1. What is Total Harmonic Distortion?

Total Harmonic Distortion (THD) is a measurement of the harmonic distortion present in a signal. It is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency.

2. How Does the Calculator Work?

The calculator uses the THD formula:

Where:

• \( V_1 \) — Fundamental voltage component
• \( V_2 \) — 2nd harmonic voltage component
• \( V_3 \) — 3rd harmonic voltage component

Explanation: The equation calculates the square root of the sum of the squares of harmonic voltages divided by the square of the fundamental voltage, expressed as a percentage.

3. Importance of THD Calculation

Details: THD is crucial in power systems to assess power quality, in audio systems to measure signal purity, and in various electronic systems to evaluate performance and potential interference issues.

4. Using the Calculator

Tips: Enter voltage values in volts (V). Fundamental voltage (V1) must be greater than zero. The calculator supports both RMS and peak voltage measurements as long as all values use the same measurement type.

5. Frequently Asked Questions (FAQ)

Q1: What is considered a good THD value?
A: For power systems, THD below 5% is generally acceptable. For audio systems, values below 1% are considered high quality.

Q2: Does this calculator include all harmonics?
A: This version calculates THD based on the 2nd and 3rd harmonics only. For complete THD, all significant harmonics should be included.

Q3: What causes harmonic distortion?
A: Nonlinear loads like power electronics, transformers operating near saturation, and certain types of lighting can cause harmonic distortion.

Q4: Can THD be negative?
A: No, THD is always a positive value or zero (in a perfect system with no harmonics).

Q5: How does THD affect electrical systems?
A: High THD can cause overheating in equipment, interference with communication systems, and malfunction of sensitive electronics.