1st Edition
Noise of Polyphase Electric Motors
Controlling the level of noise in electrical motors is critical to overall system performance. However, predicting noise of an electrical motor is more difficult and less accurate than for other characteristics such as torque-speed. Recent advances have produced powerful computational methods for noise prediction, and Noise of Polyphase Electric Motors is the first book to collect these advances in a single source. It is also the first to include noise prediction for permanent magnet (PM) synchronous motors.
Complete coverage of all aspects of electromagnetic, structural, and vibro-acoustic noise makes this a uniquely comprehensive reference. The authors begin with the basic principles of noise generation and radiation, magnetic field and radial forces, torque pulsations, acoustic calculations, as well as noise and vibration of mechanical and acoustic origin. Moving to applications, the book examines in detail stator system vibration analysis including the use of finite element method (FEM) modal analysis; FEM for radial pressure and structural modeling; boundary element methods (BEM) for acoustic radiation; statistical energy analysis (SEA); instrumentation including technologies, procedures, and standards; and both passive and active methods for control of noise and vibration.
Noise of Polyphase Electric Motors gathers the fundamental concepts along with all of the analytical, numerical, and statistical methods into a unified reference. It supplies all of the tools necessary to improve the noise performance of electrical motors at the design stage.
Vibration, Sound, and Noise
Sound Waves
Sources of Noise in Electrical Machines
Energy Conversion Process
Noise Limits and Measurement Procedures for Electrical Machines
Deterministic and Statistical Methods of Noise Prediction
Economical Aspects
Accuracy of Noise Prediction
MAGNETIC FIELDS AND RADIAL FORCES IN POLYPHASE MOTORS FED WITH SINUSOIDAL CURRENTS
Construction of Induction Motors
Construction of Permanent Magnet Synchronous Brushless Motors
A.C. Stator Windings
Stator Winding MMF
Rotor Magnetic Field
Calculation of Air Gap Magnetic Field
Radial Forces
Other Sources of Electromagnetic Vibration and Noise
INVERTER-FED MOTORS
Generation of Higher Time Harmonics
Analysis of Radial Forces for Nonsinusoidal Currents
Higher Time Harmonic Torques in Induction Machines
Higher Time Harmonic Torques in Permanent Magnet (PM) Brushless Machines
Influence of the Switching Frequency of an Inverter
Noise Reduction of Inverter-Fed Motors
TORQUE PULSATIONS
Analytical Methods of Instantaneous Torque Calculation
Numerical Methods of Instantaneous Torque Calculation
Electromagnetic Torque Components
Sources of Torque Pulsations
Higher Harmonic Torques of Induction Motors
Cogging Torque in Permanent Magnet (PM) Brushless Motors
Torque Ripple Due to Distortion of EMF and Current Waveforms in Permanent Magnet (PM) Brushless Motors
Tangential Forces vs. Radial Forces
Minimization of Torque Ripple in PM Brushless Motors
STATOR SYSTEM VIBRATION ANALYSIS
Forced Vibration
Simplified Calculation of Natural Frequencies of the Stator System
Improved Analytical Method of Calculation of Natural Frequencies
Numerical Verification
ACOUSTIC CALCULATIONS
Sound Radiation Efficiency
Plane Radiator
Infinitely Long Cylindrical Radiator
Finite Length Cylindrical Radiator
Calculations of Sound Power Level
NOISE AND VIBRATION OF MECHANICAL AND AERODYNAMIC ORIGIN
Mechanical Noise Due to Shaft and Rotor Irregularities
Bearing Noise
Noise Due to Toothed Gear Trains
Aerodynamic Noise
Mechanical Noise Generated by the Load
ACOUSTIC AND VIBRATION INSTRUMENTATION
Measuring System and Transducers
Measurement of Sound Pressure
Acoustic Measurement Procedure
Vibration Measurements
Frequency Analyzers
Sound Power and Sound Pressure
Indirect Methods of Sound Power Measurement
Direct Method of Sound Power Measurement: Sound Intensity Technique
Standard for Testing Acoustic Performance of Rotating Electrical Machines
NUMERICAL ANALYSIS
Introduction
FEM Model for Radial Magnetic Pressure
FEM for Structural Modeling
BEM for Acoustic Radiation
Discussion
STATISTICAL ENERGY ANALYSIS
Introduction
Power Flow Between Linearly Coupled Oscillators
Coupled Multimodal Systems
Experimental SEA
Application to Electrical Motors
NOISE CONTROL
Mounting
Standard Methods of Noise Reduction
Active Noise and Vibration Control
APPENDIX A: BASICS OF ACOUSTICS
Sound Field Variables and Wave Equations
Sound Radiation from a Point Source
Decibel Levels and Their Calculations
Spectrum Analysis
APPENDIX B: PERMEANCE OF NONUNIFORM AIR GAP
Permeance Calculation
Eccentricity Effect
APPENDIX C: MAGNETIC SATURATION
APPENDIX D: BASICS OF VIBRATION
A Mass-Spring-Damper Oscillator
Lumped Parameter Systems
Continuous Systems
SYMBOLS AND ABBREVIATIONS
BIBLIOGRAPHY
INDEX
Biography
Gieras, Jacek F.; Wang, Chong; Lai, Joseph Cho
"The presented book has a strong monograph attributes and the description of technical material is in the form of tutorials and technology overviews, combining fundamentals and advanced material. …The book is an attractive reference book for research, consulting and development engineers who are interested in design of modern electrical machines. Also, it can be used for advanced senior-level course as well as partially in undergraduate course in university."
-IEEE Industrial Electronics Society Newsletter, Vol. 54, No. 2, June 2006"Showing the strong relation between the mechanical vibration and the acoustics is particularly a great value of this book . . . represents the highest level of the theoretical explanation across many relevant areas including the electromagnetic field theory, the physics and the acoustics . . . a valuable reference book for those working with the noise of motors and the noise control in general."
– Dr. Laszlo Timar-Peregrin, in Acoustics Australia, December 2007
