变频技术在地下水源热泵系统中的应用

目的在地下水源热泵空调系统中,热泵机组大部分时间都在部分负荷运行,而深井泵不能随着热泵机组负荷变化而进行调节,一直处于满负荷运行,结果造成了深井泵的电费及水费的大量增加.为了能够减少深井泵的耗电量和供水量,节省运行费用.方法笔者采用理论分析和实验测量的方法,确定了某高校办公楼地下水源热泵系统深井泵变频范围和变频后整个冬季供暖期的耗电量和供水量,研究了深井泵变频调速供水节能效果和经济性.结果研究表明,深井泵采用变频调速技术后,整个冬季供暖期节省井水量404369m3,耗电量105247 9kw·h.节约运行费用16 8万元.结论得出了在地下水源热泵空调系统中,深井泵采用变频调速供水技术,可明显地节省运行费用,带来显著的经济效益.     

Engel群的几个性质

借助于Engel群上的基向量场给出了Engel群上光滑函数的泰勒展开式和群上乘法，并将粘性解定义和绝对最小者定义扩充到Engel群上，讨论了在粘性解意义下无限调和函数的存在惟一性，无限调和函数与绝对最小者的关系，得到了绝对最小者的惟一性．     

异步电动机实心转子功率损耗计算

在异步电动机实心转子表面建立空间坐标,假定磁导率恒定和材料各向同性的条件下建立麦克斯韦方程,并用傅立叶级数表示方程的解,得到磁场强度瞬时值的表达式,在此基础上求得其有功损耗。     

非正弦状态下三相异步电机无功功率测试研究

在分析了时域无功功率和频域无功功率定义后，基于Hilbert变换理论，提出了适合三相异步电机无功功率测量算法．并利用牛顿二阶插值算法来进行电压电流数据的同步运算。测试算法符合考虑谐波的设计要求。     

The location of a resistive shunt harmonic impedance along a distribution feeder and its influence on harmonic propagation

Although complete compensation is only possible using true active filters, resistive shunt harmonic impedances (SHI) have been shown to provide a considerable reduction of the harmonic propagation. In this paper, the harmonic mitigation potential of a resistive SHI is discussed concerning its influence on the voltage distortion profile along a typical distribution feeder, with the location of the SHI along the feeder as a parameter. Although the distortion values are dependent on the SHI location, it is shown that the end of the feeder is generally a good location to install the SHI, especially when the power system parameters can vary or are unknown. Calculations are performed on a typical radial distribution feeder. Both the power factor correction capacitors and the non-linear loads are concentrated in single nodes. The linear loads are disconnected to obtain the worst case for the voltage distortion. Also some measurements on a scale model of a typical distribution feeder are done and the experimental results confirm the results obtained from simulations.     

基于小波分析的光栅信号质量评估方法

依据谐波分析法给出的评定信号质量指标的准则，提出了基于小波分析的光栅信号质量评估方法，并讨论了此方法的特征与优点。与谐波分析法相比较，小波分析在时域和频域同时具有良好的局部化性质，每次小波变换所取的都是原信号的最大可能近似值，信号的失真度小，通过变更尺度，可以对信号更细微的瞬态特征进行研究，并最大可能地除去噪声，较快地得到理想的质量评定效果(通常只需3至5次变换即可)。在此基础上，给出了相应的小波分析评定光栅信号质量的实验方法。     

PROFIBUS-DP与HART协议转换研究及其网关设计

介绍了PROFIBUS和HART两种现场总线的特点,探讨了两种现场总线的协议的转换方法,并成功开发出了可将两种总线进行互连的网关模块,实现了两种现场总线的底层互连。     

Novel SIS resonators waveguide filters

A novel stepped‐impedance slot (SIS) resonator waveguide band‐pass filter with quarter‐wave couplings is investigated. SIS resonators have been studied in order to increase the stopband width between the fundamental and spurious harmonic resonant frequencies. They have been employed in the design of waveguide band‐pass filters with good harmonic suppression. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

Color‐conversion method for a multi‐primary display to reduce power consumption and conversion time

Abstract— A color‐conversion method for a light‐emitting multi‐primary‐color display is proposed. While amulti‐primary‐color display uses four or more primary colors to reproduce a wide color gamut, multiple sets of primary‐color signals are needed to reproduce one color. Therefore, linear programming, which results in low power consumption, was adopted to uniquely determine the set of primary‐color signals. Although a highly accurate color conversion was achieved by using linear programming with low power consumption, it requires a very long time to convert colors of high‐resolution images. Therefore, by categorizing the color conversion of linear programming as a classification problem, colors are converted by using the decision‐tree method, which is a classification method. As a result, color conversion with high accuracy, low power consumption, and short conversion time was achieved.     

A Broadband Quadrature-Modulator in Standard 0.13 μm CMOS

A polyphase filtering topology is proposed which uses parallel switchable RC-networks for accurate broadband 90^∘ phasing. A 0.13μm CMOS prototype using the quadrature-generation network in a direct-conversion quadrature-modulator achieves a measured image-rejection ratio of −39 dBc or better in 0.6–2.5 GHz while consuming only 66 mW from a 2.2 V single supply. Esa Tiiliharjuwas born in Rovaniemi, Finland, in 1966. He received the M.Sc. degree in Information Technology in 1995, and the Lic.Tech degree in electrical engineering in 1998, both from Helsinki University of Technology, Finland. From 1996 to July 1997 he was employed as an assistant at Helsinki University of Technology. He has held a position as a research assistant since 1997, and he is currently working towards his Ph.D. degree in the Electronic Circuit Design Laboratory at Helsinki University of Technology. His research interests include the design of integrated low-power circuits for portable telecommunication applications. He has designed and measured several integrated circuits for this application area. He is the author or co-author of several internationally-refereed conference and journal publications on analog integrated circuits. Kari A.I. Halonenwas born in Helsinki, Finland, on May 23, 1958. He received the M.Sc. degree in electrical engineering from the Helsinki University of Technology (HUT) in 1982 and the Ph.D. degree in electrical engineering from the Katholieke Universiteit Leuven, Heverlee, Belgium, in 1987. From 1982 to 1984, he was with HUT as an Assistant and with the Technical Research Center of Finland as a Research Assistant. From 1984 to 1987, he was a Research Assistant with the E.S.A.T. Laboratory, Katholieke Universiteit Leuven, with a temporary grant from the Academy of Finland. Since 1988, he has been with the Electronic Circuit Design Laboratory, HUT, as a Senior Assistant from 1988 to 1990, and as the Director of the Integrated Circuit Design Unit of the Microelectronics Center from 1990 to 1993. He was on leave of absence during the academic year 1992–1993, acting as Research and Development Manager with Fincitec Inc., Finland. From 1993 to 1996, he was an Associate Professor, and since 1997, he has been a full Professor with the Faculty of Electrical Engineering and Telecommunications, HUT. He became the Head of Electronic Circuit Design Laboratory year 1998. He was the Technical Program Committee Chairman for the European Solid-State Circuits Conference in 2000. He is the author or coauthor of over 150 international and national conference and journal publications on analog integrated circuits, and holds several patents on analog integrated circuits. His research interests are in CMOS and BiCMOS analog integrated circuits, particularly for telecommunication applications. Dr. Halonen was an Associate Editor of the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS–PART I: FUNDAMENTAL THEORY AND APPLICATIONS from 1997 to 1999. He has been a Guest Editor for the IEEE JOURNAL OF SOLID-STATE CIRCUITS. He received the BeatriceWinner Award from the IEEE International Solid-State Circuits Conference in 2002.[c-halonen.eps]