Harmonics Mitigating transformers are special kind of transformers which are used to mitigate harmonics in the connected loads. They are often confused with K Transformers. K Transformers(Refer Article) is a type of transformer which is over sized to cater to loads which generate harmonics. A Harmonics Mitigating Transformer, however, works by passively suppressing the harmonics.
Harmonics Mitigating Transformers are designed like ordinary transformers except that they have specific phase shifts (+15 deg, -15 deg, 30 degs). The primary winding is usually delta while the secondary winding is a zig zag winding. The zig zag winding of the secondary cancels a particular order of harmonics depending on the phase shift.A Harmonics Analysis is conducted to identify the order of the harmonics generated before choosing the type of Harmonics Mitigating Transformer
The harmonics are prevented from reaching the primary and affecting transformer output. Harmonics Mitigating Transformers fall under the passive methods of harmonic suppression.