Analytical modelling of stator turn fault in surface mounted permanent magnet machines
The paper presents an analytical approach to extract machine parameters for creating a machine model under stator turn fault condition for a surface permanentmagnet (SPM) motor. The development of an accurate model of turn faulted SPM motor is essential to study motor and drive behavior under fault conditions, and to develop effective turn fault detection algorithms. The main contribution of the paper is to propose a completely analytical approach to modeling turn fault in SPM machine, which has not been reported so far in literature. Further to validate the analytical method, finite element (FE) analysis of an SPM motor with stator turn fault is performed and the results are compared with the analytical prediction. It is shown that the proposed model achieves good match with the FE results.
An efficient method for optimal feeder configuration for distribution system expansion planning is presented. The problem is formulated as a combinatorial constrained optimization problem with a nonlinear, non-differentiable objective function. A solution methodology based on simulated annealing is proposed to determine an optimum configuration of existing and new feeder sections that would minimize the sum of the outage cost, the cost of feeder resistive loss, and the corresponding investment and maintenance costs of new lines and switches. Results obtained from a test distribution system show the validity and effectiveness of the proposed methodology.