THIT K B NGHCH LU BA PHA BA NHNH

S DNG MODUL CNG SUT THNG MINH CHUYN DNG PS22A76

DESIGN THE THREE-PHASE THREE-LEG INVERTER BASED ON APPLICATION

SPECIFIC INTELLIGENT POWER MODULES PS22A76

ThS. PHM VN TON

Khoa in - in t, Trng HHH Vit Nam

Tm tt

Bi bo nu ln nhng hn ch ca vic thc hin b nghch lu ba pha ba nhnh s dng modul cng

sut thng minh thng thng (Conventional Intelligent Power Modules) p dng cho cc h truyn ng

cng sut nh. T , mt gii php thay th c ch ra em li nhiu u im hn trong vic thc hin

b nghch lu ny l s dng modul cng sut thng minh chuyn dng (Application Specific

Intelligent Power Modules). M hnh thc nghim h Bin tn - ng c khng ng b c xy dng

kim chng nhng u im ca phng php thit k ny.

Abstract

This paper pointed out some drawbacks of the implementation of three-phase three-leg inverter with

application Conventional Intelligent Power Modules (Conventional IPM). Since then, an alternative

solution is showed to bring out many advantages in the realization of the three-phase three-leg inverter

with Application Specific IPM (ASIPM). An experimental model of the inverter - induction motor system

is constructed to verify these strong points of this design method.

Key words: Intelligent power modules (IPM), three-phase inverter, Digital Signal Processor (DSP).

1. t vn

Cc b nghch lu ba pha ba nhnh s dng Conventional IPM trong h truyn ng bin tn - ng c

khng ng b (CKB) cng tr nn ph bin vi di cng sut t 200W ti hn 150kW [1], [2], [3]. Hnh 1 ch

ra s khi cu to ca Conventional IPM. Theo , Conventional IPM c tch hp cc van cng sut vi cc

mch tch hp chuyn dng pha thp p (LV ASIC - Low voltage Application Specific Integrated Circuit) kch

m van v cung cp mt s chc nng bo v c s dng rng ri trong h truyn ng xoay chiu. Modul loi

ny c mt vi u im nh [4]: Gim thi gian thit k, nng cao tin cy; gim tn hao cng sut bng vic ti

u ha ng thi cc van cng sut v chc nng bo v trn cng mt modul; ci thin kh nng ch to do gim s

lng cc linh kin ph tr. Tuy nhin Conventional IPM vn cn c hn ch nht nh. Theo , c th ghp ni

gia DSPC / (vi iu khin/vi x l tn hiu s) v Convention IPM cn c tng kt ni trung gian (hnh 1) bao

gm cc mch cch ly quang m bo cch ly DSPC / vi pha cao p (cc van trn). iu ny dn ti s lng

ngun iu khin s dng kch m van tng ln. i vi cc h truyn ng cng sut nh, hn ch nu trn s

lm gia tng thm chi ph v kch thc ca thit b.

Hnh 1. S khi IPM thng thng [4] Hnh 2. S khi ASIPM [4]

Vic modul ASIPM (Application Specific IPM) ra i khc phc c mt hn ch ca Convention IPM.

Hnh 2 ch ra s khi cu to ca ASIPM. Bng vic tch hp thm cng ngh HVIC (High Voltage Integrated

Circuit) c chc nng dch mc v iu khin kch m van, ASIPM cho php kt ni trc tip 6 tn hiu PWM t

DSPC / ti u vo ca n m khng cn cch ly quang, ch cn mt ngun iu khin duy nht kch m van.

Ngoi ra, mt s ASIPM cn tch hp sn c cm bin o dng bn trong gip cho vic thit k khu o lng tr

nn thun tin hn. Bi bo ch ra vic thc hin b nghch lu ba pha ba nhnh s dng ASIPM.

2. Thc hin b nghch lu ba pha ba nhnh

Trong ng dng ny, ASIPM c s dng l modul IGBT PS22A76 ca Mitsubishi Electric vi cc tnh

nng ch yu nh sau [5]: VVAI CESC 1200,25 ; tnh nng cho nhm van trn (P-side) bao gm: Mch kch m,

dch mc, bo v thp p; tnh nng cho nhm van di (N-side) bao gm: Mch kch m, tn hiu bo li v bo v

ngn mch - thp p, u ra tng t bo nhit ti LVIC; c bit l vic cp ngun cho modul ch t mt ngun

duy nht c gi tr 15VDC.

Hnh 3a, b ch ra hnh dng bn ngoi v mt ct ngang cu trc bn trong ca modul ny.

LV ASIC

LV ASIC HVIC

LV ASIC

a)

b) Hnh 3. Modul IGBT PS22A76

a) Hnh dng bn ngoi, b) Mt ct ngang cu trc bn trong

B nghch lu ba pha ba nhnh s dng modul PS22A76 bao gm 2 khi chc nng: Khi phi ghp vi

DSPC / v khi bo v.

2.1. Khi phi ghp vi DSPC /

a)

b)

Hnh 4. Mch dch mc [5] Hnh 5. Nguyn l hot ng mch bootstrap [6]

a) Qu trnh np, b) Qu trnh phng

Mch dch mc (hnh 4) trong HVIC ca PS22A76 cho

php ghp ni trc tip 6 tn hiu PWM t DSPC / ti 6 u vo

NNNPPP WVUWVU ,,,,, ca n. Tuy nhin, m bo cch ly

gia mch iu khin v mch cng sut, s thit k s dng

cch ly quang.

- Phn t cch ly quang tc cao 6N137 c s dng c th lm vic tn s cao (khong vi kHz). Khong cch ca

cc ng tn hiu ny c thit k ngn nht c th nhm hn

ch nhiu. Ngoi ra, cc xung nhiu c rng qu nh s c

loi b bng cch lp mch lc RC trn mi ng tn hiu vo.

- Tn hiu bo li ngn mch, thp p t modul PS22A76

gi ti u vo ca DSPC / s dng cch ly quang PC817.

Hnh 6. Mch phi ghp vi C /DSP

Nng lng s dng kch m nhm van trn c cung cp t mt mch bootstrap ngoi vi nguyn l

hot ng nh sau: Khi van di c kch m (ON), t bootstrap ( bootstrapC ) c np in tch qua it (

bootstrapD ) theo ng nt t (hnh 5a); Khi van di b kha li, bootstrapC phng in tch kch m van trn

(hnh 5b). Nh vy, ch cn s dng mt ngun cung cp 15VDC duy nht cho modul PS22A76. Hnh 6 ch ra s

phi ghp gia DSPC / vi modul PS22A76.

2.2. Khi bo v

Cc chc nng bo v c xy dng bao gm: Thp p ngun iu khin, ngn mch v qu nhit van.

2.2.1. Bo v thp p ngun iu khin

Chc nng bo v thp p gip ngn nga cc ch lm vic khng mong mun c ch ra trong bng 1

[5]. C nhm van trn v nhm van di u c chc nng ny. Tuy nhin, tn hiu ra bo li thp p ch c tch

cc cho nhm van di.

Bng 1. p ng ca PS22A76 tng ng vi cc gi tr in p ngun cung cp

in p ngun cung cp Hot ng

0 4V (P, N) - Tng ng vi ngun cp bng 0V.

- Chc nng bo v thp p, u ra bo li (Fo) khng c tch cc.

- Cc van IGBT khng lm vic. Tuy nhin, nhiu bn ngoi c th gy

m van. V vy, in p trung gian mt chiu ch c cung cp cho

(U,V,W)

QR

S

+15V

(N)

(P)

U, V, WP

Vcc

U, V, WN

P(Vcc)

N(GND)

U,V,W

N-side

IGBT

P-side

IGBTVFB

VFS

HVIC

LVIC

VN1

VNC

VP1

N-side

FWDi

VPC

ON

+P-side

FWDi

DBootstrap

CBootstrap

D

P(Vcc)

U,V,W

P-sideIGBT

VFB

VFS

+15V

VP1

P-side

FWDi

C

VPC

+

Bootstrap

Bootstrap

modul sau khi cp ngun iu khin.

4 Ungng Chc nng bo v thp p, Fo c tch cc. Cc van IGBT khng lm vic.

Ungng 13,5V (N), 13,0V (P) Cc van IGBT lm vic. Tuy nhin, tn tht trn van tng, dn ti nhit van tng.

13,5V 16,5V (N);

13,0V 18,5V (P)

Ch lm vic bnh thng

16,5V 20,0V (N);

18,5V 20,0V (P)

Cc van IGBT vn lm vic. Tuy nhin, tc chuyn mch v gi tr

dng qua van tng, lm tng nguy c ngn mch.

> 20V (P, N) Mch iu khin c th b ph hy.

2.2.2. Bo v ngn mch [5]

Phng php bo v ngn mch c thc hin bng cch gim st in p ri trn in tr SR . Dng in

chy qua SR c gi tr rt nh c tch t thnh phn dng in chnh chy qua nhm van di (ng nt t

trong hnh 7). Bng cch ny, tn tht ri trn in tr c gim i ng k so vi phng php s dng in tr

shun ca th h modul trc . m bo mch bo v ngn mch hot ng tin cy, mt mch lc RC c lp

vo trc u vo CIN vi hng s thi gian =1,8 s . Khi , 3 van di s b kha sau 1,8 s khi ngn mch

xy ra.

2.2.3. Bo v qu nhit cho van

Modul PS22A76 c tch hp sn mt mch o

nhit ti LVIC. Nhit trn van IGBT, diode s gin

tip lm nng LVIC. Do , nhit ti LVIC khng th

phn nh tc thi nhit trn cc van (v d trong ch

ngn mch). V vy, mch ny ch c p dng

bo v qu nhit cho van trong trng hp iu kin lm

mt xu i hoc ng c b qu ti. Chc nng ny gip

cho ngi s dng loi b c mt mch ngoi o nhit

ca modul. Khi nhit vt qu gi tr cho php,

modul khng t ng kha cc van IGBT cng nh xut

tn hiu bo li Fo. V vy, vi iu khin s phi a ra

tn hiu kha tt c cc van IGBT khi xy ra qu nhit

van. Hnh 8 ch ra s mch thc hin chc nng bo

v qu nhit van.

2.2.4. Mch snubber

Mt t in snubber c lp song song vi

ngun trung gian mt chiu gip bo v van v tng hiu qu lm vic ca van. T in ny cn c b tr gn nht

c th vi cc P v cc NU, NV, NW nh c minh ha trong hnh 9. T snubber c la chn c gi tr 0,15uF.

Hnh 10 ch ra s nguyn l hon thin ca b nghch lu ba pha ba nhnh s dng modul PS22A76.

3. Kt qu thc nghim

Hnh 7. Mch bo v ngn mch [5]

VOT

LVIC

CFO

NU

FO

WN

VN

UN

VNC

VN1

IGBT4Di4

IGBT5Di5

IGBT6Di6

NV

NW

VscCIN

.

Hnh 8. Mch bo v qu nhit van

Hnh 9. Mch snubber

Hnh 10. S nguyn l b nghch lu ba pha ba nhnh

M hnh thc nghim h bin tn - CKB (hnh 12) c xy dng theo s khi hnh 11 kim chng

cc u im khi thit k b nghch lu ba pha ba nhnh s dng modul PS22A76. Trong , CKB c thng s:

WP 180 , VUN 380 , 3cp , pvnN /945 ; mch iu khin s dng vi x l tn hiu s TMS320F2812 ca

Texas Instruments, cc van c iu khin theo phng php iu ch vector khng gian, tn s t cho ng c f

= 50Hz. Hnh 13 ch ra th thi gian ng ngt van cho pha U ( ut ) v pha V ( vt ). in p dy vwuw UU , nhn

c t my hin sng (Oscilloscope) c ch ra trong hnh 14. Quan st trc thi gian nhn thy: Chu k ca in

p xp x 20 ms (tng ng f = 50 Hz), in p uwU v vwU lch nhau khong 3,3 ms (tng ng o60 ) m bo

ng nguyn l in p ra ca bin tn cp cho CKB

Hnh 11. S khi h bin tn - CKB

Hnh 13. th thi gian ng ngt van vu tt ,

Hnh 12. M hnh thc nghim

5ms/div Hnh 14. in p dy vwuw UU , .

4. Kt lun

Bi bo trnh by cch thit k b nghch lu ba pha ba nhnh s dng modul IGBT PS22A76 ca hng

Mitsubishi Electric. Cc kt qu thu c t m