Fiber optic digital substation comprehensive automation system

The 35KV digital substation is a new generation of fully electronic structured substations, where the measurement and processing of current transformers, voltage transformers, and their signals are all digitized. The standards adopted are IEC60044-8 (Electronic Current Transformers), IEC60044-7 (Electronic Voltage Transformers), and IEC61850 (Substation Communication Networks and Systems) protocols. Due to the use of standard interfaces and communication protocols, interoperability and interoperability among multiple manufacturers of LED (intelligent electronic devices) can be achieved, enabling seamless connection of data collection and control within the scope of the substation LAN.

Fiber optic digital substation is a substation system designed according to a new concept, which is a product of the combination of modern electronic technology and optoelectronic technology. It represents the development direction of substation automation today. The promotion and application of fiber optic digital substations make the construction of substations simpler, greatly improve safety performance, have significant anti surge and lightning protection effects, and enable faster and more accurate data collection and transmission.

Efforts are being made to build a digital rural power grid and vigorously promote digital optoelectronic technology in 35KV substations, which is in line with the current development direction of power automation. For a long time, we have been using electromagnetic power transformers to provide analog signals to protection, measurement, and metering equipment. This was feasible and necessary many years ago because the secondary equipment and meters in the station required power input - generally requiring 5A CT current and 100V PT voltage to drive electromagnetic relay protection and meters. In recent years, the automation of 35KV substations has made significant progress, with the widespread use of microcomputer relay protection and electronic meters. In addition, small current line selection, harmonic elimination devices, and measurement and control devices also require input of small signals. Therefore, it is necessary to artificially attenuate and convert the high voltage and high current signals provided by traditional CT and PT in the corresponding electronic device front-end, turning them into current or voltage signals of tens of milliamps or several volts. This not only increases the number of links, but also loses data accuracy.

With the rapid development of optical sensing technology and fiber optic communication technology, the use of digital photoelectric transformers instead of traditional electromagnetic transformers, the use of fiber optic digital communication technology instead of ordinary metal cable secondary analog power transmission methods, the use of fiber optic digital communication networks instead of metal wire communication networks, and the use of fiber optic digital interface protection and measurement devices instead of traditional analog input protection and measurement devices have matured. The fiber optic digital substation system has become one of the most dynamic directions in the development of power automation technology. It will bring revolutionary changes to the measurement, protection, and monitoring of the power system.