<正>在三相四线制供电系统中,三相负载的不平衡,不仅使配电变压器损耗增大降低了出力,而且使各相电压不平衡,增加了配电线路损耗,这不仅对电气设备的运行和安全极为不利,同时又增加了运行成本。由于三相负载不平衡会造成中性点位移,使中

文章介绍了用于测量中小型电力变压器过载、短路、漏电、触电的综合保护器的设计,阐述了该保护器的硬件电路和系统软件处理程序的设计方法,同时对系统的性能以及具体功能实现进行了分析。该设计基于AT89C51单片机,采用独特的复位电路有效防止程序跑飞;漏电检测采用鉴相模式,避免了动作死区。

<正>2007年某月,我处供电所抄表员在抄表时,发现10kV开闭所028号线路所带10kV用户的下抄电能量远远大于028号线路的总表电能量,线损率出现负值。各项主要数据如表1所示。

<正>2008年1月,我国南方地区遭遇到了五十年不遇的大雪。这场雪灾造成的损害如此严重,大部分原因是因为停电。之所以造成大面积停电,是因为电力线路覆冰压倒了杆塔,压断了电线。什么是导线覆冰,如何解

A driver circuit of step motor base on the AT89C2051 micro-controller was designed.The main components of the driver circuit are the AT89C2051 MCU and the shift and store bus register CD4094.The CP pulse is the reset signal of the driver circuit,which can improve the anti-jamming ability.The step motor driver has been used successfully in many systems,and running results show that the driver can be widely used easy.

随着我国基础建设的大力发展,涉及到了许多岩体土建工程。如何准确分析土体边坡的稳定性、提出既经济又安全的最优化方案,是人们长期以来不断探索的关键技术问题。论文介绍了基于石英挠性伺服加速度计作为敏感元件的自动测斜装置,介绍了该仪器的工作原理、组成及各部分电路的特点,通过实践表明,该仪器测试数据可靠,操作简便。

The temperature examining device consists of the preceding extremity system which collects outside temperature to Chip Microprocessor and the PC set which is backstage supporter.It achieves the longrange collecting.The device collects the outside temperature by the temperature sensor,and performs A/D conversion by the digital potentiometer 9313.The Chip Microprocessor system transmits the data to the PC set through the RS-232 interface.The PC set controls the Chip Microprocessor to achieve data's real time receiving,saving and drawing out visualized chart upon display.It can make the regulation work automatic.Compared with general methods using A/D→digital control→D/A,it has many advantages such as simple structure,user-friendly,higher measurement accuracy and reliability,which can be widely used industrial temperature measurement.