Morden induction machines/equipments working on higher flux density, due to advent in grain oriented high carbon silicon steel as core material (gives better efficiency with considerable reduction in size) produces flat top working flux/voltage wave form producing third harmonics and it's multiples, could be avoided by reducing the working flux density by design.

hi dear Bhupendra Desai,

Really thank you very good answer

But can you explain a bit more about the core and the type of operation?