Certified Energy Manager Practice Exam

What is the definition of harmonics in electrical power?

1. Variability in current due to load fluctuations

2. Distortion in the waveform adding higher frequency components

3. Reduction in voltage levels affecting equipment performance

4. Changes in phase due to reactive loads

The correct answer is: Distortion in the waveform adding higher frequency components

The definition of harmonics in electrical power pertains specifically to the distortion of the waveform that occurs when higher frequency components are added to the fundamental frequency of the system. In most electrical systems, the fundamental frequency is typically 50 or 60 Hz, depending on the region. However, when non-linear loads are present, such as certain types of electronics and fluorescent lighting, these loads can cause the current and voltage waveforms to deviate from the ideal sinusoidal shape. This deviation results in the generation of harmonics, which are integer multiples of the fundamental frequency. For example, if the fundamental frequency is 60 Hz, the harmonics would include frequencies such as 120 Hz (2nd harmonic), 180 Hz (3rd harmonic), and so on. These harmonics can lead to various issues, including overheating of equipment, inefficiencies, and even potential damage to electrical systems. Understanding harmonics is crucial for individuals involved in energy management and electrical engineering, as managing harmonic distortion is key to maintaining system reliability and efficiency.