转子极数对无刷双馈电机径向电磁力的影响

无刷双馈电机运行时依靠有用磁场分量实现机电能量转化,因而产生径向电磁力不平衡、振动和噪声问题,制约了产业化进程。基于无刷双馈电机径向电磁力的产生机理,借助解析法和有限元分析法,对气隙磁场进行分析,计算出气隙磁密的切向分量,进一步得到不同时刻、不同位置的径向电磁力,从而分析不同极数、极数配合、凸极数等因素对径向电磁力的影响,得出其影响径向电磁力的通用规律。研制了8/4极无刷双馈试验样机并进行了振动试验测试,证明了结论的有效性,为无刷双馈电机的开发设计提供了重要的参考依据。     

机电材料"期货库"管理

以引额济乌陕工局 标项目经理部机电材料"期货库"的管理模式,谈谈对于施工企业项目经理部进行机电材料管理方面的一些探索。     

A Double Excited Synchronous Machine for Direct Drive Application—Design and Prototype Tests

This paper presents the analytical, numerical, and experimental results obtained with a double excited synchronous machine (DESM) prototype designed and constructed for an electric vehicle traction system. To obtain a wide speed range, the flux-weakening technique is implemented. Analytical design, 2-D finite element method (FEM) analysis, thermal analysis, and prototype construction of the DESM are discussed, and the performances are assessed with experimental data.     

工业企业能源管理信息系统研究

针对工业企业能源管理信息系统(EEMIS)建设过程中缺乏能效诊断技术的问题,在传统信息系统和自动化系统的基础上,通过机理建模和机器学习相结合的方法,研究了重点用能设备、耗能工序和能量系统的能效分析模型,提出了一种新型的EEMIS的结构和功能,并开发了软件,弥补了EEMIS在能效分析诊断方面的不足,增强了系统的实用性。     

Approximate analytical model for PCM solidification in a rectangular finned container with convective cooling boundaries

Thermal energy storage units that utilize latent heat storage materials have received increased attention in the recent years because of their relatively large heat storage capacities and isothermal behavior during charging and discharging. In this study, an analytical approach is presented for the prediction of temperature during the solidification in a two-dimensional rectangular latent heat storage using a phase change material (PCM) with internal plate fins. The basic energy equation is formulated accounting for the presence of a heat thermal fluid (HTF) on the walls. A two-dimensional numerical model is developed based on the enthalpy method to predict the distribution temperature of the fin and solid–liquid interface in storage. Results from the analytical solution and numerical model show a good agreement. The developed analytical model estimates satisfactorily the solidification time of PCM in storage, which is useful in the design of PCM-based thermal energy storages and cooling systems.     

原生污水冷热源经济节能性研究

分析探讨了城市原生污水源的特点及其热泵系统的优缺点.以哈尔滨地区的工程实际为例,对城市原生污水源热泵、天然气直燃热泵机组、燃煤锅炉加电力冷水机组进行了经济性、环保性比较.结果表明,城市原生污水源热泵系统优于另两个系统.     

PSPICE simulation of single-phase induction motors

Dynamic analysis of a single-phase induction motor is studied using PSPICE software. The machine dynamics are presented by a set of nonlinear time-varying differential equations. The equations which define the motor operation are represented in an orthogonal system. The electric circuit presenting this set of equations is determined and solved by PSPICE software for simulation of the motor. The simulation results are compared with those obtained by EMTP and the experiment. Good agreements are observed for both cases     

同步电机转子初始位置测量方法

为使电机顺利起动,并获得最大的起动转矩,需要测量同步电机的转子初始位置,以确定合适的起动电压。在分析电机感应电动势的基础上,通过坐标变换推导出同步电机的转子初始位置计算方法,并通过仿真和试验验证了该方法的可行性。     

Research progress on cathode materials for high energy density lithium ion batteries

便携式电子设备的微型化、轻量化与电动汽车、电网储能设备的飞速发展,对高能量密度的锂离子电池的研发和性能表现提出了越来越高的要求。锂离子电池正极材料是锂离子电池的核心,其提供锂离子并参与电化学反应,因此改善正极材料性能是提高锂离子电池能量密度的关键。人们需要进一步研究开发成本较低、安全性更好的高能量密度新型锂离子电池正极材料。本文主要从提升正极材料的比容量和工作电压两方面介绍三元、富锂锰基材料和高电位镍锰酸锂等高比能量正极材料的介尺度结构设计、制备与性能调控研发进展。     

Numerical simulation of nanostructured thermoelectric generator considering surface to surrounding convection

Thermoelectric systems (TE) can directly convert heat to electricity and vice-versa by using semiconductor materials. Therefore, coupling between heat transfer and electric field potential is important to predict the performance of thermoelectric generator (TEG) systems. This paper develops a general two-dimensional numerical model of a TEG system using nanostructured thermoelectric semiconductor materials. A TEG with p-type nanostructured material of Bismuth Antimony Telluride (BiSbTe) and n-type Bismuth Telluride (Bi₂Te₃) with 0.1 vol.% Silicon Carbide (SiC) nanoparticles is considered for performance evaluations. Coupled TE equations with temperature dependant transport properties are used after incorporating Fourier heat conduction, Joule heating, Seebeck effect, Peltier effect, and Thomson effect. The effects of temperature difference between the hot and cold junctions and surface to surrounding convective on different output parameters (e.g., thermal and electric fields, power generation, thermal efficiency, and current) are studied. Selected results obtained from current numerical analysis are compared with the results obtained from analytical model available in the literature. There is a good agreement between the numerical and analytical results. The numerical results show that as temperature difference increases output power and amount of current generated increase. Moreover, it is quite apparent that convective boundary condition deteriorates the performance of TEG.     

Heat transfer and thermophotovoltaic power generation in oil-fired heating systems

The focus of this study is the production of electric power in an oil-fired, residential heating system using thermophotovoltaic (TPV) conversion devices. This work uses experimental, computational, and analytical methods to investigate thermal mechanisms that drive electric power production in the TPV systems. An objective of this work is to produce results that will lead to the development of systems that generate enough electricity such that the boiler is self-powering. An important design constraint employed in this investigation is the use of conventional, yellow-flame oil burners, integrated with a typical boiler. The power production target for the systems developed here is 100 W – the power requirement for a boiler that uses low-power auxiliary components. The important heat transfer coupling mechanisms that drive power production in the systems studied are discussed. The results of this work may lead to the development of systems that export power to the home electric system.     

Solar thermal electric power systems in Japan

The major subjects of this paper are to report the outline of the recent basic research and technical development for solar thermal electric power systems in Japan. Solar thermal electric power systems are presently being developed as one of the most important systems in Sunshine Projects which were initiated in 1974 to develop the utilization systems of new energy resources. Conceptional designs of solar thermal power systems were already done on the basis of the results of the supporting researches and two pilot plants of solar thermal electric power systems of a capacity of 1000 kWe are under construction on the basis of the conceptional and detailed designs and would be constructed by 1981. The present conditions of these pilot plants and the major researches which are thought to be most important subjects in the basic researches and technical developments for solar thermal electric power systems are described in this paper.     

Materials Informatics for Heat Transfer: Recent Progresses and Perspectives

ABSTRACT

With the advances in materials and integration of electronics and thermoelectrics, the demand for novel crystalline materials with ultimate high/low thermal conductivity is increasing. However, search for optimal thermal materials is a challenge due to the tremendous degrees of freedom in the composition and structure of crystal compounds and nanostructures, and thus empirical search would be exhausting. Materials informatics, which combines the simulation/experiment with machine learning, is now gaining great attention as a tool to accelerate the search of novel thermal materials. In this review, we discuss recent progress in developing materials informatics (MI) for heat transport: the exploration of crystals with high/low-thermal conductivity via high-throughput screening, and nanostructure design for high/low-thermal conductance using the Bayesian optimization and Monte Carlo tree search. The progresses show that the MI methods are useful for designing thermal functional materials. We end by addressing the remaining issues and challenges for further development.     

水轮发电机交流励磁的自动控制

随着电力电子技术与数字控制技术的发展，交流励磁电机应运而生，它有优于传统同步电机的性能。本文论述了水轮发电机交流励磁的原理和特点，对它的可行性进行了分析及论证。并介绍了采用交一直一交变频器对转子绕组进行控制的方法。根据SPWM控制原理，变频器的控制部分采用了软硬结合的方法进行调节。     

A generalized 3-D dynamic modelling for transverse flux homopolarlinear machines based on statistical saliency-effect superpositionmethod

This paper presents a prototype of a transverse flux homopolar linear machine system, along with a systematic and generalized 3-D approach which is capable of analyzing three kinds of these linear machines: the transverse flux linear induction machine; the homopolar linear synchronous machine; and the transverse flux linear reluctance machine; all in one compact mathematical model. A novel methodology which combines the state-space technique with the statistical saliency effect superposition method is proposed. With such a detailed and generalized modelling approach, the capability of analyzing the saliency effects induced by the distributed windings in practical linear machine systems is enhanced, and the representations of all the related linear machine system equations can be manipulated in compact matrix forms. Experimental verifications confirm that this comprehensive theoretical approach is a convenient and reliable mathematical basis for computer-aided analysis and design studies on linear machine systems     

Energy sources and multi-input DC-DC converters used in hybrid electric vehicle applications – A review

With the drastic inclination towards reduction of atmospheric issues, hybrid electric vehicles are becoming the major alternative for internal combustion engine vehicles. Compared to internal combustion engine vehicles, hybrid electric vehicles are remarkable in terms of efficiency, durability and acceleration capability. However, the major drawback of hybrid electric vehicle is energy storage capability. An electric vehicle requires the energy sources with high specific power (W/kg) and high specific energy (Wh/kg) to reduce the charging time. Generally, fuel cells, batteries, ultracapacitors, flywheels and regenerative braking systems are used in hybrid electric vehicles as energy sources and energy storage devices. All these energy storage devices are connected to the different DC-DC converter topologies to increase the input source voltage. From the recent past, most of the hybrid electric vehicles are using multi-input converters to connect more than one energy source in order to improve the efficiency and reliability of the vehicle. This survey presents an assessment of present and future trend of energy storage devices and different multi-input DC-DC converter topologies that are being used in hybrid electric vehicles. In addition, different electric vehicle architectures are also discussed.     

大型汽轮发电机通风冷却方式研究

大容量汽轮发电机由于具有良好的经济性而成为电力工业和电机制造业的发展重点。汽轮发电机通风冷却方式与单机容量和性能之间存在制约的关系，是汽轮发电机向大容量、高参数发展时需要解决的关键问题之一。分析了汽轮发电机冷却方式的发展过程以及目前的发展状况和发展趋势，同时对不同冷却方式的特点和适用范围的进行了比较。     

Decoupled control of rotor torque and rotor electric power delivered in a salient-pole, synchronous machine

A drive system with a control algorithm that provides independent control of rotor torque and rotor electric power is described in this paper. One electromechanical machine is used for two purposes, viz., firstly to provide electromagnetic torque to rotate a rotor mounted load and secondly to provide electric power to equipment mounted on the rotor. The technique eliminates the need for slip rings. Simulation and practical results verifying the analysis are given. The system has applications such as rotational antennas and turret systems.     

飞轮壳二工位钻、镗、攻丝机床的电气设计

本文针对 Ｄ６１１４柴油机飞轮壳二工位钻、镗、攻丝机床电气部分从硬件选型及电气原理和软件设计及程序中重要保护、自锁等方面剖析了在非标机床电气设计上应注意的问题及解决办法。     

基于单机无穷大等效的暂态稳定约束最优潮流算法

为解决传统的考虑暂态稳定约束的最优潮流(TSOPF)方法暂态约束条件数量庞大、计算复杂性高等问题,可通过修改Matpower工具包和PSS/E软件,进而实现了一种故障初始时刻考虑暂态约束的TSOPF算法,通过对等效系统初始稳态功角偏差的约束,一般TSOPF方法中数量庞大、复杂的暂态约束条件被简化为数量唯一的稳态约束条件,TSOPF方法的问题规模被降低到与传统最优潮流问题相同的程度。基于IEEE3机9节点系统和10机新英格兰系统的算例,验证了该算法的有效性。