DISCUSSION ON SOME PROBLEMS OF USING THE CASCADE SPEED CONTROL IN ALTERNATING CRANE

Whether the cascade speed control system can be successfully used in cranernot is an mioportant research topic for electric machinery engineers in rec-ent years.This paper analyses many probleme involved in the cascade speedcontrol detail,iin ncluding the power transfer relationship,the mechanicalcharacteristics and its fitting with the load characteristics,the calculationsofahe cpacitancet and the parameters of the (?)ariable current device in thisspeed control system,and others.This paper laso gives the comparison be-cascade spee een tehtwd control and the rotor resistance control methods.     

半导体制冷装置测定食品过冷点及冰点的研究

冰点温度的准确测定是确定食品适宜贮藏温度的关键。针对当前冰点测定方法和设备存在着测定周期长、成本较高以及设备移动不便等缺陷,本研究优化设计出一种新型的半导体制冷测定装置。该制冷装置利用半导体制冷快速降温,通过记录仪中的样品降温曲线可以清楚看到被测定样品的降温过程和相应的过冷点、冰点及整个相变过程。采用该装置对猪肉、苹果、牛奶葡萄、黄瓜、牛奶多种典型食品的过冷点和冰点进行测定。结果表明,与现有过冷点、冰点测定技术和装置相比,该测定装置具有小巧灵活,操作便利,精确度高,测定周期短、成本低的优势,而且测定过程中噪音极小,适于在冰温贮藏领域广泛应用。     

Calculation of lumped parameter of two-port network forvolume conduction energy transfer

Skin electrode unit is a channel through which energy can be transferred to the implanted device by volume conduction. The unit can be equivalent to lumped circuit, but so far there are no appropriate calculation methods of these circuit parameters, so variable load method based on field-circuit coupled is proposed. A skin electrode unit field circuit coupled model is established to obtain the relationship of the network parameters between voltage and current at electrode port, and the amplitude and phase of the power signal is extracted by the use of all phase FFT spectrum analysis. On this basis, equivalent circuit impedance parameters of the skin electrode unit under various conditions are obtained by the application of variable load method and the validity of the method is verified. As a result, the equivalent circuit impedance parameters obtained in this way can be used for the circuit analysis and optimization of the volume conduction energy transfer system.     

纯电动车车用复合储能装置控制策略及参数优化

为解决目前纯电动车动力电池比功率不足的缺陷,对纯电动车的储能装置进行了研究。根据复合储能装置的特点和目的,制定了复合储能装置的工作模式,提出了基于速度与电流约束的模糊控制策略。为了进一步提高整车性能并降低蓄电池的输出电流,对复合储能装置的关键参数进行了线性优化,仿真结果表明:加装复合储能装置的纯电动车的加速时间缩短了12%,制动能量回收效率提高了39%,百公里耗电量减少了8.55%,并显著降低了蓄电池的输出电流,有效延长了蓄电池使用寿命和整车的续驶里程。     

Integrate Reset Controlled Three Phase Power Factor Correction

A three phase power factor corrector in continuous current mode is introduced. The control equations are deduced and realized by Integrate reset controller. The integrate reset controller is composed of a integration with reset,a RS flip-flop and a comparator,which is very simple. The integrate reset controlled three phase power factor corrector has these characteristics as follows: Constant frequency operation, which is of advantage of the design of filter;the control circuit is simple and no need for multiplier;The result of simulation proves the correction of theory analysis.     

插电式混合动力汽车能量管理策略研究现状和发展趋势

目前国内外学者对插电式混合动力汽车能量管理策略进行了较为广泛和深入的研究,取得了良好的节能减排效果,为进一步提升其性能,有必要对插电式混合动力汽车能量管理策略的研究现状进行总结并对其发展趋势进行分析。首先对插电式混合动力汽车动力源能量流分配方法进行了归纳和分析,指出了当前插电式混合动力汽车能量管理策略两个亟待解决的问题：未考虑发动机冷却液温度和三元催化器温度等温度因素对油耗和排放影响;当前插电式混合动力汽车能量管理策略是以行驶功率需求作为输入,忽略了驾驶室制冷/供暖功率需求。最后提出了计及发动机冷却液温度和三元催化器温度等温度因素的能量管理策略和计及驾驶室制冷/供暖功率需求的能量管理策略两个未来研究方向。     

Analysis and experiment for reliability of power module driving circuit in renewable energy conversion system

Reducing the driving resistance for the present push-pull driving circuit for power module will make the time shorter,but this process will result in the increase of current and voltage thermal stress. Therefore,a novel driving method based on dSPACE is introduced and validated on the basis of analyzing the failure mechanism and thermal model of power module. The ascending theory of case-temperature is investigated and then an exponential curve is achieved for power module. Experiments prove that the method has a good driving and protective performance,and it effectively reduces harmonics of output current and voltage in the new energy conversion system,and enhances the voltage utilization rate and waveforms quality. Thus the reliability of power module is greatly improved.     

Optimizing energy generation from Hawaii's biomass sources: A new approach

The concept of a central power plant, with its attendant economies of scale and advanced technology, as opposed to fragmented, small-scale operations by individual plantations, is examined in the context of energy generation from Hawaii's biomass sources. The thesis that the most cost-effective conversion of Hawaii's biomass sources to electricity can be best accomplished by such a power plant is developed. The study also suggests that it is cheaper to produce electric power from a biomass-fueled plant than from a fuel oil-based facility.     

Influence Analysis Energy and Environment with DSM

As a large burning coal country, resolving the SO2 letting problem is the most important thing in the environment protection work. Electric power industry reveals the supply's load rate declining and the discrepancy between apex and vale augments year after year. It makes the load adjustment become an imminency task in the electric power industry. The article popularizes the light power saving technology in the inhabitant living lighting power through reinforcing the DSM technology. It studies the influence on energy and environment after using the technology. It studies avoidable electricity quantity, avoidable electricity power, avoidable apex load, avoidable coal consuming and avoidable SO2 lettling. At last, it makes a concrete analysis with a city's example.     

The power-supply of X-ray machine adopting PID control and high-frequency inverter technology

To solve the problem of low control accuracy and low stability of current X-ray machines, a kind of digital power supply for X-ray machine is introduced. In the digital power supply, some key technologies are used to improve the output stability of the high frequency inverter, including improved BUCK circuit for voltage regulating circuit, high frequency inverter and soft switching technology for the high-voltage generator. The PWM control technology is used to control the switch transistor of voltage regulating circuit and inverter circuit, which makes the drive waveform output stable and easy to control. In order to improve the control accuracy, reduce the volume and change high voltage consecutively, the software PID of the microcomputer is used to control the feedback circuit. The high-accuracy power chip is used for the filament power supply to make the filament electric current stable. Through the analysis of the circuit, the parameters of the circuit are calculated and the circuit is simulated by PSPICE software. The results show that the theoretical analysis is consistent with the practical simulation results. The design can meet the requirement of the technology indices of the power supply of the X-ray machines.     

Application of Sound Intensity Technique to Measure the Noise of Electromotor

This paper has explained the characteristics,virtue of sound intensity measurement and the principle. And compare with traditional sound pressure measurement. The principle and composing of virtual sound intensity measurement system based on two-channel FFT analysis are researched. The sound power of large turbogeneratorin operating site is determined by means of sound intensity measurement and sound pressuremeasurement. Itis demonstrated that the method of sound intensity measurement of engine is practicable and the measuring data are valid and the method conquers the problems of traditional method of sound pressure measurement which is apt to environmentinfluence and sound power measurement need to especially acoustic environment. It is proved that the sound intensity method is especially suited to determine highaccuratelythe sound Power level of the electrical machines operating in situated conditions especially in case of acoustically worst environments or on loadand themethod is so superiorityin noise measurement.     

A model for volume conduction energy transfer

One of the important technical problems of various implantable devices concerns effectively supplying sufficient energy to allow devices to work for extended periods, steadily and reliably. Presently, batteries and magnetic induction are only power supplies widely used in clinics. Because the capability of batteries is limited, implantable devices have shorter lives and low energy transfer efficiencies. We presented a means of transferring electrical energy into rechargeable batteries in implantable device by using volume conduction of biological organisms. An energy transfer model of volume conduction was created using ANSYS V10. We analyzed the energy transfer efficiency from simulation results and provide reference for further study of energy transfer of volume conduction.     

采用Extracellular Flux Analyzer方法测定植物线粒体能量代谢

线粒体是植物进行呼吸和能量代谢的主要场所,但目前关于线粒体能量代谢的测定方法较为繁琐,亟需一种快速有效测定线粒体能量代谢的手段。本研究采用Extracellular Flux Analyzer(Seahorse Bioscience,America)方法对玉兰(Magnolia denudata)花部器官线粒体代谢情况进行测定,并对测试技术进行改进。通过直接测定氧气消耗速率,进而检测组织细胞内的线粒体呼吸速率和能量代谢。采用该方法对同一组织样品进行多次测量,测量结果稳定,表明该方法是一种可靠的测定线粒体呼吸和能量代谢的方法。并且,通过加入不同的呼吸抑制剂来鉴定细胞的呼吸途径,可快速获取有效数据。此外,还可直接对组织内线粒体的呼吸代谢进行测定,简便性、实时性均优于其他线粒体代谢测定方法,是一种快速有效,且可以进行实时动态观测的试验方法。     

A coordinated state transition control strategy for microgrid with multi-energy generation systems

A coordinated control strategy is proposed based on state transition for a microgrid containing continuous or intermittent DG, energy storage device and sensitive loads. According to the available operation states, a scheme of operation state transition is established through setting the current operation state and trigger event as inputs of MGCC and regarding the control modes of components as outputs. By considering the no deviation control for frequency and the capacity limitation of energy storage device under all operation states, control modes of components and trigger events of state transition under all defined states are designed respectively for a reliable power supply of sensitive load. The PSCAD/EMTDC simulation software is used for analysis of the three typical transition processes of operation states. The results show that the proposed coordinated control strategy is effective for a safe and reliable power supply to the sensitive loads and ensures a smoothing transition between operation states of microgrid as well as the no deviation control of system frequency.     

The study on Harmonic Wave Compensation Method of a SCR Regulating-Speed Control Filter Device in a Serosystem

We have studied the method of eliminating the harmonic wave of SCR regulating-speed device a servosystem and increasing its power supply unit' s loading ability when its current is large. Compared with other methods by experiment,we think the compensation method using micro-computer to auto control harmonic wave filter compensation is simpler and more practical.     

Sustainable Development of Chongqing Energy Industry

The idea of the sustainable development is proposed by analyzing the present Chongqing energy industry. Enumerated some energy technologyies and energy forms, which not only save energy but also reduce enviromental pollution. Some suggestion on the development of Chongqing energy industry is given. The main content is the following:Electricity should be developed first when developing energy industry. The government should exploit and apply the technology of the clean coal, develop equipments generating electricity with gasvapor cycle, and improve actively advanced technology of thermal power joint production and thermal power cooling joint supply. It is also necessary to make full use of natural gas in favour of developing sustainable energy industry and take advantage of three gorges area. Some useful suggestions are given at last.     

Transaction Cost During Reform Process of Separation ofNetwork Operations and Generation, and Making Electric Generation Market Competitive in Power Market

This paper analyzes interior transaction cost before the reform of separation of network operations and generation, and making electric generation market competitive in power industry, and market transaction cost in complete power market with the theory of transaction cost in china on the basis of the actuality and characteristic of Chinese power industry,then the describtion and the scalar comparisim are done between two costs by curve and mathematics. Based on the economic theory,the authors analyze the compare result,and come out the economic term of separation of network operations and generation in power industry, that is to say that there isn't economic reason when the electric plant lies in the phase of scale reward increasing by degrees,on contrast,when the electric plant lies in the phase of scale reward decreasing by degrees,the reform should be done step by step.     

An Investigation on Measuring Surface Viscosity of Melting Slag

Several methods of measuring surface vescosity are discussed. An appropriate method for measuring surface viscosity of melting slag- the laser method is proposed as well as an experimental device is set. With the device the surface viscosities of some aqueors liguids are measured. The results verify that the device is feasible and lays a good foundation for measuring the surface viscosity of melting slag.     

对母猪不发情的原因调查及防治措施的研究

母猪不发情导致的不孕是困扰养猪生产的一个突出问题。为了深刻认识母猪不发情的原因,在豫北三市进行了专项调查,先天性、饲养性、繁殖技术性、气候与水土性、衰老性和疾病性等原因均可造成母猪不发情。对这些原因进行了分类统计,调查结果表明：饲养因素占54.95%,先天因素占6.5%,气候与水土因素占6.59%,繁殖技术因素占4.3%,疾病因素占27.47%。通过对母猪不发情原因的调查,有针对性地提出了预防和治疗的办法,实践证明,采取综合性的防治措施,可明显改善母猪不发情状况。     

The Study Evolution of Gear Electric Erosion Phenomenon

This paper introduces phenomenon of electric erosion of gear and the research condition and evolution of it; puts forward a point of view that a system of electric erosion of gear is a especial tribology system which is in relation to many subjects and in which many phenomena exist and coupling each other , moreover , it is very difficult and complex to study electric erosion of gear by experiment ; have made statistical datas about typical example of electric erosion of gear inland ,at this base ,summarizes characters of electric erosion of gear and the study means of it.