The Short Summary A healthy AHF typically produces two types of noise: A low hum from the internal reactor (inductor) and cooling fans. This is normal. A high-frequency "switching" whine or buzz from the Insulated-Gate Bipolar Transistors (IGBTs). This is usually very faint. If the noise becomes loud, intrusive, or changes significantly, it is often a sign of a problem. Detailed Breakdow...
EMC (Electromagnetic Compatibility) testing for an Active Harmonic Filter AHF is critical and non-negotiable. An AHF(APF) is a power electronics device (like a high-frequency inverter) that injects canceling currents into a noisy electrical system. If poorly designed, it can become a significant source of electromagnetic interference (EMI) itself, disrupting other equipment. Conversely, it mu...
The Problem: Variable Speed Drives Generate Harmonics What is a Variable Speed Drive (VSD/VFD)?A Variable Speed Drive (VSD), also commonly called a Variable Frequency Drive (VFD) or Adjustable Speed Drive (ASD), is an electronic device that controls the speed and torque of an AC electric motor by varying the motor's input frequency and voltage. How Do They Cause Harmonics?The internal design of a ...
When we talk about modern power systems, two technical domains often overlap but are not always fully understood together: electromagnetic compatibility (EMC) and power quality. Both play crucial roles in ensuring that electrical and electronic equipment perform reliably and efficiently. For companies and industries adopting Static Var Generators (SVGs) and Active Harmonic Filters (AHFs)...
Modern industrial operations rely heavily on a steady, clean supply of electricity. The integrity of this power supply is constantly challenged by the proliferation of non-linear loads like variable frequency drives (VFDs), LED lighting systems, and server power supplies, all of which introduce complex harmonic distortions into the grid. These distortions can lead to devastating consequences, incl...