Single Winding Research Articles

Design of Dual Winding Flux Modulation Machine for Performance Improvement in Variable Speed Application

In this paper, a Dual Winding Flux Modulation Machine (DWFMM) is proposed for variable speed application. The DWFMM is configured by adding windings to the Single Winding Flux Modulation Machine (SWFMM), consisting of a master winding that drives the motor and a slave winding that enables pole changing and performance enhancement. Through pole changing, the DWFMM can operate as two different machines: a Vernier Machine (VM) for varying speeds and torque operations and a Permanent Magnet Synchronous Machine (PMSM). In the VM mode, flux enhancement is applied to improve torque, and in the PMSM mode, Flux Weakening is applied to increase speed. The characteristics of the two different operating modes were analyzed using the Finite Element Method (FEM) to validate the machine’s performance. Finally, the DWFMM and SWFMM were designed and compared as variable speed application machines to confirm their suitability and superiority.

Winding Response under Difference Effective Inductance for Single Phase High Voltage Transformer

Early studies of transformer winding parameters were focused on the determination via its physical dimensions and empirical formulas. In most cases it is divided into several parts namely coil section pairs, coils distance, disc coils diameter and thickness of insulation. Maxwell’s equations are often the solution to the problem, which satisfy related boundary conditions between conductors for mutual inductance and capacitor equations. Such solutions often led to errors and hence its mathematical model. To counter the problem, it was suggested that such approximations must be conducted with experimental model windings at the same time. Frequency domain measurements and time domain measurements can be conducted to effectively determine these parameters. This in turn will investigate the behaviour of transformer winding electromagnetic transient at high frequency. From theoretical point of view, predominantly capacitive winding model often considered to represent its behaviour at high frequency and will give the results of its initial distribution. Under this consideration, a single phase plain winding is considered for investigation. A single rectangular wave was considered to represent infinitive impinge incident wave, injected at one end of transformer winding and the measured response signals of the wavetail were considered for measurement. The experimental response and modelling results were compared and proved to have high agreement between the two.

Design and harmonic analysis of single winding bearingless PM synchronous motor with high winding coefficient

Compared with double-winding bearingless permanent magnet synchronous motor, single-winding bearingless permanent magnet synchronous motor (SBPMSM) has the advantages of low copper loss and low failure rate. However, if the slot-pole combination of SBPMSM is not reasonably selected, the winding coefficient will be reduced, and even many advantages of the single-winding structure will be offset. In this paper, a single-winding design method based on magnetomotive force (MMF) star diagram is proposed, which can ensure high winding coefficient. The design process of the proposed single winding structure is introduced. This method can match the appropriate number of stator slots according to the number of rotor poles, and the winding phase separation design can be realized by reversing the slot number transposition. The mathematical models of the suspension force and torque of the bearingless permanent magnet synchronous motor are derived considering the magnetic field harmonics, and the 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are taken as examples to analyze the magnetic field. The finite element simulation models of 6-slot/2-pole SBPMSM and 18-slot/8-pole SBPMSM are built and analyzed. Through the analysis of electromagnetic torque, suspension force and air-gap magnetic field under different magnetic fields, the general rules of main torque fluctuation and suspension force fluctuation are summarized.

A Tubular Variable Reluctance Resolver With Single Coil Excitation Winding

A Tubular Variable Reluctance Resolver With Single Coil Excitation Winding

Winding Characteristics and Magnetization State Regulations of Variable Flux Memory Machines With Segregated Distributed Windings

The variable flux memory (VFM) machine with segregated multiple three-phase windings is investigated, with particular reference to its winding characteristics and magnetization state (MS) regulations. The overlapped distributed windings are separated into multiple three-phase winding sets with each set non-overlapped, which contributes to the independent relationship between the winding set and corresponding permanent magnet (PM) pole-pairs. Consequently, the single winding set can independently complete the MS regulation, and thus the overall current requirement is reduced. Moreover, it is revealed that the amplitude of de/re-magnetizing magneto-motive force (MMF) with single winding set operation is actually higher than those with multiple winding sets operation thanks to the asymmetric winding layout, resulting in the enhanced de/re-magnetizations and thus the further reduced de/re-magnetizing currents. The winding function, MMF distribution, inductance, and torque of the machine are analyzed, and intentional MS regulations with different methods are compared. A prototype machine is fabricated and tested for experimental validations.

Parameter identification of transformer lumped element network model through genetic algorithm‐based gray‐box modelling technique

AbstractThe lumped element network model has been proven to be an efficient tool for the interpretation of transformer Frequency Response Analysis. However, it is challenging to obtain parameters of the model if transformer design information is unavailable. In such a case, optimisation algorithms can be used for gray‐box model parameter estimation. A methodology is developed by the authors to establish a transformer network model without winding design data, and instead, end‐to‐end open circuit Frequency Response and other terminal test results are utilised; and Genetic Algorithm is applied to approximate the unknown parameters of the model. The modelling approach developed is independent of the unit number of the network model and therefore guarantees the accuracy of optimisation. Furthermore, it can deal with transformers with a complicated winding structure such as interleaved disc type winding. Two single windings, helical and interleaved disc type, and a single‐phase 144/13 kV 60 MVA transformer are used to demonstrate the method. FRA spectra produced by the best estimated gray‐box model and the corresponding white‐box model are compared. The main features in amplitude and phase spectra are well matched, with low values of Relative Standard Deviation, for both single windings and transformer. Estimated electrical parameters show a high consistency with reference values, which are calculated based on winding design data. This validates the methodology and gives confidence to apply grey‐box modelling for FRA interpretation.

Research and Analysis of Toroidal and Conventional Windings in Permanent Magnet Synchronous Machine

Reasonable design of winding can improve the performance of the machine without increasing the weight and cost. The toroidal (TO) and tooth-coil (TC) windings have different spatial positions in the electromagnetic field and generate vertical magnetic field. If the characteristics of winding factor and the unified analysis method of the both can be researched, the windings with better performance can be obtained. Based on this, the winding characteristics considering harmonics and the design methods of single winding and combination of windings are analyzed. The "Halbach Winding" with the same effect as Halbach PM are designed and researched based on the study of TO, TC windings and their combination. According to the characteristics of the magnetic field mentioned above, the improved method of the machine using only winding to generate the traveling wave of Halbach magnetic field is proposed and analyzed. By improving the Halbach winding, it is possible to achieve a magnetic field that enhances one side and weakens the other side while reducing the minimum repetitive unit. And the feasibility of the above methods is verified by finite element analysis (FEA).

Direct drive double fed wind generator

An electric machine topology characterized by single tooth winding in both stator and rotor is presented. The proposed machine is capable of operating as a direct drive double fed wind generator (DDDF, D3F), because it requires no gearbox. A wind turbine drive built around a D3F generator is cheaper to manufacture, requires less maintenance and has a higher energy yield than its conventional counterparts. The all tooth wound generator of a D3F turbine has a superb volume utilisation and lower stator I2R losses due to its extremely short end windings, efficient cooling and reduced active length. Both stator and rotor of a D3F generator can be manufactured in segments, which simplifies its assembly and transportation to the site, and makes its production cheaper.

Eddy Current and Loss of Graded-Resistance No-Insulation Coils in HTS Synchronous Machines of Electrical Aircraft

The No-insulation (NI) high temperature superconductor (HTS) machine is a promising propulsion technique for future large-scale electrical aircraft because of its high power density and enhanced thermal stability. However, in the machine environment, the ripple magnetic fields can induce significant eddy currents and losses on the NI coil. A grading turn-to-turn resistivity technique has been proposed to solve this problem, in which higher turn-to-turn resistivity is applied on the outermost turns of the NI coil, and lower turn-to-turn resistivity is kept on middle turns. The purpose of this research is to study the effects of grading turn-to-turn resistivity technique on the eddy current and loss of both single and multiple NI HTS coils exposed to ripple fields. To investigate the electromagnetic behavior and loss mechanism of NI HTS coils, a simulation model is proposed that couples the equivalent circuit model and finite element model. Results show that the grading turn-to-turn resistivity can effectively reduce the induced eddy current and lead to a uniform distribution of eddy current among turns of both single and multiple windings. It reduces magnetization loss in superconducting layers but increases the turn-to-turn loss on the radial contacts. These results are useful for the development of NI HTS machines with high thermal stability.

Topological antichiral surface states in a magnetic Weyl photonic crystal

Chiral edge states that propagate oppositely at two parallel strip edges are a hallmark feature of Chern insulators which were first proposed in the celebrated two-dimensional (2D) Haldane model. Subsequently, counterintuitive antichiral edge states that propagate in the same direction at two parallel strip edges were discovered in a 2D modified Haldane model. Recently, chiral surface states, the 2D extension of one-dimensional (1D) chiral edge states, have also been observed in a photonic analogue of a 3D Haldane model. However, despite many recent advances in antichiral edge states and chiral surface states, antichiral surface states, the 2D extension of 1D antichiral edge states, have never been realized in any physical system. Here, we report the experimental observation of antichiral surface states by constructing a 3D modified Haldane model in a magnetic Weyl photonic crystal with two pairs of frequency-shifted Weyl points (WPs). The 3D magnetic Weyl photonic crystal consists of gyromagnetic cylinders with opposite magnetization in different triangular sublattices of a 3D honeycomb lattice. Using microwave field-mapping measurements, unique properties of antichiral surface states have been observed directly, including the antichiral robust propagation, tilted surface dispersion, a single open Fermi arc connecting two projected WPs and a single Fermi loop winding around the surface Brillouin zone (BZ). These results extend the scope of antichiral topological states and enrich the family of magnetic Weyl semimetals.

Single Winding Type Determination of Dual Winding Three-Phase Motor Considering Overheat Problem in Integrated Electric Braking System of Autonomous Vehicles

This article introduces the single winding type selection process for a dual winding (DW) three-phase motor. Unlike the conventional DW three-phase motor design, the proposed single winding type selection process simultaneously considers the mechanical length determined by the single winding type and the motor overheating problem caused by faulty operation for each single winding type. The proposed single winding type selection process consists of four steps. First, all single-winding combinations, the point symmetry dual winding (PSDW), line symmetry dual winding (LSDW), and cross symmetry dual winding (CSDW) for DW three-phase motor are investigated. Second, according to the selected single winding types, the busbar height (BH) required for dual division is designed and compared. Third, the stack length (SL) of motor in the PSDW, the LSDW, and the CSDW obtained through overheat compensation design to avoid the overheating problem in the faulty mode are investigated and compared. In the overheat compensation design, the thermal map utilizing measurement data from the previously developed motor for an integrated electric brake (IEB) system, a radial basis function, an overheat compensation coefficient, and the IEB brake load condition are utilized. Finally, the single winding type of DW three-phase motor is selected as the CSDW by comparing the total motor size. As a result of the DW three-phase motor design, the proposed CSDW can reduce the motor size by 12.0% and 4.2%, respectively, compared with the PSDW and LSDW.

A novel multi-filament winding technique for type III composite pressure vessel: From CFRP cross-undulation concept to structural performance validation

Filament winding (FW) technique determines the production efficiency of wound products and the bearing capacity of composite layers, so the development and innovation of winding technique and equipment have become the focus of scientific researchers. This paper analyzes the influence of fiber crossing on the composite layers in the single filament winding (SFW) technique, proposes a multi-filament winding (MFW) technique. Firstly, the constitutive model of fiber cross region is constructed from mesoscopic scale, and the influence of this phenomenon on the design of composite layers is illustrated using netting theory. Then, the MFW technique is designed and developed, and the three-point bending test of CFRP is carried out with digital image correlation (DIC) technology, indicating that the MFW technique exhibits superior flexural strength of 483.71 MPa. Finally, a 35 MPa type III vessel is taken as the object for comparative numerical simulation, the results show the stress adopting the MFW technique in the dome section is reduced by 1418 MPa, and is smaller and more evenly distributed in the cylinder section. The MFW technique takes full advantage of the CFRP properties, improves the pressure bearing capacity of composite layers, meets the American DOT-CFFC standard requirements, and reduces the carbon fiber usage. The lightweight design of high-pressure hydrogen storage vessels is realized with a novel idea, and the winding efficiency is greatly improved compared with SFW technique.

Improved Multiphase Interleaved LLC Resonant Converter With Virtual Controllable Voltage Sources

In this article, a simplified virtual controllable voltage sources (SVCVSs) structure for multiphase ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n \ge3$ </tex-math></inline-formula> ) interleaved LLC resonant converter has been proposed. The SVCVS in each phase is constructed by single auxiliary winding of transformer of the nearby as the phase number is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\ge 3$ </tex-math></inline-formula> , hence printed circuit board (PCB) layout of the improved multiphase interleaved LLC resonant converter becomes much simpler. The feasibility of the multiphase interleaved LLC resonant converter with SVCVSs has been illustrated by vector diagrams, and a family of topologies has been derived. Finally, the 12-V/60-A three-phase interleaved LLC converter with VCVSs/SVCVSs has been tested based on a laboratory built-up prototype. Experimental results show that the three-phase converter with SVCVSs can achieve close output current ripple but higher efficiency than the converter with VCVSs.

Topological Structure of the Order Parameter of Unconventional Superconductors Based on d- and f- Elements

The superconducting order parameter (SOP) of a triplet superconductor UTe2 was constructed using the topological space group approach, in which, in contrast to phenomenological and topological approaches, the single pair function and phase winding in condensate are different quantities. The connection between them is investigated for the D2h point group and the m′m′m magnetic group. It is shown how a non-unitary pair function of UTe2 can be constructed using one-dimensional real irreducible representations and Ginzburg–Landau phase winding. It is also shown that the total phase winding is non-zero in magnetic symmetry only. Experimental data on the superconducting order parameter of topological superconductors UPt3, Sr2RuO4, LaPt3P, and UTe2 are considered and peculiarities of their nodal structures are connected with the theoretical results of the topological space group approach.

Experimental and numerical analysis of strengthening prestressed concrete cylinder pipes using a post-tensioning method

Prestress loss caused by broken wires can lead to a decline in the carrying capacity of prestressed concrete cylinder pipes (PCCPs). The strengthening of PCCPs using a post-tensioning method is becoming more and more widely utilized to restore strengthened pipes to the needed design capacity and to withstand combined loads. There is no need to drain the pipe during strengthening construction, and this strengthening actively replenishes the prestress loss caused by wire breakage at a cost-effective price. To verify the strengthening effect of this method, a full-scale test and its corresponding three-dimensional finite-element model were established. A three-dimensional numerical model of three continuous prototype pipes was established and accounted for the particularity of the bell and spigot. The numerical model of prestressing wires was optimized in two aspects, which was more in line with the actual situation. The spiral winding method instead of single winding was adopted to apply prestress, and the prestressing wires with a broken point were partitioned into two separate areas due to the bond quality between the mortar coating and the wires. The simulation and the full-scale test both contain the five processes of strengthening with external prestressed strands as follows: pressurized to working pressure→breaking the prestressing wires until visible cracks propagate→gradual depressurization to artesian pressure→the tensioning operation of strands→and pressurized to design pressure. A sensitivity analysis of the related factors of strengthening was performed through finite-element simulation to provide a better understanding of the design. The simulation results were consistent with the data on the full-scale test and indicated the rationality of this process. The strengthening of PCCP with a post-tensioning method can meet the design demand and is a feasible strengthening method. The working pressure and control coefficient of tensioning have the most significant impact on the strengthening effect. Technical recommendations and a better understanding of the application of the post-tensioning method on PCCP are provided in this study.

Neural adaptive braking control for single rope winding hoisting systems with disturbance compensation

In the braking control of single rope winding hoisting systems (SRWHS), reasonable braking torque is of great significance in reducing the probability of significant hidden dangers such as overwinding, overspeeding, rope breaking, vibration, conveyance crash and so on. However, dynamic nonlinearity, time-varying disturbances, mechanical dynamic uncertainties and measurement noise severely affect the practical braking control performance. To address those problems, a neural adaptive braking torque controller with disturbance compensation is developed to enhance the braking performance for a single rope winding hoisting system in this paper. Firstly, considering the elastic of steel wire rope, the nonlinear braking model of the SRWHS is established using Lagrange equations and an extended state observer (ESO) is introduced to estimate the system’s unmeasured states and modelling error. Next, a neural adaptive controller is developed to estimate and compensate the mechanical dynamical disturbances resulted from friction forces and random external disturbances. Then, a neural adaptive network controller combined with the ESO (ESONAC) is designed to solve the modelling nonlinearity, time-varying disturbances and system’s unmeasurable states. Finally, the advantages of the ESONAC in improving the braking control performance of winding hoisting systems is verified by comparative experiments.

Non‐Trivial Topological States in Spin‐Polarized 2D Electron Gas at EuO–KTO Interface with the Rashba Spin Texture

AbstractOxide heterointerfaces are gaining popularity for a variety of applications because of a wide range of emergent quantum phenomena. The creation of a highly conducting and spin‐polarized 2D electron gas (2DEG) with anomalous Hall effect at the EuO–KTaO3 (KTO) interface is reported by Zhang et al. (Phys. Rev. Lett. (2018), 121, 116803). The spin‐polarized 2DEG at the interface in EuO/KTO superlattice with a comprehensive electronic structure calculation using density functional theory (DFT) is investigated. It is shown that the magnetic ordering at the interface is related to the occupation of dxy orbitals of interfacial Ta. The band‐crossing points between the majority and minority spin states open a gap when spin–orbit coupling (SOC) is turned on. The large spikes of the Berry curvature Ω(k) at the momenta of spin–orbit (SO) gaps and integral Chern number demonstrate the non‐trivial band topology. As the system remains metallic, it can display quantum anomalous Hall (QAH) insulating characteristics possibly via strain engineering. The spin texture of the bands with the SO gap on constant energy contour displays single spin winding of electron spin with opposite chirality. The magnetic easy axis is perpendicular to the interfacial plane. Hence, our findings suggest that EuO/KTO system has potential in low‐power quantum electronics, spintronics, and spin‐orbitronics.

Synthesis of an effective system of active shielding of the magnetic field of a power transmission line with a horizontal arrangement of wires using a single compensation winding

Aim. The theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding. Methodology Spatial location coordinates of the compensating winding and the current in the shielding winding were determined during the design of systems of active screening based on solution of the vector game, in whith the vector payoffs is calculated based on Biot-Savart's law. The solution of this vector game calculated based on algorithms of multi-swarm multi-agent optimization. Results The results of theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding are presented. Originality. For the first time, the theoretical and experimental studies of the effectiveness of reducing the level of the magnetic field in two-storey cottage of the old building of a power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding are considered. Practical value. From the point of view of the practical implementation it is shown the possibility to reduce the level of magnetic field in two-storey cottage of the old building from power transmission line with a horizontal arrangement of wires by means of active shielding with single compensation winding to the sanitary standards of Ukraine.

Influence of Single Layer Winding Geometry of Inductive Element on Loss Resistance

Influence of Single Layer Winding Geometry of Inductive Element on Loss Resistance

Active and Passive Reset Circuits for Multistage Magnetic Pulse Compression (MPC) Circuits Used in Gas Laser Applications

Magnetic pulse compression (MPC) circuits are commonly used in pulsed power circuits for powering gas lasers to shorten the duration of the pulse. If the core of every magnetic switch in the MPC is biased to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$-\Delta B_{r}$ </tex-math></inline-formula> by a reset circuit, then the voltage hold-off time is doubled, and the cross-sectional area required is halved. Reset circuits must be isolated from the high-voltage pulses appearing in the pulsed power circuit using filters. The required filter (inductor) size becomes too large if the reset circuit is connected directly in parallel to the magnetic switches, especially if the volt-sec product across the filter inductor is large. The most common, existing reset circuits available in the literature directly connect in parallel to the magnetic switch ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula> ) and, therefore, require larger filter sizes to protect the reset circuitry. In addition, reset circuits cannot always be wound on the magnetic core to create a step-down transformation of the pulsed power voltages (lack of physical space or the use of a single primary winding). This article proposes a new reset circuit topology which resolves these problems by enabling the use of the smallest possible filter size (inductance value). In addition, only a single reset circuit is needed to reset multiple magnetic switches in the MPC network. An active reset circuit is also proposed which is more suitable for resetting magnetic cores that are relatively harder, i.e., requiring higher H values to saturate (equivalent currents greater than a few amperes). The reset circuits discussed in this article can in general be applied to many pulsed power applications employing MPC networks.