Undervoltage hpe makawp maga ai ngu ai gaw hpa rai ta?

Undervoltage makawp maga ai lam gaw, masat da ai threshold npu de hkrat sum mat ai shaloi, wan jak ni hpe shi hkrai shi daw kau ya ai shimlam ladat langai rai nga ai. Ndai makawp maga ladat gaw, wan n-gun hpe matut manoi yu nna, grai katsi mat ai, n-gun yawm mat ai (sh) prat tup hkra machyi mat chye ai masa ni hta, jak ni hpe bungli galaw na matu pat shingdang ya ai.

Voltage gaw, masat da ai bungli galaw ai madang npu de hkrat sum mat ai shaloi, wan jak ni gaw, shanhte a asak hpe grai kadun hkra galaw ya lu ai ladat ni hte bai htang ai. Motor ni hte transformer ni gaw, shayawm ai voltage hpe gram lajang na matu, current grau law hkra shaw la nna, grai katsi ai hpe shabyin ya ai majaw, insulation hpe hkra machyi shangun nna, component ni hpe lawan ladan hkrat sum shangun ai. Rated voltage 90% hta bungli galaw ai three-phase motor gaw 11% (sh) dai hta jan nna current jat wa ai hpe hkam sha lu nna, aten ladaw ni na wa ai hte maren grau grau jat wa ai thermal stress hpe shabyin ya lu ai.

Ndai hkra machyi ai lam a hpang na physics gaw asan sha rai nga ai. Power (watts hku shadawn ai) gaw voltage hpe current hte garan ai hte maren sha re. Voltage hkrat sum mat tim, jak gaw dai zawn re ai power output hpe naw jaw ra ai shaloi, current gaw dai hte maren jat wa ra ai. Ndai conductor hte coil ni hku nna rawt jat wa ai current gaw I2R matut mahkai lam hte maren katsi ai hpe shapraw ya ai-katsi ai hpe lahkawng lang jat nna katsi ai hpe mali lang jat ya ai.

Masha law malawng byin chye ai undervoltage byin shangun ai lam ni gaw:

Ra kadawn ai aten hta n-gun n law ai (sh) grai law ai transformer ni

Utility system manghkang byin ai aten hta grid n grin ai

Voltage grai hkrat sum ai hte galu ai shapoi ai line ni

-power load law law hpe kalang ta galaw hpang ai

Arung arai ni n kaja ai (sh) wan n kaja ai matut mahkai lam ni

Undervoltage Protection

Low voltage bungli galaw ai a jahten sharun ai ladat ni gaw jak rung amyu myu hku nna n bung tim, bung ai hkrang ni hpe garan gachyan ma ai. Induction motor ni gaw grau nna n-gun kya ai hpan langai hpe madi shadaw ya ai. Ndai motor ni gaw, n-gun jaw ai n-gun hpe n sawn ai sha, jak n-gun ra ai lam ni hpe n-gun jaw ya ai majaw, stator windings ni hpe katsi shangun ai grau tsaw ai current hpe shaw la na matu shadut ya ai. Industry data hku yu yang, 85% voltage hta matut manoi bungli galaw ai gaw, mawdaw a asak hpe 50% (sh) dai hta jan nna shayawm ya lu ai.

Compressor hte hka n-gun shayawm ai jak ni mung dai zawn re ai mayak mahkak ni hpe hkrum sha nga ai. Rated voltage npu kaw bungli galaw ai nbung laru shazim ai jak ni gaw, katsi ai atsam hpe shayawm ya ai sha n-ga, kalang ta grai law ai wan n-gun hpe shapraw ya ai. Compressor motor gaw pressure shai hkat ai lam hpe n-gun n-htum hkra shakut ai majaw, motor a windings hte refrigerant lahkawng yan hpe grai katsi shangun ai.

Regulated power supply ni nga ai Electronics ni gaw n bung ai hkrat sum ai lam ni hpe madun dan ai. Switching regulator law law gaw input voltage galai shai ai lam ni hpe gram lajang ya lu ai, raitim ndai gram lajang ai lam gaw manu jahpu jaw ra ai. Shawng na-hpang jahtum na daw ni gaw grau tsaw ai n-gun hpe hparan ra ai, galai shai ai circuit ni gaw transistor hte capacitor ni hpe n-gun grau jat shangun ai n-gun grau ja ai duty cycle ni hta bungli galaw ai.

Battery hpe hparan ai lam gaw undervoltage hpe makawp maga na matu ahkyak dik ai application langai hpe madi shadaw ya ai. Lithium-ion battery ni gaw, n-gun n-gun hpe hkrak tup hkang ra ai, hpa majaw nga yang, n-gun yawm dik htum threshold npu de jahkrat kau ai gaw, n mai nhtang wa ai chemical galai shai ai lam ni hpe byin shangun nna, n-gun hpe prat tup shayawm kau ya nna, shim lum lam hpe mung hkra machyi shangun ai.

Kalang lang lithium-ion cell langai mi hta 3.7V ngu ai n-gun rawng nna, n-gun n law htum 3.0V grup yin hta shim lum ai n-gun rawng ai. Ndai threshold npu de cell voltage hkrat mat ai shaloi, hkra machyi shangun ai lam law law byin hpang wa ai. Anode current collector kaw na magri hka mat wa chye ai, dai gaw magri magri hpe shinggyin la lu ai majaw, kata na short circuit ni byin pru wa chye ai. Anode ntsa na solid electrolyte interface (SEI) layer gaw n ngang grin mat nna, hpang na charge galaw ai shaloi grai kaba wa chye ai majaw, active lithium hpe jai lang nna, yawng a n-gun hpe shayawm kau ya lu ai.

Dai ni na aten na battery hparan ai ladat (BMS) ni gaw, n-gun n-gun n-rawng ai hpe makawp maga ai lam law law hpe galaw nga ai. Primary makawp maga circuit gaw cell langai hpra a voltage hpe matut manoi yu reng nga ai, 100Hz hte 1kHz lapran na rate ni hta sample galaw ai. Gara cell langai mi mung, 100-200mV shimlam masat masa hte law law lang tawn da ai, n-gun yawm dik htum n-gun n-gun n-gun n-gun n-gun n-gun n-gun n-gun n-gun (-) de du wa ai shaloi-BMS gaw kalang ta galaw sa wa ai.

Makawp maga ai lam hta mahtai jaw ai lahkam ni hta, laksan hku nna:

Langai, BMS gaw load de power jaw ai lam hpe shadawn sharam da ai hku nna discharge current hpe shayawm ya ai. Ndai lam gaw, n-gun kya dik ai cell hpe, kata na ninghkap ai lam a majaw byin pru wa ai voltage sag kaw na loi mi bai hkam kaja wa na ahkaw ahkang jaw ya ai. Current shayawm ai raitim, voltage matut nna hkrat sum wa yang, BMS gaw, n-gun dat dat ai lam hta MOSFETs (metal{2}}oxide-semiconductor field-effect transistors) ni hpe lang nna, n-gun dat dat ai lam hpe hkum tsup hkra dawm kau ai lam hpe shabyin ya ai. Ndai switch ni gaw microsecond laman hta current lwi ai hpe jahkring kau ya lu ai.

Grai sung ai hku pru wa ai lithium-ion cell ni hte seng ai mayak gaw, kalang ta hkra machyi ai hta lai nna, grau dam lada ai. 2.5V npu kaw na pru wa ai cell langai gaw, shi a kata na makawp maga circuit hpe prat tup hpaw ya ai makawp maga ai shutdown mode de shang wa chye ai. Dai zawn re ai battery hpe bai lu la na matu, standard charger law law n lu jaw ai laksan arung arai ni hte ladat ni ra ai. Nkau galaw shapraw ai ni gaw, threshold npu na terminal voltage nga ai battery ni hpe charge n galaw ai system ni hpe galaw nna, cell ni gaw theoretical hku nna bai gram lajang lu tim, battery hpe n mai lang hkra galaw ya ai.

Battery makawp maga ai circuit ni gaw, shim lum lam hte jai lang mai ai lam hpe rap ra hkra galaw ra ai. Undervoltage threshold hpe grai tsaw hkra tawn da yang, lang ai ni gaw battery a n-gun yawng hpe n lu lang ai. Grai npu de tawn da yang, cell ni gaw prat tup hkra machyi chye ai. Katsi ai lam gaw ndai jahpan hpe grau nna yak hkak shangun ai-lithium-ion cell ni gaw katsi ai shara hta n-gun yawm ai shara de shim lum ai hku shapraw lu ai, raitim, katsi ai shara (0℃npu) hta dai hku galaw ai gaw shim lum lam hpe hkra machyi shangun ai lithium plating byin shangun ai.

Undervoltage Protection

Makawp maga ai ladat ni gaw, jawm galaw ai madung daw nkau mi hpe kam hpa nga ai. Voltage sensing gaw shawng nnan na ahkyak ai lam hpe madi madun ai. Hpaga lam hta lang ai masum-phase masa ni gaw, line voltage hpe shim lum ai shadawn shadang madang de jahkrat kau ya ai potential transformer (PTs) ni hpe lang nna, shadawn shadang hkrak ai lam hpe n-gun jaw ya ai. Ndai transformer ni gaw, n-gun kaba ai shara ni hta hkrak ai lam hpe hkan sa ra ai-480V primary a matu masat da ai PT gaw 0.5% laman hkrak ai lam hte 120V secondary pru ai lam hpe jaw ya lu na re.

Microprocessor- hpe madung tawn ai relays ni gaw, dai ni na aten na n-gun atsam ni hpe lang ai hta, moi na wan n-gun atsam ni hpe grai galai kau ya sai. Ndai digital jak ni gaw, n-gun atsam a n-gun atsam hpe matut manoi sample galaw nna, n-gun atsam a akyu rawng ai madang hpe madi madun ai RMS (root mean square) manu ni hpe sawn la ai. 1-2kHz na sampling rate ni gaw AC cycle langai lahkawng laman voltage galai shai ai hpe relay hpe bai htang ya lu ai.

Threshold setting gaw makawp maga ai lam hpe gara aten hta galaw na hpe dawdan ya ai. Industrial standards ni gaw, undervoltage hpe stage 1 makawp maga na matu 90% nominal hte stage 2 a matu 85% ngu nna lachyum shaleng da ai. arung arai ni hten za ai hpe makawp maga na.

Aten hpe jahkring kau ai setting ni gaw kadun dawk voltage hkrat sum ai kaw na hkra machyi ai lam ni hpe pat shingdang ya ai. Kalang lang aten ladaw gaw 0.1 kaw nna 10 seconds du hkra rai nna, application hpe madung tawn nna gram lajang mai ai. Motor hpe hpaw ai shaloi voltage kadun ai hku hkrat sum ai (sh) grid hpe kadun ai hku hkra machyi ai gaw makawp maga lam hpe n shabyin ya ging ai, raitim, n-gun n law ai masa ni hpe lawan ladan dawm kau ra ai.

Disconnection galaw ai ladat gaw application hte maren n bung ai. Hpaga lam kaba ni hta relay pru ai lam ni hte hkang ai contactor (sh) circuit breaker ni hpe lang ma ai. Ndai jak ni gaw ampere latsa (sh) hkying hkum law law hpe shim lum ai hku jahkring kau lu ai. Kaji ai jai lang lam ni a matu, MOSFETs (sh) IGBTs (insulated{4}}gate bipolar transistors) ni hpe lang nna, ngang kang ai masa hpe galai shai ai gaw, jak rung n-gun n rawng ai sha, grau lawan ai hku bai htang lu ai.

DC system ni gaw, n-gun n law dik htum n-gun n-gun n-pu kaw n-gun n-gun n-gun n-nga ai (UVLO) circuit ni hpe jai lang ai. Ndai makawp maga lam gaw, n-chye na ai bungli galaw ai shara ni de, n-gun jaw ai n-gun hkrat sum mat ai shaloi, n kaja ai hku bungli galaw chye ai, n-gun n rawng ai circuit ni hte microcontroller ni a matu ahkyak nga ai.

2.7-5.5V bungli galaw na matu masat da ai Microcontroller gaw 2.6V kaw sha bungli galaw ai hpe jahkring kau ai n re. De a malai, circuit nkau mi bungli galaw nna nkau mi hkrat sum ai n teng n man ai masa de shang wa ai. Logic gates ni gaw n jaw ai output ni hpe shapraw ya lu ai, memory cell ni gaw random hku shinggrup mat chye ai, processor gaw n tara ai matsun ni hpe galaw lu ai. Dai a mahtai gaw, data hpe jahten kau ai kaw nna, hkrit tsang hpa hkang zing ai lam ni du hkra rai chye ai.

UVLO circuit ni gaw, n-gun jaw ai n-gun gaw, n-gun yawm dik htum threshold hpe lai mat wa ai shaloi, chye na lu na matu, hkrak tup ai n-gun atsam hpe shingdaw ai lam ni hte shingdaw ai lam ni hpe lang ma ai. Kaja wa -hpan da ai UVLO hta hysteresis lawm ai-dai voltage gaw trip point hta na millivolt latsa daram rawt jat wa ra ai, dai hpang circuit hpe bai n galaw shi yang. Ndai hysteresis gaw, n-gun dat n-gun gaw threshold makau e shingbyi nga ai rai yang, n-gun shayawm ai lam hpe pat shingdang ya ai.

Battery- hte galaw ai jak ni a matu, UVLO gaw yaw shada lam lahkawng hpe galaw ya ai. Langai, dai jak a circuit ni hpe n kaja hkra makawp maga ya ai. Lahkawng, battery hpe grai n-gun n rawng hkra makawp maga ya ai. UVLO circuit law law gaw n-gun n rawng ai masa hta 5μA hta n law ai hpe jai lang ai majaw, battery ni hpe aten galu- tawn da ai aten hta shim lum ai voltage madang hpe tawn da lu ai, makawp maga ai circuit hkum nan gaw sung ai n-gun n pru ai sha.

Mungkan madang ni gaw jak rung amyu myu a matu voltage hkam sharang ai lam hpe tsun da ai. Wan n-gun masa ni a matu ANSI C84.1 madang gaw, daw jau ai lam galaw ai shara ni hta hkap la mai ai wan n-gun n-gun ni hpe masat da ai. 120V n-gun rawng ai masa ni a matu, hkap la mai ai n-gun gaw 114-126V (n-gun rawng ai 95-105%) rai nga ai. Arung arai galaw ai ni gaw ndai shadawn sharam kata hta myit dik ai hku bungli galaw lu na matu, arung arai ni hpe hkrang shapraw ra ai.

IEC 61000-4-11 hta jak rung ni a matu voltage dip hkamja lam hpe chyam dinglik ra ai lam ni hpe tsun da ai. Ndai madang gaw, jak ni hpe magnitude hte duration amyu myu a voltage shayawm ai lam hpe hkam sharang lu ai atsam hpe madung tawn nna, class ni hku nna garan ginhka da ai. Class 3 jak ni gaw 30% voltage dip ai aten hta 0.5 seconds tup bungli galaw ra ai, Class 1 jak ni gaw bungli n galaw lu tim, hkra machyi ai lam n mai byin ai.

Motor makawp maga ai madang ni gaw, shinggrup ai arung arai ni a matu, hkrak ai lam matsun ni hpe jaw ya ai. NEMA MG 1 hta, voltage gaw nameplate rating a ±10% laman hta rai yang, rated load hta myit dik ai hku bungli galaw ra ai ngu tsun da ai. Ndai range npu na voltage ni hta bungli galaw ai shaloi, nbung n-gun n hkra hkra makawp maga ra ai.

Hpaga lam galaw ai shara ni gaw, bungli galaw ai lam matut manoi galaw lu na matu hte jak rung ni hpe shim lum hkra galaw na matu, undervoltage makawp maga ai lam hpe grai kam hpa nga ai. Automated galaw shapraw ai line ni gaw, voltage galai shai ai majaw n myit mada ai sha jak rung ni hkra machyi ai hpe hkam sharang lu na n re. Kalang lang mawdaw galaw ai rung langai hta, mawdaw langai hkrai hpe hkang ai shara ni hpe makawp maga ya ai undervoltage relay latsa daram nga na re, dai set langai hte langai hta, jak langai ngai a matu threshold hte aten ladaw ni hpe n-gun jaw da ai.

Data center ni gaw undervoltage masa ni hte laklai ai mayak mahkak ni hpe hkrum sha nga ai. Server power supply ni hta, n-gun kaba ai input voltage range (90-264VAC) ni lawm ai, raitim, n-gun n law ai shara hta matut manoi bungli galaw ai gaw, power supply a akyu hpe shayawm ya nna, katsi ra ai lam hpe grau law hkra galaw ya ai. Data center UPS (n-htum n-wai ai wan n-gun jaw ai) system ni hta, shang wa ai wan n-gun hpe jat ya lu ai, grai kungkyang ai wan n-gun hpe hkang ai lam lawm ai, raitim ndai htingnut ai lam gaw shadawn sharam nga ai. Monitoring system ni gaw, utility voltage hkrat sum wa ai shaloi, alarm ni hpe shabyin ya nna, operator ni hpe ahkyak ai threshold de n du shi yang, generator power de galai na matu ahkang jaw ya ai.

Sut hpaga nta ni hta HVAC system ni gaw, undervoltage hpe makawp maga na matu, jawm galaw ra ai. Amperes latsa daram hpe hkam la ai chiller system gaw, voltage yawm mat ai hpang, asan sha bai n mai hpaw ai-inrush current gaw, overcurrent makawp maga ai lam hpe hkra machyi shangun na re. Dai ni na aten na nta gawgap ai ladat ni gaw, voltage hkra machyi ai hpang, staged restart sequences hpe lang nna, secondary fault ni hpe pat shingdang ai hku nna, hkang zing da ai ladat hte jak ni hpe online de bai woi wa ai.

Nta kata na application ni hta voltage makawp maga ai jak ni hpe grau grau jai lang wa ai, grau nna n grin ai grid power nga ai ginra ni hta. Ya aten hta nta ting na surge makawp maga ai lam ni hta, manu dan ai arung arai ni hpe brown-out hkra machyi ai kaw na makawp maga ya ai, undervoltage hpe dawm kau ai lam hpe lang ma ai. Ndai jak ni gaw, nta madu ni hpe buga na voltage n-gun n-gun n-gun n-gun n-gun hpe madung tawn nna, hkrun lam hkawm na shara ni hpe masat da lu ai, gram lajang mai ai thresholds ni hpe lang ma ai.

Undervoltage Protection

Htap htuk ai makawp maga lam hpe lata na matu, n-gun atsam masa a arawn alai hte makawp maga nga ai arung arai lahkawng yan hpe chye na ra ai. Three-phase motor lang ai ni a matu, makawp maga ai lam gaw, n-gun n bung ai zawn, n-gun n law ai hpe mung myit yu ra ai. Motor langai gaw phase A hta 460V, phase B hta 445V, phase C hta 435V hpe mu lu na re.Dai kaw na pru wa ai negative sequence current ni gaw, hkap la mai ai zawn rai tim, motor hpe hkra machyi shangun chye ai.

Makawp maga ai arung arai ni a lapran hta jawm galaw ai lam gaw, cascading hkrat sum ai lam ni hpe pat shingdang ya ai. Main breaker hte branch circuit breaker lahkawng yan hta n-gun n-gun n-nga ai hpe makawp maga ya ai rai yang, shanhte a setting ni gaw, branch circuit gaw buga ginra hta byin ai manghkang ni a matu shawng n-gun n-gun shayawm ai lam ni hpe galaw na matu, n-gun shayawm ai jak gaw system-wide voltage manghkang ni hpe hparan na matu, shada da hkan sa ra ai. Aten hpe jahkring kau ai coordination gaw, lata la ai lam-branch circuit ni hpe second 0.5 laman hkawm sa shangun nna, main breaker gaw second 2-3 laman hta hkawm sa mat wa ai.

Makawp maga ai lam amyu myu hku nna gram lajang ra ai lam ni n bung ai. Electromechanical relays ni gaw coil bungli galaw ai lam hte matut mahkai ai lam hpe jep chyoi na matu aten kadun laman chyam dinglik ra ai. Relay n hkrat sum ai gaw makawp maga lam n jaw ai, aten garai n du yang hkrat sum mat ai gaw n ra ai sha hkrat sum mat ai. Undervoltage masa hpe shingdaw lu ai test set hpe lang nna shaning shagu chyam dinglik ai gaw kam mai ai hku bungli galaw lu hkra karum ya ai.

Ya aten na digital relays ni gaw tinang hkum hpe-yu reng ai lam hte data ni hpe ka bang ai lam ni lawm ai akyu ni hpe jaw ya nga ai. Ndai jak ni gaw shanhte a kata na circuit ni hpe matut manoi jep joi nna, makawp maga lam n hkrat sum shi yang, manghkang byin wa ai hpe gram lajang ai ni hpe sadi jaw lu ai. Event recording gaw, n hkru n kaja ai lam ni byin ai aten na voltage profile ni hpe hkam la lu nna, bai byin pru wa ai manghkang ni hpe hparan na matu manu dan ai shiga ni hpe jaw ya lu ai.

Standard thresholds ni gaw, shawng nnan sadi jaw ai lam ni a matu, nominal voltage a 90% hta dung nna, tsep kawp dawm kau ai a matu, 85% hta dung nga ai. 480V system gaw 432V (stage 1) hte 408V (stage 2) hta trigger galaw na re. Battery system ni hta chemistry a matu laksan voltage threshold ni hpe lang ai -lithium{10}}ion cell ni gaw cell langai hta 3.0V grup yin hpe dawm kau nna, lead{12}}acid battery ni gaw cell langai hta 1.75V lang ai.

Mahtai jaw ai aten gaw makawp maga ladat hta madung nga ai. Solid-state galai shai ai lam hpe lang ai electronic system ni gaw millisecond 1-2 laman hta n-gun ni hpe dawm kau lu ai. Wan jak relay ni gaw millisecond 50-200 laman hta bai htang ai. Voltage dips kadun ai kaw na n kaja ai lam ni hpe koi gam na matu aten hpe jahkring kau ai hpe yaw shada let jat bang chye ai (0.5-5 seconds typical).

Ndai gaw application ra ai lam ni hte makawp maga ai hkrang masa hta madung nga ai. Ahkyak ai shimlam arung arai ni gaw, bai n hpaw shi yang, shimlam masa hpe operator langai mi jep yu na matu, manual reset galaw ra ai. Battery charger ni hte power supply nkau mi hta automatic reset galaw ai hpe mu lu ai rai nna, voltage bai jat wa ai shaloi kalang ta bai matut mahkai ai gaw shimlam a matu hpa hkrit tsang hpa n byin shangun ai. Auto-reset system ni hta, n-gun dat hpe n-gun n-gun n-rawng hkra galaw na matu, program galaw mai ai delay (second 10-60) hpe bang chye ai.

Undervoltage makawp maga ai lam gaw hkra machyi na hpe grai shayawm ya lu tim manghkang yawng hpe n mai yeng seng kau ya lu ai. Voltage hkrat ai aten hte makawp maga ai lam galaw ai aten lapran na aten laman hta, jak ni gaw thermal stress nkau mi hpe hkam sha chye ai. Dai hta n-ga, voltage sags grai kadun ai majaw aten-makawp maga ai lam hpe jahkring kau ai gaw, motor torque pulsations (sh) power supply glitches zawn re ai manghkang ni hpe naw byin shangun chye ai. Hkum tsup ai makawp maga lam a matu, circuit sizing hpe hkrak hkrak galaw ai, power factor hpe sharai la ai, voltage madi shadaw ai arung arai ni hpe zai ladat hte tawn da ai zawn re ai ladat law law ra nga ai.

Dai ni na aten na wan jak ni gaw kam hpa mai ai hku bungli galaw lu na matu, band kaji kata kaw sha nga ai voltage hpe kam hpa nga ai. Arung arai ni grau grau kungkyang wa nna manu dan wa ai hte maren, voltage- hte seng ai hkrat sum ai lam ni a manu mung dai hte maren jat wa ai. Voltage hpe makawp maga na matu hkum tsup ai ladat-htuk manu ai system hkrang shapraw ai lam, htap htuk ai makawp maga ai arung arai ni, aten tup gram lajang ai lam ni hpe kayau kaya galaw ai-dai ni na aten na shara ni hta ra kadawn ai kam hpa mai ai lam hpe jaw ya lu ai. Quality makawp maga lam hta shawng nnan bang ai gumhpraw gaw, jak rung a prat hpe galu shangun ai, bungli n galaw ai aten hpe shayawm ya ai, jak rung hte bungli galaw masha ni hpe makawp maga ya ai shimlam margin ni hpe grau kaja hkra galaw ya ai hku nna, akyu jaw ai.