Brushless DC Motors Electronics Commutation

and Controls

Thomas J . Sokira and Wolfgang Jaffe

TAB BOOKS Inc. Blue Ridge Summit, PA

Contents Acknowledgments v

Preface v

Introduction viii

1 Conventional DC Motors 1 I . l . Introduction-1.2. Structures-1.3. Basic Relationships-1.4. DC Shunt Motors- 1.5. Series Motor-1.6. Compound Motors-1.7. Permanent-Magnet Motors

2 Armature Windings and Commutation 23 2.1. Armature Reaction-2.2. Armature Windings-2.3. Commutation

3 AC Motors and Stepper Motors 37 3.1. Introduction-3.2 The Induction Motors-3.3. The AC Commutator Motors- 3.4. Synchronous Motors-3.5. Stepper Motors

4 AC and DC Speed Control 101 4.1. AC Motor Speed Con t ro l4 .2 . Variable-Frequency Drives-4.3. DC Motor Dnves- 4.4. Thyristor and Triac Drives-4.5. Linear Amplifier Drives-4.6. Feedback Devices, Basic Applications-4.7. Basic Phase-Locked Loops-4.8. Nonlinear PWM Drives- 4.9. Elemental Current Limiting-4.10. S u m m q

5 Brushless DC Motors 127 5.1. Introduction-5.2. Brushless DC Motor System-5.3. Mode of Operation- 5.4. Winding and Switching Patterns-5.5. Motor Constants-5.6. Effect of Winding Resistance and Inductance-5.7. Cogging and Rotor Construction-5.8. Thermal Considerations-5.9. Unequal Distribution of Currents in Motor Windings- 5.10. S~ecialtv BLDC Motors-5.11. The Hall Effect Sensor

6 Brushless Motor Drives and Systems 169 6.1. Introduction-6.2. Elements of a Typical Brushless Drive-6.3. Output Stages for Three-Phase Drives-6.4. Other Output Configurations-6.5. Output Current Considerations-6.6. Power Supply Considerations-6.7. Commutation Logic- 6.8. Commutation Sensors-6.9. Control Circuits-6.10. Current Control- 6.11. Conclusion

7 Applications and Uses of BLDC Motors 218 7.1. Introduction-7.2. Semo Applications-7.3. Constant-Speed Synchronous- 7.4. Centrifuge and Fan Applications-7.5. Pumps-7.6. Industrial Processes- 7.7. Traction and Torquing-7.8. Esoteric Applications-7.9. Special Drive Systems

8 Testing Method and Evaluation of Motors and Controls 226 8.1. Purpose of Testing-8.2. General Measurements-8.3. DC Motor Tests-8.4. AC Motor Tests-8.5. Testing Brushless dc Motors

9 Additional Application Notes and Summary 253 9.1. Introduction-9.2. Direct Drive, Belt Drive, and Gear Drive-9.3. Application Considerations for BLDC Motors-9.4. Conclusion

Appendix A List of Symbols 258

Appendix B Conversion Table 261

Index 262

Index

rum of. 38 rclstionlhlp in rirrvhr usmg. 41 r a n m a n qusm ralvrr d. 42 ainulloidsl rcissonship. 43

sc mamrr. 11-93 E iuirenr r u m . 38 cunntm"d ",,,age agc,#tsa""ahlp. "l.

a1niso magnet.. 18 ammcrr, nvilrlng, no cvrrsn, inrerwp~

lion. 139 smomrwur wldings. 83 anguiar di,pisranml. 22 sppl#csc#on%, 253.257 *,c,ng, 3, armaturr l,.. dl" vmdinga. amaurr,.

1 . 2 . 1 "Urn*. dconduCmrs m. 6 "vmbrrd pnralld pxhr m. ,h"",

molol 9 rhunl mtor 7, l l

'Fed rrgul.,lonconsm, Ecebmtlon. 19

rlndlngr snd ~ornmum~on. 23-35 srmarure cuncnl. 6. 31

permarm-magnet m-orr. I5 ,h"", molor. l

ermstvrs in*ucsnrr. I" annnlure rcscrim. 23. 24

" back LMF 4

iurxn, power and w l q r requirr- men* for Bapsroldal. IM

cerrnsmt-mgnn maora. I 8 ,D"", m o i . 7

bans-ban& rontmllrn. 224 batunra, rrrhsrprbh. 2 braringr. 2. 3 brll driver. 253.255 b n k test. 236537

bmshlsaa d" rmcora, ill

roegin$ and rmor conaruruan. $53- I58

romm"" nna1og rneccr mmcmrntr rnd

motor ~onslnnls m. 143-147 molar umdlngr, ""equd rurren, d i , ~

Irlbulron in. 159 -er o u l m t d tomur. 145~148

*nchmnoua-a@ F'"rmn"cc in. 255

=ling. 239-251 lhsrlnll cons,drr.l,"na. ,,V rhrrr~phssc tvlluavc. 133.114 ihrer-phase haltwlve. 134~131 time dlspIEcme", cnor and. 220 laalhhah. hlrlur curt and rot07 cun6g-

"ration. I54 lorgur dlrlonlon Elvwd by ruzor tlrld

~nVraniun. IB. 149 lnrqur mnlnr pcrformsnci. 256 tovur rcimmrhlpr, rlnvloldlll

coumer EMF 147, l48 lrsclion sndlorqumg.222-223 lurnmbbr. 223 I w o p h full wnuc. 137.138 vliriabl.-spcrd pcrfuinanc. 8". 256 "OliagC and mrqur rmilsncr m, i43-

141. 2412a2 vlndlng an* rrllchlng parcrmr m.

113-111 rlndlng malrmncs and iiriuclsnrr.

(49 brvrhlrss mulllrdriuis. 169-217

hang-bang ~mlrollcra. 224 i loredlmp wed rcgv,mor c,mui,.

203 rommulaliun. I11 commuullon loglc. 189-192 Eommuvri"" wnrorr. ,92198 conlml ilmurs, 170. 198-208 rumnlrontml. 208416 CurPe", flow in coluinvova currcnl

mode. 201 C""F"l nw in diwmt,""0"3 m d e .

70, ... currcn, monilorpom,i in, 2m e l b l r m c whomerr 196 elcmmtr of. 169~171 ryu~valrnl clnut d a phru. 185

mducson monr5. 46 mslantmwu,, 22 FPL, 37 Wl,",ing. 211, 2 , quadrature m, 5 5 , l 7 'm, W." rylurr. 21.22 Wndmgr, amturn, dlrulian of. 25

E u l x n l control. 208~216 Eu"e"t-l>milmgcircuil. 210 c~rrrn~-i im~tmg rimun, sm ddnynl.

211 dual iurrrn?~l,mi,i"g. rirrui, for 212 fault-p*h 00% and surge lndiratoi

211 .215 LmnsfmeC*mplcd mUvd for 211

cuinnl-lw""g i,rcu,r. 1," r p d c n n l r o l . I24-l26 ,>m delay, 121 1

cvltlng nu", a

*Id if&, irmnslrron. bru,hii., dC mo<air runtm, an*. 129

A I I ~ ~ Y X . 5 , s hm8gncli2nmn ol, 13

flsld nismncc rm-r motor 12 shun, momr V

nrld rator 3 flrid lmnplh. rhvnl motor, V Flcld Wlndlng

~ U X path p r ~ l r c s d by 8 xr>rs momr. I I shunt motor, i l

fields, l , 3 , 4, 7 Flcmmmng's rlghr hand mir , induceon

molm. 16~48 Rur, 6

brushks. *c motor,. 129

'U,

Power dllslpatlan m. 186 POUErlupplicl ind, 171, 187~189 rend~nnly m m v w ramnum,,on. I", nolver conrro, and. 191-,P, ""'Y'"ndo"lp"l zimw ens". ,m ""'Or Eombinlng logic. 193 ""'Or CUming. hmr-phasr. 193 ~musordll. 224 riip, ic4 s p e d cnniml. 188 switched rr+lsl"r for ,Wd CO",,.,.

2 M Inlemulrs. 3, 31 mvrmd brurhlesr dc moron. 161

C capacitor-sun mdurtlon mo,orr. M CI"'"1 profcrnne units (CPUr,, com-

mu!x>on iogc, (90 ctnlnlupra. brvnhlslr d i mnom m*.

22"-22, ceramic m l g n ~ o . 16 rhoppr s p e d mntro,. 120. 121 clulnl-l- sped rcgubtor clrcuil. 203 rogerng. 14-35. 113-158 coll. 6.6, i 2 Y rummuatlon. 29-35

hruBlCrn lllalvrdrivra, l,, i o e ~ m g , 3+-35 r l icfnrnl ionlunlr *d. 1 1 ~ 3 3 . 31 wer-. 11 synchzrnrd. 196 under^, 3 ,

COmmYYllon dlodrs. 172 rummumiiun iqucncy, l79 cnmmulnlion lwir. 189-192 romrnuullon smmn. 192.1'18 rummufator 1. 2. 29, (29 rnmpund 646 dc mvlurr. 2 compound malor in

lorqur~sped cuwe rnr I S rundurtmr. 4~6. I2 con,rmt-aped Fr formncr . brurhlrrr

d" W,".,, 255 c o n r u n t r ~ c d Synchrom", br"rhl.sr *c

mulun. 119220 CO"%rn"L5

bmihleir dr momn. 143.149 elsclncal, CommuUllrnand. 3 1 4 3 ~n! l~nEnl -n la~nct muan. 19 CorquE. I v~tugc . I

conimuou,currrn, mode. cvr,En, ""W

m. 201 control nrcua,, bru3hl.n m a n dnvrr.

I ° % ~ i O X convenrlond *c macor.. 1~22 runucr,8un lilbir. 261. 258 cnrc. 2

rrmlghi vs. skcwd slot,, 35 cuss, brushless dr mman. i J b i S 7 counter EMF 4 cvmnl"lsli"r uumnuund mow. 16 current, 4. h

ar (566 E moron). 17 a"cra%s ".l". Of. 21, 22 bmshlrr3 dc maim. 130 tmqu<nc> 0,. 59

wrarr motor, l 2

G gear driver. 255231 %"aa mrrr o u p l , 7. 145.148

H Hall-~ffcildeuues, l d l l O 7

h l r l i cimuil Tor 163 CommuYllonrmaon. I92 dr x l r x i V imp. 116 dl81Yil. dlapnrn for 166 equalinn dractibinp, 162, 163 Hsil-r.%ctgenrrarion. 162 Icdrvir , "S,"$, ,M laichim bipolar rwlkh. oprn lnp

charmcr18lxr. 167

d.magn.lnall"n. field ""X. 33 dirrcientnl 14 dlgilai-inlrpralor PLL. I t 9 direcl dnvcr, 253.255 diwo"t,nuou. rvrrcn, c"rrrnr

""W m. 202 duplex-lap wu,ndxns, 27 dy"'amm*r 241

Imeor oulpul. 164 p r f u r m A n c c c h ~ n i l m % ~ ~ c s . IM Yniplolo diglU switch, oprnung char-

ulrnsecs. 166 hy3,cnl. Imp. S9~%, hyarmri, momn. 89~92

hyrumsla l- m. 90 rclallonrhlpb.lvrrn mla,,n~.ndpo,.r

milgnc,,c fidd,. 9, rrluclanci rvrrhmnour mornrvs 9 3

mngnrnr fir,* 0( 4 neodymlumlmn-bomn. 16 prrmAnmt. 3 F m u n e n f - W n e C m o m . I 6 DImnbli i tv sld. P

N Nudymlum-imebomn ma&nc&, 16 "'I plwrr m w . 7 no~lonl s p d . 13 nonlmear PWM a p d runtiol. 120.113

c h o p p r t y p . 120. 121 eIEmmml slMI. 121. 121 FETs m. 111 f u l l ~ b n d g . 122

noMlml Wlc field c n n s n u c i i ~ . 76

0 optm~sl *an e n d r , dr ue~alty loop,

116

F fans. bru.hlc.rdc mo,orr ."d. 220.221 his1 rvvrisr ,nslrfoimr. ,ra,,np *.ling

end cud".,"," and, 261 f=ul l~pnth~vrrrntf low. 214. 211 feedback r a o d conlml. 113-117

dc vrlocll). Imp Cur 115. 116 mrUl* l0 obum dam for, ,I3 P i l i u n ss-, l , , s y " ~ ~ ~ . ~ m , " e , , l , ,

field cumnt, shun, 9

fmo"~"~; in.

,77

pnlhl. .h"", m m . 9 P* curxnt. 37 pUX in,ununsara iurrrnc. 22 p U k inamnurrarr ,m. wiwr. 22 p m a m n c mngrru, pmwnl rn of. 17 p m . n m l - m . ~ e t mocora. 2. 15~22

moliimlona fo r 16 ~~

ci.clnc.1 r i m ronomnt, I9 .q*,"rlcnt cmvi, (0,. I 8 Inride-a*,. m mnsnrr~ mrrrimls m. 16 mGhmnisai bnx consrsnr. IY motor l y p r . I 9 - M pnosketyp . 19. 20 p*rormancr immg, 233-231 pmpnies d mqnrl compounds. 17 rCclirrcd power aupplill. 20-22 rh.ll-,yp .m.mrr momr. 20. 21 rempnturc vs pcformsncc. 16 toque consul. 19. 232 torque-r@cwr. IS, 19. 233. 234 vo,ur ."d cvrren, rcl.lionrhlC m. 22 ,l,, C,,",. 19. 232

pmw.bility. shun, m a a 9 ohas, quiualmi~#i iu#ln i . 185 phase l a k r d , h p

ran,lM, r p c d or ponian Cosrol. 207 .,erncnu,, l i n por#xla, conlml, 207 spdcomlrol . 118-IX I@ comtiol, d~p8ral~~mcgmaor 119

p l u p g m ~ I08 pier nndpolamy I . 2,4

flux pi. ,h"* motor 9 hnter-, 3, nonrnllrnl Wd. 76 nvmrrr Of, ,h", motor 9 ,h"", molar. 9

o o l ~ o h s v indunion mmor.. 45. M ~ 6 1 . . .. 238

poSlll"" rmtm1, PLL for 207 p o s > i i ~ n r w o . 117 poxlcr frcar 41.41 mu.. ,mars, rhunr marr. 11 p m < ? nuvut. I pmer rrlumn%hips. bruahlrar dr

mutm. 245-248 power ruppi,rr, brushlcs moror d.>".l.

171. 187~189

R rsmDin*, rcrppr motora, 99 <.is-csnh magnets. I6 ,encWcI, *c iumn,. 43 rw,rficmon, 2 rcr.hd porsr l u ~ l x r , pm&-

mngm, motorr. 20.22 rslai"epmc.bl l l~, ,h"", molar. 9. 10 rcbcunce njnchmnous mown. 9293 npulsion m,,,"<

slnglc-phsss. 80-82 s q u I c ~ ~ . c ~ c , 81

rcnsf.nrc. U, 229-230 rcn,wnco "awn. Ihrrc-phse2 power

supply and. 38 rcro,ver h r d b r k .p.dconrml. 117.

195. 191 rrqonsr,imr. thynetor s p e d Eonrml.

,m n$hr h a d rule. induclirn matorr. 48 nng msgnns. L56 ROM. cmmuunnn lozu. 189 r m l mean ~qulre. 21.42 mor m a n , d inrma, prmanmi-

m g n l molora. 19 rotor 1~6YUnec. 74 mor-wwnd lndlrrlon mnon, 7c75 man, 129. 1SS158

.~ ~ T - ~ .

lorque-rpcdcunr for. 13 sew0 app1icatims

b m r h l l s ili naloraand. 2!8-2,° romrnvrnllon mrlhodl <or 219 p"'i0nmg rYVm for 2 19

rhadd-poir maor. 72-71 rhadingia,,, 45 r h e l l ~ l y p armamre muUlr. 20. 2 1 shunt motor. 2.7-11

srm.,urc msclwn. IO. I I Dmkc IE~C tor 236-237 8 m m v d volwr ten, 234 p w c r IOSE, in, 1 I wrqur-aped " W C 8 for. 10. 1 I

il l lC"" ionlrollrd rwc,flrr. 2 btd~recltond bndgc wth, I07 spud conlrol with. IOS vs". form$ m. 106

nmplerbp winding. 27 singlr-phahaw ac secis, muton, 75. 231 ~mgb-phrw indrclion molon. 45, 6 2 ~ 6 4 sm%lr -phn~ repvli~on molor. 80-82 ixnuroldni brushirsr maror dii=r. 224 nr~ph- bmrhlcr,di mutoo. 138-143 d ~ p , M. 58-59, 2M SmCn mqncrc. 16 rovndmu.urmxnt, brurhl.lldr motors

and. I 8 rpsrwng, i IPDTruluh. 171 rteedcmrml. 101-126

.c m u l r r . 101 ban. phanr- lam Imp, 118-120 bru8ler i mowr dnvcs, i70. I88 chopper. 120 dc motor driura. 103-105 irctrornsanalr inrrtecencr. I W

~ L L hr. 201 rrsislxrc dc. IM c"- :" ,,X "-.. .,,, $,mpb rlolcd-Imp. 2m swhchd rrgulam, 2Ol Ihynrtur and triar dnxs. 105-IW trsnairmr ,M uarinblr~fquency dri i rr , 101-103

r p r d rrguis,ion i""3UN scrdcmllon of a m s u n . I9

rplit-pha* lnducrion maors. 62

dic-era mlan fur, 61 m8nutncturrr\ Nrvca for. 68 moic o f ~ r n i . " m, 55 p r l o m s n r s &snclensl~rs. 66, 68 mlor rlac corsigumtion in, 66 wrpue-r@cun. for. 66. 67. 69

rquirrrlLr.%c rmuirion moton. 8, rUnlnp crpaclla M 8mrors

brurhkn dc moton. rorqur .i,amn,on caused iy mwrainon in, 148, 249

rolnling 6rld M u p b , ~lndurt>vn mninr. W-53

1.94~1m zccclcrslion d, P8 bsslc cham~ctcnn~cn d. 38-99 holdlq xorqur in. 99 IimlUuonl d. ,m magnrtir i i i a r l t in, 94 oprnllon ol, M-98 mmping. W lorquc~sped iuwe for 99

surge indirslor bruahlrsi moor drives and, 214. 2IJ

rwllrh. I rwllChEd rCpYIPlor, s p e d CUnlml with.

2 m ~ymbols. I 5 R ~ Z X synchronovs m o n , 82-91

artlon wi!h 1 4 . 87 action with m losd, 84-86 qplliatianr to& 82-83 dampr wmdmgr and. 83. 88 m& o f o p m s o n . 81 m,uimnc*, a~93 wrque-rpcdcurvr. 88

ry"chmnuus ,Fed hrushlsaadc na,ori, 255 lnduillon mamrr. 46

ryncm fccdbnckrpcdcon%ml, 117 brushlrss mumrdriurs and. 191

synthssircd co~nurpson. I96

~ x t i n g and evnlu8om. 226-212 S molars. 237.239 bmrhlrzs dr m m . 239-251 common lnslogmlFr mwrmnts .od

RMS m r l u m m r . 240

".".,*,. Ulrcr-ph-8 full wmc b m l l c r s dr

m o w . 111.114 Ulrre-phse half wwc bmrMsr &

",,,,-~ , > A . ! > ,

~~~~~~ ~-~~~~ ~~~. ~~

r c r p n w ,,m in, 109 rollspr dmp. IW

,,mrdia~l~emnlemr. eru,h,e.. dr molon and. 220

torque, 2 . 1 . 6.9 h y a r r n r m a o n , 89 mnducson mobm, 74 mcarvnmenl of. 228 prmnml-magrs l maon. I 5

haw.t<S mow., 12, 14 ninglr-phmr rcpllrIon mmm, 81 s m r r maar. 99

"","E conaunt. 7 brurhlr3sdr maon. 113, 141 dr mowrs. 232 p m a n c r n ~ m a g m mobis. 19. 232

lorqw m m p a f o m c e , bnuhleas dc motors. 256

torquo-spsd E-. 227-229 riard-Imp sauq. 264 campun* m.r, I 5 hynrisss maors. PI induceon moon. 71. 12 pmamncm.gmr w o n . IS. 19.

211. 214

. ~~

r Y p p r molon. 99 .Y""hrn"W. mmr.. 88 unflledhlll-W.". reillfled mwcr

rupply snd. 235 vniv.ra., moon. 79

,orqu,ng. brul",*,. d. mnon for. 222~ 332 --.

totem-plc NPN mnaiators. 171 ,,,.ion, brurhkrr d' molar, cm, 222-

221

U undrrmmmuurion. 31 "ndmn.r's Llbon,.nc. (UL,. 4 unlvrorl m m . 11.76

p r f v m n r e mamrctrns>cs d. 11,78 r a r q w ~ r p e d c u m . 79

L",

u.osbb-8p.rd perhmcr.bmrhl.r. dc m m n , 256

uclwiri loop, dc, 115. 116 rul%c. r l l - > d u d . 12 uo1u.r d r u m " , m,.laruhrmr, m m -