电机学英文版课件.ppt

Electric Machinery and Drive Fall Semester 2009,Dept.of Electrical Engineering,PowerPoint Slidesto accompanyElectric MachineryFourth EditionStephen J.Chapman,Chapter 1Introduction to Machinery Principles,Objectives To instill an understanding of the underlying electromagnetic effects permitting electric machine operation and introduce basic machine types To describe the construction of these machines To examine the main types of these machines To be skilled in analyzing the characteristic of these machines,Introduction and Overview,Reference Books 1.Theodore Wildi.Electrical Machines,Drives,and Power Systems(Fifth Edition)Pearson Education.2002 2.A.E.Fitzgerald,Charles Kingsley,Jr.,Stephen D.Umans Electric Machinery(Sixth Edition)McGraw-Hill.2003 3.李发海 王岩.电机与拖动基础 北京：清华大学出版社，1994.4.顾绳谷.电机及拖动基础(上、下册)北京：机械工业出版社，19805.汤蕴缪 史乃.电机学 第二版 北京：机械工业出版社，2005.16.姚舜才付 巍 赵耀霞 电机学与电力拖动技术 北京：国防工业出版社，2006.1,What is an Electric-Machine Drive?,Type of Electrical Machines,EM,Motor,Generator,DC Motor,AC Motor,Separately Excited,Non-Separately Excited,Series,Shunt,Compound,Synchronous,Asynchronous,Single Phase,Double Phase,Three Phase,DC Generator,AC Generator,Angular PositionAngular VelocityAngular Acceleration,Torque T T=(Force Applied)(Perpendicular Distance)=(F)(r sin)Newtons Law of Rotation T=JWork WPower P,Electric Drives An electric drive is a system that converts electrical energy to mechanical energy Parts:electric motor(or several)control system(including software)Constant-speed drives only a start/stop and protection system in addition to the electric motor Variable-speed drives(VSDs)include an electronic power converter,Electric Drive and the Surrounding System,Acceleration of Inertial Mass,Torque needed for accelerating the moment of inertia J:,Moment of inertia ofa thin-walled cylinder,Moment of inertia of a solid cylinder,Equation of Motion,Inertia J is a theoretical parameter.In engineering,Fly Wheel GD2 is used to replace inertia.That is：,Copyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.,Simple magnetic circuit.Figure 1.1,1-14,Copyright The McGraw-Hill Companies,Inc.Permission required for reproduction or display.,Magnetic circuit with air gap.Figure 1-3,1-15,Production of a Magnetic Field Amperes Law H=magnetic field intensity(Ampere-turns per meter)B=magnetic flux density/intensity of magnetic induction=magnetic permeability,Magnetic fluxMagnetomotiveMagnetic reluctance,Analogy between electric and magnetic circuits.(a)Electric circuit,(b)magnetic circuit.Figure 1-4,Kirchhoffs Law in Magnetic Circuit,Air-gap fringing fields.Figure 1-6,Simple synchronous machine.Figure 1-9,(a)Magnetic circuit and(b)equivalent circuit for Example 1.3.Figure 1.6,MATLAB plot of inductance vs.relative permeability for Example 1.5.Figure 1.7,Magnetic circuit with two windings.Figure 1.8,B-H loops for M-5 grain-oriented electrical steel 0.012 in thick.Only the top halves of the loops are shown here.(Armco Inc.)Figure 1-10,Dc magnetization curve for M-5 grain-oriented electrical steel 0.012 in thick.(Armco Inc.)Figure 1.10,Excitation phenomena.(a)Voltage,flux,and exciting current;(b)corresponding hysteresis loop.Figure 1.11,Exciting rms voltamperes per kilogram at 60 Hz for M-5 grain-oriented electrical steel 0.012 in thick.(Armco Inc.)Figure 1-10,Hysteresis loop;hysteresis loss is proportional to the loop area(shaded).Figure 1-11,Core loss at 60 Hz in watts per kilogram for M-5 grain-oriented electrical steel 0.012 in thick.(Armco Inc.)Figure 1.14,Laminated steel core with winding for Example 1.8.Figure 1.15,(a)Second quadrant of hysteresis loop for Alnico 5;(b)second quadrant of hysteresis loop for M-5 electrical steel;(c)hysteresis loop for M-5 electrical steel expanded for small B.(Armco Inc.)Figure 1.16,Magnetic circuit for Example 1.9.Figure 1.17,Magnetic circuit for Example 1.10.Figure 1.18,Magnetization curves for common permanent-magnet materials.Figure 1.19,Magnetic circuit including both a permanent magnet and an excitation winding.Figure 1.20,Portion of a B-H characteristic showing a minor loop and a recoil line.Figure 1.21,Magnetic circuit for Example 1.11.Figure 1.22,(a)Magnetization curve for Alnico 5 for Example 1.11;(b)series of load lines for Ag=2 cm2 and varying of values of i showing the magnetization procedure for Example 1.11.Figure 1.23,(a),(b),Magnetic circuit for Problem 1.1.Figure 1.24,Magnetic circuit for Problem 1.6.Figure 1.25,Magnetic circuit for Problem 1.9.Figure 1.26,Inductor for Problem 1.12.Figure 1.27,Pot-core inductor for Problem 1.15.Figure 1.28,Inductor for Problem 1.17.Figure 1.29,Toroidal winding for Problem 1.19.Figure 1.30,Iron-core inductor for Problem 1.20.Figure 1.31,Magnetic circuit for Problem 1.22.Figure 1.32,Symmetric magnetic circuit for Problem 1.23.Figure 1.33,Reciprocating generator for Problem 1.24.Figure 1.34,Configuration for measurement of magnetic properties of electrical steel.Figure 1.35,Magnetic circuit for Problem 1.28.Figure 1.36,Magnetic circuit for the loudspeaker of Problem 1.34(voice coil not shown).Figure 1.37,Magnetic circuit for Problem 1.35.Figure 1.38,Production of Induced Force On a Wirei=magnitude of current in the wireB=magnetic flux density vectorl=length of conductor in the magnetic field,Induced Voltage On a Conductor Moving In a Magnetic Fieldv=velocity of the wireB=magnetic flux density vectorl=length of conductor in the magnetic field,Three Phase Power,The instantaneous total power is constant!,Three Phase Power,Real Power per phase isP=Vp Ip cos()Real Power for all three phases isP=3 Vp Ip cos()Since for a balanced load the power is constantP(t)=3 Vp Ip cos()alsoPower in Terms of Line QuantitiesP=3 Vll Ill cos(),Three Phase Reactive Power Q,Total supply Volt Amps product(VA)isVA=3 Vll IllReactive power Q is the Quantity making up the difference between VA and PowerQ=3 Vll Ill sin()Thus VA2=P2+Q2Q is a measure of the energy storage capability of the circuitFor the greatest Power per amp of supply the Power Factor should be Unity and Q should be zero,