电气专业毕业设计外文翻译---电力系统自动化.docx

电气专业毕业设计外文翻译-电力系统自动化 外文资料翻译 Power System Automation Power system integration is the act of communication data to, or among IED s in the I&C system and remote users. Substation integration refers to combining data from the IEDs local to a substation so that there is a single point of contact in the substation for all of the I&C data. Poletop devices often communicate to the substation via wireless or fiber connections. Remote and local substation and feeder control is passed through the substation controller acting as a single point of contact. Some systems bypass the substation controller by using direct connections to the poletop devices, such as RTU s, protective relays, and controllers. Power system automation is the act of automatically controlling the power system via I&C devices. Substation automation refers to using IED data, control and automation capabilities within the substation, and control commands from remote users to control power system devices. Since true substation automation relies on substation integration, the terms are often used interchangeably. Power system automation includes processes associated with generation and delivery of power. A subset of the process deal with delivery of power at transmission and distribution levels, which is power delivery automation. Together, monitoring and control of power delivery system in the substation and on the poletop reduce the occurrence of outages and shorten the duration of outages that do occur. The IEDs, communications protocols, and communications methods described in previous sections, work together as a system to perform power system automation. Though each utility is unique, most consider power delivery automation of transmission and distribution substation and feeders to include : Supervisory Control and Data Acquisition(SCADA)-operator supervision and control; Distribution Automation-fault location, auto-isolation, auto-sectionalizing, and auto-restoration; Substation Automation-breaker failure, reclosing, battery monitoring, dead substation transfer, and substation load transfer; Energy Management System (EMS)-load flow, VAR and voltage monitoring and control, generation control, transformer and feeder load balancing; Fault analysis and device maintenance. System without automated control still have the advantages of remote monitoring and operator control of power system devices, which includes: Remote monitoring and control of circuit breakers and automated switches; Remote monitoring of non-automated switches and fuses; Remote monitoring and control of capacitor banks; Remote monitoring and voltage control; Remote power quality monitoring and control. IED s described in the overview are used to perform power system integration and automation. Most designs require that the one IED act as the substation controller and perform data acquisition and control of the other IED s. The substation controllers is often called upon to support system automation tasks as well. The communications industry uses the term client/server for a device that acts as a master, or client, retrieving data from some devices and then acts as a slaver, a server, sending this data to other devices. The client/server collecting and concentrating dynamically. A data concentrator creates a substation databases by collecting and concentrating dynamic data from several devices. In this fashion, essential subsets of data from each IED are forwarded to a master through one data transfer. The concentrator databases is used to pass data between IED s that are not directly connected. A substation archive client/server collects and archives data from several devices. The archive data is retrieved when it is convenient for the user to do so. The age of the IED s now in substations varies widely. Many of these IED s are still useful but lack the most recent protocols. A communications processor that can communicate with each IED via a unique baud rate and protocol extends the time that each IED is useful. Using a communications processor for substation integration also easily accommodates future IED s. It is rare for all existing IED s to be discarded during a substation integration upgrade project. The benefits of monitoring, remote control, and automation of power delivery include improved employee and public safety, and deferment of the cost of purchasing new equipment. Also, reduced operation and maintenance costs are realized through improved use of existing facilities and optimized performance of the power system through reduced losses associated with outages and improved voltage profile. Collection of information can result in better planning and system design, and increased customer satisfaction will result from improved responsiveness, service reliability, and power quality. Power system automation includes a variety of equipment. The principal items are listed and briefly described below. Instrument transformers are used to sense power system current and voltage. They are physically connected to power system apparatus and convert the actual power system signals, which includes high voltage and current magnitudes, down to lower signal levels. Transducers convert the analog output of an instrument transformer from one magnitude to another or from one value type to another, such as from an ac current to dc voltage. As the name implies, a remote terminal device, RTU, is an IED that can be installed in a remote location, and acts as a termination point for filed contacts. A dedicated pair of copper conductors are used to sense every contract and transducer value. These conductors originated at the power system device, are installed in trenches or overhead cable trays, and are then terminated on panels within the RTU. The RTU can transfer collected data to other devices and receive data and control commands from other device through a serial port. User programmable RTUs are referred to as “smart RTUs.” A communication switch is a device that switches between several serial ports when it is told to do so. The remote user initiates communications with the port switch via a connection to the substation , typically a leased line or dial-up telephone connection. Once connected, the user can route their communication through the port switch to one of the connected substation IEDs. The port switch merely “passes through” the IED communication. A meter is an IED that is used to create accurate measurement of power system current, voltage, and power values. Metering values such as demand and peak are saved within the meter to create historical information about the activity of the power system. A digital fault recorder ,is an IED that records information about power system disturbances. It is capable of storing data in digital format when triggered by conditions detected on the power system. Harmonics, frequency, and voltage are examples of data captured by DFRs. Load tap changer are devices used to change the tap position on transformers. These devices work automatically or can be controlled via another local IED or form a remote operator or process. Recloser controllers remotely control the operation of automated reclosers and switches. These devices monitor and store power system conditions and determine when to perform control actions. They also accept commands form a remote operator or process. 电力系统自动化 电力系统集成是在I&C系统中的IED和远程用户之间进行数据通信的操作。变电站集成指的是将局部和整个变电站的IED数据进行合成，对于变电站内所有I&C数据，只有一个单一联系点。杆顶设备通常通过无线或光纤连接与变电站进行通信。远程、本地变电站和馈线控制像单一联系点一样通过变电站控制器。一些系统用直接连接与RTU，保护继电器和控制器等杆顶设备进行旁路连接。 电力系统自动化是通过I&C设备自动控制电力系统的行为。变电站自动化指的是使用IED数据、变电站内部的调节和自动控制能力和来自远程用户的控制命令去控制电力系统设备。由于真正的变电站自动化依赖于变电站集成，这两个术语通常互用。电力系统自动化涵盖电力生产和发送的各个环节。其中一些环节涉及电力传输和分配的各个级别，即电力输送自动化。对于变电站和杆顶电力输送系统的监控能减少断电的发生，缩短断电时间。IED、通信协议和前面描述的通信方法作为一个系统协同工作，实现电力系统自动化。 尽管各个公共部门不同，但大多数认为电力输送自动化，配电变电站和馈电线路应包括：监控和数据采集操作员监视和控制，配电自动化故障定位，自动隔离，自动分段，自恢复供电，变电站自动化断路器故障（失灵），自动重合闸，电池监视，故障变电站转移和变电站负荷转移，能源管理系统潮流，无功和电压监控，发电控制，变压器和馈电线路负荷平衡，故障分析和设备维护。没有自动控制的系统仍然具有远程监视和操作员控制电力系统设备的优点，包括:远程监控断路器和自动开关远程监视非自动开关和熔丝远程监控电容组合远程监视和电压控制远程电力质量监控 前面描述的IED用来执行电力系统集成和自动化。很多设计要求一个IED 扮演变电站控制器的角色，执行数据采集和控制其它IED的功能。变电站控制器也要求支持系统自动化任务。通信行业对设备使用术语客户/服务器，主设备或客户从其它设备得到数据，从设备或服务器向其它设备发送数据客户端/服务器动态地收发数据。数据集中器通过收集，集中来自其它设备的动态数据创建变电站数据库。在这种方式下，来自每个IED的重要数据子集通过一次数据转移发送给主设备。数据集中器数据库用于间接连接的IED之间的数据传输。变电站档案客户端/服务器从几个设备收集、存储数据。存档数据可以方便供用户检索。现在变电站的IED寿命差别很大。大多数IED仍然有用但是缺少最新的协议。通过特定波特率和协议与IED通信，通信处理机可以延长每个IED的可用时间。使用通信处理机进行变电站集成可以很容易地适应未来的IED。在变电站升级工程中，弃用所有现存的IED是很少见的。 电力传输的监视，远程控制和自动化的优点包括提高员工和公众安全，推迟购买新设备的花销。同时，运行和维护成本的降低得益于现存设备的使用，通过降低断电造成的损失优化电力系统性能，提高电压分布。信息的收集可以用于进行更好的计划和协调设计，日益增加的客户满意度源自改善的响应性、服务可靠性和供电质量的提高。 电力系统自动化包括很多设备。下面列出主要设备并进行简单描述。 仪表（用）互感器用来检测电力系统电流和电压值。它们和电力系统设备连接在一起，把实际的电力系统信号，包括高电压，电流幅值，转换为小信号水平。 变换器把仪表（用）互感器输出的模拟信号从一种幅值变换到另一种，或者 从一种类型变换到另一种，如把交流电流信号转换位直流电压信号。 远程终端设备，是安装在远端，操作起来像终端点控制现场触点一样的IED。特意安排的一对铜导线用来检测每个触点和变换器的值。这些导体引自电力系统设备，安装在电缆沟或架空电缆盘中，终端连与RTU的面板。RTU可以通过串口把采集到的数据传送给其它设备，并接收来自其它设备的数据和命令。用户可编程RTU指的是智能RTU。 通信交换机是能按照要求在不同串行口之间转换的设备。远程用户通常用租用线路，或者电话拨号与变电站建立连接，并用端口交换机进行通信。一旦建立链接，用户可以通过端口交换机与连接的变电站IED进行通信。端口交换机只不过是IED通信的通道。 仪表是用来对电力系统电流、电压和功率进行精确测量的IED。测量值（如需求量和峰值）可以保存在仪表中，用于创建电力系统运行的历史信息。 数字故障记录仪，是记录电力系统干扰信息的IED。当检测到电力系统出现情况时，它能以数字形式存储数据。谐波、频率和电压都是能被DRF捕捉到的例子。 负载抽头开关转换器是用来改变变压器抽头位置的装置。这些设备可以自动工作，或者受控于现场IED或者远程操作人员或过程。 自动重合闸控制器远程控制自动重合闸装置和开关。这些设备监视、存储电力系统状况，决定进行控制操作的时机。它们也接收来自远程人员或过程的命令。