3/20/22, 1:20 PM
NEPSI - Total Harmonic Voltage Distortion Calculator
CALCULATION OF TOTAL HARMONIC VOLTAGE DISTORTION
The following calculator computes the total harmonic voltage distortion, Peak Voltage, RMS Voltage, and Crest Factor based on individual harmonic
voltage distortion values between the 1st and the 50th harmonic. Input the fundamental voltage and individual harmonic voltages to compute results
also to view a waveform plot based on the input values. The waveform plot assumes all phase angles for individual voltage distortion values to be
zero degrees (in phase with the fundamental voltage).
When inputting the data, be sure to use consistent units of Volts, KV, or Per Unit Volts. Additionally, be consistent with either line-to-line values or
line-to-neutral values.
Formulas and Variables
Of Interest...
Total Harmonic Voltage Distortion or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum
of the power of all harmonic components to the power of the fundamental frequency. THD is used to characterize the power quality of electric power
systems. Distortion factor is a closely related term and sometimes used as a substitute term.
IEEE 519, "Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems" provides suggested limits for harmonic
voltage distortion as shown in Table 10.4 below. A 5% voltage distortion is barely noticeable on a voltage waveform plot but can result in power
quality issues. This is especially true in an environment where resonance may exist at the frequency of the individual harmonic voltage that
contributes to the total harmonic voltage distortion.
Harmonic Filters sold by NEPSI can be used to mitigate and reduce voltage distortion on utility and industrial power systems.
Crests Factor is a measure of a waveform showing the ratio of the peak value to the RMS value. A crest factor of 1.0 indicates no peaks, such as
the case with DC Voltage. A voltage waveform with 0% THD will have a crest factor equal to 1.414. Crest Factors greater than 1.414 usually
indicates the presence of harmonic distortion.
Calculator
Known variables: Fundamental Frequency Voltage, Harmonic Voltages
V1
V2
V3
V4
V5
V6
100.00
0.52
1.32
0.27
1.58
0.60
V11
V12
V13
V14
V15
V16
1.47
0.23
1.05
0.12
0.14
0.11
V21
V22
V23
V24
V25
V26
https://www.nepsi.com/resources/calculators/total-harmonic-voltage-distortion.htm
0.15
0.08
0.79
0.07
0.52
0.08
V31
V32
V33
V34
V35
V36
0.32
0.06
0.11
0.06
0.38
0.06
V41
V42
V43
V44
V45
V46
0.24
0.07
0.20
0.06
0.09
0.05
1/2
3/20/22, 1:20 PM
V7
V8
V9
V10
NEPSI - Total Harmonic Voltage Distortion Calculator
V17
1.64
0.28
0.23
0.23
V18
V19
V20
0.60
0.18
0.69
0.09
V27
V28
V29
V30
Total Harmonic Voltage Distortion (THD):
Perunit Total Harmnic Voltage Distortion (THD):
Peak or Crest Voltage:
RMS Voltage:
Creast Factor:
0.13
0.08
0.44
0.06
3.7%
0.037
164.38
100.07
1.643
V37
V38
V39
V40
0.33
0.06
0.11
0.07
V47
V48
V49
V50
0.16
0.05
0.10
0.05
Fundamental Frequency Waveform
Distorted Waveform
Unable to load Flash content. The Charts Control requires Flash Player 9.0.45 or higher. You can download the latest version of Flash Player from
the Adobe Flash Player Download Center
0
0.03
0.06
0.09
0.12
0 15
164.3788277165
141.4
160.5451427103 141.3363747721
152.5831939714 141.1455563468
146.6898988852 140.8277164478
144.7422574105 140.3831411097
143 7602168656 139 8122304201
https://www.nepsi.com/resources/calculators/total-harmonic-voltage-distortion.htm
10000
0.2704
1.7424
0.0729
2.4964
0 36
2/2