超谐波

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 千赫.

EV Charging and Power Quality in LV Residential Networks — From Individual Charger to Fleet Penetration

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Level 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 (2–150 kHz) that can disrupt the PLC communications intended to manage EV charging itself.

太阳能发电 (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.

传导噪声 (HIOKI)

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Conductive noise — high-frequency electrical disturbances spreading through power, signal, and ground cables from lightning surges, 静电放电, 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.

高次谐波 (HIOKI)

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Power supplies with semiconductor control devices generate high-frequency noise above several kHz — high-order harmonics that cause equipment malfunction and radio/TV interference. HIOKI measurement at 1-phase 100V shows the frequency spectrum, resonance amplification effects, and the threshold at which the noise becomes dangerous to connected equipment.

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