2022年电力系统监控 2.pdf

Electric Power System Monitoring A modern electric power system is an assembly of, many components, each which influences the behavior of every other part, Proper functioning of the system as a whole makes it necessary to monitor conditions existing at many different points on the system in order to assure optimum operation. The concern of the customers is primarily that the frequency and voltage of the supply are held within certain rather narrow limits. Since frequency of the system is the same everywhere, it may be monitored by a single frequency meter located at any convenient point . In contrast, the voltage of the system may be quite different at different points. Consequently, it is necessary to make continuous observation of the voltage at certain key points in the system in order to provide acceptable service. Efficient operation of the system is obtained by assigning proper load schedules to each of the generators of the system. Newer plants, although individually more efficient, may be located at points of the system whiter their loading occasions large system losses. It is desirable to operate with such a division of the load between generators that the total cost of fuel consumed is minimized. To provide reliability of the power supply in the event of unexpected conditions, it is desirable for all machines in operation to have the total kilowatt rating somewhat greater than the total load plus losses. Instrumentation is necessary to permit billing of customers for energy used. Many interconnections exist between different power systems. Instruments must be provided at interchange points to permit billing for energy transferred from one system to another. The continuous monitoring of energy 电力系统监控现代供电系统是许多部分的组合，每个部分都影响其它部分的运转。为使系统作为整体正常运作，有必要监控系统中许多不同位置的情况，才能确保最佳运转。用户主要关心的是频率和把供电电压限制在某些有限的范围。既然在任何地方系统的频率都相同，所以可在任一方便的地方安装单个的频率测试仪来监控。 相反，系统的电压可能在不同的地方差别较大。因此必须在系统某些关键位置对电压不断进行观察；才能提供令人满意的服务。将合适的负荷计划分配给系统中每台发电机， 才能使系统达到高效运转。新的设备虽然单机效率较高，但它们在系统中被安装的位置可能会由于它们的加载而造成系统巨大的损失。应该将负荷在发电机之间分配后进行运作， 才能使所消耗燃料的费用总额降至最低。 为在意外情况下可靠供电，最好使运行中的所有机器的千瓦定额比负荷加上损耗的总数高一些。要想把用户的用电量记入帐目，就必须安装测试设备。 在不同的供电系统间存在着许多互连。必须在连接点配备测量仪器才能将从一个系统转换到另一个系统的能量记入帐目。必须对能量转换不断监测，才能保证交换的电力在协议规定的限度之内。名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 1 页，共 4 页 - - - - - - - - - transfer is necessary to assure that interchanged power is within the limits of contract agreements. The continuous measurement of conditions of major pieces of equipment is necessary to avoid damage due to overload. Instrumentation serves as a guide for future construction in a growing power system. Occasionally, under emergency conditions, a system operator observes that his system load exceeds the ability of the available generating and transmission equipment. He is then faced with the problem of load shedding or more properly. load conservation. It is then necessary to drip selected loads where service interruption is least objectionable. In such an event, he relies on the many instruments, which provide information relative to system-operation conditions. Instruments may sound alarms as advance warnings of conditions requiring action to avoid damage to equipment operating beyond its design limitation. In the event of extreme conditions such as power-system faults, defective equipment is switched out of service automatically. Instruments that continuously monitor current, voltage, and other quantities must be able to identify the faulted equipment and to bring about iteration of the circuit breakers which remove it from service, while leaving in service all other equipment on the operating system. The many different electrical devices in a power system and those owned by the customers are designed for operation within certain specified ranges. Operation outside these designed limits is undesirable, as it may result in inefficiency of operation, excessive deterioration or (in extreme 要避免由于超载造成的损害，必须对大件装置的状态不断测量。测试设备在未来扩充供电系统的建设中起指导作用。有时在紧急情况下，一位系统操作人员注意到他的系统负荷超过了现有发电和输电设备的能力。于是他就面临着限制用电的问题，更恰当地说，是保持负荷的问题。于是就有必要在最合适中断供电服务的地方减少一定的负荷。 在此情况下， 他依赖于许多测试仪表来提供有关系统运行状况的信息。当要求采取操作避免超过限定运行设计给设备带来损害时，测量仪会发出警报声， 作为提前警告。 万一出现最糟的情况，如电力系统出现故障，有毛病的设备将会自动关闭，停止运行。 要对电流、 电压和其它量的测量仪器进行监控， 必须能够辨别出产生故障的设备， 使断路器开始起作用并将有故障的设备排除在供电服务之外，而让运行系统中其它所有设备继续运行。电力系统和用户拥有的许多不同的电力装置都是为在某些特定范围内运行而设计的， 不可以在设计限定范围之外运行， 因为它会导致低效运行、 过度磨损或者 （在极端的情况下）设备损坏。认真观察设备运行状态才会知道应该如何采取正确行动。所有电力装置都不可以过电流，因为这会导致温度过高、低效运行并减名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 2 页，共 4 页 - - - - - - - - - cases) the destruction of the device. Careful attention to the conditions under which equipment is operating may indicate corrective action that must be taken. Overcorrect is undesirable for all electrical devices , as it produces excessive temperatures, inefficient operation, and reduced service life. Overcorrect in residential circuits may bring about disconnection of the circuit by fuse or breaker action. Overcorrect inresidential circuits may bring about disconnection of the circuit by fuse or breaker action. Overcorrect in motors may also damage insulation. 少使用寿命。居民电路若电流过载，会导致因熔丝烧断而产生断路，或使断路器动作。 电动机者电流过载，会损坏绝缘，使绝缘失效。New Words l. optimum 最佳的，最适宜的2Meter 仪表3Occasion 致使 ,引起4Rating 定额，额定值5. Instrumentamon 测试设备6Interchange交换，互换7billing 记帐8Objectionable 不合适的，不化采用的9defective 有故障的10.deterioration 恶化；磨损，损耗11.overcorrect 过载电流12.fuse 熔丝Phrases and Expressions; 1.electric power system monitoring 对电力系统的监控2.in contrast 相反3.efficient operation 高效运行4.in the event of 万一5.interchange points 交叉点6.transfer fromto 从转换到7.energy transfer 能量转换8.major pieces of equipment 大件设备9.load shedding 限电10. load conservation 保护负荷11. circuit breaker 电路保护器，断路器12. within the specified ranges 在限定的范围内名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 3 页，共 4 页 - - - - - - - - - 13. service life 使用寿命名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 4 页，共 4 页 - - - - - - - - -