Maximation of starting torque of a 10/8 SRM with short flux path based on numerical analysis and calculation

This paper presents a novel approach for starting torque maximization of a five-phase 10/8 SRM with short flux path. Unlike the conventional method, this approach emphasizes maximizing the average torque of any one phase during one electrical cycle at a given speed regardless of possible instantaneous negative torque during part of the conduction interval. For the purpose of numerical calculation of the optimal turn-on and turn-off angles, a simplified self-inductance nonlinear model is adopted and verified against FEA data. Then, the theoretical analyses of the numerical model for current and torque calculation under two typical operating modes are provided. Dynamic simulations based on MATLAB^TM Simulink together with a complete set of flux linkages with respect. to rotor position and phase current were carried out to validate this numerical model for off-line auto searching for the optimal turn-on and turn-off angles so as to maximize starting torque. Similar procedure of numerical calculation can be followed to implement energy-efficiency optimization or torque-ripple minimization