间谐波

Interharmonics — frequency components that are not integer multiples of the fundamental (例如，. 75 赫兹, 130 赫兹上 50 赫兹系统) — are produced by PV inverters, 风力涡轮机, 电动车充电器, cycloconverters, and HVDC links. Their most dangerous effect: 间谐波在 58 Hz creates an 8 Hz beat frequency — squarely in the range of peak human visual sensitivity. 现场案例: simultaneous PV + 电动车充电器 + microwave on one LV circuit produces stochastic interharmonics causing light flicker. Standard IEC 61000-4-7 analysers cannot correctly characterise them.