Development and validation of InDel markers for identification of QTL underlying flowering time in soybean

Soybean [Glycine max(L.) Merrill] is a major plant source of protein and oil. An accurate and well-saturated molecular linkage map is a prerequisite for forward genetic studies of gene function and for modern breeding for many useful agronomic traits. Next-generation sequence data available in public databases provides valuable information and offers new insights for rapid and efficient development of molecular markers. In this study, we attempted to show the feasibility and facility of using genomic resequencing data as raw material for identifying putative In Del markers. First, we identified 17,613 In Del sites among 56 soybean accessions and obtained 12,619 primer pairs. Second, we constructed a genetic map with a random subset of 2841 primer pairs and aligned 300 polymorphic markers with the 20 consensus linkage groups(LG). The total genetic distance was 2347.3 c M and the number of mapped markers per LG ranged from 10 to 23 with an average of 15 markers. The largest and smallest genetic distances between adjacent markers were 52.3 c M and 0.1 cM, respectively. Finally, we validated the genetic map constructed by newly developed In Del markers by QTL analysis of days to flowering(DTF) under different environments. One major QTL(qDTF4) and four minor QTL(qDTF20, qDTF13, qDTF12,and q DTF11) on 5 LGs were detected. These results demonstrate the utility of the In Del markers developed in this work for map-based cloning and molecular breeding in soybean.

Design and Analysis of Asymmetric Rotor Pole Type Bearingless Switched Reluctance Motor

Bearingless switched reluctance motor(BSRM) not only combines the merits of bearingless motor(BM) and switched reluctance motor(SRM), but also decreases the vibration and acoustic noise of SRM, so it could be a strong candidate for high-speed driving fields. Under the circumstances, a 12/14 BSRM with hybrid stator pole has been proposed due to its high output torque density and excellent decoupling characteristics between torque and suspension force. However, this motor has torque dead-zone, which leads to problems of self-start at some rotor positions and large torque ripple during normal operation. To solve the existing problems in the 12/14 type, an asymmetric rotor pole type BSRM is proposed. The structure and design process of the proposed motor is presented in detail. The characteristics of the proposed motor is analyzed and compared with that of the 12/14 type. Furthermore, prototype of the proposed structure is designed, manufactured and experimented. Finally, simulation and test results are illustrated and analyzed to prove the validity of the proposed structure.

Study on Calculation Model of High Speed Machine Silicon Steel Sheet Electromagnetic Characteristics Considering Magnetic, Stress and Temperature Condition

High-speed motor has the characteristics of high frequency, high temperature, and more stress, resulting in the field distribution inside the motor being complicated. To better study the electromagnetic characteristics of silicon steel sheet for high-speed motor. In this article, a study on the calculation model of silicon sheet electromagnetic characteristics considers the effects of electromagnetic, stress, and temperature factors. The study is divided into two parts, one is to propose the calculation model of silicon steel sheet’s permeability;the other is to improve the calculation model of silicon steel sheet’s loss. Then, the magnetic field, stress field, and temperature field of a surface mount high speed permanent magnet motor(SMHSPMSM) are analyzed by finite element method(FEM), and the results under the consideration of magnetic, stress, and temperature factors are brought into the calculation model for calculation. Finally, the accuracy of the calculation model for electromagnetic characteristics of silicon steel sheet is verified by comparing the calculated results with the finite element results.

Message from Editors

SPECIAL motor systems are high-efficiency and high-quality electromechanical energy conversion devices suitable for complex operating conditions.As key components,special motor systems are widely used in the fields of aerospace,energy,power,transportation,high-end manufacturing,etc.Innovations of fundamental theories and application technologies in special motor systems can promote the progress of related disciplines and fields,which has drawn great attentions from countries all over the world.

Message from Editors

IN recent years,4th Industrial Revolution and Industry 4.0 have swept the world and deeply influenced the development of global industry market.This movement arises wide attention to electric motor drive system which is playing an increasing important role in energy consumption transformation and environment protection.Amid this tremendous change in industry field,the concept of high-efficient,energy-saving and intelligent motor system has been proposed.On one hand,motor system with advantages such as low vibration,low noise,weak magnetic interference,renewable utilization capacity,high-efficiency and high-reliability could promote the progress of major industries such as mining,renewable energy and cutting-edged equipment manufacturing.On the other hand,the realization of intelligent and automated operations of motor drive system would help boosting the automation of industrial production.

Comprehensive Analysis of Suspending Force for Improved Bearingless Switched Reluctance Motor with Permanent Magnets in Stator Yoke

Different from conventional switched reluctance motor(SRM),bearingless SRM not only provides torque but also supplies levitation force for free-friction of rotor.In order to make sure that bearingless SRM can steadily levitates in static and dynamic rotating operation,it is necessary to analyze suspending force.Therefore,suspending force performance of an improved bearingless SRM with permanent magnets in stator yoke is comprehensively investigated in this paper.Basic structure and operation principle with permanent magnets in stator yoke are introduced firstly.Furthermore,mathematical model is built up for design of suspending force.In addition,parametric analysis for levitation performance is implemented.Finally,validity of proposed method is verified by experimental results.

Scalar induced gravitational waves in light of Pulsar Timing Array data

The power-law parametrization for the energy density spectrum of gravitational wave(GW)background is a useful tool to study its physics and origin.While scalar induced secondary gravitational waves(SIGWs)from some particular models fit the signal detected by NANOGrav,Parkers Pulsar Timing Array,European Pulsar Timing Array,and Chinese Pulsar Timing Array collaborations better than GWs from supermassive black hole binaries(SMBHBs),we test the consistency of the data with the infrared part of SIGWs which is somewhat independent of models.Through Bayesian analysis,we show that the infrared parts of SIGWs fit the data better than GW background from SMBHBs.The results give tentative evidence for SIGWs.

Fault-tolerant control of an open-winding brushless doublyfed wind power generator system with dual three-level converter

To improve the fault redundancy capability for the high reliability requirement of a brushless doubly-fed generation system applied to large offshore wind farms,the control winding of a brushless doubly-fed reluctance generator is designed as an open-winding structure.Consequently,the two ends of the control winding are connected via dual three-phase converters for the emerging open-winding structure.Therefore,a novel fault-tolerant control strategy based on the direct power control scheme is brought to focus in this paper.Based on the direct power control(DPC)strategy,the post-fault voltage vector selection method is explained in detail according to the fault types of the dual converters.The fault-tolerant control strategy proposed enables the open-winding brushless doubly-fed reluctance generator(BDFRG)system to operate normally in one,two,or three switches fault of the converter,simultaneously achieving power tracking control.The presented results verify the feasibility and validity of the scheme proposed.

Equivalent circuit and characteristic simulation of a brushless electrically excited synchronous wind power generator

A brushless electrically excited synchronous generator （BEESG） with a hybrid rotor is a novel electrically excited synchronous generator. The BEESG proposed in this paper is composed of a conventional stator with two different sets of windings with different pole numbers, and a hybrid rotor with powerful coupling capacity. The pole number of the rotor is different from those of the stator windings. Thus, an analysis method different from that applied to conventional generators should be applied to the BEESG. In view of this problem, the equivalent circuit and electromagnetic torque expression of the BEESG are derived on the basis of electromagnetic relation of the proposed generator. The generator is simulated and tested experimentally using the established equivalent circuit model. The experimental and simulation data are then analyzed and compared. Results show the validity of the equivalent circuit model.

Overview of Research and Development Status of Brushless Doubly-Fed Machine System

The brushless doubly-fed machine(BDFM)has been widely used due to its advantages of robustness,reliable operation,ease of maintenance,adjustable power factor,small converter capacity and low cost.BDFM is attractive for use in many applications such as variable frequency speed regulation systems and variable speed constant frequency generation systems.Hence,there is a rapidly growing interest in design and control of BDFM.In this paper,the origin and development of BDFM are reviewed,the structural characteristics of BDFM are discussed at length,the principles of operation and design are analyzed,and the different control methods used for BDFM are overviewed and compared in detail.Finally,challenges and opportunities of BDFM are concluded.