1、COOV 2 TM 5-811-13 e-494 ( 1 TECHNICAL MANUAL STANDARDS AND HIGH-EFFICIENCY MOTORS AND CONTROLLERS v HEADQUARTERS, DEPARTMENT OF THE ARMY AUGUST 1988 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-W 3515789 0238636 498 W TECHNICAL MANUAL NO. 5-811-1
2、3 TM 5-811-13 HEADQUARTERS DEPARTMENT OF THE ARMY WASHINGTON, D.C., II Ai4gust 1988 STANDARD AND HIGH-EFFICIENCY MOTORS AND CONTROLLERS CHAPTER 1. a .- CHAPTER 2. CHAPTER 3. CHAPTER 4. CHAPTER 5. APPENDIX A. APPENDIX B. APPENDIX C. APPENDIX D. 3945 GENERAL Purpose . d . Energy savings basis Appendic
3、es . APPLICATION, POLICY, AND CRITERIA Policy. . Electric motor-driven and control systems. Application . Use of high-efficiency motor controllers Use of high-efficiency motors . . HIGH-EFFICIENCY MOTORS General Motor efficiencyidesign . High-efficiency motor considerations. Motor operating conditio
4、n considerations . Applications of high-efficiency motors . . HIGH-EFFICIENCY MOTOR CONTROLLERS . siderations Induction-motor considerations. ASDMC operating elements Electric system performance and loa ASDMC considerations. . Other operational considerations . . Other energy-saving motor control ap
5、plications ASDMC design . ECONOMIC EVALUATIONS Requirement . Guidance . Use of consistent values An example of an alternative flow control system economic evaluation . . REFERENCES GENERALIZED CONSIDERATIONSISUMMARY MATRICES HIGH-EFFICIENCY MOTOR PAYBACK ANALYSES VOLTAGEIEFFICIENCY RELATIONSHIPS Par
6、agraph 1-1 1-2 1-3 14 1-5 2- 1 2-2 2-3 2-4 2-5 24 3-1 3-2 3-3 3-4 3-5 4-1 -1-7 4-3 44 4-5 44 4-1 48 4-9 5- I 5-2 5-3 5-4 Page 1-1 1-1 1-1 1-1 1-1 2-1 2- I 2- I 2- 1 2- I 2-1 3- I 3- I 3-2 3-3 3-5 4-1 4-1 4-1 4-1 4-1 4-3 4-5 44 44 5-1 5- I 5- I 5- I i Provided by IHSNot for ResaleNo reproduction or n
7、etworking permitted without license from IHS-,-,-TM 5-811-13 FIGURE 3-1. 3-2. 3-3. 34. 3-5. 36. 3-1. and for estimating the cost for collecting data and providing the harmonic analysis study. Manufacturers of ASDMCs may be able to provide such a study at nominal cost if they have developed computeri
8、zed programs. To complete calculations required to determine the harmonic distortion factor, manufacturers will need to be furnished with a single-line diagram of the existing electrical system and the proposed modifications to the system to sup- ply the ASDMCs. The diagram must show impedances of e
9、xisting and new equipment, and impedances or sizes and lengths of feeders to ASDMCs from the power source or sources to input terminals of the ASDMCS. Calculation re- sults are used to determine the characteristics of equipment which must be provided to attenuate excessive harmonics. . = 2-2 Y-. 395
10、 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3535789 0238622 793 W TM 5811-13 CHAPTER 3 HIGH-EFFICIENCY MOTORS 3-1. General Selection of such motors should be limited to low-slip ap- plications, and only then when at least three motor manu- fac
11、turers can provide motors which have an efficiency rating that is consistent with NEMA MG 1. This will ensure ad- equate competition between manufacturers, the availability of suitable motors, and a common basis for discussing the efficiency of motors. a. Definition. Currently, there is no industry
12、definition of “high-efficiency” or “energy-efficient” motors. Instead. those terms are used by motor manufacturers to indicate motors which have a significantly higher efficiency than their stand- ard product line, or than standard motors available from other motor manufacturers. b. Cost considerati
13、ons. The research. development, and manufacture of high-efficiency motors necessarily results in a higher initial cost for purchase of those types of motors. However, and because of cost reductions associated with less energy consumption during the “life expectancy” of high- efficiency motors, the h
14、igher initial cost may be offset on an annual or life-cycle-cost basis. A cost evaluation or “trade-off study has been necessay in the past to justify the selection of high-efficiency motors. This manual should exclude the necessity for completing such studies except as otherwise noted herein. c. ES
15、Jiciency. The NEMA MG 1 efficiency rating is based on conventional or standard motor types when supplied by a 60-hertz sine-wave power source. It also applies to hiph- efficiency motors. However. the efficiency of motors supplied by the nonsinusoidal output of ASDMCs discussed in chap- ters 2 and 4
16、will vary. and cannot be accurately related to the basis of efficiency ratings contained in NEMA MG 1. 3-2. Motor efficiencyldesign The following is intended to aid designers in deciding on the advantages and disadvantages of standard-efficiency and high-efficiency motors. a. Motor eflciency factors
17、. Various factors ictluence elec- tric-motor efficiency. Internal losses are inherent because of the design and manufacture of the motor. Other losses result from the performance of the motor under actual operating conditions. (1) Motor design and manufacture. In converting elec- trical energy to me
18、chanical energy, losses are incurred which are generally categorized as I, (resistance), core (iron). fric- tiodwindage (mechanical). and stray load losses. (a) Standard motors. A standard motor is designed so that temperature rise requirements for that particular motor are provided in a cost-effect
19、ive manner with motor efficiency being of secondary importance. A typical loss versus load curve for a standard motor is shown on figure 3-1. (b) High-efficiency motors. Energy-efficient or high- efficiency motors have been developed by achieving reduced clearances between the stator and the rotor;
20、by using better 5r000 4,000 A Co + +- 3,000 3 cn Co cl 2,000 -I a - 1,000 - T O 20 40 60 90 100 120 140 160 LORD (99) U.S. Department of Energy quality magnetic steel. thinner and better-insulated magnetic core laminations. additional copper. or a combination of these methods: and closer manufacturi
21、ng tolerances to reduce elec- tric. magnetic. and mechanical losses. The data of figure 3- 1 are not available for a high-efficiency motor. (2) Operating conditions. Operating conditions. such as service conditions and duty cycle. affect motor efficiency, regardless of the kind or type of motor. The
22、refore. operating conditions are discussed in more detail below. O. WitYdoti.s in inotor tcierzc. Variations in motor losses occur even in motors of duplicate design and repetitive manufacture. The use of consistent and accurate test meth- ods. such as Method B of IEEE 112. minimize errors which mig
23、ht result in test variations due to test equipment. instru- ment characteristics and. sometimes. personnel factors. NEMA MG 1 has developed u motor labeling basis. which applies only to certain stated motor designs. horsepower rat- ings. and speeds. This motor group comprises more than 50 percent of
24、 the electric motors purchased each year. NEMA MG 1 labeling applies to both standard and high-efficiency motors having the same horsepower and speed. (1) NEMA MG 1 efficiency labeling. NEMA MG 1 provides a tabular listing of nominal efficiencies with each related to a specific minimal efficiency, a
25、s shown in table 3- 1. The nominal full-load efficiency is required to be shown on the motor nameplate under the caption ”NEMA Nominal Efficiency” or an acceptable abbreviation. The associated 3-1 3952 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
26、3535789 0238623 628 W TM 5-811-13 Table 12-4 A Nominal Minlmum Nominal Minimum Effirlcnry Efficicncy Efficicnry Efficicncy 98.0 97.6 87.5 85.5 97.8 91.4 86.5 84.0 91.6 97.1 85.5 82.5 97.4 96.8 84.0 81.5 97.1 96.5 82.5 80.0 96.8 96.2 81.5 78.5 96.5 95.8 80.0 77.0 96.2 95.4 78.5 75.5 95.8 95.0 95.4 94
27、.5 95.0 94.1 94.5 93.6 94. I 93 .O 93.6 92.4 93.0 91.7 92.4 91 .O 71 .O 74.0 75.5 72.0 74.0 70.0 72.0 68.0 70.0 66.0 68.0 64.0 66.0 62.0 64.0 59.5 91.7 90.2 62.0 57.5 91 .O 89.5 59.5 55.0 90.2 88.5 57.5 52.5 89.5 87.5 55.0 50.5 88.5 86.5 52.5 48.0 50.5 46.0 This material is reproduced by permission
28、of the National Electrical Manufacturers Association from NEMA Standards Publication MG-1-1978 (R 1981), “blotors and Generators, I copyright 1978 by NEMA. Table 3-1. NEMA MG I, fable 12-4, listings of n firll-lmd. rioniitinl-to- niiriirniiiti eficieriq rating relationships. minimum efficiency must
29、be that met or exceeded by all like motors when operating at full load and at rated voltage and frequency. The nameplate nominal efficiency thus cannot be greater than the average efficiency of a large population of motors of the same design, which have been tested on a common basis. The use of a co
30、nsistent nominal-t+minimum efficiency relationship defines a band of efficiencies. The nominal efficiency should be used in energy consumption and related cost studies. (2) Limitations in NEMA .efficiency labeling. NEMA MG 1 stipulates identification in accordance with the listings of table 3-1 only
31、 for single-speed, polyphase, squirrel-cage, integral-horsepower induction motors in .the range of 1 to 125 horsepower for Designs A, B, or C requirements, Single- speed, squirrel-cage, Design D, and wound-rotor induction motors; synchronous motors; and multispeed motors are ex- cluded from the NEMA
32、 efficiency labeling considerations. (3) Effect of NEMA requirements. NEMA MG 1 pro- vides assurance of a guaranteed minimum full-load efficiency measured on a common industry-wide basis. However, NEMA MG 1 is a voluntary standard which is not necessarily followed by all motor manufacturers. Some ma
33、nufacturers use the listed efficiency band to rate larger motor sizes. Therefore, compliance with NEMA MG 1 must be specified to ensure that motor efficiency ratings are Consistent. Inter- changeability of high-efficiency and standard motors will 3-2 - _- -. 395 3 also be obtained, since NEMA MG 1 m
34、andates that both be built to the same horsepowerlfranie standards. 3-3. Applications of high-efficiency motors Functional requirements dictate minimum horsepower rat- ings and number of phases, type, and design. The designer must then specify a suitable motor controller or starter after determining
35、 whether the motor voltage is to be constant or variable; and whether single, multiple, or variable speed is necessary for the application. The motor manufacturer or the manufacturer of the motor-driven equipment usually selects a motor that will perform satisfactorily to meet the specified requirem
36、enfs or application. As a guide in the determination as to when high-efficiency motors can be considered for a particular application, basic motor performance character- istics and typical applications for the various electric-motor types are provided. a. Induction motor perfommice and application.
37、Rep- resentative speed-torque relationships are shown for squirrel- cage, single-speed induction motors on figure 3-2 and for various wound-rotor motor varying-speed (resistance) con- .1 e I O 20 40 60 80 100 SPEED (PERCENT SYNCHRONOUS SPEED) This material is reproduced by permi ssi on of the Nati o
38、nal El ectri cal Manufacturers Association for NEMA Standards Publication MG 10-1983, “Energy Management Gui de for Sel ecti on and Use of Polyphase Motors,“ copyright 1983 by NEMA. Figure 3-2. Standard squirrel-cage motor speed-torque citrws. Provided by IHSNot for ResaleNo reproduction or networki
39、ng permitted without license from IHS-,-,-TM 5-811-13 = 3535789 O238624 5b4 W ditions on figure 3-3. Table 3-2 indicates the niachines on which induction motors can be applied. Note that the motors which are manufactured for increased energy efficiency are low-slip units. Slip is the change in motor
40、 speed from syn- chronous speed to operating speed and is expressed as a percent of the difference of the two speeds over the syn- chronous speed. Since slip is related to the rotor losses. the higher the slip, the larger the rotors resistance losses. How- ever, rotor losses are also proportional to
41、 starting torque which must meet NEMA MG 1 specified values. Conse- quently. rotor losses will be the least affected by changing to a high-efficiency motor. Low slip is less than 5 percent. Table 3-2 indicates the type of slip for the various motor classifications. b. Synchronous and multispeed moto
42、r applications. Table 3-3 indicates the typical application for these types of motors. 3-4. High-efficiency motor considerations The following are considerations to be taken into account before specifying higkfficiency motors as a part of a new motor-driven assembly or as a replacement for an existi
43、ng motor. Where such considerations affect costs, such costs must be included in economic evaluations. a. Equipment packages. Generally, when properly ap- plied, use of high-efficiency motors will require only a minor a redesign of standard motor-driven equipment. if the speed, torque, and slip requ
44、irements remain relatively unchanged. In checking their use in equipment packages. the designer should determine that the manufacturer can meet applicable requirements for product standards, satisfactory service, and guarantees. b. Power fcctor correction capcicitors. Some manufac- turers may alread
45、y utilize capacitor units to achieve power factor improvement, or can provide capacitor assemblies as an available option. Specifying the use of power factor cor- rection capacitors as an integral part of the motor-driven equipment assemblies may not be necessary when specifying high-efficiency moto
46、rs, since high-efficiency motors may have higher power factors than standard motors. However, depending upon the manufacturer and ratings, there are some high-efficiency motors where the power factor has been sac- rificed in order to obtain the higher efficiency. Installing capacitors which are prop
47、erly mated with existing standard motors or with new replacement standard motors may be more economical than specifying the use of high-efficiency motors in some instances. Use of power factor correction capacitors can cause additional losses. If switched under load conditions capacitors can cause d
48、angerous transient electrical voltages. Power factor correction capacitors can cause op- erational problems when used with ASDMCs having a phase- - a 300 250 200 150 100 50 O O !O 40 60 80 SPEED (PERCENT SYNCHRONOUS SPEED1 Reprinted based on data from Energy-Effic Motors by John C. Andreas, copyrigh
49、t 1982 by courtesy of Marcel Dekker, Inc. SHORT- CIRCUITED 100 ent Electric Page 12, Figure 3-3. Standard wound-rotor motor speed-torque curves. 3-3 3954 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TM 5-811-13 3535787 0238625 4TO High Class if ica tion Typical application Relative efficiency Design A and B, Used on machines, such as most normal starting fans, blovers, centrifugal pumps torque, no
