1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUL 1004-4Electric GeneratorsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTIO
2、N ORDISTRIBUTION WITHOUT PERMISSION FROM ULUL Standard for Safety for Electric Generators, UL 1004-4Second Edition, Dated October 25, 2011Summary of TopicsThis new edition of ANSI/UL 1004-4 includes the following change:Revision to the generator overspeed testThe new requirements are substantially i
3、n accordance with Proposal(s) on this subject dated August 26,2011.All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, ortransmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwisewithout prior permission of UL.UL p
4、rovides this Standard as is without warranty of any kind, either expressed or implied, including butnot limited to, the implied warranties of merchantability or fitness for any purpose.In no event will UL be liable for any special, incidental, consequential, indirect or similar damages,including los
5、s of profits, lost savings, loss of data, or any other damages arising out of the use of or theinability to use this Standard, even if UL or an authorized UL representative has been advised of thepossibility of such damage. In no event shall ULs liability for any damage ever exceed the price paid fo
6、rthis Standard, regardless of the form of the claim.Users of the electronic versions of ULs Standards for Safety agree to defend, indemnify, and hold ULharmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonableattorneys fees) resulting from any error or
7、deviation introduced while purchaser is storing an electronicStandard on the purchasers computer system.The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, figures,and/or other elements of the Standard having future effective dates as indicated in the
8、note following theaffected item. The prior text for requirements that have been revised and that have a future effective dateare located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice.OCTOBER 25, 2011 UL 1004-4 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT
9、ION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 25, 2011 UL 1004-4tr2No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 25, 20111UL 1004-4Standard for Electric GeneratorsFirst Edition September, 2008Second Edition
10、October 25, 2011This ANSI/UL Standard for Safety consists of the Second Edition.The most recent designation of ANSI/UL 1004-4 as an American NationalStandard (ANSI) occurred on October 24, 2011. ANSI approval for a standarddoes not include the Cover Page, Transmittal Pages, Title Page, or effective
11、dateinformation.Comments or proposals for revisions on any part of the Standard may besubmitted to UL at any time. Proposals should be submitted via a ProposalRequest in ULs On-Line Collaborative Standards Development System (CSDS)at http:/.ULs Standards for Safety are copyrighted by UL. Neither a p
12、rinted nor electroniccopy of a Standard should be altered in any way. All of ULs Standards and allcopyrights, ownerships, and rights regarding those Standards shall remain thesole and exclusive property of UL.COPYRIGHT 2011 UNDERWRITERS LABORATORIES INC.ANSI/UL 1004-4-2011UL COPYRIGHTED MATERIAL NOT
13、 AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 25, 2011ELECTRIC GENERATORS - UL 1004-42No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 Components 4PERFO
14、RMANCE3 Overspeed Test .44 Short Circuit Test .55 Output Waveform Distortion 56 Surge Tests 6Appendix A Surge testing of induction machinesA1 Principle of the Surge Test A1A2 Automatic Fault Detection Methods .A3OCTOBER 25, 2011 ELECTRIC GENERATORS - UL 1004-4 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED
15、 FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 This Standard is intended to be read together with the Standard for Rotating Electrical Machines General Requirements, UL 1004-1. The requirements in this Standard supplement or amend therequirements in UL 1004
16、-1. The requirements of UL 1004-1 apply unless modified by this Standard.1.2 This Standard covers electric generators, sometimes referred to as generator heads, which, whencoupled with prime movers, such as engines or electric motors, are used to produce electricity. ThisStandard covers generators (
17、DC machines) and alternators (AC machines) rated 7,200 volts or less.1.3 This Standard does not cover stationary or portable generator assemblies, which are respectivelycovered under the Standard for Stationary Engine Generator Assemblies, UL 2200, and the Standard forPortable Engine-Generator Assem
18、blies, UL 2201.1.4 This Standard does not cover generators intended for use in hazardous locations as defined in theNational Electrical Code , NFPA 70.The National Electrical Code and NEC are registered trademarks of the National Fire ProtectionAssociation, Inc., Quincy, MA 02169.1.5 In the context
19、of this document, the term generators shall be understood to apply to both AC and DCmachines.2 Components2.1 Voltage regulators shall comply with the requirements of the Standard for Industrial ControlEquipment, UL 508.PERFORMANCE3 Overspeed Test3.1 The generator, arranged for operation in its inten
20、ded manner, shall be subjected to an overspeedcondition as described in 3.2.3.2 The generator is to be connected to a resistive load, run at rated RPM and then the load adjusted sothat the generator is delivering full rated output power. The rotational velocity of the generator is then tobe increase
21、d to 120 percent of rated RPM and maintained at that speed for 1 minute.Exception: Generators rated larger than 5 kw may have the overspeed test conducted loaded orunloaded at the manufacturers option.3.3 There shall be no evidence of a risk of fire, shock, or personal injury as a result of this tes
22、t.OCTOBER 25, 2011ELECTRIC GENERATORS - UL 1004-44UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4 Short Circuit Test4.1 A generator provided with an output overcurrent protective device shall be subjected to the testdescribed in 4.2.4.2 The
23、generator is to be run at rated RPM and then the output shall be short-circuited. For multi-phasemachines, each phase shall be individually and separately short-circuited both phase to phase as well asphase to ground (or neutral).4.3 As a result of this test, the overcurrent protective device shall
24、operate as intended and there shall beno evidence of a risk of fire, shock, or personal injury.4.4 At the conclusion of the Short Circuit Test, the generator shall be subjected to and comply withSection 6, Surge Tests.5 Output Waveform Distortion5.1 When tested as described in 5.2, the total rms val
25、ue of the harmonic voltages, excluding thefundamental, and the rms voltage of any single harmonic, delivered by a generator shall not exceed thevalues in Table 5.1.5.2 The generator is to be connected to a linear load having an adjustable impedance so that thegenerator is able to deliver power at ra
26、ted power factor. The measurements are to be conducted at opencircuit (0 percent), and with the generator delivering 33 percent, 66 percent, and 100 percent of ratedpower.Table 5.1Generator output RMS distortion limitsHarmonic 15KW or Larger Generator DistortionLimit (Percent)Less than 15KW Generato
27、rDistortion Limit (Percent)Odd3rdthrough 9th4.0 8.011ththrough 15th2.0 4.017ththrough 21st1.5 3.023rdthrough 33rd0.6 1.235ththrough 39th0.3 0.6Even2ndthrough 10th1.0 2.012ththrough 16th0.5 1.018ththrough 22nd0.375 0.75Total Harmonic Distortion 5.0 10OCTOBER 25, 2011 ELECTRIC GENERATORS - UL 1004-4 5
28、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6 Surge Tests6.1 At the conclusion of the Short Circuit Test of Section 4, the generator shall be subjected to andcomply with the Surge Test of this Section (see Appendix A). The Surge Test is to
29、 be conducted at anamplitude of 3.5 pu, where 1 pu is defined as:in which:VLis the rated rms line-to-line voltageand with a pulse rise time between 100 ns and 1.2 s.6.2 Pulse-to-Pulse Error Area Ratio (EAR) Test Each phase of the generator under test shall besubjected to a series of impulses with ea
30、ch impulse having the rise time described in 6.1. Each impulseis to be the result of a capacitor discharge. The pulses are to be applied with increasing amplitude fromzero to VLwith a difference of no more than 25 volts between successive pulses. The EAR betweensuccessive pulses (defined in the equa
31、tion below) is to differ by no more than 10 percent. The formula forEAR between successive pulses is given by:This is generated text for figtxt.OCTOBER 25, 2011ELECTRIC GENERATORS - UL 1004-46UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULin
32、which:Fi(1)is a point in the time series of the first waveform;Fj(2)is the corresponding point in the time series of the second waveform;Npts is the number of points in the time series sampled at each “jth” point; andEAR1-2is the Error Area Ratio of the test Fj(2)waveform with respect to the referen
33、ce Fi(1)waveform.OCTOBER 25, 2011 ELECTRIC GENERATORS - UL 1004-4 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULOCTOBER 25, 2011ELECTRIC GENERATORS - UL 1004-48No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT
34、ION ORDISTRIBUTION WITHOUT PERMISSION FROM ULAppendix A Surge testing of induction machinesA1 Principle of the Surge TestA1.1 If a rapidly increasing current is applied to a coil, a voltage will be generated across the coil by theprinciple of induction. The voltage across the coil is given by V=L*di
35、/dtin which:V is the terminal voltage across the coil;L is the coils inductance; anddi/dt is the time derivative of the applied current pulse.A1.2 The terminal voltage V at the leads of the coil is actually a summation of the induced voltage createdbetween individual loops in the coil. If the insula
36、tion separating adjacent coils is weak and if the inducedvoltage is higher than the dielectric strength of the weak insulation, an arc will form between the coils.Surge testing equipment is designed to create the induced voltage between adjacent coils and detect thearcing indicative of weak or faili
37、ng insulation.A1.3 Figure A1.1 shows a block diagram typical of todays instrumentation. The internal capacitor ischarged to a known voltage by the power supply. At a specific time, a high voltage switch closes whichtransfers the charge from the capacitor through the windings of the coil. If the resi
38、stances and loss of theentire circuit are such that the system is under damped, charge will be able to flow through the inductorand on to the other side of the capacitor resulting in an oscillation This process of ringing will repeat untilthe resistances and losses in the circuit completely absorb a
39、ll of the energy that was originally on thecapacitor. The measurement of the terminal voltage of the coil vs. time gives the surge waveform, whichshows the damped oscillation.This is generated text for figtxt.OCTOBER 25, 2011 ELECTRIC GENERATORS - UL 1004-4 A1UL COPYRIGHTED MATERIAL NOT AUTHORIZED F
40、OR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULA1.4 The ringing frequency of the dampened sinusoidal waveform will be according to the followingformula:in which:f = the ringing frequency of the resulting waveformL = the inductance of the machine winding under testC = the capacitanc
41、e of the internal charge capacitorFigure A1.1Block diagram typical surge instrumentationOCTOBER 25, 2011ELECTRIC GENERATORS - UL 1004-4A2UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULR = the system resistanceIf the turn-turn insulation fails
42、 with an arcing short between two turns in the coil, a fraction of theinductance will be shorted out of the circuit. From the equation above, the ringing frequency f will increaseas the inductance decreases due to the short. An increase in the ringing frequency will show itself to bea jump to the le
43、ft of the ringing pattern. To reiterate, it is this sudden increase in ringing frequency that isthe indication of the arcing turn-turn fault. Depending on the coil and the location of an arcing short, themagnitude of the surge waveform may also slightly decrease. Todays instrumentation will slowly i
44、ncreasethe test voltage and “look” for the increase in ringing frequency.A2 Automatic Fault Detection MethodsA2.1 The greatest advancement in surge testing has come about with use of high-speed analog anddigital electronics and the application of computers to control the testing process. Algorithms
45、programmedinto the computer can detect small variations in the shape of the waveform that peoples eyes miss. Anadditional benefit to having a computer control the test is the immediate shutdown of the test after theinsulation “fails” a single pulse. The detection algorithms include:a) Zero Crossing
46、Shiftb) Pulse-to-Pulse EARc) Line-to-Line EARA2.2 Pulse-to-Pulse EAR Where the computer has the advantage over the human is detecting slightchanges of the waveform shape. The computer uses the Error Area Ratio (EAR) to get a quantitativemeasure of the difference in shape of two subsequent waveforms
47、called the Pulse-to-Pulse EAR (ppEAR).Before describing the ppEAR, the EAR calculation will be introduced.The formula for the Error Area Ratio is:This is generated text for figtxt.OCTOBER 25, 2011 ELECTRIC GENERATORS - UL 1004-4 A3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDIS
48、TRIBUTION WITHOUT PERMISSION FROM ULThis simple formula is a fast calculation for a computer, yet it is very accurate at detecting a difference inthe shape of the two waveforms. Two exactly identical waveforms will have an EAR of 0%. Twowaveforms that look identical to the eye can have EAR values in
49、 the 4-5% range. Two waveforms with anoticeable difference will have an EAR value in the range of 10% or higher.The application of this formula for the ppEAR is to compare the most recently acquired waveform to thepreviously acquired waveform as the test voltage is slowly increased. The two waveforms are expected tobe different since one is at a slightly higher test voltage than the other. This difference is on the order of4%. However, if the most recently acquired waveform is above the arcing voltage for the failed insulation,
