Harmonics and Flicker Monitoring/Test Set - Conducted Emissions

General Information 

Harmonics and flicker both center around the concept of noise or disturbances on sinusoidal voltages, often in low voltage power systems. The large amount of electrical devices with non-linear loads (often using variable frequency drives) in these types of systems causes the flicker occurrence. This is most often thought of in the example of a washer machine running and a light bulb flickering. There are a variety of conducted emissions requirements on what constitutes acceptable variations. The majority of test systems include a monitoring system, power supply, and line conditioning unit. These components help ensure that clean power is supplied to the equipment under test (EUT) and accurate readings from monitoring software are achieved.

Harmonics and Variation in Waveforms

Associated Standards (common) 

Harmonics standard:

  • IEC 61000-3-2 < 16 A per phase
  • IEC 61000-3-12 > 16 to 75 A per phase

Flicker standard:

  • IEC 61000-3-3 < 16 A per phase
  • IEC 61000-3-11 < 75 A per phase

Voltage Dip, interruption & variation:

  • IEC 61000-4-11 < 16 A per phase
  • IEC 61000-4-34 > 16 A per phase

Other immunity tests:

  • IEC 61000-4-8 Power line magnetic field
  • IEC 61000-4-13 Immunity to harmonics & inter-harmonics
  • IEC 61000-4-14 Repetitive voltage variations
  • IEC 61000-4-17 Ripple on DC input power ports
  • IEC 61000-4-27 Voltage & Phase unbalance immunity
  • IEC 61000-4-28 Frequency variations
  • IEC 61000-4-29 DC dips, variation and short interruption

Commonly Used Equipment

  1. AC/DC Source & Analyzer
  2. Arbitrary waveform generator
  3. Computer system for monitoring 
  4. Associated software capable of analyzing data
Flicker Emission Monitoring Diagram