1、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
2、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 connectio
3、ns 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 comma
4、nds 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
5、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,
6、 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 Acquisiti
7、on(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)-
8、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 mo
9、nitoring 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 pe
10、rform 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 u
11、ses 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 colle
12、cting 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 c
13、ollects 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 w
14、ith 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 benefit
15、s 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 th
16、e 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 au
17、tomation 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 v
18、oltage 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
19、 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
