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This article proposes a position detection method for a multi-to-one wireless power transmission (WPT) system for the first time and applies it to the position detection of a spherical motor. The traditional contact detection system has high friction resistance and poor rotor positioning accuracy. Although some noncontact measurement systems are not directly connected to the rotor, the structure or calculation of the measurement system is more complicated. To solve the abovementioned problems, this article proposes two structural topologies, which are evenly arranged on the upper part of the rotor and the receiving coil is placed on the rotor shaft. When the motor rotor rotates along with the three motion states of yaw, spin, and tilt, the receiving and multitransmitting coils will have an angular offset. The rotor position is obtained by a method of accurately estimating the mutual inductance. This method avoids complicated finite element calculations and saves a lot of time. Finally, the experiment verifies the above analysis and compares the data with the microelectromechanical system three-degree-of-freedom attitude detection method. This article provides insights into the position detection of spherical motors. This method simplifies the previous measurement system and obtains higher positioning accuracy. [ABSTRACT FROM AUTHOR]

A holographic spectrum method (HSM) of multi-phase and multi-layer winding magnetomotive force (MMF) for 12-slot/10-pole combination with fractional-slot concentrated-winding (FSCW) is proposed in this paper. Taking two kinds of traditional winding layout as example, amplitude and phase distribution of the vth harmonic are calculated. The holospectrum of the multi-phase and multi-layer winding are derived based on three-phase single-layer (TP-SL) and three-phase double-layer (TP-DL) holospectrum theory. Then the finite element method (FEM) is used to validate the resultant winding MMF calculated by the holospectrum method. Results show that two methods have a good consistency in changing tendency. Prototype manufacture and test of axial-flux PMSM with a double-three-phase four-layer (DTP-FL) winding have been completed. A load experiment with two groups of resistance is established to validate its output power of axial-flux permanent magnet synchronous machine (PMSM). The temperature distribution of axial-flux PMSM is evaluated with PT100 and infrared thermal imager. The experiments shows that the axial-flux PMSM runs at a relative temperature rise. [ABSTRACT FROM AUTHOR]

This paper proposes a monolayer Halbach array based permanent magnet spherical motor (PMSpM) using cubic permanent magnets (PM). The research aims to provide a fast computing model to calculate the magnetic field for this PMSpM, which helps for future PMSpM optimization and control study. Three thickness equivalence principles are provided and compared for cubic PMs. The magnetic scalar potential is introduced, and the spherical harmonics expansion is implemented for rotor magnetic field analysis. Engineering revision is used to reduce the Legendre function deviation in polar angle direction. Torques and forces are deduced using the Lorentz force law, and relatively simple models of this PMSpM for both magnetic fields and torques are acquired. In addition, a prototype motor has been developed, and the analytic results of air-gap flux density and torque are compared with their finite element simulation and experimental results, which are proved consistent. It is concluded that the fundamental component of the spherical harmonics can be used to present the magnetic field model, which uses fewer integrals than the Biot-Savart law based solution, and the modeling results of the magnetic field flux density, forces and torques are in line with the expectations. The analytic models are proved correct. [ABSTRACT FROM AUTHOR]

This paper investigates the modeling methods for the structural design optimization of permanent magnet synchronous linear motors (PMSLMs), which are applied to linear motion machines. First, an initial PMSLM model is established by finite element analysis (FEA), and the data space is obtained for subsequent rapid regression modeling. Second, a powerful regression machine learning method, that is, distance-weighted K-nearest neighbor algorithm (DW-KNNA), is introduced to establish a calculation model by grasping the nonlinear relationships between input structural parameters and output motor performances. Model comparison experiments among analytical method, response surface method, K-nearest neighbor algorithm, and DW-KNNA demonstrate the superiority of the DW-KNNA. Finally, the differential evolution algorithm is used to determine the best combination of structural parameters and performances. The FEA and prototype motor experiments proved the validity and advantages of the proposed method. [ABSTRACT FROM AUTHOR]

A 40 kW–4000 rpm interior permanent magnet synchronous machine (IPMSM) applied to an electric vehicle (EV) is introduced as the study object in this paper. The main work of this paper is theoretical derivation and validation of the first-order and multi-order transient lumped-parameter thermal network (LPTN) for the development of a fast thermal model. Based on the first-order LPTN built, the study finds that the heat transfer coefficient of fluid and thickness of the air gap layer are the main influencing factors for the final temperature and time of reaching the steady state. The larger the heat transfer coefficient of fluid is, the lower the steady node temperature is. The smaller the air layer thickness is, the lower the steady node temperature is. The multi-order LPTN theory is further deduced based on the extension of the first-order LPTN. For the constant load and rectangular periodic load, transient node temperatures of the IPMSM are obtained by modeling and solving the first order inhomogeneous differential equations. Temperature rise curves and efficiency maps of the IPMSM under load conditions are realized on a dynamometer platform. The FLUKE infrared-thermal imager and the thermocouple PTC100 are used to validate the mentioned method. The experiment shows that the LPTN of the IPMSM can accurately predict the node temperature. [ABSTRACT FROM AUTHOR]