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介绍了油田配电自动化系统的主要功能,阐述了该系统的软硬件结构、通信方式的选择,以及系统远程重构的实现方法.基于GPRS网络的配电自动化通信方案能够提供高速、可靠、安全的无线连接,实现无处不在的I P通信,为配电网的自动化提供了一个理想的通讯平台. 相似文献
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为准确测量油井中的油位,以便提高抽油机工作效率,研究设计了基于单片机实现的测控系统.系统以AT89 C2051单片机为主控制器,用新型振动模式超声波探头和超声波接收器构成油液位检测电路及LED数字显示器,从而对油井油位检测、显示和对抽油机工作状态进行控制.采用单线数字温度传感器为核心的温度补偿电路,以校正由于检测电路工作环境温度变化引起的测量误差,提高了系统抗干扰性.系统软件由C语言实现,采用中断方式,完成超声波发射到接收从石油液面反射回波的时间记录和处理,以得到准确的油位高度.系统通过实验调试,运行可靠、测量准确,具有一定的推广价值. 相似文献
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对现行的油质合格率统计方法的局限性进行了分析,提出了一种新的油质合格率统计方法,分析了它的科学性并介绍了试用情况。 相似文献
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A new concept for using a ferroelectric field effect transistor in a memory configuration is presented without the requirement of a negative voltage or an erase operation. The transistor is designed so that the accumulation sets in at a lower gate source voltage making it possible to reverse the polarization without applying a negative pulse to the gate. 相似文献
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根据相关国际标准(IEC,ITU)和我国标准(GB,YD),本文阐述通信局(站)接地系统的新观念和实施原则,介绍联合接地、接地电阻、等电位连接和接地的实施方法、防雷接地、交流和直流配电系统的接地等方面的技术。此外,分析了当前实际工程中存在的问题并提出了改进建议。 相似文献
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湛江奥里油电厂一期工程210m烟囱钢内筒施工采用气顶升倒装法施工工艺。气顶升倒装法施工工艺是根据钢内筒等直径的特点,在筒内设置临时封头和密封内底座形成1个可伸缩的套筒,在其内充入压缩空气后,形成向上的顶升力来提升钢内筒。在烟囱混凝土筒首安装支承梁,配合钢平台来安装和钢内筒气顶升助吊。在施工过程中,根据工艺流程,制定科学合理的关键工序和技术要求来指导施工。 相似文献
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The intent of this paper is to discuss the general merits and accomplishments of a new concept in process heating called the Serpentine coil, and by general comparisons with conventional coiling methods, briefly discuss and graphically indicate the Serpentine concept and then delve into applications of importance and of a beneficial nature to many industries. 相似文献
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针对目前常规的油枪装置普遍存在的油喷嘴频繁堵塞和烧坏、启动时间太长、油枪难以保持完好备用状态等问题,开好了一种新型的免维护节能快投油枪。其特征是不用推进器,油枪固定安装在工作位置,采用深度空气冷却,并配套采用一种完全不渗漏的电磁阀,从而完全消作了油喷嘴的堵塞和烧坏,并且可以瞬时投入。 相似文献
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High-power phase-controlled converters suffer from several fundamental disadvantages. They inject current hannonics into the input ac mains due to their nonlinear characteristics, thereby distort the supply voltage waveform, and demand ractive power from the associated ac power systems at retarded firing angles; also the output voltage is not smooth dc but contains superimposed harmonic ripples. A novel sequential control technique is suggested, which, when applied to more than one converter in cascade, substantially overcomes these disadvantages. The method consists of specifying the proportions of the maximum power to be handled by the individual converters and incorporating a sequence controller, the function of which is to ensure that at any output voltage the converter supplying the minimum power operates over the ful range of thyristor firing angles. The firing angles of other converters are restricted to values corresponding to their ratings. A generalized method of optimizing the performance of sequentially controlled cascaded converters is presented, and the economic viability of the proposed scheme is examined. It is shown that the effective ratings of thyristors in the proposed scheme are greatly reduced. The method should offer improved converter performance in variable speed dc drives, solid-state slip-energy recovery systems, or high-voltage dc transmission systems. 相似文献
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Common motor circuit protection has consisted of thermal overload to sense motor overcurrent and a short circuit protective device which acts after a catastrophic condition has occurred. While this combination has provided adequate protection for the most common motor and motor circuit problems, it has not provided good protection against many of the problem conditions that can occur in the motor circuit. Common motor and motor circuit problems, the circuit variances that occur and the use of common devices under these conditions are discussed. It is shown how a solid-state logic approach can sense these circuit variances and result in an economical package providing improved protection, coordinated and easily applied, which can help eliminate or minimize loss due to many of these common problems. 相似文献
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电能质量的新概念 总被引:1,自引:0,他引:1
电能是特殊商品.电能是不能储存的,而是发、供、用电同时完成,并由用电来决定发电和供电.故对用户连续不断供电是电能质量的重点标志.传统的电能质量包含频率、电压和不断电.进而认识到电网中的谐波和三相不平衡的危害性.故电能质量又增加了这两个内容.常规改善电能质量的设施有调相机、电容器、电抗器、变压器分接开关、电压调整器、稳压器、滤波器、多电源自动切换、自动重合闸、不间断电源和静止无功补偿器等.此后,电压波动和闪变也列入了电能质量标准.电能质量国家标准有<供电电压允许偏差>、<电压允许波动和闪变>、<公用电网谐波>、<三相电压允许不平衡度>、<电力系统频率允许偏差>. 相似文献
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根据无拉线小抱杆分解组塔时的受力状况 ,推导出小抱杆容许吊重的计算公式 ,并通过实例验证了公式的正确性。 相似文献