A magnetically controlled multi-winding sub-compensated active harmonic isolator

The addition of various distributed new energy sources and nonlinear loads has caused various harmonic problems, but the mainstream passive filter has poor dynamic performance, can not solve the reactive power problem, and has the risk of resonant amplification. The mainstream active power filter also has some problems, such as the inability of parallel structure to filter background harmonics, poor filtering effect on high and ultra-high harmonics, high fundamental voltage and high cost. Aiming at the above problems, this paper proposes a multi-functional active filter with low cost, high reliability and fast dynamic response. By adopting the transformer design scheme of secondary side winding, different windings can be compensated for different harmonics, which has the advantages of high control reliability and small harmonic injection. The effect of harmonic elimination is verified by the simulation of efficiency enhancement and capacity reduction of the active harmonic isolator.