电压不平衡

Power Quality in the German Transmission System — Large-Scale Monitoring, Correlation Analysis, and Long-Term Forecasting

85 符合IEC 61000-4-30 Class A monitoring sites across 50 substations in the German transmission system — 38 在 110 千伏, 21 在 220 千伏, 26 在 380 千伏. Hierarchical clustering reveals which sites are redundant and which are uniquely informative. Ensemble forecasting of weekly 95th-percentile PQ parameters outperforms any individual model. The first dataset to demonstrate systematic, recurring PQ correlation structures at transmission level driven by inverter-based generation.

低压住宅网络中的电动汽车充电和电能质量 - 从个人充电器到车队渗透

等级 2 EV chargers at 7.2 kW produce third-harmonic dominant current that accumulates in the neutral conductor and causes voltage unbalance increasing with distance from the transformer. Monte Carlo simulation across multiple penetration levels shows uncontrolled charging at 30%+ penetration can push VUF beyond 2% at feeder end buses. Smart charging eliminates the problem without hardware mitigation. EV chargers also produce supraharmonic emissions (2–150kHz) that can disrupt the PLC communications intended to manage EV charging itself.

富含 DER 的网络中的电压不平衡 — 太阳能光伏何时有帮助,何时无帮助

Single-phase PV panels can either worsen or improve voltage unbalance on LV feeders — depending entirely on the existing load phase distribution. UPM Madrid analysis on the IEEE European LV Test Feeder shows PV reduced mean VUF from 1.255% 至 0.702% in a medium-unbalance scenario, but increased it from 0.787% 至 0.963% in a low-unbalance scenario. Equally important: IEEE PVUR1 and PVUR2 indices can overestimate the true VUF by a factor of 10–16× in DER-rich networks — the CIGRE index is the only reliable alternative that requires only line voltage magnitudes.

高压网络电压不平衡——阿曼主要互联系统

Voltage unbalance measurements at three 132 kV grid stations in Oman’s Main Interconnected System. All measurements within EN 50160 and Omani code limits. 主要发现: the HV transmission network is balanced — unbalance problems at industrial equipment terminals originate downstream, not from the utility.

医院电气系统中数据驱动的电能质量评估

Full PQ audit at University of Lampung Hospital, 印尼. Voltage and frequency compliant at the meter — but current TDD exceeded IEEE 519 限制多次, voltage unbalance non-compliant, power factor lagging. All problems originated inside the facility from non-linear loads: 开关电源, UPS, 变频驱动器, 影像设备.

提高电力系统的可靠性

Czech Technical University analysis of distribution network device failure data from multiple utilities. Identifies patterns in outage causes and proposes reliability improvement strategies using advanced materials and network restructuring. Provides a methodology for uniform cross-utility reliability benchmarking.

电能质量研究的一个实际案例 (橄榄树, 何塞C.)

IEEE conference paper by Prof. José Carlos de Oliveira (乌贝兰迪亚联邦大学) — site measurements at a Brazilian textile factory. Four-parameter framework: voltage profile, 谐波失真, 电压不平衡, and feeder transfer risk. A foundational industrial PQ assessment methodology paper. The PDF is available for download from the IPQDF library.

可靠的电力保持漂浮研究 (可靠的电力公司)

Canada’s oldest marine biological station at St. Andrews, NB, pumps seawater with two 100 HP pumps — whose speed and flow rate are controlled by variable frequency drives sensitive to supply quality. The case examines VFD-based pump control and power reliability requirements for continuous marine research operations.

分布式发电和电能质量

Belgian MV distribution network segment used to study the impact of distributed generation technologies (风, 光伏, CHP) on power quality and voltage stability. Four cable feeders from a 14 MVA 70/10 kV transformer. Analysis shows how DG penetration affects voltage profiles, harmonic injection, and voltage stability — with practical implications for network planning with high DG penetration.

电压下降 (Microplanet科技股份有限公司)

超过 90% of worldwide facilities operate at voltages higher than required — a consequence of distribution network design that delivers minimum voltage at the far end of the feeder. MicroPlanet’s voltage reduction technology captures wasted energy by operating equipment at optimal voltage, reducing heat losses in electronic components without affecting performance.

低电压 (Microplanet科技股份有限公司)

An Australian utility serving remote outback areas via Single Wire Earth Return systems faced severe power quality complaints — lights flickering, unstable voltage, and very low voltage levels at remote customers. MicroPlanet’s Low Voltage Regulator restored voltage stability and reduced flicker to acceptable levels in areas where traditional network reinforcement was not economically viable.

相不平衡问题 (Microplanet科技股份有限公司)

A Hawaiian utility’s water supply pumps — driven by 3-phase motors — were burning out within one year of installation due to high voltage and phase imbalance. Voltage unbalance caused negative-sequence currents to overheat motor windings, dramatically shortening service life. MicroPlanet voltage regulation and balancing equipment extended motor life to near-nameplate expectancy.

第四频道的利用率 (HIOKI)

HIOKI PW3198 Channel 4 is isolated from the three voltage measurement channels — enabling DC power supply monitoring, second-circuit measurement, or neutral current measurement simultaneously with three-phase voltage. Practical measurement configurations for complex industrial monitoring scenarios.

失灵的交通灯 (吸虫)

Traffic light controller at a main town intersection malfunctioning randomly — sometimes working, sometimes causing long unexplained delays in one direction. Fluke 43B investigation found voltage unbalance and harmonics from a nearby industrial customer on the same distribution transformer. The traffic light controller was sensitive to supply quality — a finding not obvious without measurement.

机店马达故障 (吸虫)

Machine shop motors failing repeatedly despite no change in mechanical loads and other equipment on the same service working normally. Motor rewind shop supervisor used Fluke measurement to identify voltage unbalance plus harmonic distortion — classic combination that produces negative-sequence rotor currents, dramatically increasing motor winding temperature and shortening motor life.

重载服务入口 (Dranetz)

A trading floor’s six air handling units — fed from a single 480V, 400A service — were stalling, malfunctioning, and unable to start, causing control room temperature to rise dangerously. Dranetz monitoring revealed the service voltage averaged 450V instead of 480V, with neutral current issues. 根本原因: overloaded service entrance, not equipment failure.

新建成的公寓楼在威彻斯特 (Dranetz)

A Westchester condominium could not get permits because elevators would not run on emergency generator power. Diagnosed as a voltage drop problem and chased with expensive fixes — new transformer, tap adjustments — that failed to help. Dranetz monitoring identified the real cause: generator output waveform distortion incompatible with the elevator drive controllers.

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