System Harmonic Pollution thiab Tag Nrho Harmonic Distortion

"Koj lub zog faib hluav taws xob raug kev puas tsuaj loj heev. Qhov sib txawv ntawm qhov sib txawv yog siab tshaj 30% thiab yuav tsum tau kho!" "Qhov kev sib haum xeeb yog ntau dhau thiab ua rau muaj kev hem thawj rau cov khoom siv hluav taws xob. Saib, qhov sib txawv ntawm qhov ntsuas ntawm qhov ntsuas yog 45%!" "Qhov sib txawv ntawm qhov sib txawv tsuas yog 6%.

 

Nyob rau hauv xyoo tas los no, raws li qhov teeb meem ntawm kev sib haum xeeb hauv lub tshuab hluav taws xob tau sib tham dav dav, txhua tus neeg saib xyuas hluav taws xob tau txais kev nkag siab txaus ntawm harmonics. Txawm li cas los xij, yuav ua li cas txiav txim siab txog qib ntawm kev sib haum xeeb hauv lub cev zoo li yog qhov tseeb thiab tsis meej.

Nws yog qhov tseeb vim hais tias lub teb chaws tus qauv fais fab zoo - Harmonics hauv Public Supply Networks muab cov ntsiab lus meej thiab cov txheej txheem txiav txim siab rau qib kev sib haum xeeb, thiab cov ntsuas hluav taws xob zoo tuaj yeem ntsuas cov kev sib haum xeeb tshwj xeeb.

 

Nws yog qhov tsis meej vim hais tias feem ntau siv harmonic distortion tus nqi- feem pua ​​uas tuaj yeem yooj yim thiab ncaj qha ntsuas los ntawm cov ntsuas hluav taws xob zoo- tsis tuaj yeem ib txwm muaj kev cuam tshuam cov pa phem.

 

Tag nrho Harmonic Distortion (THD)yog qhov taw qhia feem ntau siv los ntsuas qhov℃ntawm kev sib haum xeeb muaj kuab paug hauv lub zog hluav taws xob. Nws yog saws nyob rau hauv cov qauv kev thiab cov cuab yeej hluav taws xob raws li lub ntsiab metric rau lub hwj chim harmonic pa phem. THD yog intuitive thiab yooj yim to taub: yooj yim muab, nws yog feem pua ​​ntawm harmonic cov ntsiab lus txheeb ze rau cov ntsiab lus tseem ceeb, zoo ib yam li cov ntsiab lus ntawm cov cawv nyob rau hauv cov dej cawv.

THD yog ib lo lus dav dav. Hauv kev siv tswv yim, lub zog zoo ntawm lub zog hluav taws xob raug ntsuas los ntawm ob qhov kev xav:hluav taws xobthiabtam sim no, sawv cev los ntawmTag nrho Voltage Harmonic Distortion (THDu)thiabTag nrho tam sim no Harmonic Distortion (THDi)raws. Lawv cov lus txhais tau ua kom zoo rau feem pua ​​​​ntawm kev sib haum xeeb voltage / tam sim no cov ntsiab lus txheeb ze rau qhov tseem ceeb voltage / cov ntsiab lus tam sim no.

Cia peb saib ua ntejTHDu.Nquag, qhov hluav taws xob ntawm lub zog hluav taws xob yog tsau, nrog rau qhov sib txawv ntawm qhov sib txawv rau ntau yam kev siv, xws li qis-voltage 400 V, nruab nrab- thiab siab-voltage 10 kV, 35 kV, thiab lwm yam. Rau ib daim phiaj nrog rau qib voltage, tus nqi ntawm THDu tuaj yeem cuam tshuam rau kev tshawb fawb thiab kev ua kom pom tseeb. Qhov no yog vim hais tias tus denominator nyob rau hauv tus qauv THDu- lub hauv paus voltage U₁- yog tas li. Yog li, qhov loj dua qhov harmonic voltage U_H, qhov siab dua THDu. Lub teb chaws cov qauv siv THDu ua qhov ntsuas qhov kev xav tau rau kev txwv kev sib haum xeeb voltage.

Nominal Grid Voltage (kV)	Tag nrho Voltage Harmonic Distortion (%)	Tus kheej Harmonic Voltage Cov ntsiab lus (%)
		Odd- xaj Harmonics	Txawm tias - xaj Harmonics
0.38	5.0	4.0	2.0
6	4.0	3.2	1.6
10
35	3.0	2.4	1.2
66
110	2.0	1.6	0.8

Hwj chim Zoo - Harmonics hauv Public Supply Networks txwv rau Harmonic Voltage

 

Tom ntej no, cia peb tshawb xyuasTag nrho tam sim no Harmonic Distortion (THDi).Raws li nws cov ntsiab lus thiab cov qauv, THDi zoo li THDu. Tab sis THDi puas tuaj yeem ntsuas qhov kev sib haum xeeb ntawm lub cev raws li kev tshawb fawb thiab meej meej li THDu?

Ua piv txwv: A 37 kW / 380 V lub cev muaj zog nruab nrog lub tshuab hloov pauv zaus.

Nyob rau hauv ib txwm load: fundamental tam sim no=50 A, harmonic tam sim no=15 A, yog li THDi=30%.

Nyob rau hauv lub teeb load: fundamental tam sim no=10 A, harmonic tam sim no=5 A, yog li THDi=50%.

Los ntawm qhov piv txwv no, peb tuaj yeem pom qhov ntawdTHDi feem ntau tsis tuaj yeem ua tiav thiab qhia meej txog qhov xwm txheej tam sim no.Qhov no yog vim tus denominator hauv THDi xam - qhov tseem ceeb tam sim no - tsis kho. Yog li ntawd, kev suav tag nrho tam sim no harmonic distortion tsuas yog muaj txiaj ntsig nyob rau hauv ib qho kev thauj khoom tshwj xeeb, zoo ib yam li kev sib piv ntawm cawv concentration.

Ib qho tseem ceeb tshaj qhov taw qhia rau kev ntsuam xyuas qhov teeb meem ntawm harmonic tam sim no rau lub system yog qhovqhov tseeb harmonic tam sim no magnitude, uas qhia txog ntau npaum li cas ib qho kev sib haum xeeb ua rau lub cev muaj kuab lom. Cov kev txwv tsim nyog kuj tuaj yeem teem caij rau qhov sib haum xeeb tam sim no txhaj rau hauv daim phiaj raws li qhov ntsuas ntawm lub zog hluav taws xob. National standard siv lubtso cai harmonic tam sim no tus nqitxwv tsis pub lub harmonic tam sim no txhaj los ntawm cov neeg siv ntawm qhov taw tes ntawm kev sib txuas.

Nominal Voltage (kV)	Luv -Circuit Capacity (MVA)	Harmonic Order thiab Allowable Harmonic Current (A)
		2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19
0.38	10	78	62	39	62	26	44	19	21	16	28	13	24	11	12	9.7	18	8.6	16
6	100	43	34	21	34	14	24	11	11	8.5	16	7.1	13	6.1	6.8	5.3	10	4.7	9.0
10	100	26	20	13	20	8.5	15	6.4	6.8	5.1	9.3	4.3	7.9	3.7	4.1	3.2	6.0	2.8	5.4
35	250	15	12	7.7	12	5.1	8.8	3.8	4.1	3.1	5.6	2.6	4.7	2.2	2.5	1.9	3.6	1.7	3.2
66	500	16	13	8.1	13	5.4	9.3	4.1	4.3	3.3	5.9	2.7	5.0	2.3	2.6	2.0	3.8	1.8	3.4
110	750	12	9.6	6.0	9.6	4.0	6.8	3.0	3.2	2.4	4.3	2.0	3.7	1.7	1.9	1.5	2.8	1.3	2.5

Hwj chim Zoo - Harmonics nyob rau hauv Public Supply Networks txwv rau Harmonic tam sim no

 

 

Tom qab nyeem cov ntsiab lus saum toj no, koj yuav tsum muaj kev nkag siab meej txog lub tswv yim thiab kev siv ntawmTag nrho Harmonic Distortion (THD).THD yog siv dav hauv kev ntsuas kev sib haum xeeb thiab kev tsom xam, kev tsim qauv, kev ntsuam xyuas cov nyhuv lim dej, thiab lwm yam xwm txheej. Yog nkag siab tus yam ntxwv thiab kev txwv ntawmTHDuthiabTHDinyob rau hauv voltage thiab tam sim no harmonic tsom xam pab peb scientific txiav txim siab harmonic pa phem theem, tsim nyog xaiv filtering txoj kev, thiab siv cov kev ntsuam xyuas cov nyhuv.