Analysis of Mutual Inductance Between Parallel Branches for ANPC Laminated Busbar

Multiple power modules are interfaced in parallel via laminated busbar in high-capacity active neutral-point clamped (ANPC) converters. Consequently, the complex mutual coupling among parallel branches profoundly affects their equivalent stray inductance. This study analyzes mutual coupling between parallel branches on the same plane of the busbar and how it affects the equivalent stray inductance, which has not been thoroughly reported. A mutual inductance experimental extraction method is proposed and a mathematical model of stray inductance is established. Then, using the proposed method, stray inductance and mutual inductance of two parallel branches for an ANPC busbar are calculated. Experimental tests verify the accuracy of the proposed method.