8 Harmonic Mitigation Strategies (Techniques) in Power Systems

Harmonics, which are undesired consequences of nonlinear loads, impact power system stability and efficiency.

Implementing strong mitigation methods is essential for ensuring a resilient & high-performing electrical system.

Here’s a summary of the most effective approaches to reduce harmonics:

1). Passive Harmonic Filters

2). Active Harmonic Filters

3). Harmonic-Resistant Equipment

4). Isolation Transformers

5). Active Front-End Drives

6). Distributed Generation

7). Power Factor Correction

8). Harmonic Surveys and Monitoring

1). Passive Harmonic Filters

Function: Passive harmonic filters, including tuned and LC filters, reduce the effects of targeted harmonics by providing a passive, frequency-specific route.

Advantages: Cost-effective and straightforward implementation of specified harmonic frequencies.

2). Active Harmonic Filters

Function: Active harmonic filters use equal but opposite currents to cancel out undesired harmonics and provide real-time mitigation.

Advantages: Adaptable to changing harmonic situations and effective across a wide frequency range.

3). Harmonic-Resistant Equipment

Function: Using harmonic-resistant equipment, such as transformers and motors, can lower the power system’s sensitivity to harmonic disturbances.

Advantages: Provides intrinsic safety for essential equipment and improves system reliability.

4). Isolation Transformers

Function: Isolation transformers create a physical barrier in between the source & load, reducing harmonic distortions.

Advantages: Efficient for protecting sensitive equipment & isolating harmonic disturbances.

5). Active Front-End Drives

Function: Active front-end drives regulate input current waveforms to reduce harmonic distortion caused by variable frequency drives (VFDs).

Advantages: Reduces harmonics created by VFDs and improves power quality.

6). Distributed Generation

Function: Distributed generating using power electronics can lower the level of harmonics in the power system.

Advantages: Uses renewable energy sources, resulting in a cleaner and more dependable power supply.

7). Power Factor Correction

Function: Capacitors minimize harmonic distortion by decreasing reactive power.

Advantages: Improve power factor and indirectly reduces harmonics.

8). Harmonic Surveys and Monitoring

Function: Conducting harmonic surveys and ongoing monitoring identifies certain harmonic frequencies and their sources.

Advantages: Informs specific mitigation strategies and promotes proactive maintenance.

Additionally, a combination of all of these mitigation methods adapted to the individual features of the power system provides the most effective solution.