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Total Harmonic Distortion Factor Formula:
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Total Harmonic Distortion Factor is defined as the measure used to quantify the extent of harmonic distortion present in a signal. It represents the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency.
The calculator uses the THD formula:
Where:
Explanation: The formula calculates the total harmonic distortion by summing the squares of all harmonic voltages from the 2nd harmonic up to the highest order harmonic, taking the square root of this sum, and then dividing by the input voltage.
Details: Accurate THD calculation is crucial for assessing power quality, identifying harmonic pollution in electrical systems, and ensuring compliance with power quality standards. High THD values can indicate problems with electrical equipment and power distribution systems.
Tips: Enter input voltage in volts, highest order harmonic (must be ≥2), and RMS voltage in volts. All values must be valid positive numbers.
Q1: What is considered an acceptable THD value?
A: Generally, THD values below 5% are considered acceptable for most power systems, though specific applications may have stricter requirements.
Q2: Why do we start summing from the 2nd harmonic?
A: The fundamental frequency is considered the 1st harmonic, so harmonic distortion calculation begins from the 2nd harmonic onward.
Q3: What causes harmonic distortion in power systems?
A: Harmonic distortion is typically caused by non-linear loads such as variable frequency drives, switching power supplies, and other electronic equipment.
Q4: How does THD affect electrical equipment?
A: High THD can cause overheating in transformers and motors, malfunction of sensitive electronic equipment, and increased power losses.
Q5: Can THD be negative?
A: No, THD is always a positive value since it represents a ratio of power components and is calculated using squared voltage values.