1NON-LINEARTRANSFORMERPRESENTATIONNON-LINEARTRANSFORMERPRESENTATION2PROBLEM: HARMONICS CAUSE EXCESSIVE PROBLEM: HARMONICS CAUSE EXCESSIVETRANSFORMER HEATING TRANSFORMER HEATINGIncreased Losses Increased LossesProximity ProximitySkin Effect Skin EffectStray Losses Stray LossesCirculating Effect Circulating EffectTriplen Triplen Harmonics Add in Neutral Harmonics Add in NeutralIncreased Eddy Currents Increased Eddy CurrentsCore Saturation Core Saturation3NOTHING NEW:NOTHING NEW:Rectifier TransformersPower Supply TransformersPrecipitation TransformersFilament Transformers4WHAT IS NEW:WHAT IS NEW:Many New Sources Many New SourcesElectronic Electronic Ballasts BallastsSwitching Mode Power Supplies Switching Mode Power SuppliesSolid State Motor Drives Solid State Motor Drives56REMEMBER!REMEMBER!The nonlinear transformer does not generate, The nonlinear transformer does not generate,nor does it eliminate harmonics.The nor does it eliminate harmonics.Thetransformer toleratesthe nonlinear load transformer toleratesthe nonlinear loadcondition. condition.7LINEAR VS NONLINEAR LOADSLINEAR VS NONLINEAR LOADSLINEAR LOADS: LINEAR LOADS:A load that does not affect the input waveform, A load that does not affect the input waveform,which is a pure which is a pure sinewave sinewave, composed of a 60 , composed of a 60 hz hzcomponent with no multiple frequencies. component with no multiple frequencies.NONLINEAR LOADS: NONLINEAR LOADS:A load that distorts the input A load that distorts the input sinewave sinewave such that such thatthe resultant waveform is composed of a 60 the resultant waveform is composed of a 60 hz hzcomponent and multiple frequency components component and multiple frequency componentscalled harmonics. called harmonics.8Voltage WaveCurrent Is Demanded Only At ThePeaks Of The Voltage WaveCurrent Wave9HARMONICSGAS PUMP ANALOGY10NON-LINEAR TRANSFORMERSNON-LINEAR TRANSFORMERSWHAT ARE HARMONICS?WHAT ARE HARMONICS?Harmonic Harmonic Frequency in Hz Frequency in HzFundamental Fundamental 60 603rd 3rd 180 1805th 5th 300 3007th 7th 420 4209th 9th 540 54011th 11th 660 660etc. etc. etc. etc.11RECENT HISTORYRECENT HISTORY1990 1990 ITC Introduces K-FactorTransformer ITC Introduces K-FactorTransformerNov. 1990 - ITC Receives UL Listing Nov. 1990 - ITC Receives UL Listing1991 1991 Square D, Acme, Square D, Acme, Hevi Hevi Duty, MGM, Duty, MGM,General Electric, Westinghouse General Electric, WestinghouseUL UL Standard 1561 Standard 1561Effective 1992 Effective 1992Much Discussion Much Discussion12NON-LINEAR TRANSFORMERSNON-LINEAR TRANSFORMERSPertinent FactsPertinent FactsRated by K Factor Rated by K FactorK Factor Related to Heat K Factor Related to HeatBand Aid - Dont Solve the Problem Band Aid - Dont Solve the ProblemTolerate Intolerable Condition Tolerate Intolerable Condition13KEY DESIGN FEATURESKEY DESIGN FEATURES1. 1. Reduced Induction Core Reduced Induction Core2. 2. Properly Sized Winding Conductors Properly Sized Winding Conductors3. 3. Oversized Neutral Oversized Neutral14NON-LINEAR TRANSFORMERSWHAT IS K FACTOR?Ih = Percent Current at Harmonic hh = Harmonic Order, i.e. 3rd, 5th, 7th, etc.K=(Ih)2 (h)215K FACTOR CALCULATIONK FACTOR CALCULATIONh Ih (Ih)2h2(Ih)2h21 1 1 1 13 0.1000 0.0100 9 0.09005 0.1500 0.0225 25 0.56257 0.1000 0.0100 49 0.49009 0.1000 0.0100 81 0.810011 0.1400 0.0196 121 2.371613 0.2000 0.0400 169 6.760015 0.0200 0.0004 225 0.090017 0.0500 0.0025 289 0.722519 0.0075 0.0001 361 0.020321 0.0050 0.0000 441 0.0110SUM 1.1151 12.9279K FACTOR16K FACTORK FACTORA common industry term for the amount of harmonics produced by A common industry term for the amount of harmonics produced bya given load is thea given load is the K Factor K Factor. .The larger theThe larger the K Factor K Factor, the more harmonics are present.Linear , the more harmonics are present.Linearloads, for example, have aloads, for example, have a K Factor K Factor of 1. of 1.Transformers may carry aTransformers may carry a K Factor K Factor rating to define the rating to define thetransformers ability to withstand the additional heating generated transformers ability to withstand the additional heating generatedby the harmonic currents. by the harmonic currents.Standard Industry K FACTOR Transformer Ratings: Standard Industry K FACTOR Transformer Ratings:K-4 K-4 K-30 K-30K-9 K-9 K-40 K-40K-13 K-13 K-50 K-50K-20 K-2017K-FACTOR REDUCTIONK-FACTOR REDUCTIONMultiple LoadsMultiple LoadsHarmonic Cancellation Harmonic Cancellation3rd Harmonic Reduction in Delta- 3rd Harmonic Reduction in Delta-Wye Wye Transformer TransformerSource Impedance Effects Source Impedance EffectsLinear Load Dilution Linear Load Dilution18K =12.1K =13.6K =9.5Compaq386/33LCompaqPortablePackardBellK = 7.8HARMONIC CANCELLATION19NON-LINEAR TRANSFORMERSNON-LINEAR TRANSFORMERSUL LISTINGUL LISTINGNo UL listing for K Factor means transformer is ratedNo UL listing for K Factor means transformer is rated only onlyfor linear loads. for linear loads.UL listing requires label stating: Suitable for non- UL listing requires label stating: Suitable for non-sinusoidal current loads with K Factor not to exceed __. sinusoidal current loads with K Factor not to exceed __.K Factors can be 4, 9, 13, 20, 30, 40, or 50. K Factors can be 4, 9, 13, 20, 30, 40, or 50.20FEATURES AT A GLANCEFEATURES AT A GLANCEThree phase 480 delta - 208Y / 120 standard. Three phase 480 delta - 208Y / 120 standard.Other voltage combinations are available. Other voltage combinations are available.Class 220 Class 220 deg deg C insulation system. C insulation system.Available with 150, 115, or 80 Available with 150, 115, or 80 deg deg C winding rise. C winding rise.Aluminum windings are standard (copper optional). Aluminum windings are standard (copper optional).NEMA 2 ventilated enclosure. NEMA 2 ventilated enclosure.An electrostatic shield and 200% neutral are standard An electrostatic shield and 200% neutral are standardfeatures. features.