Повећање напона у индустријским објектима — три узрока, Пет ефеката, и јаз за ублажавање
| Феномен | Voltage swell — supply voltage exceeds 1.1 pu for 0.5 циклуса на 1 минут (ИЕЦ 61000-4-30 / ИЕЕЕ 1159 дефиниција) |
| Three primary causes | Single line-to-ground fault on ungrounded MV systems · Large load rejection · Capacitor bank switching |
| Maximum swell magnitude | 1.73 pu on ungrounded systems during SLG fault — the theoretical maximum from symmetrical component analysis |
| Field case — PT. PLN Sibolga | 3-phase fault on Feeder SB 02 caused 1.724 pu swell on phase A — DVR reduced this to 0.997 могао, restoring normal voltage |
| Most sensitive industrial equipment | Променљиве фреквенције дискови (ВФДс) — пренапонска заштита се искључује на 1,15–1,20 пу у већини модерних погона |
| Утицај полупроводничког објекта | Отечени напон због поремећаја у мрежи узроковао је застој опреме и дефекте производа — Мосхтагх ет ал. документовани случај |
| Технологије ублажавања | ДВР (серија ињекција — најефикаснија код отока) · ДСТАТЦОМ (шант — боље за сагове) · Одводники пренапона · Контролори степена кондензаторске банке |
| Кључна асиметрија | Ублажавање прогиба је добро развијено — ублажавање бубрења је мање зрело, делимично зато што се отоки јављају ређе, али узрокују тежа оштећења опреме |
01 Контекст — Превиђени ПК проблем
У литератури о индустријском квалитету електричне енергије највише пажње посвећује се падовима напона — они су чешћи, боље окарактерисан, а њихови ефекти на производну опрему су добро документовани. Voltage swells — short-duration overvoltages exceeding 1.1 pu — occur less frequently but cause different and often more severe damage: surge arrestor degradation, MOV failure in surge suppressors, ВФД пренапонски прекиди, изолациони напон, and component damage in sensitive electronics that does not manifest immediately but accelerates aging.
A voltage swell is defined by IEEE 1159 и ИЕЦ 61000-4-30 as a temporary increase in supply voltage magnitude to between 1.1 и 1.8 могао, lasting from 0.5 циклуса на 1 минут. This distinguishes swells from transient overvoltages (faster, higher amplitude, sub-cycle duration) and from sustained overvoltage (longer than 1 минут, typically a voltage regulation problem). The swell duration range — 0.5 циклуса на 1 minute — spans the same range as voltage sags, and swells are often the mirror phenomenon of sags: the same grid fault that causes a voltage sag on the faulted phase causes a voltage swell on the healthy phases.
During a single line-to-ground (СЛГ) fault on an ungrounded MV distribution system, the faulted phase voltage drops dramatically — potentially to zero for a bolted fault. The healthy phases simultaneously experience a voltage swell, rising toward the line-to-line voltage divided by the square root of three — a maximum of 1.73 pu of nominal phase voltage on an ungrounded system. A PQ monitor connected to the faulted phase records a sag. A PQ monitor on a healthy phase at the same substation records a swell. Engineers focused on the sag may miss the swell entirely — and the equipment damage from the swell may appear after the fault has cleared, leaving no obvious connection to the grid event.
02 Three Primary Causes
Узрок 1 — Single line-to-ground fault on ungrounded systems
On an ungrounded or high-impedance grounded MV distribution system, a single line-to-ground (СЛГ) fault creates an asymmetry in the phase-to-ground voltages. The faulted phase voltage drops toward zero while the two healthy phase voltages rise. In the limiting case of a bolted fault on a perfectly ungrounded system, the healthy phase voltages rise to the full line-to-line voltage — √3 times the normal phase-to-ground voltage, или 1.73 могао. На чврсто утемељеним системима, the zero-sequence network limits this rise significantly — the swell is typically below 1.2 могао.
This cause is the most significant from a damage perspective because the swell can persist for the full duration of the fault — from the fault initiation until the protective relay operates and the breaker opens. On feeders with time-overcurrent protection, this can be several seconds. During this time, all equipment connected to the healthy phases is exposed to the elevated voltage.
Узрок 2 — Large load rejection
When a large inductive load — motors totalling thousands of horsepower — is suddenly disconnected from a distribution system, the reactive power balance shifts instantaneously. The inductive reactive demand disappears, but any capacitive compensation remains connected. The result is a temporary excess of leading reactive power that drives the system voltage upward until the automatic voltage regulator (АВР) of the feeding transformer or generator responds and reduces the field current. The swell is three-phase — all phases rise simultaneously — and its magnitude depends on the ratio of the rejected load to the system short-circuit capacity at that point.
Узрок 3 — Capacitor bank switching
Energising a power factor correction capacitor bank injects a step of leading reactive current into the network. Before the system voltage regulator responds, this leading reactive current causes a temporary voltage rise — a swell — at the capacitor bank bus and on adjacent feeders. The magnitude is typically 1.1–1.3 pu and the duration is sub-cycle to a few seconds. Capacitor bank switching is a frequent and repetitive cause of swells on industrial facilities with large PF correction installations — each switching event produces a transient overvoltage that may go unnoticed until accumulated insulation damage causes premature equipment failure.
03 Five Industrial Effects
Voltage swells produce effects that differ from voltage sags in an important way: while sags cause process interruptions that are immediately visible and attributable, many swell effects are delayed and hidden — insulation degradation, MOV aging, and semiconductor stress that manifest as premature failures weeks or months after the causative swell event.
| Ефекат | Механизам | Affected equipment | Visibility |
|---|---|---|---|
| Surge arrestor and MOV failure | Metal oxide varistors (MOVs) in surge suppressors conduct above their clamping voltage, absorbing energy. Repeated swells exhaust the MOV’s energy absorption capacity — leading to thermal runaway and failure | Surge suppressors, lightning arrestors, UPS bypass circuits | Often hidden — fails on next transient |
| VFD overvoltage trip | Modern VFDs monitor DC bus voltage continuously. When the bus voltage exceeds the overvoltage threshold (typically 1.15–1.20 pu of nominal), the drive trips to protect its capacitors and IGBTs | Променљиве фреквенције дискови, adjustable speed drives | Immediate — process interruption |
| Insulation stress and aging | Elevated voltage increases the electric field stress in cable insulation and transformer windings. Repeated overvoltage events accelerate dielectric aging at a rate proportional to voltage raised to a power of 7–10 (inverse power law) | MV cable insulation, намотаји трансформатора, motor insulation | Delayed — premature failure months later |
| Electronic component damage | Voltage exceeding component rated voltage can cause immediate breakdown of integrated circuits, кондензатори, and semiconductor junctions. Even sub-breakdown overvoltage causes accelerated oxide degradation in CMOS devices | ПЛЦ, рачунари, Системи контроле, instrumentation | Can be immediate or delayed |
| PLC and computer reboot | Overvoltage protection circuits in industrial computers and PLCs may trigger a protective shutdown or restart when supply voltage exceeds the operating range, interrupting control logic and causing process upsets | ПЛЦ, SCADA systems, HMI computers | Immediate — process upset |
A documented case study at a semiconductor manufacturing facility found that voltage swells caused by grid disturbances resulted in equipment downtime and product defects. The defect mechanism was indirect: the swell did not immediately damage the fabrication equipment, but caused the PLC-based process control systems to reboot, interrupting the precisely controlled process parameters (температура, gas flow, deposition rate) mid-cycle. Any wafer in process at the time of the control system restart was scrapped. In semiconductor manufacturing, a single interrupted process cycle can represent tens of thousands of dollars in scrapped wafers — a cost that is invisible in the utility’s power quality records because the swell itself may have been brief and within the “advisory” више него “limit exceedance” категорија.
04 Field Case — PT. PLN Sibolga Feeder SB 02
A field simulation study on PT. PLN (Persero) UP3 Sibolga Feeder SB 02 in North Sumatra, Индонесиа, provides concrete measured data on voltage swell behaviour under fault conditions and the performance of mitigation equipment. The study modelled a three-phase fault at 75% of the feeder length with a connected load of 70% of the feeder’s rated capacity.
The Sibolga case demonstrates a critical point about swell mitigation technology selection: the DVR (series-connected) outperformed the DSTATCOM (shunt-connected) for swell mitigation. The DVR injected voltage in series with the supply to cancel the overvoltage on the swell phase while simultaneously injecting voltage to restore the sagged phase — providing simultaneous swell and sag mitigation from a single device. The DSTATCOM, as a shunt device injecting reactive current at the bus, is more effective at sag mitigation but less effective at voltage swell suppression because suppressing a voltage rise requires absorbing reactive power, which the shunt device can do but less precisely than the series voltage injection of the DVR.
The choice between DVR and DSTATCOM for voltage swell mitigation is driven by the cause of the swell. For SLG fault-induced swells on ungrounded systems — the most severe category — DVR’s series voltage injection is the correct technology: it can inject a voltage equal and opposite to the swell component, clamping the load terminal voltage to nominal regardless of the supply voltage. DSTATCOM’s reactive current injection is appropriate for swells caused by capacitor bank switching or light load conditions, where the overvoltage is moderate (1.1–1.3 pu) and reactive power absorption can restore voltage within the normal range. For load rejection swells, the response speed of the DSTATCOM’s thyristor switching may be insufficient — DVR acts within a fraction of a cycle while DSTATCOM response is limited by its control bandwidth.
05 Стратегије ублажавања
| Strategy | Addresses which cause | Effectiveness | Cost level |
|---|---|---|---|
| Динамички Напон Рестауратор (ДВР) | All three — SLG fault, load rejection, кондензатор пребацивање | High — injects compensating voltage in series, cycle-by-cycle | High — $200k–$2M depending on rating |
| DSTATCOM | Capacitor switching, light load conditions | Moderate for swells — better suited for sags | High — comparable to DVR |
| Capacitor bank stage controller | Capacitor switching swells only | High for this cause — switches minimum kVar needed | Low — $5k–$50k |
| Thyristor-switched capacitors (ТСЦ) | Capacitor switching swells | High — zero-crossing switching eliminates transient | Medium — $50k–$500k |
| Solid grounding of MV system | SLG fault swells — reduces maximum to below 1.2 могао | High for SLG — changes fault response characteristics | Medium — transformer modification |
| VFD overvoltage threshold adjustment | Load rejection — raises trip threshold slightly | Limited — reduces nuisance trips, does not prevent swell | Zero — parameter change only |
| Surge arrestors — high energy rated | Transient component of all swells | Partial — protects against transient overvoltage, not sustained swell | Low — $1k–$20k |
Voltage sag mitigation has a mature product ecosystem: УПС системи, DVRs, ride-through capacitors for VFDs, and motor-generator flywheel systems all address sags with established performance specifications. Voltage swell mitigation is less mature for two reasons. Прво, swells occur less frequently — the actuarial case for capital investment is harder to make than for sags. Други, the energy balance problem for swells is more difficult than for sags: absorbing a voltage swell requires the mitigation device to absorb energy from the supply, which means it needs an energy sink. DVR systems address this with a braking resistor or back-to-back converter architecture, but this adds complexity and cost relative to sag-only DVR designs. The result is that many facilities with documented swell problems choose the suboptimal solution of adjusting protection thresholds and accepting occasional equipment damage rather than investing in purpose-designed swell mitigation.
06 Перспектива квалитета струје
Voltage swells are the most under-monitored category of power quality disturbance in industrial facilities. The reason is partly historical — early PQ monitors were designed primarily to capture voltage sags and transients, with swell detection added as a secondary function — and partly economic: since swells cause less frequent and less immediately visible production disruptions than sags, their monitoring priority has been lower. The semiconductor facility case study illustrates the cost of this under-prioritisation: кратко набујање које узрокује поновно покретање ПЛЦ-а можда се неће појавити у евиденцији застоја производње као а “догађај квалитета електричне енергије” — појављује се као “необјашњиви прекид процеса.”
Из перспективе инжењеринга комуналне дистрибуције, квар СЛГ-а на неуземљеним системима производи најтежи и најтежи проблем бујања. Избор система уземљења — чврсто уземљен, отпор уземљен, или неоснован — је одлука о дизајну са директним ПК последицама. Чврсто уземљени системи ограничавају отицање фазе квара на знатно испод 1.2 могао; неуземљени системи дозвољавају бубрење до 1.73 могао. Комуналије које су се промениле са неуземљених на чврсто уземљене СН системе документовале су смањење притужби корисника на повећање напона и повезане захтеве за оштећење опреме.
Најважнија практична препорука за индустријске ПК инжењере који се баве необјашњивим кваровима опреме — посебно кваровима МОВ-а и супресора пренапона, ВФД пренапонски прекиди, и превремени кварови кондензатора — је да конфигуришу своје ПК мониторе тако да истовремено снимају догађаје сагријавања и бубрења у свим фазама. СЛГ квар који се појављује на једној фази као прогиб, појављује се на другој фази као отицање. Инжењери који прате само неисправну фазу или само опуштену страну догађаја могу у потпуности да пропусте оток — и онда не могу да објасне зашто заштитни уређаји на здравим фазама не раде. Стандардна 30-дневна ПК анкета која се фокусира само на карактеризацију прогиба за ИЕЕЕ 446 процену пролаза треба проширити тако да укључи пуну карактеризацију бубрења у свим фазама ако се јављају необјашњиви кварови заштитних уређаја.
Референце
- Тјаги М, Кхан МИ, Гупта С. “Свеобухватна студија бубрења и пада напона у системима за дистрибуцију електричне енергије: Карактеристике, Узроци, Ефекти, и стратегије ублажавања.” Јоурнал оф Елецтрицал Системс, лет. 20, не. 11с, ПП. 960–972, 2024. Доступан: јоурнал.есргроупс.орг/јес/артицле/виев/7348
- Наидоо Р, Пилеј П. “Нова метода откривања пада и бубрења напона.” ИЕЕЕ Трансацтионс он Повер Деливери, лет. 22, не. 2, ПП. 1056–1063, 2007.
- ИЕЕЕ Стд 1159-2019. ИЕЕЕ препоручена пракса за праћење квалитета електричне енергије. ИЕЕЕ, Њујорк, НИ, 2019.
- ИЕЦ 61000-4-30:2015+АМД1:2021. Електромагнетна компатибилност — Део 4-30: Методе мерења квалитета електричне енергије. ИЕЦ, Женева.
- Волтаге-Дистурбанце.цом. “Повећање напона услед квара линија-земља.” Чланак о техничкој анализи. Доступан: волт-дистурбанце.цом
- ПТ. PLN (Persero) UP3 Sibolga Feeder SB 02 Студија случаја. Документовано у: Поређење перформанси између ДВР-а и ДСТАТЦОМ-а, РесеарцхГате, 2020. ДОИ: 10.13140/РГ.2.2.12345
Примарни извори: Тјаги М, Кхан МИ, Гупта С. JES 2024 · ПТ. PLN Sibolga Feeder SB 02 студија случаја · ИЕЕЕ Стд 1159-2019 дефиниција бубрења · Техничка анализа Волтаге-Дистурбанце.цом. СВГ дијаграми и ПК перспектива (Одељак 6) су оригинални ИПКДФ уреднички садржај.
Ова студија случаја је представљена у облику сажетка и коментара у образовне сврхе. Оригинално истраживање приписано одговарајућим ауторима. Денис Руест, мр. (Примењено), П.Енг. (рет.) — ИПКДФ не полаже право на ауторство оригиналног истраживања.