Indirect boundary integral equation method as applied for wave propagation in the stator winding of an electric machine

The author presents the indirect boundary integral equation method (IBIEM) for capacitance computation. It is shown that parallel plate approximation leads to significant errors, especially for the capacitance to ground. The method has been used to compute the capacitance of the slot and the end region of an electric machine winding. The capacitances calculated by the IBIEM have also been used in a multiconductor transmission line and scatter matrix theory to calculate the transient voltage distribution in an electric machine winding subjected to steep-fronted surge. The results of voltage distribution have been compared with experimental results. The proposed IBIEM can be applied in other engineering applications where static capacitance is acceptable. The indirect boundary integral equation method can also be used in conjunction with other numerical techniques, such as finite element or finite difference methods in hybrid formulation. It can also be used for permeance computation when analysing the magnetic circuit