Parallel Magnetic Core Shaping
Parallel Multiwinding Autotransformer is a key element of a Magnetically Coupled Multilevel Converter. For a > 20 MHz bandwidth, coupling between multiple turns should be as high as possible. High coupling minimizes the common mode, forward inductance (seen by the load), and maximizes the differential inductance seen by the switching stages. Commonly known techniques for maximizing coupling of multiwinding structures do not apply to parallel structures. The patent describes optimal shaping of the core.