Most probable failure point update method for accurate first-order reliability-based electromagnetic designs

A most probable failure point update method is proposed to obtain an accurate reliability-based design of electromagnetic devices or systems in the presence of uncertainties. The first-order reliability method has been recently adopted to solve electromagnetic design problems. However, its result could be very erroneous especially for nonlinear or multi-dimensional performance functions. To overcome the drawback, a three-step computational procedure is additionally executed to ensure prescribed design feasibility at an optimum obtained from the conventional first-order reliability method: failure rate calculation, reliability index update, and most probable point update. A mathematical example and a blushless DC motor design problem are provided to demonstrate numerical accuracy of the proposed method by comparison with the conventional method.