Thermal Analysis of Power Semiconductor Converters

Transcription

1 5 hermal Analyss of Power Semconductor Converters Adran Plesca Gheorghe Asach echncal Unversty of Ias Romana 1. Introducton Power devces may fal catastrophcally f the juncton temperature becomes hgh enough to cause thermal runaway and meltng. A much lower functonal lmt s set by temperature ncreases that result n changes n devce characterstcs, such as forward breakover voltage or the recovery tme, and falure to meet devce specfcatons. Heat generaton occurs prmarly wthn the volume of the semconductor pellet. hs heat must be removed as effcently as possble by some form of thermal exchange wth the ambent, by the processes of conducton, convecton or radaton. Heat loss to the case and heat-snk s prmarly by conducton. Heat loss by radaton accounts for only 1-2% of the total and can be gnored n most stuatons. Fnally, loss from the heat-snk to the ar s prmarly by convecton. When lqud coolng s used, the heat loss s by conducton to the lqud medum through the walls of the heat exchanger. Heat transfer by conducton s convenently descrbed by means of an electrcal analogy, as t shows n able 1. HERMAL ELECRICAL Quantty Symbol Measure unt Quantty Symbol Measure unt Loss P W Electrc I A power current emperature 0C Voltage U V varaton hermal R th 0C/W Electrcal R resstance resstance hermal C th J/ 0 C Electrcal C F capacty capacty Heat Q J Electrcal Q As charge hermal conductvty W/m 0 C Electrcal conductvty 1/m able 1. hermal and electrcal analogy

2 132 Power Qualty Harmoncs Analyss and Real Measurements Data akng nto account the thermal phenomena complexty for power semconductor devces t s very dffcult to study the heatng processes both n steady-state or transtory operatng condtons, usng the tradtonal analytcal equatons. he modelng concepts have ther strength for dfferent grades of complexty of the power crcut. It s mportant to acheve an effcent tradeoff between the necessary accuracy, requred smulaton speed and feasblty of parameter determnaton, (Kraus & Mattausch, 1998). Approaches to smulate these processes have already been made n earler work. Numercal programs based on the method of fnte dfferences are proposed n (Wenthen, 1970), or based on formulaton of charge carrer transport equatons, (Kuzmn et al., 1993). A physcal model usng the applcaton of contnuty equaton for descrpton of the carrer transport n the low doped layer of structures s proposed n (Schlogl et al., 1998). A smple calculaton procedure for the tme course of slcon equvalent temperature n power semconductor components based on the prevously calculated current loadng s shown n (Sunde et al., 2006). In order to take nto account the nonlnear thermal propertes of materals a reducton method based on the Rtz vector and Krchoff transformaton s proposed n (Gatard et al., 2006). he work descrbed n (Chester & Shammas, 1993) outlnes a model whch combnes the temperature dependent electrcal characterstcs of the devce wth ts thermal response. he most papers are based on the thermal RC networks whch use the PSpce software, (Maxm et al., 2000; Deskur & Placnsk, 2005). In (Nelson et al., 2006) a fast Fourer analyss to obtan temperature profles for power semconductors s presented. Electro-thermal smulatons usng fnte element method are reported n (Pandya & McDanel, 2002) or combnaton wth the conventonal RC thermal network n order to obtan a compact model s descrbed n (Shammas et al., 2002). Most of the prevous work n ths feld of thermal analyss of power semconductors s related only to the power devce alone. But n the most practcal applcatons, the power semconductor devce s a part of a power converter (rectfer or nverter). Hence, the thermal stresses for the power semconductor devce depend on the structure of the power converter. herefore, t s mportant to study the thermal behavour of the power semconductor as a component part of the converter and not as an solated pece. In the secton 2, the thermal responses related to the juncton temperatures of power devces have been computed. Parametrc smulatons for transent thermal condtons of some typcal power rectfers are presented n secton 3. In the next secton, the 3D thermal modellng and smulatons of power devce as man component of power converters are descrbed. 2. ransent thermal operatng condtons he concept of thermal resstance can be extended to thermal mpedance for tme-varyng stuatons. For a step of nput power the transent thermal mpedance, Z thjcdc (t), has the expresson, Z thjcdc t jc t (1) P where: Z thjcdc (t) means juncton-case transent thermal mpedance; jc (t) dfference of temperature between juncton and case at a gven tme t; P step of nput power. he transent thermal mpedance can be approxmated through a sum of exponental terms, lke n expresson bellow,

3 hermal Analyss of Power Semconductor Converters 133 where j rc j j means thermal tme constant. t k j ZthjCDC t r j 1 e (2) j1 he response of a sngle element can be extended to a complex system, such as a power semconductor, whose thermal equvalent crcut comprses a ladder network of the separate resstance and capactance terms shown n Fg. 1. Fg. 1. ransent thermal equvalent crcut for power semconductors he transent response of such a network to a step of nput power takes the form of a seres of exponental terms. ransent thermal mpedance data, derved on the bass of a step nput of power, can be used to calculate the thermal response of power semconductor devces for a varety of one-shot and repettve pulse nputs. Further on, the thermal response for commonly encountered stuatons have been computed and are of great value to the crcut desgner who must specfy a power semconductor devce and ts deratng characterstcs. 2.1 Rectangular pulse seres nput power Fgure 2 shows the rectangular pulse seres and the equaton (3) descrbes ths knd of nput power. PFM f n t n, Pt 0 f n t n 1 (3) Fg. 2. Rectangular pulse seres nput power he thermal response s gven by the followng equaton,

4 134 Power Qualty Harmoncs Analyss and Real Measurements Data jcn1 t tn n1 n e 1 e 1 e e k PFM r 1 f n t n, 1 1 e tn n1 k 1 e PFM re 1 e f n t n1 1 1 e For a very bg number of rectangular pulses, actually n, t gets the relaton: t k 1 e PFM r 1 e f n t n, 1 1 e jc t t k 1 e PFM re f n t n1 1 1 e herefore, the juncton temperature varaton n steady-state condtons wll be, k k 1 k e 1 e jc PFM PFM r PFM re PFM r 1 e e 1e k 1 e PFM r 1 1 e (4) (5) (6) 2.2 Increasng trangle pulse seres nput power A seres of ncreasng trangle pulses s shown n Fg. 3 and the equaton whch descrbes ths seres s gven n (7). Fg. 3. Increasng trangle pulse seres nput power

5 hermal Analyss of Power Semconductor Converters 135 P FM t f n t n, Pt 0 f n t n 1 In the case when n, the thermal response wll be, 1 1 e t P k FM r t 1 e f n t n, 1 1 e jc t e 1 t P k FM r e f n t n1 1 1 e (7) (8) 2.3 Decreasng trangle pulse seres nput power Fgure 4 shows a decreasng trangle pulse seres wth ts equaton (9). Fg. 4. Decreasng trangle pulse seres nput power P FM 1 t f n t n, Pt 0 f n t n 1 At lmt, when n, the thermal response wll be: 1 e t P k FM r t 1 e f n t n, 1 1 e jc t 11 e P k FM r f n t n1 1 1 e (9) (10)

6 136 Power Qualty Harmoncs Analyss and Real Measurements Data 2.4 rangle pulse seres nput power A seres of trangle nput power s shown n Fg. 5. he equaton whch descrbes ths knd of seres s gven n (11). Fg. 5. rangle pulse seres nput power. PFM t f n t n, t Pt 2 PFM f n t 2 n, 0 f 2 n t n 1 (11) For juncton temperature computaton when n, the followng relaton wll be used: 2 t P k FM 1 2e e r e t, f n t n 1 1 e t k P FM 2 e e jc t r e 2 t f n t 2 n, (12) 1 1 e 2 1 e t2 P e f 2 n t n1 k FM r 1 1 e 2.5 rapezodal pulse seres nput power Fgure 6 shows a trapezodal pulse seres wth the equaton from (13).

7 hermal Analyss of Power Semconductor Converters 137 Fg. 6. rapezodal pulse seres nput power t P1FM P2FM P1 FM f n t n, Pt 0 f n t n 1 (13) At lmt, n, the thermal response s gven by, jc t t 1 k F PP 1 2 P 2FM P1FM r e P1 FM t f n t n, 1 1 e t 1 k G PP 1 2 r e f n t n1 1 1 e (14) where: FP 1P P 2 2FM P1FM 1 P1FM P2FM 1 e, GP 1P P 2 1FM P2FM 1 P2FM P1FM 1 e (15) 2.6 Partal snusodal pulse seres nput power A partal snusodal pulse seres waveform s shown n Fg. 7. he equaton whch descrbes ths knd of waveform s gven by (16).

8 138 Power Qualty Harmoncs Analyss and Real Measurements Data Fg. 7. Partal snusodal pulse seres nput power PFM sn t f n t n, Pt 0 f n t n 1 (16) In order to establsh the juncton temperature when n, t wll use the relaton, jc where: t t k e PFM Zsn t r sn sn e e 1 (17) f n t n, t k e PFM r sn sn e 1 2 1e 1 f n t n 1 k 2 1 k k r 1 2 ; cos sn2 ; k r 1 ctg Z r tg r sn 2 2 cos Extremely short overloads of the type that occur under surge or fault condtons, are lmted to a few cycles n duraton. Here the juncton temperature exceeds ts maxmum ratng and all operatonal parameters are severely affected. However the low transent thermal (18)

9 hermal Analyss of Power Semconductor Converters 139 mpedance offered by the devce n ths regon of operaton, s often suffcent to handle the power that s dsspated. A transent thermal calculaton even usng the relaton (2), s very complex and dffcult to do. Hence, a more exactly and effcently thermal calculaton of power semconductors at dfferent types of nput power specfc to power converters, can be done wth the help of PSpce software and/or 3D fnte element analyss. 3. hermal smulatons of power semconductors from rectfers Further on, t presents the waveforms of nput powers and juncton temperatures of power semconductors, dodes and thyrstors, from dfferent types of sngle-phase brdge rectfers. Also, temperature waveforms n the case of steady state thermal condtons, are shown. Usng PSpce software, a parametrc smulaton whch hghlghts the nfluence of some parameter values upon temperature waveforms has been done. On ordnate axs, the measurement unt n the case of nput power waveforms, s the watt, and n the case of temperatures, the measurement unt s the 0 C, unlke the volt one that appears on graphcs. hs apparent unconcordance between measurement unts s because thermal phenomena had been smulated usng electrcal crcut analogy. he notatons on the graphcs P 1, P 2 and P 3 mean nput powers and 1, 2 and 3 temperatures, respectvely. 3.1 Sngle-phase uncontrolled brdge rectfer he waveforms of the nput powers and juncton temperatures of power dodes from the structure of a sngle-phase uncontrolled brdge rectfer are shown n the below dagrams... s ms ms ms ms ms me Fg. 8. Input power waveforms at load resstance varaton wth 10, 20, 50Ω From the above graphcs, Fg. 8, the nput power varaton P 1, P 2 and P 3 wth the load resstance values can be notced. he ncrease of load values leads to small nput power values, and fnally, to the decrease of juncton temperature magntudes, 1, 2 and 3, Fg. 9, and also to the decrease of temperature varatons. In the case of quas-steady state thermal condtons, Fg. 10, there are a clearly dfference between temperatures waveforms varaton. Also, the tme varatons of temperature values are nsgnfcantly. he maxmum value of 1 temperature, Fg. 10, outruns the maxmum admssble value for power semconductor juncton, about C. herefore, t requres an adequate protecton for the power dode or ncreasng of load resstance.

10 Power Qualty Harmoncs Analyss and Real Measurements Data.. s ms ms ms ms ms me Fg. 9. emperature waveforms of thermal transent condtons at load varaton wth 10, 20, 50Ω.s.s.s.s.s me Fg. 10. emperature waveforms of quas-steady state thermal condtons at load varaton wth 10, 20,50Ω 3.2 Sngle-phase semcontrolled brdge rectfer In the case of a sngle-phase semcontrolled brdge rectfer made wth power dodes and thyrstors, the tme varatons of nput powers and temperatures are presented below. s ms ms ms ms ms me Fg. 11. Input power waveforms at frng angle varaton wth 60, 90, el.

11 hermal Analyss of Power Semconductor Converters s ms ms ms ms ms me Fg. 12. emperature waveforms of thermal transent condtons at frng angle varaton wth 60, 90, el..s.s.s.s.s me Fg. 13. emperature waveforms of quas-steady state thermal condtons at frng angle varaton wth 60, 90, el. s ms ms ms ms ms me Fg. 14. Input power waveforms at load nductance varaton wth 0.1, 10, 50mH It has been done a parametrc smulaton both at frng angle varaton of thyrstors from semcontrolled brdge rectfer, Fg , and at load nductance varaton, Fg As n prevous stuaton, the case wth uncontrolled brdge rectfer, the varaton of nput power values depend on load nductance, Fg. 14. he ncrease of nductance value, from

12 142 Power Qualty Harmoncs Analyss and Real Measurements Data 0.1mH to 50mH, leads not only to nput power decreasng, P 3 < P 2 < P 1, but also ts shape changng. he same thng can be observed at frng angle varaton, Fg Hence, the ncrease of the frng angle from 60 to el., leads to decrease of nput power values P 3 < P 2 < P 1. Also, the ncrease of load nductance leads to decrease of temperature values, 3 < 2 < 1, as shown n Fg. 15 and Fg. 16. he steady state thermal condtons allow to hghlght the temperature dfferences n the case of frng angle varaton, 3 < 2 < 1, Fg. 13, and load varaton, 3 < 2 < 1, Fg s ms ms ms ms ms me Fg. 15. emperature waveforms of thermal transent condtons at load nductance varaton wth 0.1, 10, 50mH.s.s.s.s.s.s me Fg. 16. emperature waveforms of quas-steady state thermal condtons at load nductance varaton wth 0.1, 10, 50mH 3.3 Sngle-phase controlled brdge rectfer Next dagrams present nput power varaton and temperature values n the case of a snglephase controlled brdge rectfer made wth power thyrstors. As n the case of sngle-phase semcontrolled brdge rectfer, a parametrc smulaton for frng angle varaton has been done. It can be notced that ncreasng of frng angle leads to nput power and temperature decrease, Fg. 17 and Fg. 18. he quas-steady state thermal condtons hghlght the dfferences between temperature values and ther varatons, Fg. 19. In order to valdate the thermal smulatons some expermental tests have been done. It was recorded the temperature rse on the case of the thyrstors used for sem-controlled

13 hermal Analyss of Power Semconductor Converters 143 power rectfer. he temperatures have been measured usng proper ron-constantan thermocouples fxed on the case of power semconductor devces. he measurements have been done both for the frng angle values of 60, 90 and el., and load nductance values of 0.1, 10 and 50mH. he results are shown n Fg. 20 and Fg. 21. s ms ms ms ms ms me Fg. 17. Input power waveforms at frng angle varaton wth 60, 90, el.... s ms ms ms ms ms me Fg. 18. emperature waveforms of thermal transent condtons at frng angle varaton wth 60, 90, el..s.s.s.s.s me Fg. 19. emperature waveforms of quas-steady state thermal condtons at frng angle varaton wth 60, 90, el.

14 144 Power Qualty Harmoncs Analyss and Real Measurements Data [ºC] t[s] 60el.sm 90el.sm 120el.sm 60el.exp 90el.exp 120el.exp Fg. 20. Comparson between smulaton and expermental temperature rse of the case at frng angle varaton [ºC] t[s] L1sm L2sm L3sm L1exp L2exp L3exp Fg. 21. Comparson between smulaton and expermental temperature rse of the case at nductance load varaton In both cases, at frng angle and load nductance varaton, t ca be notced closer values between smulaton results and measurements. Of course, there are dfferent temperature

15 hermal Analyss of Power Semconductor Converters 145 values resulted from expermental tests (60el.exp, 90el.exp and 120el.exp from Fg. 20 and L1exp, L2exp, L3exp as shown n Fg. 21) wth respect to smulatons (60el.sm, 90el.sm and 120el.sm from Fg. 20 and L1sm, L2sm, L3sm as n Fg. 21), because of measurement errors, thermal model smplfcatons and mountng test condtons. Anyway, the maxmum dfference between expermental and smulaton results s less than 3ºC. 3.4 D thermal modellng and smulatons of power semconductors Durng former work, (Chung, 1999; Allard et al., 2005), because of lmted computer capabltes, the authors had to concentrate on partal problems or on parts of power semconductors geometry. he progress n computer technology enables the modellng and smulaton of more and more complex structures n less tme. It has therefore been the am of ths work to develop a 3D model of a power thyrstor as man component part from power semconductor converters. he startng pont s the power balance equaton for each volume element dv, n the ntegral formulaton: 2 j dv c dv dv( grad) dv (19) t where: means the temperature of element [ºC]; j current densty [A/m 2 ]; σ electrcal conductvty [1/Ωm]; ρ materal densty [kg/m 3 ]; c specfc heat [J/kgºC]; λ thermal conductvty [W/mºC]. he left term of before equaton (t exsts only n the devce conductor elements), denotes the heatng power from the current flow. It s n balance wth the heat stored by temporal change of temperature, and the power removed from the element by thermal conducton. For the steady state temperature calculaton, the heat storage term s zero, and the equaton (19) becomes, 2 j dv dv( grad) dv (20) akng one's stand on the above thermal equatons, frst of all a 3D model for a power thyrstor has been developed usng a specfc software, the Pro-ENGINEER, an ntegrated thermal desgn tool for all type of accurate thermal analyss on devces. It has been consdered an applcaton whch ncludes a bdrectonal brdge equped wth power thyrstors type A505, wth the average drect current of 430A and an nternal resstance of 0.68m. he current whch flows through the converter branches s about 315A. hs value allows computng the power loss for each tyrstor, whch results n 67.47W. he materal propertes of every component part of the thyrstor are descrbed n the able 2 and the 3D thermal models of the thyrstor wth ts man component parts and together wth ts heatsnks for both sdes coolng are shown n Fg. 22, respectvely, Fg

16 146 Power Qualty Harmoncs Analyss and Real Measurements Data Fg. 22. hermal model of the thyrstor (1 cathode copper pole; 2 slcon chp; 3 molybdenum dsc; 4 anode copper) Fg. 23. hermal model of the assembly thyrstor - heatsnks

17 hermal Analyss of Power Semconductor Converters 147 he thermal model of the power semconductor has been obtaned by ncludng all the pece part that s drectly nvolved n the thermal exchange phenomenon, whch s: anode copper pole, molybdenum dsc, slcon chp, cathode copper pole, Fg. 22. he devce ceramc enclosure has not been ncluded n the model snce the total heat flowng trough t s by far less mportant than the heat flowng through the copper poles. All the mechancal detals whch are not mportant for the heat transfer wthn the thyrstor and from the thyrstor to the external envronment (e.g. the centerng hole on the poles) have been suppressed. Parameter Materal Copper Slcon Molybdenum Alumnum (kg/m 3 ) c (J/kgºC) (W/mºC) able 2. Materal Data and Coeffcents at 20ºC he heat load has been appled on the actve surface of the slcon of power semconductor. It s a unform spatal dstrbuton on ths surface. he ambent temperature was about 25ºC. From expermental tests t was computed the convecton coeffcent value, k t = 14.24W/m 2 ºC for ths type of heatsnks for thyrstor coolng. Hence, t was consdered the convecton condton lke boundary condton for the outer boundares such as heatsnks. he convecton coeffcent has been appled on surfaces of heatsnks wth a unform spatal varaton and a bulk temperature of 25ºC. he mesh of ths 3D power semconductor thermal model has been done usng tetrahedron solds element types wth the followng allowable angle lmts (degrees): maxmum edge: 175; mnmum edge: 5; maxmum face: 175; mnmum face: 5. he maxmum aspect rato was 30 and the maxmum edge turn (degrees): 95. Also, the geometry tolerance had the followng values: mnmum edge length: ; mnmum surface dmenson: ; mnmum cusp angle: 0.86; merge tolerance: he sngle pass adaptve convergence method to solve the thermal steady-state smulaton has been used. hen, t has been made some steady-state thermal smulatons for the power semconductor. For all thermal smulatons a 3D fnte elements Pro-MECHANICA software has been used. he temperature dstrbuton of the tyrstor whch uses double coolng, both on anode and cathode, s shown n the pctures below, Fg. 24 and Fg. 25. he maxmum temperature for the power semconductor s on the slcon area and s about 70.49ºC and the mnmum of 47.97ºC s on the heatsnk surfaces. Further on, the thermal transent smulatons have been done n order to compute the transent thermal mpedance for power thyrstor. he result s shown n Fg. 26. From thermal transent smulatons we obtan the maxmum temperature tme varaton and the mnmum temperature tme varaton. From the dfference between maxmum temperature tme varaton and ambent temperature dvded to total thermal load t gets the thermal transent mpedance. Dvdng the thermal transent mpedance to the thermal resstance, the normalsed thermal transent mpedance can be obtaned. hs s a thermal quantty whch reflects the power semconductor thermal behavour durng transent condtons. o understand and to optmze the operatng mechansms of power semconductor converters, the thermal behavour of the power devce tself and ther applcaton s of major nterest. Havng the opportunty to smulate the thermal processes at the power

18 148 Power Qualty Harmoncs Analyss and Real Measurements Data Fg. 24. emperature dstrbuton through the thyrstor mounted between heatsnks at 50% cross secton, yz plane Fg. 25. emperature dstrbuton through the thyrstor mounted between heatsnks at 50% cross secton, xz plane

19 hermal Analyss of Power Semconductor Converters 149 0,7 0,6 0,5 Zth [ C/W] 0,4 0,3 0,2 0,1 0 1E-06 0, ,0001 0,001 0,01 0, t [s] Fg. 26. ransent thermal mpedance of the thyrstor semconductor juncton dependent on the power devce desgn enables new features for the optmzaton of power semconductor converters. hs has a great mpact to the development and test costs of new power converters. 4. Concluson From all prevous thermal modellng, smulaton and expermental tests, the followng conclusons about transent thermal evoluton of power semconductor devces can be outlned: the shape of nput power and temperatures evoluton depend on load type, ts value and frng angle n the case of power semcontrolled rectfers; ncreasng of load nductance value leads to decrease of nput power and temperature values; n the case of steady state thermal condtons, the temperature varaton s not so mportant at bg values of load nductance and frng angle; at bg values of frng angle t can be notced a decrease of nput power values and temperatures; there s a good correlaton between smulaton results and expermental tests; because of very complex thermal phenomenon the analyss of power semconductor devce thermal feld can be done usng a specfc 3D fnte element method software; therefore, the temperature values anywhere nsde or on the power semconductor assembly can be computed both for steady-state or transent condtons; usng the 3D smulaton software there s the possblty to mprove the power semconductor converters desgn and also to get new solutons for a better thermal behavour of power semconductor devces. Extendng the model wth thermal models for the specfc applcatons enables the user of power semconductors to choose the rght ratngs and to evaluate crtcal load cycles and to dentfy potental overload capactes for a dynamc grd loadng. It was shown that the descrbed thermal network smulaton has a hgh potental for a varety of dfferent applcatons: development support;

20 150 Power Qualty Harmoncs Analyss and Real Measurements Data dentfyng user rsks; evaluatng the rght rated current; evaluatng overload capacty wthout destructve falure of the power semconductor. 5. References Allard, B., Garrab, H. & Morel, H. (2005). Electro-thermal smulaton ncludng a temperature dstrbuton nsde power semconductor devces, Internatonal Journal of Electroncs, vol.92, pp , ISSN Chester, J. & Shammas, N. (1993). hermal and electrcal modellng of hgh power semconductor devces, IEE Colloquum on hermal Management n Power Electroncs Systems, pp. 3/1-3/7, London, UK Chung, Y. (1999). ransent thermal smulaton of power devces wth Cu layer, Proc. 11th Internatonal Symposum on Power Semconductor Devces and ICs. ISPSD'99, pp , ISBN Deskur, J. & Placnsk, J. (2005). Modellng of the power electronc converters usng functonal models of power semconductor devces n Pspce, European Conference on Power Electroncs and Applcatons, ISBN Gatard, E., Sommet, R. & Quere, R. (2006). Nonlnear thermal reduced model for power semconductor devces, Proc. 10th Intersocety Conference on hermal and hermomechancal Phenomena n Electroncs Systems, ISBN Kraus, R. & Mattausch, H. (1998). Status and trends of power semconductor devce models for crcut smulaton. IEEE ransactons on Power Electroncs, vol.13, pp , ISSN Kuzmn, V., Mnatsakanov,., Rostovtsev, I. & Yurkov, S. (1993). Problems related to power semconductor devce modellng, Ffth European Conference on Power Electroncs and Applcatons, pp , ISBN Maxm, A., Andreu, D., & Boucher, J. (2000). A unfed hgh accuracy SPICE lbrary for the power semconductor devces bult wth the analog behavoral macromodelng technque, Proc. 12th Int. Symp. on Power Semconductor Devces and Ics, pp , ISBN Nelson, J., Venkataramanan, G. & El-Refae, A. (2006). Fast thermal proflng of power semconductor devces usng Fourer technques, IEEE ransactons on Industral Electroncs, vol.53, pp , ISSN Pandya, K. & McDanel, W. (2002). A smplfed method of generatng thermal models for power MOSFEs, Proc. Eghteenth Annual IEEE Semconductor hermal Measurement and Management Symposum, ISBN Schlogl, A., Mnatsakanov,. & Schroder, D. (1998). emperature dependent behavour of slcon power semconductors-a new physcal model valdated by devce-nternal probng between 400 K and 100 K, Proc. of the 10th Int. Symp. on Power Semconductor Devces and ICs ISPSD, pp , ISBN Shammas, N., Rodrguez, M. & Masana, F. (2002). A smple evaluaton method of the transent thermal response of semconductor packages, Mcroelectroncs Relablty, vol.42, pp , ISSN Sunde, V., Jakopovc, Z. & Cobanov, N. (2006). Smple Hybrd Electrothermal Smulaton Procedure, 12th Internatonal Power Electroncs and Moton Control Conference, pp , ISBN Wenthen, F. (1970). Computer-aded thermal analyss of power semconductor devces. IEEE ransactons on Electron Devces, vol.17, pp , ISSN

21 Power Qualty Harmoncs Analyss and Real Measurements Data Edted by Prof. Gregoro Romero ISBN Hard cover, 278 pages Publsher Inech Publshed onlne 23, November, 2011 Publshed n prnt edton November, 2011 Nowadays, the ncreasng use of power electroncs equpment orgns mportant dstortons. he perfect AC power systems are a pure snusodal wave, both voltage and current, but the ever-ncreasng exstence of nonlnear loads modfy the characterstcs of voltage and current from the deal snusodal wave. hs devaton from the deal wave s reflected by the harmoncs and, although ts effects vary dependng on the type of load, t affects the effcency of an electrcal system and can cause consderable damage to the systems and nfrastructures. Ensurng optmal power qualty after a good desgn and devces means productvty, effcency, compettveness and proftablty. Nevertheless, nobody can assure the optmal power qualty when there s a good desgn f the correct testng and workng process from the obtaned data s not properly assured at every nstant; ths entals processng the real data correctly. In ths book the reader wll be ntroduced to the harmoncs analyss from the real measurement data and to the study of dfferent ndustral envronments and electronc devces. How to reference In order to correctly reference ths scholarly work, feel free to copy and paste the followng: Adran Plesca (2011). hermal Analyss of Power Semconductor Converters, Power Qualty Harmoncs Analyss and Real Measurements Data, Prof. Gregoro Romero (Ed.), ISBN: , Inech, Avalable from: Inech Europe Unversty Campus SeP R Slavka Krautzeka 83/A Rjeka, Croata Phone: +385 (51) Fax: +385 (51) Inech Chna Unt 405, Offce Block, Hotel Equatoral Shangha No.65, Yan An Road (West), Shangha, , Chna Phone: Fax: