P1 Functions of power transmissionThe function of (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 (power networks)、Power transmission is pleted by step-up substations, (step-down substations and connected transmission equipment)、The transmission line mainly consists of the transmission conductors (transmission at high voltage) can reduce the line loss and the voltage drop, ensure the power quality, raise the economy of (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、功率传输功能(输电)得功能就是要把电力从发电厂负荷中心或功率交换网络之间为了达到代消费平衡或供求之间得平衡(电网)。
电力传输就是通过升压变电站完成,(降压变电站与连接传输设备)。
输电线路主要由输电导线(高压输电),可以减少线路损耗与电压降,保证电能质量,提高经济性(电网运行)。
输电线路电压得增加不仅可以提高输电线路得传输功率,而且可以降低线路损耗与线路压降,提高电压质量。
A 、step-down substations and connected transmission equipment降压变电站与连接传输设备B、power network operation 电网运行C、power transmission 功率传输D、transmission at high voltage 高压直流输电E、power networks一。
电力网络P2 A brief introduction on the development of supercritical boilers and their main advantagesIn ( some advanced countries )such as U、S、A, Japan and European countries, the supercritical boiler has been developed since the 60s of last century、It has been proved by data and experience, the supercritical unit has (great advantages on economy and environmental protection)、As for its reliability, because the steam-water flow passages in supercritical boiler is same as that in the (subcritical once-through boiler),there isn’t anything special, But as far as hydraulic characteristic, a symbol of reliability, is concerned, in a supercritical boiler, under supercritical condition, medium is of single phase which has a (good homogenization of distribution)、So that the problem caused by uneven distribution of steam phase and water phase can be avoided、It is admitted that, if (whole process management is strengthened), both supercritical and subcritical units can get an excellent reliability index、超临界锅炉得发展及其主要优点在(发达国家)如美国,日本与欧洲国家,超临界锅炉已自上世纪60年代以来发达。
数据与经验证明,超临界机组具有经济与环境保护得巨大优势。
作为其可靠性,因为在超临界锅炉得水蒸汽流通道相同得作为,在得(亚临界直流锅炉),那里就是没什么特别,但至于水力特性,可靠性得象征,有关,在超临界锅炉,超临界条件下,介质就是单相(良好得同质化分布)。
从而避免了汽相、水相分布不均造成得问题。
这就是承认,如果(全过程管理加强),超临界与亚临界机组可以得到一个极好得可靠性指标。
A、good homogenization of distribution 良好得均匀分布B、some advanced countries一些发达国家C、whole process management is strengthened全过程管理加强D、great advantages on economy and environmental protection具有经济与环境保护得巨大优势E、subcritical once-through boiler亚临界直流锅炉P3 Circuit breakerCircuit breakers are automatically operated high voltage (or high current) switches、Circuit breakers are required (to control electrical power networks)by switching circuits on, by carrying load and by switching circuits off under manual or automatic supervision、Their duty is as follows: In closed position the circuit breaker must be a good conductor for the normal load current、In operating the circuit breaker must be able contacts shall have full insulation level、At operation the circuit breaker must close be able (to switch the current which can be from a few amperes)to many thousands of amperes, and independently of the characteristics from purely inductive to fully capacitive、At closing operation the circuit breaker must close fast and be safe also against full short circuit conditions、They must, therefore, be effective instantaneously when are called upon (to perform any switching operation after longperiods )without movement、As the circuit breaker is the last link in the chain of protective equipment, the circuit breaker reliability is (of the highest importance for high reliability )of the total electric power system、So the importance (of the circuit breaker )cannot be over emphasized、断路器断路器就是自动操作高压(或大电流)开关。
断路器就是必需得(以控制电力网络)得开关电路,通过负载与开关电路得手动或自动监控。
她们得职责如下:在闭合位置,断路器必须就是正常负载电流得良好导体。
在操作断路器必须能够接触应具有完全得绝缘水平。
在操作断路器必须关闭能(开关电流可从几安培到几千安培),与独立得特点,从纯感性充分电容。
在关断操作时,断路器必须要关闭快速,并能安全地进行全短路工况。
因此,她们必须就是有效得瞬间被调用时(长时间)执行任何切换操作不运动。
断路器就是保护设备链中得最后一个环节,其可靠性就是全电力系统中(最高)得可靠性。
因此,重要性(断路器)不能过分强调。
A、to perform any switching operation after long periods在长时间后执行任何切换操作B、to control electrical power networks控制电力网C、of the circuit breaker断路器得D、to switch the current which can be from a few amperes开关得电流可从几安培E、(of the highest importance for high reliability高可靠性得最高重要性P4 Fuel cellsFuel cells are devices that when a fuel such as hydrogen or hydrogen-rich pounds and oxygen are supplied to materials arranged like the anode and cathode of a conventional battery, bine to convert chemical energy directly into electrical energy、Unlike conventional batteries where the conversion of chemical to electrical energy requires only the closing of a circuit between the cathode and anode to produce and electrical current, (there is no storage capacity in a fuel cell)、These cells require the fuel and oxygen that will produce the chemical reactions that produce an electrical output、Fuel cells have been made that will supply power in the megawatt range, and (further development is under way)、Such cells are not yet widely used on power systems, but (as they are being developed there have been some applications)to supply fuel cell power to isolated loads、As the voltage output of a cell is in the order of to 2、5V, (many cells are operated in series to obtain voltages) and power output in ranges that are normally required、Inverters are used to (supply alternating current from fuel cells)when and AC output is desired、燃料电池燃料电池就是,当一个燃料如氢或氢化合物丰富与氧气供给排列像传统电池得阳极与阴极材料,结合转换化学能量直接转化为电能得装置。