Spannungsspitzen

Voltage Swell in Industrial Facilities — Three Causes, Five Effects, and the Mitigation Gap

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Voltage swells (1.1–1.8 pu, 0.5 Zyklen 1 Minuten) cause MOV failures, VFD overvoltage trips, insulation stress, and PLC reboots — often with delayed, hidden damage. Three causes: SLG fault on ungrounded MV (max 1.73 pu on healthy phases), large load rejection, and capacitor bank switching. PT. PLN Sibolga field case: 3-phase fault produced 1.724 pu swell on phase A — DVR reduced to 0.997 pu simultaneously with sag recovery on phase C.

Supraharmonic Distortion in MV and LV Grids — Four Documented Negative Effects and the Limits Gap

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Four documented negative effects of supraharmonic distortion (2–150 kHz) on MV and LV distribution networks: power loss and heating from skin effect, dielectric material aging at accelerated stress cycle rates, MV cable termination failures from combined dielectric stress and local heating, and PLC interference in smart metering and demand response systems. Key finding: MV/LV transformer transfer ratio is 0.5–3.0 — some supraharmonic components are amplified crossing from MV to LV. Strong correlation measured at substations 16 km apart. No planning or compatibility limits currently exist above 9 kHz.

Erstaunlicher Intl – Sinewave Filter vs. dV/dT Filter for Long-Cable VFD Applications: A Head-to-Head Field Comparison

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Long cable VFD applications produce cable resonance that amplifies dV/dt at the motor terminals — causing insulation stress and premature motor failure. A dV/dt filter limits the voltage rise rate but does not produce a true sine wave. A sinewave filter eliminates both the resonance and the harmonic content. Field comparison at San Antonio Water Authority shows measured motor terminal voltage for both filter types.

Erstaunlicher Intl – Marine Duty Harmonic Mitigation Saves an Offshore Service Vessel Program

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An offshore service vessel DC drive system produced voltage notching severe enough to cause control system malfunctions on other vessel systems. The vessel program was at risk of cancellation. A Mirus Lineator filter on the DC drive eliminated the notching — restoring compatibility between the drive and the vessel’s sensitive electronics. Documented with oscilloscope waveforms before and after.

Erstaunlicher Intl – Sinewave Filters for ESP Motor Protection: A Field Case Study in Filter Design and Motor Thermal Response

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Submersible ESP (Electric Submersible Pump) motors fed via VFDs through long cables: sinewave filter design must account for the cable capacitance, motor inductance, and the filter’s own resonant frequency. Incorrect filter design can produce resonance at a harmonic frequency, amplifying distortion rather than reducing it. Case documents the filter design process and measured thermal response of the motor under harmonic loading.

Wirkung von Utility-induzierte Überspannungen in einem Stahlwerk mit Frequenzumrichter (Praktische Erdung, Bonding, Schirmung und Überspannungsschutz)

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A steel mill with variable speed drives experienced frequent VSD tripping with “Überspannung in Wechselstromleitung” indication despite normal steady-state voltage. Utility-induced switching surges — invisible to RMS voltmeters — were the root cause. Case demonstrates why true PQ monitoring with transient capture is essential in facilities with long cable runs and VSD loads.

Power Quality im Major U.S.. Automobil-Montagewerk mit Dual-Utility-Feeds

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Dual utility feeds prevented a multi-hour outage when a wind-induced fault caused a line-to-line fault at the automobile assembly plant substation — but did not prevent the 4.8-cycle voltage sag at 68% voltage that still caused process disruptions. Four GPS-synchronised monitors confirmed the fault on both transmission lines simultaneously. A DVR would have prevented the process disruptions entirely.

Oberschwingungen und Kerben im dynamischen Test Load

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A major European manufacturer’s dynamic test bench — with highly variable loading — produced harmonics up to and beyond the 100th order plus voltage notching that corrupted test results. Active harmonic filters compensating up to the 100th order eliminated both phenomena, restoring the integrity of development testing and preventing false test failures from power supply artefacts.

ADF Verbessert dynamischen Prüfstand (Comsys AB)

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Dynamic test bench with programmable loading patterns produced harmonics up to the 100th order and significant voltage notching. Comsys ADF Active Harmonic Filter installation reduced notching and harmonic distortion, restoring supply quality to other equipment on the same transformer. A duplicate of case 2328 with slightly different background — Comsys vs. Active Harmonic Filters branding.

Copper Grounding System schützt Mt. Washington Towers (Copper Devel Association Inc)

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Mt. Washington’s communication towers serving northern New England — carrying TV, Radio, telephone, FAA air traffic control, and emergency services — were vulnerable to lightning until 1993. A comprehensive copper grounding system redesign eliminated lightning-related equipment damage and downtime, demonstrating the economic case for proper grounding in high-exposure communication infrastructure.

Lightning Strikes Twice: Ordnungsgemäße Erdung Verhindert Ausfälle (Copper Development Association Inc)

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Florida’s Lightning Alley sees 130+ lightning days per year — communications towers are struck regularly. Orange County’s experience demonstrates that a total systems approach to electrical grounding, treating the tower, building, and all connected equipment as a single grounded system, prevents millions in lightning damage. Case covers the engineering and economics of comprehensive lightning protection.

Remote Operation and Measurement (HIOKI)

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Remote monitoring of a power quality analyser via LAN using the HTTP server function — no special software required. HIOKI PW3198 screen mirroring at 0.5 second refresh rate with password protection for setting changes. Eliminates the need for on-site technician visits during extended monitoring campaigns.

Die Synchronisation auf den GPS-Uhr (HIOKI)

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GPS clock synchronisation of the HIOKI PW3198 to UTC with ±2ms accuracy — enabling multi-point power quality measurement under a common time reference. Essential for correlating lightning strike propagation, voltage sag source attribution, and power outage spread across geographically separated monitoring locations.

Wind Power Generation (HIOKI)

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Wind power generation creates unique PQ challenges: output voltage fluctuates with wind speed, frequency deviates from nominal, transient overvoltages occur from lightning and grid switching, and inrush current and harmonics accompany inverter operation. Simultaneous measurement of all parameters is essential for grid interconnection compliance assessment.

Solar-Power Generation (HIOKI)

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Solar PV power conditioners maintain output by monitoring grid voltage and frequency — but malfunction when grid voltage rises above threshold or frequency deviates. Problems include inverter trips, inability to sell back power due to overvoltage, and high-order harmonic injection from neighbouring PV systems. Field measurement identifies the dominant disturbance type.

Leitende Lärm (HIOKI)

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Conductive noise — high-frequency electrical disturbances spreading through power, signal, and ground cables from lightning surges, elektrostatische Entladung, and high-order harmonics — causes equipment malfunction and radio/TV interference in neighbouring premises. HIOKI measurement techniques covering up to 100 MHz identify the noise frequency band and propagation path for targeted mitigation.

Spannung Waveform Lärm & UPS Switching (HIOKI)

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Eighteen days of monitoring on a 1-phase 100V circuit recorded 68 identical waveform distortion events, subsequently classified into two types: UPS switching transients and persistent waveform noise. The systematic waveform comparison technique demonstrates how event classification reveals root cause — the UPS was not returning to sine wave output after switching.

Allgemeine UPS Switching Waveforms (HIOKI)

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Low-cost UPS systems sold in retail stores output square waves rather than sine waves — a fact most users are unaware of. HIOKI measurement shows voltage swells and dips at UPS switching transitions in systems without output voltage compensation. Equipment designed for sine wave supply may malfunction on square wave UPS output.

Transiente Überspannungen (HIOKI)

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A factory 200V three-phase circuit recorded recurring transient overvoltages on all three phases simultaneously — occurring twice per fundamental cycle with 820 µs spacing, zwischen 10 kHz und 30 kHz, peaking at 120–260 V. The simultaneous three-phase occurrence and precise timing pattern indicates a resonance phenomenon, not a switching event — root cause undetermined.

Spannungseinbruch durch Blitzeinschlag - an der Distribution Panel (HIOKI)

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HIOKI headquarters building distribution panel recorded 4 voltage dips caused by lightning during a 2-month summer measurement period. Residual voltages and durations documented for each dip — the 6.6 kV supply was affected via the HV distribution network. Lightning-caused voltage dips cannot be prevented by utilities but can be mitigated with surge protection and ride-through equipment at sensitive loads.

Spannungseinbruch durch Blitzeinschlag - an der Steckdose (HIOKI)

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One year of monitoring at HIOKI’s 6.6 kV receptacle captured 6 voltage dips in 3 consecutive days during August lightning season. One dip on the T-R phase showed 4.708 kV residual voltage for 109 ms — a severe sag by any standard. IN 50160 classification mode counted simultaneous three-phase events as single events for statistical reporting.

Schalten eines Power Factor Compensation Kondensator (HIOKI)

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Equipment power supply damage traced to transient overvoltages caused by power factor correction capacitor switching within the facility. The switching waveform propagated through the LV circuit without filtering and combined with impulse transients at switch-off, creating damaging voltage peaks. A filtering device at the capacitor bank would have prevented the equipment failures.

Transient von Glow Neonlicht hervorgerufen (Hioki)

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Glow fluorescent lighting generates transient overvoltage when the glow lamp initiates the warm-up sequence — a known but frequently overlooked phenomenon. The transient occurs at first ignition and can affect nearby electronic equipment connected to the same circuit. Measurement shows the waveform characteristics and suggests threshold settings for event detection.

Automatische Verteilung Fehlerortung (Dranetz)

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Consolidated Edison New York deployed Dranetz Encore Series and legacy PQNode instruments across their distribution network. Electrotek’s PQView Fault Analysis Module identifies and characterises faults automatically — enabling automatic distribution fault location from power quality monitoring data without requiring field crew dispatch.

Wind Generation Power Quality & Interconnect Fragen (Dranetz)

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Wind generation plant interconnection requires assessment of harmonics, Flimmern, voltage fluctuation, frequency deviation, and fault ride-through capability. Dranetz monitoring solutions cover both temporary commissioning assessment and permanent 24/7 monitoring for continuous interconnection compliance verification on wind farms of any size.

Data Center Inbetriebnahme Case Study (Dranetz)

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High-reliability facilities invest heavily in UPS systems and generators — but these mitigation devices themselves can fail without obvious alarms. Dranetz continuous power monitoring evaluates UPS health at commissioning and throughout service life, identifying degrading performance before a failure causes the protected equipment to lose supply.

Glass Factory Ausfall Electronic Controls Case Study (Dranetz)

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A glass factory imported from a 60 Hz country to a 50 Hz country suffered repeated electronic control failures, reducing production capacity by 50%. Voltmeters and simple monitors failed to capture the cause. Full PQ monitoring eventually revealed voltage transients and harmonic distortion incompatible with the 60 Hz-designed electronics — a frequency migration problem compounded by poor power quality.

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