Harmonics are extra currents and voltages at integer multiples of the supply frequency that non-linear loads draw on top of the fundamental sine wave. Their effect is costly: transformers, motors and neutral conductors overheat, relays mis-trip, and equipment life shortens even below rated load. This guide covers measurement at the point of common coupling (PCC) and how to compare the main mitigat...
An Active Harmonic Filter (AHF) is a parallel-connected, closed-loop power-electronic device that measures load harmonic current with current transformers and injects an opposing current to cancel distortion at the point of common coupling (PCC). The engineering conclusion is blunt: an AHF is selected against the measured harmonic spectrum, load variability, site ambient temperature, and network i...