Electrician's Technical Reference Variable Frequency Drives

by Carrow, Robert

• ISBN13: 9780766819238
• ISBN10: 076681923X
• Format: Hardcover
• Copyright: 2000-09-05
• Publisher: Cengage Learning

Summary

The variable frequency drive industry is growing rapidly, and it is now more important than ever for technicians and maintenance personnel to keep VFD installations running smoothly! Part of the Electrician's Technical Reference Series, this field guide is ideal for gaining access to information about variable frequency drives, including how they work, how to apply them, and how to troubleshoot them. A hands-on reference, Variable Frequency Drives contains sufficient information for a technician to troubleshoot any AC variable frequency drive, virtually eliminating the need for manufacturer-specific manuals! Both industrial and commercial variable frequency drive applications are addressed, with discussion of installation issues, troubleshooting, metering, sizing and selection, energy savings with variable frequency drives, and more. A final chapter preps readers for future developments in variable frequency drive technology, while appendices feature addresses of relevant organizations and a bibliography of suggested readings.

Table of Contents

Dedication	ix
Preface	xi
Variable-Speed-Drive Basics	1	(11)
Speed and Motion Control	1	(2)
Reasons to Consider Using Variable-Speed Equipment	3	(1)
Traditional Variable-Speed Systems	4	(4)
Static and Solid-State Variable-Speed Controllers	8	(1)
Variable-Speed-Drive-System Efficiency	9	(1)
Speed Regulation	10	(2)
Electric and Power-Transmission Basics	12	(19)
Electricity and Power Transmission	12	(2)
Horsepower	14	(1)
Torque	15	(2)
Inertia and Acceleration Torque	17	(1)
Electric Basics	18	(1)
Frequency and Amplitude	19	(2)
Power Factor	21	(3)
Capacitors	24	(1)
Inductors	25	(3)
Semiconductors	28	(3)
AC-Induction-Motor Theory and Variable-Frequency-Drive Basics	31	(39)
AC-Induction-Motor Theory	31	(1)
AC-Motor Construction	31	(14)
Inverter Duty Motors: NEMA MG-31 Standard	45	(1)
Variable-Frequency-Drive Basics	45	(4)
Variable-Frequency-Drive Types	49	(1)
Voltage-Source Inverters	49	(1)
Variable-Voltage Inverters	49	(1)
Current-Source Inverters	50	(1)
Pulse-Width Modulation and Pulse-Amplitude Modulation	50	(3)
How Variable-Frequency Drives Operate	53	(1)
Volts-per-Hertz Control	54	(2)
Variable-Frequency-Drive Selection	56	(4)
Adjustable Variable-Frequency-Drive Functions and Features	60	(3)
High-Performance, Specialty, Variable-Frequency Drives	63	(1)
Flux-Vector Control (FVC), Including Sensorless-Vector Control (SVC)	64	(3)
Field-Oriented Control	67	(1)
Direct-Torque Control	68	(2)
Installation Issues Concerning Variable-Frequency Drives	70	(24)
Control and Power Wiring Methods	70	(2)
Harmonic Distortion/Power Quality	72	(6)
Overvoltage Reflection	78	(2)
Shaft Voltages and Bearing Currents	80	(3)
Carrier Frequency	83	(1)
Electric Noise, Electromagnetic Interference, and Radio-Frequency Interference	84	(6)
Location, Enclosures, and Heat Dissipation	90	(4)
Troubleshooting Variable-Frequency Drives	94	(24)
Proper Setup	94	(1)
Fault Handling	95	(1)
Variable-Frequency-Drive Maintenance	96	(1)
Troubleshooting and Repair of AC Drives	97	(1)
Diagnostics	98	(12)
Measurements and Tools for Troubleshooting Variable-Frequency Drives	110	(5)
Tips on Troubleshooting Variable-Frequency Drives	115	(3)
Metering of Variable-Frequency Drives	118	(7)
Input Waveforms	119	(1)
DC Bus	119	(1)
Output Waveforms	119	(3)
Power-Module Testing	122	(1)
Harmonic Analysis	123	(1)
Checking Pulse Generators	123	(2)
Sizing and Selection of Variable-Frequency Drives	125	(9)
Ambient Conditions	125	(2)
Constant versus Variable Torque	127	(1)
High-Starting Torque Applications	128	(1)
Multiple Motors	128	(1)
Closed-Loop and High-Performance Drives	128	(3)
Braking Methods	131	(2)
Other Considerations	133	(1)
Industrial and Commercial Variable-Frequency-Drive Applications	134	(9)
Heating, Ventilation, and Air-Conditioning Systems	134	(4)
Proportional, Integral, Derivative Loop Control	138	(2)
Process Control with Sensors	140	(1)
Automated Systems and Machine Control	141	(2)
Energy Savings with Variable-Frequency Drives	143	(13)
Determining Energy-Saving Opportunities	143	(3)
Affinity Laws	146	(3)
Fan and Pump Curves	149	(1)
Energy Policy Act	150	(1)
Optimizing a Motor-Driven System	151	(5)
Future Variable-Frequency-Drive Technology	156	(6)
New Control Platforms	156	(1)
New Power Modules	157	(1)
New Designs	157	(1)
Residential Applications	158	(3)
Electric-Vehicle Applications	161	(1)
Appendix A English-Metric Conversions	162	(3)
Appendix B Acronyms	165	(8)
Index	173