What are harmonics in a 3-phase electrical system?

Harmonics in a 3-phase electrical system refer to unwanted frequencies that can introduce distortion into the power system, negatively affecting the operation of equipment and devices connected to the system. These harmonics are typically multiples of the fundamental frequency (for instance, if the fundamental frequency is 60 Hz, then the harmonics could be 120 Hz, 180 Hz, etc.).

When non-linear loads, such as certain types of electronic devices and machinery, draw power, they can create these harmonic frequencies. This leads to a situation where the original sine wave form of the electrical current is distorted. The presence of harmonics can create several issues, including overheating of equipment, increased losses in transformers and cables, and overall reduction in the efficiency of the electrical system.

Understanding harmonics is crucial for maintaining system stability, ensuring proper function of devices, and prolonging the lifespan of electrical equipment.