Enhancing physical resolution of constructed ladder network for an interleaved winding

The number of detectable natural frequencies in a frequency response governs the number of sections of the ladder network that can be constructed, starting from the measured frequency response data. This number, particularly in case of interleaved windings, is woefully small rendering the entire exercise pointless. An attempt is described wherein this physical resolution can be enhanced. This is achieved by augmenting the measured driving-point admittance data (of the interleaved winding) with information regarding natural frequencies that are observable, and hence extractable, from an additional measurement of the open-circuited neutral-end voltage spectrum. By this process, a few more additional natural frequencies become available for processing, resulting in a ladder network with an increased physical resolution, i.e., more number of sections. Measurements done on an actual interleaved winding are presented to demonstrate feasibility of the proposed method.