Shape optimization of BDC wheel motor using Powell's method

Powell's conjugated directions method is used to optimize the teeth and mag net shapes of a brushless direct current (BDC) wheel motor. The aim of opti mization is to have the most constant electromotive force (e.m.f.) at no-lo ad during the phase conduction with a value equal to half of the lower volt age supply. The e.m.f is computed using a finite element model (FEM). The F EM and Powell's method are integrated in an optimization loop in order to f ind the best shape for the BDC motor. A comparison between Powell's conjuga ted loop in order to find the best shape for the BDC motor. A comparison be tween Powell's conjugated directions method and the conjugated gradient met hod is carried out. It shows the superiority of the conjugated direction me thod that does not need the gradient of the objective function.