工业设施电压骤升——三个原因, 五效, 和缓解差距
| 现象 | 电压骤升——电源电压超过 1.1 普为 0.5 周期来 1 分钟 (符合IEC 61000-4-30 / IEEE 1159 定义) |
| 三个主要原因 | 不接地中压系统上的单线接地故障 · 大甩负载 · 电容器组切换 |
| 最大膨胀幅度 | 1.73 SLG 故障期间不接地系统上的 pu — 对称分量分析的理论最大值 |
| 现场案例——PT. PLN 西博尔加 | 3-馈线 SB 缺相 02 造成的 1.724 pu swell on phase A — DVR reduced this to 0.997 可以, restoring normal voltage |
| Most sensitive industrial equipment | 变频驱动器 (变频驱动器) — overvoltage protection trips at 1.15–1.20 pu in most modern drives |
| Semiconductor facility impact | Voltage swells from grid disturbances caused equipment downtime and product defects — Moshtagh et al. documented case |
| Mitigation technologies | DVR (series injection — most effective for swells) · DSTATCOM (shunt — better for sags) · Surge arrestors · Capacitor bank stage controllers |
| Key asymmetry | Sag mitigation is well-developed — swell mitigation is less mature, partly because swells occur less frequently but cause more severe equipment damage |
01 Context — The Overlooked PQ Problem
电压暂降在工业电能质量文献中受到大多数关注——它们更加频繁, 更好地表征, 它们对生产设备的影响有据可查. 电压骤升 — 短时过电压超过 1.1 pu — 发生频率较低，但会造成不同且通常更严重的损害: 避雷器退化, 浪涌抑制器中的 MOV 故障, VFD过压跳闸, 绝缘应力, 敏感电子设备中的组件损坏不会立即显现出来，但会加速老化.
电压骤升由 IEEE 定义 1159 和IEC 61000-4-30 作为电源电压幅度暂时增加到 1.1 和 1.8 可以, 持续从 0.5 周期来 1 分钟. 这可以区分骤升和瞬态过电压 (快, 更高的振幅, 子周期持续时间) 和持续的过电压 (长于 1 分钟, 通常是电压调节问题). The swell duration range — 0.5 周期来 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 (SLG) 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
Cause 1 — Single line-to-ground fault on ungrounded systems
On an ungrounded or high-impedance grounded MV distribution system, a single line-to-ground (SLG) 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, 或 1.73 可以. 在牢固接地的系统上, the zero-sequence network limits this rise significantly — the swell is typically below 1.2 可以.
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.
Cause 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 (AVR) 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.
Cause 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.
| 影响 | 机制 | 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), 驱动器跳闸以保护其电容器和 IGBT | 变频驱动器, 可调速驱动器 | 立即——进程中断 |
| 绝缘应力和老化 | 电压升高会增加电缆绝缘层和变压器绕组中的电场应力. 重复的过压事件会加速电介质老化，其速率与电压升高到 7-10 的幂成正比 (逆幂律) | 中压电缆绝缘, 变压器绕组, 电机绝缘 | 延迟——几个月后过早失效 |
| 电子元件损坏 | 电压超过元件额定电压会导致集成电路立即击穿, 电容, 和半导体结. 即使是亚击穿过压也会导致 CMOS 器件中的氧化层加速退化 | PLC的, 电脑, 控制系统, 仪器仪表 | 可以立即或延迟 |
| PLC和电脑重启 | 当电源电压超过工作范围时，工业计算机和PLC中的过压保护电路可能会触发保护性关闭或重新启动, 中断控制逻辑并导致过程混乱 | PLC的, 监控与数据采集系统, 人机界面计算机 | 立即——流程混乱 |
半导体制造厂的一项记录案例研究发现，电网干扰引起的电压骤升会导致设备停机和产品缺陷. 缺陷机制是间接的: 膨胀并没有立即损坏制造设备, 但导致基于 PLC 的过程控制系统重新启动, 中断精确控制的工艺参数 (温度, 气体流量, 沉积率) 周期中期. 控制系统重启时任何正在处理的晶圆都被报废. 在半导体制造领域, 一个中断的工艺周期可能意味着数万美元的废弃晶圆——这一成本在公用事业公司的电能质量记录中是不可见的，因为膨胀本身可能是短暂的并且在 “咨询” 而不是 “超出极限” 类别.
04 现场案例 — PT. PLN Sibolga 馈线 SB 02
PT现场模拟研究. PLN (佩尔塞罗) UP3 Sibolga 喂料器 SB 02 位于北苏门答腊省, 印尼, 提供故障条件下电压骤升行为和缓解设备性能的具体测量数据. 该研究模拟了三相故障 75% 连接负载的馈线长度 70% 馈线的额定容量.
Sibolga 案例展示了膨胀缓解技术选择的关键点: 硬盘录像机 (串联) 优于 DSTATCOM (并联连接) 用于缓解膨胀. DVR 注入电压与电源串联，以消除骤升阶段的过压，同时注入电压以恢复骤降阶段 — 通过单个设备同时缓解骤升和骤降. 静止无功补偿器, 作为在总线上注入无功电流的分流装置, 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 Mitigation Strategies
| Strategy | Addresses which cause | Effectiveness | Cost level |
|---|---|---|---|
| 动态电压恢复器 (DVR) | All three — SLG fault, load rejection, 电容开关 | 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 | 高 — 与 DVR 相当 |
| 电容器组级控制器 | 仅电容器开关膨胀 | 因该原因而高 — 开关所需的最小 kVar | 低 — 5,000 美元–50,000 美元 |
| 晶闸管开关电容器 (TSC) | 电容器开关骤升 | 高 — 过零开关消除瞬态 | 中等 — 5 万美元至 50 万美元 |
| 中压系统可靠接地 | SLG 故障膨胀 — 将最大值降低至以下 1.2 可以 | SLG 高 — 改变故障响应特性 | 介质 — 变压器改造 |
| VFD过压阈值调整 | 甩负载 — 略微提高跳闸阈值 | 有限——减少滋扰行程, 不能防止膨胀 | 零 — 仅参数更改 |
| 避雷器 — 高额定能量 | 所有膨胀的瞬态分量 | 部分 — 防止瞬态过压, not sustained swell | Low — $1k–$20k |
Voltage sag mitigation has a mature product ecosystem: 不间断电源系统, 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. 第一, swells occur less frequently — the actuarial case for capital investment is harder to make than for sags. 第二, 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 电能质量视角
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: a brief swell causing a PLC reboot may not appear in the production downtime log as a “power quality event” — it appears as an “unexplained process interruption.”
From a utility distribution engineering perspective, the SLG fault on ungrounded systems produces the most severe and the most manageable swell problem. The choice of system grounding — solidly grounded, resistance grounded, or ungrounded — is a design decision with direct PQ consequences. Solidly grounded systems limit fault-phase swell to well below 1.2 可以; ungrounded systems allow swells up to 1.73 可以. Utilities that have changed from ungrounded to solidly grounded MV systems have documented reductions in customer voltage swell complaints and associated equipment damage claims.
The most important practical recommendation for industrial PQ engineers dealing with unexplained equipment failures — particularly MOV and surge suppressor failures, VFD过压跳闸, and premature capacitor failures — is to configure their PQ monitors to capture both sag and swell events simultaneously on all phases. A SLG fault that appears on one phase as a sag appears on another phase as a swell. Engineers who monitor only the faulted phase or only the sag side of events may miss the swell entirely — and then be unable to explain why protective devices on the healthy phases are failing. The standard 30-day PQ survey that focuses only on sag characterisation for IEEE 446 ride-through assessment should be extended to include full swell characterisation on all phases if unexplained protective device failures are occurring.
参考文献
- Tyagi M, Khan MI, Gupta S. “A Comprehensive Study of Voltage Swell and Sag in Power Distribution Systems: Characteristics, 原因, Effects, and Mitigation Strategies.” Journal of Electrical Systems, 飞行. 20, 不. 11小号, PP. 960–972, 2024. 可用的: journal.esrgroups.org/jes/article/view/7348
- Naidoo R, Pillay P. “A New Method of Voltage Sag and Swell Detection.” IEEE电力输送交易, 飞行. 22, 不. 2, PP. 1056–1063, 2007.
- IEEE StD里 1159-2019. IEEE 监测电力质量的推荐做法. IEEE, 纽约, 纽约, 2019.
- 符合IEC 61000-4-30:2015+AMD1:2021. 电磁兼容性 - 部分 4-30: 电能质量测量方法. 符合IEC, 日内瓦.
- Voltage-Disturbance.com. “Voltage Swell Due to Line-Ground Fault.” Technical analysis article. 可用的: voltage-disturbance.com
- PT. PLN (佩尔塞罗) UP3 Sibolga 喂料器 SB 02 case study. Documented in: Performance comparison between DVR and DSTATCOM, 研究之门, 2020. DOI: 10.13140/RG.2.2.12345
主要来源: Tyagi M, Khan MI, Gupta S. 杰斯 2024 · PT. PLN Sibolga 馈线 SB 02 case study · IEEE StD里 1159-2019 swell definition · Voltage-Disturbance.com technical analysis. SVG 图和 PQ 透视图 (部分 6) are original IPQDF editorial content.
本案例研究以总结和评论的形式呈现，用于教育目的. Original research attributed to respective authors. 丹尼斯Ruest, 硕士. (应用), P.Eng. (ret。) — IPQDF does not claim authorship of the original research.