U1 U2 M Z2 Z1 Capacitor motor – basic arrangement of the two windings b) Describe the function of the capacitor motor c) Which function does the operating capacitor fulfil? © Festo Didactic GmbH & Co KG 571791 Name: Date: Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) d) Which function does the starter capacitor fulfil? Motor connection plate – Designate the individual terminals at the connection plate on the capacitor motor U1 U2 Z1 Z2 CB CB Name: Date: © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Capacitor motor circuit including main and auxiliary windings, as well as starter and operating capacitors – Complete the circuit for the motor L1 N PE CA CB U1 U2 n> Z2 M Z1 Wiring for clockwise and anti-clockwise motor operation – Complete the wiring diagrams for clockwise and anti-clockwise motor operation L1 L1 N N PE PE U1 Z1 U1 Z1 Z2 U2 Z2 U2 CA CB U1 U1 U2 M CA CB n Z2 Z1 © Festo Didactic GmbH & Co KG 571791 U2 M n Z2 Z1 Name: Date: Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Measuring circuit for checking the specifications in the rating plate a) Complete the measuring circuit for checking the specifications in the rating plate Set up the circuit and start up the motor L1 N PE V A W CB CA U1 U2 M n Quantity Identification n> Z2 Z1 Designation Capacitor motor Digital multimeter Single-phase power meter Motor test bench, servo brake and drive system Equipment list 10 Name: Date: © Festo Didactic GmbH & Co KG 571791 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) b) Set up the circuit – Use the 230 V capacitor motor (order no 571872) Checking the specifications in the rating plate by means of measurement and calculation a) The motor is connected to the motor test bench in order to perform measurement The motor test bench is switched on but it is not connected to the PC The motor is switched on b) Measurement is performed first of all during no-load operation Enter the measured values to the “Noload” column in the table c) For measurement at nominal load, the motor is loaded by the test bench up to nominal current (see rating plate), and the measurements are documented Enter the measured values to the “Nominal load” column the table No-load Nominal load V [V] I [A] P [W] n [rpm] d) Calculate values for apparent power, power factor and reactive power on the basis of the measured values in the table for no-load and nominal load operation No-load © Festo Didactic GmbH & Co KG 571791 Name: Date: 11 Exercise – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) Nominal load Monitoring capacitance of CA Monitoring capacitance of CB 12 Name: Date: © Festo Didactic GmbH & Co KG 571791 [...]... with DriveLab software _ 53 © Festo Didactic GmbH & Co KG 571791 1 2 © Festo Didactic GmbH & Co KG 571791 Overview of alternating current machines AC machines Transformers Single-phase transformer Rotating machines Three-phase transformer Special transformers e.g leak and auto transformers Motors Synchronous machines Generators Asynchronous machines Single-phase machines Three-phase machines Motors... Overview of alternating current machines AC machines Transformers Single-phase transformer Rotating machines Three-phase transformer Special transformers e.g leak and auto transformers Motors Synchronous machines Generators Asynchronous machines Single-phase machines Three-phase machines Motors with auxiliary winding or capacitor Motors with squirrel-cage rotor Special machines e.g pole switching and repulsion... impermissibly hot The capacitance of the operating capacitor accommodates close to 1 kvar of reactive power per kilowatt of motor power © Festo Didactic GmbH & Co KG 571791 7 Exercise 1 – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) d) Which function does the starter capacitor fulfil? In order to increase the motor’s starting torque, the capacitor’s capacitance value... package for “basic principles of AC machines impart knowledge regarding setup, connection and the range of applications of AC machines In order to set up functional circuits, you will also need a laboratory workstation (optionally equipped with an A4 frame), “servo brake and drive system” equipment set TP 1410, a 230 V AC power supply and controllers for the electric machines “Servo brake and drive... AC motor with squirrel-cage rotor (capacitor motor) 571871 1 Universal motor 571872 1 Component Order no Quantity EduTrainer 3-phase power supply 571812 1 EduTrainer 24 V power supply 571813 1 EduTrainer contactor board 571814 1 Motor technology contactor set 571816 1 EduTrainer operator and signaling unit 571815 1 Electric machines, “basic principles of AC machines Controllers for the electric machines. .. motor with squirrel-cage rotor (capacitor motor) _5 Exercise 2: Single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads _ 13 Exercise 3: Single-phase AC motor with squirrel-cage rotor: measurements with DriveLab software 23 Overview of direct current machines, single-phase AC machines 37 Exercise 4: Basic principles of the universal motor ... alternating current machines 3 Exercise 1: Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) _5 Exercise 2: Single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads _ 13 Exercise 3: Single-phase AC motor with squirrel-cage rotor: measurements with DriveLab software 23 Overview of direct current machines, single-phase... of measurement and calculation Work aids Textbooks, books of tables Excerpts from manufacturers’ catalogues Data sheets Servo brake and drive system manual Internet WBT, “Electric drives 1” © Festo Didactic GmbH & Co KG 571791 Exercise 1 – Basic principles of the single-phase AC motor with squirrel-cage rotor (capacitor motor) 1 Basic function of the capacitor motor a) Describe the layout of a capacitor... Festo Didactic GmbH & Co KG 571791 XV Graphic symbols, equipment set Component Graphic symbol Single-phase AC motor with squirrel-cage rotor (capacitor motor) M 1 Universal motor M XVI © Festo Didactic GmbH & Co KG 571791 Notes for the teacher/trainer Learning objectives The overall learning objective of this workbook is familiarisation with the basic principles of AC machines Direct interplay of theory... principles of AC machines – single-phase AC motor with squirrel-cage rotor (capacitor motor) with different loads You become familiar with the basic function of the capacitor motor You become familiar with the connection plate on the motor with all of its designations You become familiar with the motor’s circuitry including main and auxiliary windings, as well as the starter and operating capacitors You ... Training package, “basic principles of AC machines The subject matter of this section of the TP 1410 training package is basic principles of AC machines Individual components from training package... AC machines • Basic principles of 3-phase machines The workbook entitled “Basic principles of alternating current machines provides an introduction to the topic of electric machines with AC. .. principles of DC machines Basic principles of AC machines Basic principles of 3-phase machines Digital training programmes WBT, “Electric drives 1” WBT, “Electric drives 2” Overview of media for