毕业设计--外文翻译 -变电站与电力系统继电保护.doc

-1- 中文 3826 字附录 1 :外文资料翻译 Substation and Power S ystem Protection With the development of undertaking of the electric ting , the pattern of work has already taken shape basically. Scientific and technological level raise, electric environmental protection can strengthen, make scientific and petence and advanced international standards, Chinese of power industry close day by day. Electric management level and service level are being improved constantly, strategic planning management of electric power development, production operate manage , electric market administration and electric information management level , high-quality service level ,etc. general to raise enterprise. The purpose ofa substation is to transform the characteristics of the electrical energy supplied to some form suitable for use, as for example, a conversion from alternation current to direct current for the use of city railway service, ora change from one voltage to another, or one frequency to another. Their functions include: Tap. ─ TO be economical, transmission of larger amounts of power over long distances must be done at voltages above 110,000 volts. Substations for supplying small amounts of power from such high-voltage lines are not satisfactory from the standpoint of operation and are also uneconomical. It is, therefore, common practice to install a few substations at advantageous points along