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Summary: Rhizomicrobiome plays important roles in plant growth and health, contributing to the sustainable development of agriculture. Plants recruit and assemble the rhizomicrobiome to satisfy their functional requirements, which is widely recognized as the 'cry for help' theory, but the intrinsic mechanisms are still limited.In this study, we revealed a novel mechanism by which plants reprogram the functional expression of inhabited rhizobacteria, in addition to the de novo recruitment of soil microbes, to satisfy different functional requirements as plants grow. This might be an efficient and low‐cost strategy and a substantial extension to the rhizomicrobiome recruitment theory.We found that the plant regulated the sequential expression of genes related to biocontrol and plant growth promotion in two well‐studied rhizobacteria Bacillus velezensis SQR9 and Pseudomonas protegens CHA0 through root exudate succession across the plant developmental stages. Sixteen key chemicals in root exudates were identified to significantly regulate the rhizobacterial functional gene expression by high‐throughput qPCR.This study not only deepens our understanding of the interaction between the plant–rhizosphere microbiome, but also provides a novel strategy to regulate and balance the different functional expression of the rhizomicrobiome to improve plant health and growth. [ABSTRACT FROM AUTHOR]

Based on the emission factor method and LMDI-LEAP model, this paper systematically studies the current situation, influencing factors and changing trend of carbon emissions from rural buildings in a typical village located in southern China. The results showed that (1) the per capita carbon emissions generated by the energy consumption of rural buildings is 2.58 tCO2/a. Carbon emissions from electricity consumption in buildings account for about 96.07%; (2) the per capita building area, building area energy intensity, population size, population structure and carbon emission coefficient affect rural building carbon emissions, with contribution rates of 70.13%, 31.27%, 0.61%, −1.21% and −0.80%, respectively; (3) from 2021 to 2060, the carbon emissions of rural buildings are expected to increase first and then decrease. In 2021, the base year, carbon emissions from buildings were 2755.49 tCO2. The carbon emissions will peak at 5275.5 tCO2. Measures such as controlling the scale of buildings and improving the utilization rate of clean energy can effectively reduce carbon emissions, in which case the peak can be reduced to 4830.06 tCO2. Finally, the countermeasures and suggestions about rural building energy saving and emission reduction are proposed, including improving the construction management, raising energy efficiency standards in buildings, increasing the proportion of clean energy and raising residents' awareness of energy conservation. [ABSTRACT FROM AUTHOR]

High-throughput sequencing, culture-dependent workflows, and microbiome transfer experiments reveal whether potassium phosphite (KP), an environmentally acceptable agricultural chemical, could specifically enrich the antagonistic bacterial community that inhibited the growth of the pathogen Ralstonia solanacearum. The application of KP enriched the potential antagonistic bacteria Paenibacillus and Streptomyces in soil, but depleted most dominant genera belonging to gram negative bacteria, such as Pseudomonas, Massilia, and Flavobacterium on day 7. Moreover, the KP-modulated soil microbiome suppressed R. solanacearum growth in soil. The predicted functions related to the synthesis of antagonistic substances, such as streptomycin, and the predicted functions related to tellurite resistance and nickel transport system were significantly enriched, but the synthesis of lipopolysaccharide (distinct component lipopolysaccharide in gram negative bacteria) were significantly depleted in the KP-treated soils. In addition, the copy numbers of specific sequences for Streptomyces coelicoflavus and Paenibacillus favisporus were significantly increased in the soil amended with KP, inhibited the growth of R. solanacearum, and had a higher tolerance of KP than R. solanacearum. Our study linked the application of fertilizers to the enrichment of antagonistic bacteria, which could support future work that aims to precisely regulate the soil microbiome to protect the host from infection by soil-borne pathogens. [ABSTRACT FROM AUTHOR]

The mass production of the motors causes tolerance of shape and dimension, deviation of permanent magnet remanence and rotor eccentricity error, which affect the cogging torque and torque ripple amplitude and performance consistency. In order to reduce the torque ripple of the motor in the actual condition, the robustness optimization is performed in the paper. Firstly, an improving convex arc type permanent magnet structure is adopted to improve air gap flux density and suppress the cogging torque. Secondly, the structure parameters of the magnetic pole are selected as optimization variables, and the magnetization angle, remanence and position of the permanent magnet, static and dynamic rotor eccentricity are considered as noise factors. To improve the overall robustness of the motor under different operating conditions, the dynamic Taguchi method is used to optimize the robustness of the motor, and the test data is processed through the relation analysis method to obtain the optimal combination of control factors. Finally, the prototype is manufactured for the experiment. Compared with the single‐operating conditions robust optimization results, the robust optimization method improves the robustness of the motor. The cogging torque amplitude is reduced by 39.2%. The torque ripple is 38.4% lower than that before optimization. [ABSTRACT FROM AUTHOR]

A two degrees of freedom (2-DOF) actuator capable of producing linear translation, rotary motion, or helical motion would be a desirable asset to the fields of machine tools, robotics, and various apparatuses. In this paper, a novel 2-DOF split-stator induction motor was proposed and electromagnetic structure parameters of the motor were designed and optimized. The feature of the direct-drive 2-DOF induction motor lies in its solid mover arrangement. In order to study the complex distribution of the eddy current field on the ferromagnetic cylinder mover and the motor's operating characteristics, the mathematical model of the proposed motor was established, and characteristics of the motor were analyzed by adopting the permeation depth method (PDM) and finite element method (FEM). The analytical and numerical results from motor simulation clearly show a correlation between the PDM and FEM models. This may be considered as a fair justification for the proposed machine and design tools. [ABSTRACT FROM AUTHOR]

In this article, a suspension‐guided permanent magnet synchronous linear motor (SG‐PMSLM) for ropeless elevator is proposed, which can meet the requirements of high thrust and high thrust density for ropeless elevator, and reduce vibration noise and wheel‐rail wear during motor operation. The structure, working principle and electromagnetic characteristics of SG‐PMSLM are analysed. In order to improve the overall performance of SG‐PMSLM, this article aims at improving the average thrust and thrust density, reducing the thrust fluctuation of SG‐PMSLM. Firstly, the sensitivity analysis of the key structural parameters of SG‐PMSLM is conducted, and the parameters that have significant influence on the three optimisation objectives are selected as the optimisation variables. Secondly, the response surface model of three optimisation objectives is built, and the Particle Swarm Optimisation algorithm is combined to conduct the multi‐objective optimisation design for SG‐PMSLM. Thirdly, the optimised solution set is obtained for three objectives. Finite Element Analysis is used to verify that the optimised solution set has better diversity and can effectively improve SG‐PMSLM overall performance compared with the initial design. Finally, the electromagnetic performance of SG‐PMSLM is verified by experiments. [ABSTRACT FROM AUTHOR]

Permanent magnet linear synchronous motor (PMLSM) is one of the ideal driving sources of ropeless elevators. However, such motors, whether moving magnetic or moving coil, will produce the problem of excessive cost under long travel. The permanent magnet flux switched linear motor (PMFSLM) with permanent magnets (PMs) and copper coils on the mover side greatly reduces the cost. A U‐type PMFSLM is proposed in the paper. First, a PMFSLM is proposed and investigated, quantitatively comparing with PMLSM for the ropeless elevator system. Second, aiming at the problem of flux leakage at the top of PMFSLM, a U‐type PM (UPM) structure is presented. The electromagnetic performance of PMFSLM and UPM‐FSLM have been compared and summarised. The comparison results show that UPM‐FSLM solves the defect of top flux leakage, increases thrust by 4.34%, reduces thrust ripple by 28.10%, and has better electromagnetic performance than PMFSLM. Afterwards, the elevator passenger capacity of PMFSLM and UPM‐FSLM are simulated and calculated and the feasibility is analysed. Finally, a prototype of PMFSLM has been built and measured. [ABSTRACT FROM AUTHOR]

Chemotaxis, the ability of motile bacteria to direct their movement in gradients of attractants and repellents, plays an important role during the rhizosphere colonization by rhizobacteria. The rhizosphere is a unique niche for plant–microbe interactions. Root exudates are highly complex mixtures of chemoeffectors composed of hundreds of different compounds. Chemotaxis towards root exudates initiates rhizobacteria recruitment and the establishment of bacteria–root interactions. Over the last years, important progress has been made in the identification of root exudate components that play key roles in the colonization process, as well as in the identification of the cognate chemoreceptors. In the first part of this review, we summarized the roles of representative chemoeffectors that induce chemotaxis in typical rhizobacteria and discussed the structure and function of rhizobacterial chemoreceptors. In the second part we reviewed findings on how rhizobacterial chemotaxis and other root–microbe interactions promote the establishment of beneficial rhizobacteria-plant interactions leading to plant growth promotion and protection of plant health. In the last part we identified the existing gaps in the knowledge and discussed future research efforts that are necessary to close them. [ABSTRACT FROM AUTHOR]

A tubular permanent-magnet linear generator is suitable for direct drive wave energy conversion owing to its simple structure, easy maintenance and high efficiency. In this study, a novel Gramme winding tubular permanent-magnet linear generator (GW) is designed to increase power density. First, the structure of the Gramme winding and concentrated winding tubular permanent-magnet linear generator is introduced and the operation principle of the generator is analysed. Second, the initial parameters of GW are determined based on the similar overall dimensions to those of the concentrated winding tubular permanent-magnet linear generator. Third, the air gap flux density, external characteristics, voltage regulation, output power, and loss of the two generators are compared. Finally, the DC load capacities of the two generators are compared based on a three-phase full-control bridge rectifying circuit. The results show that the GW has a higher power density than the latter. [ABSTRACT FROM AUTHOR]

A tubular permanent-magnet linear generator is suitable for direct drive wave energy conversion owing to its simple structure, easy maintenance and high efficiency. In this study, a novel Gramme winding tubular permanent-magnet linear generator (GW) is designed to increase power density. First, the structure of the Gramme winding and concentrated winding tubular permanent-magnet linear generator is introduced and the operation principle of the generator is analysed. Second, the initial parameters of GW are determined based on the similar overall dimensions to those of the concentrated winding tubular permanent-magnet linear generator. Third, the air gap flux density, external characteristics, voltage regulation, output power, and loss of the two generators are compared. Finally, the DC load capacities of the two generators are compared based on a three-phase full-control bridge rectifying circuit. The results show that the GW has a higher power density than the latter. [ABSTRACT FROM AUTHOR]

Two degree‐of‐freedom direct drive induction motor (2DoFDDIM), capable of rotary, linear and helical motion, has widespread application. A new mover structure is proposed, which is made from a hollow cylinder with copper cast in the axial slots and the circumferential slots on its surface. Then, three‐dimensional finite element models of 2DoFDDIM are used to determine the performances of rotary, linear and helical motion developed by the motor. The results show that the new mover has a great improvement on the motor performances of all modes of motions compared with the initial mover. The researches on mover structure and characteristics of 2DoFDDIM present a new path of optimisation on 2DoFIM. [ABSTRACT FROM AUTHOR]

Seed‐borne pathogens can inhabit the rhizosphere and infect the plant after germination. The rhizosphere microbiome plays critical roles in defending against seed‐borne pathogens. However, the assembly of a core rhizosphere microbiome to suppress seed‐borne pathogens is unknown. Here, the root‐associated microbiome is infested with seed‐borne Fusarium in sterile environment, while the root‐associated microbiome is not infested when it interacts with the native soil microbiome across maize cultivars, suggesting that a core rhizosphere microbiome assembles to suppress seed‐borne Fusarium. Two strategies of progressive dilution and rhizodepositional attraction are applied to identify the core rhizobacteria. A synthetic microbiota (SynM) is constructed using the isolates of the core rhizobacteria and optimized according to superior community stability and Fusarium‐suppression capability, which surpasses the single strain and randomly formed microbiota. The optimized SynM (OptSynM) presents a distinctive cooperative pattern in which a key strain harbors the Fusarium suppression function by synthesizing the antagonistic substance fengycin, while other members intensify the functional performance by promoting the growth and the expression of the antagonistic and plant‐growth‐promoting related genes of the key strain. This study demonstrates innovative approaches to construct stable and minimal microbiota for sustainable agriculture and proposes a unique cooperative pattern to sustain community stability and functionality. [ABSTRACT FROM AUTHOR]

This study presents a fault coil localisation approach for a direct‐drive permanent magnet synchronous motor (DDPMSM) with inter‐turn short‐circuit fault (ISF) using the search coil (SC) array. The SCs are wound around specific stator tooth of DDPMSM through the proposed SC array arrangement principle, which reduces the invasiveness of the fault coil localisation method. The SCs are classified as several search coil groups (SCGs), the differential between SC back electromotive forces (EMFs) in the same SCGs (δ1) and SC residual back EMF (δ2) are used as fault indicators for ISF localisation. The peak values extracted from δ1 and δ2 are the basis for diagnosing ISF. Hence, the proposed approach does not need a complicated signal processing algorithm, and it is less complex. First, the SC back EMF analytical model is developed to investigate the mapping relationship between the back EMF of each SC and fault coil location. Second, fault coil localisation indicators for ISF are analysed based on the proposed analytical model, and the exact ISF localisation approach is presented. Finally, two basic installation units and the arrangement principle of SC array in DDPMSM are proposed. Simulation and experimental results justify the effectiveness of the selected fault indicators and the feasibility of the proposed SC array for diagnosing ISF. [ABSTRACT FROM AUTHOR]

The nonlinearity of sinusoidal doubly salient electro-magnetic machine (SDSEM) leads to the fuzzy optimization range of its design parameters. And there is a conflict problem in multiple optimization objectives. Therefore, the multi-objective optimization of SDSEM with two different excitation modes is carried out based on the Gray-Fuzzy-Taguchi method. Firstly, the proposed sinusoidal method of square wave back electromotive force (EMF) phase modulation is introduced. And the key parameters to improve the symmetry and sinusoidal degree of the back EMF waveform are pointed out. Then, the sensitivity of key parameters is analyzed and the signal-to-noise (S/N) ratio is calculated by Taguchi orthogonal test. Secondly, the S/N ratio is linearly normalized by grey correlation analysis. Then, fuzzy reasoning is used to synthesize multiple performance indexes of the motor into a multiple performance characteristics index (MPCI) value, and the optimal scheme is obtained. Finally, the optimized SDSEM with concentrated magneto-motive forces (SDSEM-CF) and SDSEM with distributed magneto-motive forces (SDSEM-DF) are simulated and compared. The SDSEM-DF prototype is developed and verified by experiments. The results show that the no-load back EMF of the prototype has a good sinusoidal degree. Based on vector control, the sinusoidal drive of DSEM is realized without increasing the control complexity, which greatly reduces the torque ripple of the flux reluctance motor. [ABSTRACT FROM AUTHOR]

This paper studies a superconducting maglev submersible cryogenic liquid pump (CLP) using superconducting magnetic bearing (SMB). A new structure is proposed for the self‐stability of high‐temperature superconducting magnetic levitation, and the compact structure of disk motor‐pump. The rotor of the axial‐flux disk motor is connected with a centrifugal impeller to form an impeller‐rotor of the proposed superconducting CLP. Supported by a SMB system, the impeller‐rotor rotates frictionlessly with self‐stabilisation as a suspension rotor. The SMB system includes a radial‐type SMB, an auxiliary permanent magnet bearing, and an electromagnetic bearing composed of the stator and the rotor of disk motor. Theoretical calculations and experimental measurements are performed to examine the axial and radial levitation force behaviours of the SMB system. Then, a kinetic model of the suspension rotor is established and analysed to assure force balance and stable levitation. Finally, a prototype pump is fabricated and an experimental setup for liquid nitrogen transmission is constructed for validation purposes. The experimental tests on the pump head and the flow rate are carried out, which demonstrate the effectiveness of the proposed superconducting maglev submersible CLP. [ABSTRACT FROM AUTHOR]

The phase redundancy and freedom of the five-phase permanent magnet motor (FPPMM) enhance the reliability of the motor system. However, the temperature rise and torque reduction issues of the motor during open-circuit fault operation need to be further studied. In order to study the temperature distribution characteristics and the output capability of the motor under fault operation subject to temperature rise constraints, a 3-D global temperature field model containing a complex heat dissipation structure has been established. And the equal-amplitude temperature rise constraint current control method is proposed under open-circuit fault-tolerant operation to improve its output capability. The temperature distribution of the motor during steady state operation under rated operating conditions is analyzed with emphasis. Based on this, the temperature field changes of the motor during single-phase and two-phase open-circuit fault-tolerant operation are investigated. Then, the proposed equal-amplitude temperature rise constrained current method is introduced in detail to ensure the safe operation of the motor. An experimental platform is built, which verifies the accuracy of the temperature field calculation, as well as the correctness of equal-amplitude temperature rise constrained current method. [ABSTRACT FROM AUTHOR]

A permanent magnet synchronous motor (PMSM) is introduced with 120° phase belts toroidal windings (PBTWs) (120°PBTWPMSM), in which its armature reaction field principle is elaborated. Then, the experiment concerning the 120°PBTWPMSM is conducted to verify the validity of the related analysis and the feasibility of the 120°PBTWPMSM. In addition, a method of shifting the magnetic poles (SMP) is adopted to suppress the cogging torque and the torque ripple. After this, the 120°PBTWPMSM after SMP is further optimised by the Taguchi method to obtain the structural parameters of the motor with optimal comprehensive performance. Finally, the performance of the original motor, the 120°PBTWPMSM after SMP and the optimal motor are compared, which verify the effectiveness of the optimization methods. [ABSTRACT FROM AUTHOR]

Inter‐turn short‐circuit fault (ISF) degrades its reliability and may cause serious catastrophes for direct‐drive permanent magnet synchronous motor (DDPMSM). Fault location technology can reduce maintenance time, increase the mean time between failure (MTBF), and then improve the reliability of DDPMSM. Hence, an intelligent fault locating system for DDPMSM is proposed in this paper. This system proposes a knowledge graph (KG) based diagnostic tool for detection and location of the fault coil. First, the fault model of the DDPMSM with multiple branches parallel winding is established, which is used to analyze the fault characteristics of motor. Second, the BDC and BRC are proposed as the fault indicator. The effectiveness and robustness of fault indicator are analyzed. Then, the KG system are designed and established according to the relationship between fault indicator and location of fault coil. Finally, the system is tested by data under different fault and operation conditions. The test results showed that the proposed fault locating system can detect and locate the fault coil in early stage. The minimum ratio of shorted turns to branch turns that can be detected is 0.52%. The minimum ratio of shorted turns to branch turns that can be located is 6.25%. [ABSTRACT FROM AUTHOR]

Owing to its many benefits, including convenient and short computing time, the analytical model (AM) is widely used in the performance analyse of the permanent magnet synchronous motor (PMSM). The existing analytical models based on phase winding cannot sufficiently speculate about the contribution of the coil to the performances of direct‐drive PMSM (DDPMSM) with series coils and multiple branches. Hence, in this work, a novel AM for the DDPMSM is proposed. This model, which is based on the winding sub‐element, can analyse the influence of coil on motor performance. First, the structure and key parameters of the DDPMSM are reported. Second, an inductance matrix, which considers the spatial disposition of coils and the characteristics of large self‐inductance and small mutual inductance, is constructed. Then, the influence of the coil on motor performance is analysed based on the proposed AM. Finally, the results of AM, finite‐element model and experiment are compared. The results validate the correctness of the proposed AM. Furthermore, the proposed AM can speculate about the contribution of a coil in the DDPMSM performances with satisfactory accuracy. [ABSTRACT FROM AUTHOR]

The 2-degree-of-freedom direct drive induction motor (2DoFDDIM) is capable of implementing rotary linear or helical motion, which has the definite advantages of integrated structure, high material utilization, and so on. In this paper, the characteristics analysis of the three kinds of motions is presented. The air-gap magnetic field distributions and mechanical characteristics of the 2DoFDDIM with three motions are derived respectively. The results show that there is super synchronous speed or velocity phenomenon for rotary or linear motion. Moreover, the coupling effects between the rotating and travelling wave magnetic fields and that between the two mechanical motions will deteriorate the performance of the three-dimensional (3-D) helical motion compared with the two-dimensional (2-D) motion (rotary or linear). The expressions of the resistant torque and force caused by the coupling effect are derived, which are verified by 3-D finite-element models (FEMs). The results regarding the weakening of the output torque of helical motion and interacting magnetic field obtained from FEMs are then verified by experimental tests. Finally, the skewed slot method is applied to 2DoFDDIM, which successfully improves the performance of helical motion aiming to compensate the coupling resistant torque and force. [ABSTRACT FROM AUTHOR]

A two-degree-of-freedom direct-drive induction motor (2DoFDDIM), whose solid rotor is coated with a copper layer, is capable of linear, rotary, and helical motions and has widespread applications. For solid-rotor motors, the calculation and analysis of rotor total eddy current loss (TECL) are crucial in studying the factors causing such a loss and possible loss reduction methods. In this study, a new nonlinear analytical method considering the saturation of the rotor core is proposed to solve the fundamental magnetic field. The new method divides the time period into segments. The magnetic field distribution at any time is obtained using Maxwell equations. The eddy current losses in the copper layer and rotor core caused by the fundamental magnetic field are calculated. The surface eddy current losses in the copper layer and rotor core caused by harmonics are calculated using a 2D analytical method. TECL is determined by the sum of eddy current and surface eddy current losses. Coefficients are utilized to consider eddy, saturation, and end-region effects when calculating the rotor core TECL. The new method is verified using 3D FEM, and the results show the proposed method has higher accuracy than the original method. The errors of the rotor core and copper layer TECLs are less than 6 % and 7.3 % , respectively. [ABSTRACT FROM AUTHOR]

In this paper, the characteristics of the helical motion of the rotatory-linear 2-degree-of-freedom split-stator induction motor (2DoFSSIM) are investigated, which cannot be regarded as the simple superimposition of the 1DoF rotary and linear motions. A set of torque and force equations of the helical motion is deduced. It illustrates that the interacting electromagnetic torque and force are opposite to the directions of rotary and axial movements, respectively. For the rotating movement, the interacting torque is related to the axial velocity. Moreover, the axial velocity significantly influences the output torque performances and no-load speed. Similar conclusions can be obtained for axial movement of the helical motion. The 3-D finite-element method is applied to calculate the exact output performance considering the interacting influence. Furthermore, the prototype machine is manufactured and tested to verify the analytical results. [ABSTRACT FROM AUTHOR]

The original fuzzy-based Taguchi method is restricted with the number of objective functions. Aiming to solve this problem, this paper describes an improved fuzzy-based Taguchi method (IFBTM) coupled with finite-element analysis (FEA) for the multi-objective optimization of direct-drive permanent magnet synchronous motors (DDPMSMs). To reduce the number of dimensions in the fuzzy rule base, the IFBTM uses a factor stratification method to establish multilayer fuzzy rule base. The fuzzy inference system with multilayer fuzzy rule base is introduced to translate the multiple optimization objectives to a single objective. After optimal selection analysis, the best combination of motor structure factors is obtained with small FEA computation. Finally, the performances of DDPMSM are analyzed and compared with those of IFBTM. The results certify the superiority and validity of IFBTM. [ABSTRACT FROM AUTHOR]

This study presents a composite multilayer method (CMM) to evaluate the performance of a two‐degree‐of‐freedom (2DoF) direct drive induction motor (2DoFDDIM) whose solid rotor is coated with a copper layer. It includes a rotary part and a linear part. Based on the traditional multilayer theory, a complete 2DoFDDIM CMM computer program importing propagation constants is built. Due to the complex magnetic field in a 2DoFDDIM, this study mainly analyses it from the perspective of a single DOF motor. An equivalent circuit for the rotary part of the 2DoFDDIM is then derived applying CMM and the 2D magnetic field distribution is obtained by solving Maxwell's equations in motor layers. The developed torques, power factors and stator currents of the rotary part with different slips and the latter two of the linear part at zero speed are calculated by CMM, which are then compared with results from the finite element method (FEM) and experimental results. The computation time of the CMM is far less than that of the FEM. The acceptable accuracy confirms the effectiveness of the CMM for analysis and performance calculations of the 2DoFDDIM. [ABSTRACT FROM AUTHOR]

This paper proposes a demagnetization fault detection, mode recognition, magnetic pole positioning, and degree evaluation method for permanent magnet synchronous motors. First, the analytical model of the single-coil no-load back electromotive force (EMF) of demagnetization fault for Permanent magnet synchronous motor (PMSM) arbitrary magnetic poles is established. In the analytical model, the single-coil no-load back EMF residual of the health state and the single magnetic pole sequential demagnetization fault are calculated and normalized. Model results are used as the fault sample database. Second, the energy interval database of the single-coil no-load back EMF residual with different numbers of magnetic pole demagnetization is established. Demagnetization fault detection and degree evaluation are performed by the real-time acquired amplitudes of the single-coil no-load back EMF residual. The number of demagnetization poles is determined by comparing the energy of the single-coil no-load back EMF residual with the energy interval database. Demagnetization mode recognition and magnetic pole positioning are realized by analyzing the correlation coefficients between normalized the single-coil no-load back EMF residual and the fault sample database. Finally, results of analysis of the finite element simulation validate the feasibility and effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]