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Calcimator

Harmonic Distortion Calculator

Calculate Total Harmonic Distortion (THD) and check compliance with IEEE 519 harmonic limits.

Inputs

A
A
A

IEEE 519-2022: VFD 6-pulse: 5th harmonic ~20–25%, 7th ~11–15%, 11th ~4–6% of fundamental current

A
A
A

Results

Total Harmonic Distortion (THD)

6.42%

IEEE 519 Compliant?

0 (1=yes, 0=no)

Max Individual Distortion5%
IEEE 519 THD Limit5%
How to Use This Calculator
  1. Enter the Fundamental (60 Hz) current in amperes from a power quality meter or analyzer.
  2. Enter the measured RMS current for each harmonic order: 3rd (180 Hz), 5th (300 Hz), 7th (420 Hz), 9th (540 Hz), and 11th (660 Hz).
  3. The 5th harmonic is typically the largest for six-pulse VFDs and rectifiers; the 3rd harmonic dominates in single-phase loads.
  4. Read the Total Harmonic Distortion (THD) percentage — IEEE 519 limits THD to 5% at the point of common coupling for most systems.
  5. Check Max Individual Distortion — IEEE 519 limits individual odd harmonics below the 11th to 4%.
  6. If the IEEE 519 Compliant? output is 0, consider passive harmonic filters, active front-end drives, or 12-pulse converter configurations.

How the result changes with Fundamental (60 Hz) Current

Fundamental (60 Hz) CurrentTotal Harmonic Distortion (THD)IEEE 519 Compliant?
1,0000.64%1 (1=yes, 0=no)
3,5000.18%1 (1=yes, 0=no)
6,5000.1%1 (1=yes, 0=no)
9,0000.07%1 (1=yes, 0=no)

What each input means

Fundamental (60 Hz) Current
RMS current at the fundamental frequency (60 Hz or 50 Hz).
3rd Harmonic Current
RMS current at the 3rd harmonic (180 Hz).
5th Harmonic Current
RMS current at the 5th harmonic (300 Hz). Per IEEE 519-2022, 5th and 7th harmonics dominate six-pulse VFDs (typically 5th = 18–25%, 7th = 11–15% of fundamental). Mitigation: 12-pulse drives, line reactors, active filters.
7th Harmonic Current
RMS current at the 7th harmonic (420 Hz).
9th Harmonic Current
RMS current at the 9th harmonic (540 Hz).
11th Harmonic Current
RMS current at the 11th harmonic (660 Hz).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Fundamental (60 Hz) Current = 100, 3rd Harmonic Current = 3, 5th Harmonic Current = 5, 7th Harmonic Current = 2 = 6 input(s) provided
  2. Calculate Total Harmonic Distortion
    Total Harmonic Distortion
    6.42 = 6.42
  3. Calculate IEEE 519 Compliant?
    IEEE 519 Compliant?
    0 = 0
  4. Calculate Max Individual Distortion
    Max Individual Distortion
    5 = 5
  5. Calculate IEEE 519 THD Limit
    IEEE 519 THD Limit
    5 = 5

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