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The magnetic effects and consequently the radial force are the main causes of noise in switched reluctance motors (SRMs). In this study a new design for SRM is developed in order to reduce acoustic noise. In this research a new design for SRM is developed in order to reduce the acoustic noise. In this investigation, at first, different SRM structures are simulated using JMAG software. An 8/6‐pole SRM is designed and built with special modification in the rotor and stator structures. For increasing mechanical strength, trapezoidal stator and rotor pole shape with poles arc βr = βs = 21° are proposed. In this design the taper angles of stator and rotor poles are equal. For noise reduction, the mechanical restructuring is done according to stress analysis. The new designed SRM are simulated and tested experimentally under no‐load and full‐load conditions. The results are shown and compared. Comparison between these results and the results of other structures shows that the acoustic noise of the newly designed motor is reduced considerably. The results show an acoustic noise reduction of ∼72% in new structure SRM. [ABSTRACT FROM AUTHOR]

Here, based on wide‐area measurement systems (WAMS), an adaptive tripping index (TI) is proposed for online prediction of tripping signals with respect to wide‐area out‐of‐step (WAOOS) protection of synchronous generators. The proposed TI included two different equations consisting of a straight line for unstable inter‐area oscillations and a sinusoidal line for WAOOS transient instability. For online identification of coherent generators with respect to inter‐area oscillations, based on evaluating the correlation coefficients between generator behaviours, an index is proposed from which the global tripping signals (GTS) are calculated. The GTS consist of the rate of change of inter‐area rotor angle oscillation between two oscillating areas in the centre of inertia frame. Actually, the proposed scheme is an adaptive and online index from which the critical inter‐area angle is adjusted individually by evaluating GTS at each sampling time gathered from the WAMS data. The proposed strategy is implemented on an IEEE 39‐bus test system and its performance is investigated by simulating typical scenarios during time‐domain simulations. The results show the effectiveness of the proposed scheme for fast prediction of WAOOS protection in real‐time environment. [ABSTRACT FROM AUTHOR]

In engineering terms, it is always desirable to maximise the efficiency of the motor and to look the problem in economic viewpoint, minimisation of the weight and cost of the motor is required. As these two aspects are like two sides of a coin, it is usually aimed to acquire the best efficiency per weight and cost. As a result, the performance improvement of permanent‐magnet synchronous motor (PMSM) has two sides: technical and economic. This study proposes a new approach for design optimisation of an interior PMSM (IPMSM) taking into account both technical performances and economic considerations. The selected rotor configuration is a good candidate for general purpose industrial applications. A multi‐objective optimisation technique based on a new and efficient magnetic equivalent circuit of the motor is applied to obtain optimal motor parameters. A Pareto front composed of possible optimal solutions is provided. The best optimal solution is then selected using a k‐means clustering algorithm. To verify the efficacy of the design optimisation, the performance characteristics of the optimal PMSM are compared by both the finite element simulations and the experiments. In the test setup, an 8‐pole, 200‐Watt, four‐phase IPMSM with an optimised structure is prototyped where the results give agreeable accuracy. [ABSTRACT FROM AUTHOR]