Harmonic Mitigation Techniques

When considering mitigating harmonic problems, first decide whether to mitigate the harmonic or the problem it is causing.

Harmonics tend to present themselves with over current symptom conditions. For example - hot transformers, tripped breakers, blown fuses - relays and capacitors. In some cases it may be acceptable to oversize these components to handle the harmonic currents. This should only be done if the rest of the system, conductors in particular, are in no danger of failing due to over current conditions.

Doing this does not eliminate the harmonic, but rather eliminates the symptom (and therefore the problem.) It is important to realize that the problem may crop up again at some other point, if the harmonic source is not dealt with.

To mitigate the harmonic itself, you will first need to have a spectral analysis to know what harmonic you are looking for. Then you can have a filter built to trap the harmonic(s) at the source or at the victim.

In some cases, the distribution system will amplify the harmonic condition. Computer simulation programs such as Harmflow can be used to predict this problem and develop potential solutions.