Rotor Construction Research Articles

Analysis of Disc Motor with Asymmetrical Conducting Rotor

The homogenous disc rotor construction allows higher rotational speeds and relatively higher power densities. This paper deals with a two-phase induction motor with homogenous disc rotor construction. The field analysis of an axial flux disk motor with a conducting disc rotor is carried out, using a new application of the Maxwell's field equations. A Suggested model is introduced to establish the geometry of motor construction and to enable the derivation of the field system differential equations. A new strategy is applied for the boundary conditions to complete the field solution. This is carried out by determining the complex integration constants. The current density is completely derived with it is components (the radial, the tangential current density and the axial air gap flux density). The performance of the flux density, rotor current components and the torque-slip characteristics are determined with and without disk rotor ends. The effects of the disk rotor design data and the rotor asymmetry on the motor performance are investigated.

Formation and Manipulation of Diatomic Rotors at the Symmetry-Breaking Surfaces of a Kagome Superconductor.

Construction of diatomic rotors, which is crucial for artificial nanomachines, remains challenging due to surface constraints and limited chemical design. Here we report the construction of diatomic Cr-Cs and Fe-Cs rotors where a Cr or Fe atom switches around a Cs atom at the Sb surface of the newly discovered kagome superconductor CsV3Sb5. The switching rate is controlled by the bias voltage between the rotor and scanning tunneling microscope (STM) tip. The spatial distribution of rates exhibits C2 symmetry, possibly linked to the symmetry-breaking charge orders of CsV3Sb5. We have expanded the rotor construction to include different transition metals (Cr, Fe, V) and alkali metals (Cs, K). Remarkably, designed configurations of rotors are achieved through STM manipulation. Rotor orbits and quantum states are precisely controlled by tuning the inter-rotor distance. Our findings establish a novel platform for the controlled fabrication of atomic motors on symmetry-breaking quantum materials, paving the way for advanced nanoscale devices.

Construction of triptycene molecular rotors with intermeshing arrangement and low rotational barrier

Abstract Molecular rotors are one of the building blocks of molecular machines and they are nano-sized with mechanically rotating moieties. Among them, intermeshing triptycenes with a gear-like skeleton allow the construction of a molecular rotor that transmits rotational motion. For triptycenes to mesh with each other without loss of rotation, intermeshing them in parallel and adjusting the distance between their axes to 8.1 Å are required. However, with conventional methods, because of the restrictions on bond lengths and atomic radii, achieving an ideal arrangement in which the triptycenes mesh in parallel at 8.1 Å has been difficult. In this work, we synthesized disulfonic acid containing a triptycene as a rotator and combined it with amines of 2 different steric factors (normal-amylamine [nAmA] and guanidine [Gu]), which allowed us to prepare organic salts with varying arrangements of triptycenes. In the organic salt with the planar amine (Gu), the crystal structure was close to the ideal intermeshing arrangement of the triptycene and the distance between their axes was 7.7 Å. The T1ρ 13C spin-lattice relaxation time using solid-state nuclear magnetic resonance (NMR) demonstrated that triptycene rotates efficiently at 24 kHz at 313 K with a low rotational barrier (10.9 kcal/mol) compared with non-intermeshing structures.

Design procedures for small synchronous generators with interior permanent magnet rotors

This paper presents the design and analysis of a three phase synchronous generator with an interior permanent magnet rotor (NdFeB). The main point of such a rotor construction is the design of the flux barriers because of its direct connection with the saliency of the machine. The performance analysis is derived from the results of a transient 2D-finite-element method with a direct coupled electrical circuit. Furthermore an optimized rotor design results in an elementary reduction of the supplementary losses caused by the higher harmonics.

Multi-objective optimization of slotted stator switched reluctance motor for electric vehicle application

The popularity of electric vehicles (EVs) and hybrid electric vehicles (HEVs) is projected to increase as environmental consciousness rises. They have emerged as a potential substitute for traditional electrical machines like the switched reluctance motors (SRMs). SRMs are renowned for their low cost of production and maintenance, built-in fault tolerance, and simple design. Additionally, because the machine's rotor construction does not require copper coils or permanent magnets, production costs are significantly reduced. However, it has disadvantages, including as high non-linearity, high torque ripple, and acoustic noise production. In this research, a method for designing slotted stator teeth switched reluctance motors (SST-SRM) in EVs using a genetic algorithm (GA) optimization design with multiple targets is provided. In order to achieve the best possible balance between peak torque (Tp), average torque (Tavg), and efficiency, the developed optimization function is chosen. The stator/rotor pole arc angle and slot width/depth are chosen as the optimized variables. When compared to traditional SRM, the optimization results of proposed SST-SRM demonstrate improvements in peak torque (24.40%, 36.98%, 42.73%, and 42.45%), average torque (7.40%, 29.94%, 33.00%, and 33.62%), and efficiency (0.27%, 0.52%, 0.97%, and 1.03%).

Parameters Variation to Estimate Performance Characteristics of 3-Phase Asynchronous Motor

The 3-phase asynchronous squirrel cage motors (SCIM) are main competitor machines placed instead of other motors in the commercial and industrial fields. The stator and rotor material selection and construction topology influence the electrical machine design. The results illustrated with the motor of a 15KW, variable controlled speed, for the constant frequency of 50 Hz or 60 Hz. The motor parameters created inside the simulation model must be matched with the value of a standard parameter for SCIM to achieve a high dynamic response. This work examines the effect of the parameters variation for synchronous motor on the performance characteristics at starting point and at a load change for different time and speed regions. Changing of the rotor power is taken into consideration, this occurs with dynamic change of the hydraulic pump load from the valve.In the industrial applications, production,and manufacturing, till present there are still struggles to find the most holistic environment of the SCIM to achieve its efficiency at the lowest cost and same time control the motor performance, so we predicted the method of reducing the most effective motor parameters to improve the efficiency.The offline method used the SCIM parameters to calculate the time-varying current, torque, and rotor speed. The results illustrated that this method was fully consistent with the experiment tests and the standard theoretical values.A MATLAB program is used to simulate this study. The simulation model proved the feasibility of the proposed method with encouraging performance.

Experimental and Numerical Studies on a Single Coherent Blade of a Vertical Axis Carousel Wind Rotor

This article presents the results of experimental and numerical studies on a single coherent rotor blade. The blade was designed for a vertical-axis wind turbine rotor with a self-adjusting system and planetary blade rotation. The experimental tests of the full-scale blade model were conducted in a wind tunnel. A computational fluid dynamics (CFD) analysis of the blade’s cross section was then carried out, including the boundary conditions corresponding to those adopted in the wind tunnel. The main objective of the study was to determine the aerodynamic forces and aerodynamic moment for the proposed single coherent cross-section of the blade for the carousel wind rotor. Based on the obtained results and under some additional assumptions, the driving torque of the wind rotor was determined. The obtained results indicated the possibility of using the proposed blade cross-section in the construction of a carousel wind rotor.

High-speed rotor for microparticle impact studies.

We report on the design, construction, and testing of a high-speed rotor intended for use in hypervelocity microparticle impact studies. The rotor is based on a four-wing design to provide rotational stability and includes flat "paddle" impact surfaces of ∼0.5cm2 at the tips of each wing. The profile of each wing minimizes the variation in tensile forces at any given rotational speed. The rotor was machined using titanium (grade 5) and operated in high vacuum using magnetically levitated bearings. Initial experiments were run at several speeds up to 100000 rpm (revolutions per minute), corresponding to a tip speed of 670m/s. Elongation at the wing tips as a function of rotational speed was measured with a precision of several micrometers using a focused diode laser and found to agree with an elastic modulus of 1.16GPa for the rotor material. Applications to microparticle impact experiments are discussed.

Simulation and Analysis of Steady-State and Dynamic Performance of Asymmetric Half Bridge Converter-Fed SRM using Finite Element Analysis

Variable reluctance motor is becoming a competitive candidate among all other machines available due to its added features. The development of variable reluctance motor is simple due to the simple construction of rotor without any permanent magnets. Reduced complexity in structure paves the way for low-cost motor and it also leads to the application of SRM in a wide manner. In order that the machine could be used in various applications, it is much necessary to have a suitable driving system (converter configuration). The best choice of converter for SRM would pave the way for desirable control of the machine. The proposed work includes the design and analyses of an appropriate driver configuration for SRM and interface it with the motor which is already designed and analyzed using ANSYS Maxwell. The design and analysis of the converter are carried out using the ANSYS Simplorer tool box.

Functionally integrated additive manufactured rotor components for torque-dense aircraft electric motors

In dealing with emissions targets worldwide, fundamental questions about the future arise for commercial aviation. The resulting consequences for aviation require efforts to make air traffic CO2 neutral. In this context, electrification is an important building block to enable the aviation industry to provide transport in the future with increasing traffic volumes. To achieve this goal, electric motors for flight operation must have a high power and torque density and operate as energy-efficiently as possible. The PM synchronous motors predominantly proposed for such applications have above average efficiencies but could provide higher peak powers if they could be thermally more loaded. In particular, the sensitive permanent magnets lose efficiency as the operating temperature of the electric motor increases, reducing the maximum possible torque of the motor. Since conventional rotor construction methods limit the design, additive manufacturing is used to develop a rotor design that allows the rotor magnets to be cooled in close range to their contours. In addition, by selective laser melting mechanical, thermal, and magnetic functions are integrated. A process for hybrid manufacturing of novel rotor topologies is proposed. For this purpose, the rather conventional rotor topology is replaced by an additive function-integrated component for a reference electric motor. By means of an FEM analysis, it was shown that the mechanical strength of the alternative fixation method is maintained. Using adequate design guidelines, the AM structural components were fabricated in aluminum and an iron-nickel alloy and the permanent magnets were secured on it using 1K-epoxy adhesive. CFD analysis was used to simulate the flow conditions and heat transfer to the coolant in the internal structures of the AM components. Finally, the effect of the integrated cooling function was verified with an experimental setup. The results show that the torque influencing factor of the magnetic induction can be increased.

A Crystalline Supramolecular Rotor Functioned by Dual Ultrasmall Polar Rotators†

Comprehensive SummaryAs an extended model of conventional molecular rotors, a conceived construction of novel crystalline molecular rotor that simultaneously contains two discrete polar rotators is presented here. The supramolecular self‐assembly of 18‐crown‐6 host and two rotator‐containing ion‐pair guests affords a three‐in‐one cocrystal, (2‐NH3‐iBuOH)(18‐crown‐6)[ZnBr3(H2O)], in which the hydroxyl group and aqua ligand both function as ultrasmall polar rotators. On the basis of the variable‐temperature single‐crystal X‐ray diffraction, variable‐temperature/frequency dielectric response, density functional theory calculations, and molecular dynamics simulations, it is found that such dual polar rotators experience a gradually enhanced rotation with increasing temperature, and more importantly, could be controlled by a reversible polar‐to‐polar structural phase transition, i.e., from a “single‐(polar rotator)” state at low‐temperature phase to a “mixed‐dual‐(polar rotator)” state in the vicinity of transition, and to an unusual “synchronized‐dual‐(polar rotator)” state at high‐temperature phase.

Rotor Modification of Switched Reluctance Motor to Improve Multiphysics Performance on EV Grade

The magnetless electrical machine Switched Reluctance Motor (SRM) for low-cost Electric Vehicles (EVs) drive. Compared to induction motor and permanent magnet synchronous motor, the SRM has simple steel rotor construction, high reliability, high fault tolerance capability, wide operating frequency range, high constant power speed range, high-temperature operation, and low-cost steel materials. This paper design was carried out for EV grade 1200kg drive optimal duty cycle characteristics, SRM topology optimized the 8/6 geometry rating for 20kW and 2750rpm. The SRM rotor modification comparison performance of torque, efficiency, line current, and power for EVs. The five rotor modifications are rotor round teeth, straight teeth, taper and round teeth, taper and straight teeth, and straight and round rotor teeth are analyzed using the finite element method. The optimized geometry model analyses using JMAG software and compared with all rotor modifications for the improving performance on torque density, operating efficiency, rated power, and speed for EVs.

Remotely controllable supramolecular rotor mounted inside a porphyrinic cage

Remotely controllable supramolecular rotor mounted inside a porphyrinic cage

Permanent Magnet Machines for High-Speed Applications

This paper overviews high-speed permanent magnet (HSPM) machines, accounting for stator structures, winding configurations, rotor constructions, and parasitic effects. Firstly, single-phase and three-phase PM machines are introduced for high-speed applications. Secondly, for three-phase HSPM machines, applications, advantages, and disadvantages of slotted/slotless stator structures, non-overlapping/overlapping winding configurations, different rotor constructions, i.e., interior PM (IPM), surface-mounted PM (SPM), and solid PM, are summarised in detail. Thirdly, parasitic effects due to high-speed operation are presented, including various loss components, rotor dynamic and vibration, and thermal aspects. Overall, three-phase PM machines have no self-starting issues, and exhibit high power density, high efficiency, high critical speed, together with low vibration and noise, which make them a preferred choice for high-performance, high-speed applications.

An alternative for wind energy conversion using improved Savonius rotor turbine model

The current society development is dependent of the planet energy resources and if we take an overview on renewable energies used worldwide it can be said that they are constantly gaining ground. This trend represents an important step forward towards maintaining a clean environment by focusing on capitalizing considerable resources that are sustainable over time, such as solar energy, together with waves and wind force. Regarding the energy production solution based on the atmospheric air masses movements or wind energy, the alternative to the constructive model of horizontal axis turbines (HAWT), currently widely used in wind farms is presented the alternative of using vertical shaft turbines (VAWT) for reduced installed power wind farms. The aspects that form the advantages of these turbines are presented as well as the fact that although they offer a lower power coefficient, they can play an important role for smaller power farms, the investment being at lower values. The basic rotor construction model is based on the SAVONIUS type which has been continuously improved, the results being better in terms of energy performance. A rotor concept that can be used within wind turbines with better performance results compared to SAVONIUS classic model is presented in this paper. The novelty elements consist in the use of a larger number of blades as well as the placing method on the rotor basic circle profile. The numerical analysis results made on virtual rotor model are presented, which highlight the improved values obtained on the analysed model.

The Use of Wind Turbines in Ports and Sea Vessels

The technical result of the research of presented wind turbine is simplification and rise of the practical application of its main body – the rotor construction, which shall be achieved via transformation of wind shifting movement into rotating movement is implemented by rotor blades, which present bent or inclined shape plates and during rotation, these plates are not influenced with decelerating resistance of surrounding air.The technical novelty of the turbine construction is presented with the following features: each profile blade of the rotor presents concave arc placed eccentrically towards its rotative axis, and the rotor may be equipped with one, two or more wings.

Characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications

Permanent magnet motors (PMMs) are widely used in electric vehicles because of their benefits. Based on the permanent magnet topologies on the rotor, PMMs are classified into three types: surface mounted PMM, inset PMM, and interior PMM. This paper discusses a comparison of the characteristics of interior and inset types of PMMs for electric vehicle applications. The study aims to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. Simulations were carried out analytically and numerically using the FEMM 4.2 software. The simulation results at the base speed show that the interior PMM generates a higher torque but with a lower rotation, namely 56.47 Nm and 3162 rpm, respectively, while the inset PMM produces higher rotation 4200 rpm but lower output torque of 46.01 Nm. However, with a higher saliency ratio, the interior PMM produces higher maximum torque and speed at both constant torque and field weakening regions than the PMM inset, which is 92.87 Nm and 6310 rpm, consecutively. In terms of cogging torque, the interior PMM raises it slightly higher (2.90 Nm) than the inset PMM (1.93 Nm). The results conclude that, in general, the interior PMM shows better performance in all studied regions and is preferable for electric vehicle applications.

A Robust Current Controller Design Method for Highly Nonlinear Synchronous Reluctance Motors

Due to the rotor construction, Synchronous Reluctance (SynRel) machines exhibit high magnetic saturation and cross-saturation. This leads to strongly variable dq inductances, which affect the current loop response. In order to achieve constant current loop dynamics, controller gains need to be adapted according to the current bias. In this paper, three different methods for implementing a PI current controller are analyzed and tested. The magnetic characteristics of the tested SynRel are obtained using the FEA and also a state-of-the-art experimental procedure. The experimental verification of the current loop response is given for a 15 kW 3-phase SynRel motor, using a standard industrial 3-phase inverter.

Optimal Design of Spoke-Type IPM Motor Allowing Irreversible Demagnetization to Minimize PM Weight

In this study, we introduce an optimal design for a spoke-type interior permanent magnet (IPM) motor that can minimize PM weight by allowing irreversible demagnetization, unlike the conventional motor design method that does not allow irreversible demagnetization. The spoke-type rotor structure has the advantage of concentrating the magnetic flux around the rotor core. However, part of the PM near the surface of the stator tooth becomes sensitive to the armature reaction and external magnetic factors. Therefore, typical spoke-type rotor construction follows a limited design process that does not allow irreversible demagnetization. Although the manufacturing process allows tolerance for the demagnetization rate, motor design without considering the demagnetization rate in all the design stages becomes a design constraint and limits the performance area. In this study, the performance improvement is examined, when irreversible PM demagnetization is allowed up to −3%, and is not zero. For optimal design, Latin hypercube sampling (LHS), the kriging model, and genetic algorithm (GA) are utilized. With the proposed design process, motors are effectively designed to reduce the PM weight by 23.7%, compared to the initial design model while maintaining an efficiency almost similar to that of the initial design model.

Kinerja Motor Induksi 1-fasa Disain 4 Kumparan dengan Kapasitansi Kapasitor Jalan Terkendali

Single phase induction motor usually has two windings. Because of that, the motor usually operated at lower efficiency than the poly-phase induction motor. A new design had been developed by using poly-phase winding to improve motor efficiency, but characteristic of the current winding at low load condition is not good. So that, this study was aimed to design a 4 phase windings construction of a single phase induction motor that using capacitance control of the run capacitor on auxiliary winding. This design was focused for capacitor-start capacitor-run induction motor that had 4 windings, one winding act as the main winding and the other three windings act as the auxiliary windings. The main and the auxiliary windings current rating of the proposed motor were 2.74A and 3.15A, respectively. The auxiliary winding current of the proposed motor was controlled by the ‘Arduino Uno’ control system. To get the best control system of the proposed motor, the performances of the proposed motor were compared to the performances of a conventional single-phase induction motor that had the same current rating, stator and rotor construction. The single-phase comparator motor used in this study was a conventional single-phase induction motor of 220V, 50 Hz, 1 HP, 8.3A, 4 poles, 1400 RPM cage rotor. The result showed that the proposed motor with capacitance control in auxiliary winding had better performances than the conventional induction motor.