补全短文 1 Passage1 Functions of power transmission The function of （1）power transmission is to send power from power plants to load center or to exchange power between networks in order to attain the generation-consumption balance or the supply-demand balance between（2）power networks. Power transmission is completed by step-up substations,（3）step-down substations and connected transmission equipment. The transmission line mainly consists of the transmission conductors (4)transmission at high voltage can reduce the line loss and the voltage drop, ensure the power quality, raise the economy of （5）power network operation. The increase of transmission line voltage can not only raise the amount of transmitted power, but also reduce the line loss and line voltage drop, and improve the voltage quality. Passage 2 Substation misoperation and its preventing The misioeration that can lead to (1) accidents in the electrical operation of the substation mainly are: ○1on-load switching of isolating switch; ○2connecting (2) the grounding wire (closing the grounding switch) with power on; ○3closing the circuit breaker (isolating switch)with ground lines (ground switch) earthed. The “five preventings” for (3) preventing the misoperation in substation includes: ○1preventing the wrong opening or closing of circuit breaker; ○2preventing the on load opening and closing of isolating switch; ○3 preventing (4)the closing of grounding switch with power on; ○4preventing the closing of circuit breaker with grounding wire connected; ○5preventing(5)the persons from illegal entering the lived bay. Passage 3 A brief introduction on the development of supercritical boilers and their main advantages In (1) some advanced countries such ...
