How to scientifically configure Static Var Generators (SVGs) and Active Power Filters (APFs) in wind farm applications. Wind farms, particularly those using Doubly-Fed Induction Generators (DFIGs), are not only power producers but also major sources of power quality issues. The need and logic for configuring mitigation equipment here are significantly different from traditional commercial and indu...
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 ...
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...
1. Why Do SVGs Generate Harmonics? Unlike ideal components, the real-world power electronic switches (IGBTs) in an SVG do not switch sinusoidally. They use Pulse Width Modulation (PWM) to synthesize a sinusoidal output current. This switching action is the primary source of harmonics. PWM Switching Frequency Harmonics: The output voltage of the SVG's H-Bridge inverters is a series of high-fre...
SVG Parallel Operation Test via CAN Communication Test Objective This test aimed to verify the performance and stability of multiple SVG (Static Var Generator) units operating in parallel via CAN communication when internal CTs are not used. Specifically, eight SVG modules were tested to evaluate their operation, communication reliability, and reactive power compensation consistency under CAN-base...