Certified Energy Manager Practice Exam

What technology can be used to mitigate harmonics in electrical systems?

1. Capacitor banks

2. Transformer isolation

3. Active harmonic filters

4. Voltage regulators

The correct answer is: Active harmonic filters

Active harmonic filters are specifically designed to mitigate harmonics in electrical systems. Harmonics are voltage or current waveforms that are integer multiples of the fundamental frequency, which can lead to various issues such as overheating, reduced efficiency, and equipment malfunctions. Active harmonic filters work by dynamically adjusting their response to various frequencies and injecting counter-harmonics into the system, effectively canceling out the undesirable harmonic components. These filters can adapt to changing loads and conditions in real time, providing more effective harmonic mitigation compared to passive solutions. They can significantly improve power quality in electrical systems, making them a preferred choice for applications with fluctuating loads or varying harmonic distortion levels. In contrast, other options like capacitor banks can help with power factor correction but may not be effective in more complex harmonic situations and can even amplify certain harmonics. Transformer isolation is valuable for protecting equipment and reducing electrical noise but does not inherently mitigate harmonics. Voltage regulators are intended to maintain voltage stability and quality but do not specifically address harmonic distortion. Each of these options serves important roles in electrical systems, yet when specifically tasked with harmonic mitigation, active harmonic filters are the most effective solution.