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Torque of motor before and after optimisation (a) Cogging torque under no‐load condition, (b) Peak torque under peak condition
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The electrical machine design method plays a decisive role in electric vehicles (EVs). However, only a few designs consider the coupling of multiple fields simultaneously. This study proposes an improved multi‐physics and multi‐objective optimisation design approach for designing a 75 kW interior permanent‐magnet synchronous machine dedicated to EV...
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In this article, rotor designs utilizing assisted-poles are investigated for a high-torque density spoke-type permanent magnet synchronous machine (PMSM) with fractional slot concentrated winding (FSCW) to explore the rich air-gap magnetic field harmonics and torque generation mechanism. Due to their higher average torque output, spoke-type PMSMs w...
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... The larger the value of CoP, the greater the influence of structural parameters X i on optimization objective y i , and the higher the sensitivity. The optimization design of IPMSM can be simplified to the multi-stage and multi-physical field optimization through sensitivity analysis [19]. The sensitivity of each parameter to each optimization target and the overall sensitivity results are shown in Table 5 after the sensitivity calculation of structural parameters. ...
The key to the suppression of vibration and noise for PMSM is the optimization of electromagnetic excitation force. The method of motor body optimization can effectively reduce the radial excitation force of the motor, so as to suppress the vibration and noise of the motor. Firstly, the stator structure of the motor is optimized with V-shape skew slot based on the analytical modeling of the radial electromagnetic excitation force of the motor. Then, the structural parameters of the motor that affect the electromagnetic excitation force of the motor are determined, and the average torque, torque ripple and radial electromagnetic excitation force generated by tangential electromagnetic excitation force are taken as the optimization objectives. The sensitivity analysis and classification of the structural parameters of the motor are carried out. The multi-objective genetic algorithm and response surface method are combined to optimize the structural parameters of the motor. Finally, the finite element analysis, modal analysis, multi-speed vibration and noise analysis of the optimized motor are done. The performance comparisons before and after optimization have proved that the peak of equivalent sound power level have decreased by 8.65% after the optimization of V-shaped skewed slot structure. After the optimization of structural parameters, the power level of permanent magnet synchronous motor has been reduced by 9.22%. For the vibration noise caused by resonance and the main frequency of vibration noise harmonics, the suppression effects are also better than those of V-shape skewed slots optimization, and the ERPL values are reduced by 9.22% and 10.12%, respectively, in two cases. The results show that the vibration and noise of permanent magnet synchronous motor are effectively suppressed.
... ( Formula (9) is the calculation of stator flux linkage [21,22]. In Formula (9), L x and L y are the inductance components on the x and y axes, respectively. ...
The synchronous control system of multi-permanent magnet motor has the characteristics of many parameter variables and mutual coupling. The use of sliding mode control to optimize the parameters in the multi-permanent magnet motor system not only ensures the stability of the system operation, but also improves the control accuracy of the system, which is of great importance in practical applications. Based on this background, the study combines the new adaptive integral sliding mode control (NAISMC) with the improved sliding-mode disturbance observer (SMDO) and uses it for the multi-permanent magnet synchronous motor (MPMSM). In NAISMC, the controller updates and adjusts the parameters of the controller using an adaptive algorithm according to the state of the system and the error signals, which further improves the stability and robustness of the system. SMDO utilizes the principle of the sliding-mode observer to estimate the disturbance of the system, and eliminates the effect of the disturbance on the system by introducing a compensation term. The sliding mode observer calculates the disturbance estimate by comparing the difference between the actual and the estimated outputs. The disturbance estimate is finally used to generate the corresponding compensation signal to eliminate or minimize the effect of the disturbance on the system. NAISMC is combined with SMDO and used in the deviation coupling control of MPMSM. The study established a simulation experiment environment in MATLAB, set the simulation time to 0.4s, and the rated speed of the motor to 1000r/min. The improved sliding mode control scheme is tested, and the results show that the motor output speed, tracking error and electromagnetic torque variation under the improved sliding mode control scheme are smaller than those under the traditional sliding mode control scheme. Under the same simulation conditions, the multi-motor speed synchronization error under the improved sliding mode control scheme is around 0r/min, and its error value is close to 0, so the control effect is higher. In conclusion, the optimization scheme proposed in this study can effectively improve the stability and control accuracy of the multi-motor system.
... In this simulation, a properly defines sampling by LHV of input/sensitive parameter values are chosen, and their corresponding response is evaluated, again going for the optimal solution per the objective or cost function selected in (7). Variation of the input set of values gives the responses, and a multi-level set of simulations is required with time cost functions to calculate the optimal value by using the OptiSLan automated software (Fig.6). ...
... Since electromagnetic, mechanical stress and rotor dynamics should be comprehensively considered in the HSPMM design process [19,20], this will greatly increase the difficulty in the design process. The traditional design process is generally based on the serial design of multi-physics, and the design process often needs to adjust the parameters according to the designer's experience, which is time-consuming and it is difficult to find an optimal solution. ...
Abstract High‐speed permanent magnetic machine (HSPMM) is attracting more attention due to its high power density, compact size, small rotating inertia, and rapid response capability. However, the design of the HSPMM rotor is a non‐linear, multi‐physics coupled process that makes it difficult to build an accurate mathematical model for optimisation. This study proposes a multi‐objective optimisation method based on the multi‐physics surrogate model (MPSM). This method uses an MPSM to replace the finite element model (FEM) for optimisation, which can effectively solve the problem of non‐convergence and time consumption of the traditional FEM in the optimisation process. Finally, a 1.1 MW, 18,000 r/min HSPMM is produced and related experiments are carried out; the feasibility of the method proposed in this study for HSPMM optimisation is verified.
Because of the complex and frequent multi-operation conditions of pumped storage machine and the difficulty of its numerical analysis, an optimized network parameter method (ONPM) is given to identify the second harmonic electromagnetic torque of large salient-pole generators. Different from the former research which only considers the positive and negative sequence components, the second harmonic electromagnetic torque of pumped storage machine under power generation state is identified in neutral point grounded system, which are displayed by the lumped parameters. Then, in order to test the validity of the theoretical analysis among power generation salient-pole generators, the finite element model of 300 MVA pumped storage machine under power generation is established. Through the comparison and analysis of the finite element result data with the actual experimental data in the steady state of no-load test and short-circuit test, the correctness of the finite element model is completely verified. Finally, in the case of small current asymmetry and large current asymmetry, the second harmonic electromagnetic torques obtained by ONPM and finite element method (FEM) are found respectively, and their relative errors are elaborately displayed. The results display that ONPM can accurately identify the electromagnetic torque parameters which indicate the specific operation and fault state of pumped storage machine under power generation state. This fault parameter identification has practical significance for monitoring and improving the operation state and stability of large salient-pole generator.
The permanent magnet is subject to high-temperature demagnetization under high-torque or high-speed operating conditions. Accurate estimation of the temperature of the permanent magnets allows for better improvement of the cooling system, such as flow distribution and structural optimization. It is also the object of research in tracking and monitoring technology, because timely sensing of the temperature of the permanent magnet is the key to generate thermal protection mechanisms for the cooling system and active thermal protection system. In recent years, techniques for estimating and monitoring the temperature of permanent magnet have evolved, and a large body of valuable literature has been generated in the process. Therefore, this paper discusses this literature by systematically categorizing it into estimation and monitoring techniques in order to promote more researchers to understand the advantages of various methods and rationally choose the research topics they are most interested in. In addition, trends and challenges in various research directions were discussed.
div>Electric motors constitute a critical component of an electric vehicle powertrain. An improved motor design can help improve the overall performance of the drivetrain of an electric vehicle making it more compact and power dense. In this article, the electromagnetic torque output of a double V-shaped traction IPMSM is maximized by geometry optimization, while considering overall material cost minimization as the second objective. A robust and flexible parametric model of the IPMSM is developed in ANSYS Maxwell 2D. Various parameters are defined in the rotor and stator geometries to perform an effective multi-objective parametric design optimization. Advanced sensitivity analysis, surrogate modeling, and optimization capabilities of ANSYS optiSlang software are leveraged in the optimization. Furthermore, a demagnetization analysis is performed to evaluate the robustness of the optimized design. At high-speed operation, a rotor core is usually subject to higher deformation due to the high centrifugal force. Thus, rotor stresses are reduced in the optimized design by shaping the flux barriers around the permanent magnets. This enables high structural integrity of the optimized design for high-speed operation along with the improved electromagnetic performance. The multi-physics design approach proposed in this article provides the capability to design and optimize an IPMSM geometry for performance and cost, which are essential objectives to achieve in an electrified powertrain development. Moreover, consideration of rotor stress at high operating speeds extends the applicability of the proposed design approach to high-power, high-speed electric propulsion applications.</div
This paper aims to study the calculation method of the bi-direction coupling of electromagnetic (EM) -thermal field, focusing on the data transfer method between different types of mesh elements in different physical fields. First, a complete EM-thermal field bi-directional coupling analysis model is established, based on which the changing rule between the EM losses of different components of the motor and their temperature rise curves is studied. Although the complete bi-direction EM-thermal field coupling analysis method is closest to the actual operation of the motor, this method is computationally intensive and takes a long time to calculate. For this reason, this paper also proposes an improved EM-thermal field bi-directional coupling calculation method based on the changing rule between the EM losses of different components of the motor and their temperature rise curves, significantly reducing the calculation time. The innovation of this paper is to realize the data transfer between different types of mesh elements in different physical fields, find the changing rule between EM loss and temperature rise curve, and establish a fast calculation method of bi-direction coupling of EM-thermal field. Finally, an experimental platform is built, and the experimental results verify the accuracy of the proposed methods.
To demagnetization fault for permanent magnet synchronous motor, referring to the 96-slot 32-pole permanent magnet synchronous motor, set up motor model using finite element software, and the demagnetization fault of single magnetic steel and double magnetic steel in the motor were simulated and analyzed. The motor flux-density waveforms on different kinds of demagnetization fault were analyzed for the flux-density wave-form periodic trends and volatility in different numbers of magnets or different demagnetization rates. The motor flux-density component path diagram on different kinds of demagnetization fault were analyzed to get radial-tangential flux-density path diagram to analyze regular of path diagram distribution. The air gap flux-density waveform is analyzed by finite element software on different kinds of demagnetization fault, which fourier analysis is used to analyze each harmonic frequency and its weight, and the rule of change of harmonic between the normal condition and under the condition of demagnetization fault is compared. The simulation of tooth electromagnetic force density waveform curves and harmonics for different demagnetization faults is used to analyze its effect on the vibration. The results concerning permanent magnet motor of demagnetization fault lays the foundation of motor fault tolerance analysis and characteristic analysis.
