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This paper proposes a new method to estimate the electrical parameters of five-phase induction motors based on the response to a step voltage applied to the stator with the rotor at standstill. The first part of the method consists of the identification of the parameters of the dynamic model expressed in terms of transfer functions including the fundamental and third-harmonic components of the airgap induction. The second part consists of an open-phase test proposed to estimate the stator leakage inductances of each circuit separately. Further, the impact of iron saturation on the parameters is discussed through Finite Element Analysis of a case study. The accuracy of the proposed method is experimentally assessed through the analysis of the behavior of a 4.5-kW motor running in a closed loop under Rotor Field-Oriented Control. The theoretical and practical results suggest that the method can also be applied to self-commissioned drives, given that the estimation proceeds under null torque and speed. The prominent advantages of the proposed method are (i) the possibility of tracking the saturation effects on the parameters, (ii) the tests are easy to execute, and (iii) few sensors are required. [ABSTRACT FROM AUTHOR]

The paper proposes a multiobjective optimization procedure for five-phase induction machines based on the NSGA-II (nondominated sorting genetic algorithm). In the optimization procedure, two objective functions are used (efficiency and cost of conductor material) along with 14 design variables, producing a large number of viable solutions. The design variables describe geometrical constraints, electrical and magnetic loading, and the waveshape of the airgap induction. The underlying analytical model of the machine includes the saturation of the iron parts and magnetic losses produced by higher space harmonic waves present in the airgap induction. The most relevant solutions regarding the objectives are validated through the finite element method, showing that the method proposed here is able to find practical solutions which represent a high efficiency, a reduced volume, or even a compromise between these objectives. [ABSTRACT FROM AUTHOR]