Summary of the development of automation technolog

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Summary of development of substation automation technology Abstract This paper reviews the development process of domestic substation automation technology, analyzes the current situation and development trend of domestic substation automation system, and emphasizes the integrated development of relay protection and monitoring in technology and management, the development of digital substation, and the application trend of IEC61850 standard

Reviewing the development of the domestic SA technology , analyzing the current situation and development tendency of the domestic SA technology, the developing tendencies of integrated SA including protection and local SCADA . The digitaliged SA technology ,and the application of IEC61850 standard in SA technology are emphatically discussed in this paper.

keywords substation automation status and development hierarchical distributed structure integration

1 introduction

the term "Substation Automation System SAS", IEC interprets it as "SAS substation automation system:the SAS provides automation in a substation including the communication infrastructure". In China, the substation automation system we call includes traditional automatic monitoring system, relay protection, automatic devices and other equipment. It is a set of microcomputer secondary equipment and system that integrates protection, measurement, control, remote transmission and other functions and realizes information sharing through digital communication and network technology

since the 1990s, substation automation technology has been one of the hot technologies in China's power industry. At present, there are about 20000 35~500kv substations (excluding user substations) that have been put into operation nationwide, and the number of new substations is about 3%~5% each year, that is to say, hundreds of new substations are put into operation every year, and the new substations basically adopt the automation system model. At the same time, there are many technical transformations of old substations every year, which are basically based on the automation system model

among the substations that have adopted automation technology, foreign products used more in the early stage include products from ABB, Siemens, GE and other companies. However, with the improvement of product technology content and process level of domestic manufacturers and the support of national industrial policies, at present, domestic products are mostly used in the automation of 220kV and below voltage level substations, and 330kV and above voltage level substations also use a large number of domestic products. At present, domestic product manufacturers mainly include NARI Group, Beijing Sifang, XJ electric, Guodian Nanzi, etc

2 status of substation automation technology

2.1 development stage of substation automation in China

the secondary part of substation is traditionally divided into four categories according to functions: relay protection, fault recording, local monitoring and telecontrol. According to the sequence of system modes, the development of substation automation can be divided into three stages:

(1) the first stage: centralized RTU and conventional protection mode for function design

. In fact, this kind of system is to add RTU device on the basis of conventional relay protection and secondary wiring, and its function is mainly to realize "two remotes" or "four remotes" (telemetry, remote signaling, remote control and remote adjustment) with remote dispatching communication; The connection with relay protection and automatic safety device is connected through hard contact or serial port. This kind of system is called centralized RTU mode. At present, it is still used in a small amount in the transformation of some old stations. This stage is the primary stage of automation

(2) the second stage: function oriented distributed measurement and control device plus microcomputer protection mode

the second stage began in the early 1990s. The unit microcomputer protection and distributed microcomputer measurement and control device designed according to function have been widely used. The protection and measurement and control device are relatively independent, and their respective information can be sent to the background or dispatching computer through the communication management unit. The characteristic is that the measurement and control device of relay protection (including safety automatic device) divided by function operates independently, and the field bus and network technology are applied to exchange information through data communication. There are still many cables interconnected in this system, and the expansibility function is not strong

(3) the third stage: the layered and distributed structure mode of interval oriented and object-oriented design

the third stage began in the mid-1990s. With the rapid development of computer technology, network and communication technology, the protection and measurement unit is designed according to the interval as the object, and the layered and distributed system structure is adopted to form a truly layered and distributed automation system. At present, the mainstream manufacturers at home and abroad have adopted this structure mode. For substations with voltage levels below 110KV, protection, measurement and control devices are required to be integrated, and protection, measurement and control devices with voltage levels above 110kV are mostly designed according to intervals. For large-scale systems of EHV substations, in order to reduce intermediate links and avoid communication bottlenecks, devices are required to communicate directly with the monitoring background via Ethernet, and even independent groups of protection and monitoring networks are required. Due to the adoption of advanced network communication technology and object-oriented design, The system configuration is flexible and easy to expand

2.2 layered and distributed technology becomes the trend

according to the distribution status of secondary equipment in substation automation system, it can be vertically divided into three layers: substation layer, network layer and bay layer; Some manufacturers or scholars classify the network layer into the substation layer for description, that is, it is vertically divided into two layers: the substation layer and the Bay layer

(1) the horizontal distribution of substation level is local monitoring, protection information management and remote communication according to functions. The form of substation layer function distribution depends on the network layer structure, substation voltage level and the actual needs of users

as a human-computer interaction window for local operators, the local monitoring function realizes the local "four remotes" by means of graphic display, report printing, voice alarm, etc. Through the tripping of "five prevention" system interlocking control switch and knife switch, and the automatic synchronization of circuit breaker closing operation, adjust the transformer gear or switch capacitor bank according to VQC principle, and realize information sharing with MIS system

as a human-computer interaction window for local relay protection personnel, the protection information management function can also monitor the operation status of relay protection and automatic safety device, such as whether the device is faulty, whether the setting value is changed, and whether the sampling is accurate, in various ways such as graphic display, report printing, voice alarm, etc., and determine the protection on/off and the setting value modification according to the operation needs, After the fault occurs, fault analysis and diagnosis are carried out through fault record and protection action information

the remote communication function is to realize the local monitoring and protection information management function remotely through communication, and it is the prerequisite for the unattended substation. The remote monitoring and protection information management functions can also be independent, that is, they can be connected to the dispatching center and the protection information management master station through different channels and protocols, or they can be combined into one, that is, they can be connected to the remote master station through the same channel

(2) the network layer completes the functions of information transmission and system timing. Through information exchange, realize information sharing, reduce the equipment configuration of substation, and improve the safety and economy of substation automation system as a whole. At present, two kinds of complex structures are popular in domestic and foreign products: double-layer structure and single-layer structure

at present, the field buses used include LonWorks, CANbus, WorldFIP, PROFIBUS, etc., with a speed of 1~12mbps; Ethernet communication mode, the rate is mostly 10mbps/100mbps adaptive. Fieldbus is easy to use, simple and economical. Ethernet has the characteristics of standard network, good openness, high speed and large transmission capacity. However, at present, Ethernet can not completely replace Fieldbus in terms of performance and application characteristics. Industrial Ethernet technology and standards for real-time control are in the process of researching and formulating safe and reliable operation, so fieldbus and Ethernet will coexist for quite a long time

(3) the Bay layer is mainly relay protection and monitoring equipment layer. The panel can be assembled intensively, distributed in each relay protection room or installed on the switch cabinet. Relay protection and monitoring can be independent or integrated. It protects, measures and controls the relevant primary equipment, responds to the operation requirements of the stratum, substation layer and remote master station, processes and transmits the collected information, and can still complete the protection, measurement and control functions in case of control failure of the substation layer and remote master station

the relationship among the three layers. Substation layer, network layer and bay layer are independent and interrelated. The realization of substation layer function depends on the integrity of network layer and bay layer; However, the realization of the function of the Bay layer, especially the function of relay protection and safety automatic device, must not depend on the network layer and substation layer; The realization of remote master station monitoring function shall not depend on the substation level equipment

2.3 operation management mode and substation integrated automation

(1) impact of protection and telecontrol professional management mode on the development of substation integrated automation technology, Especially in the recent stage, the integrated device of protection and measurement and control has been adopted in the medium and low voltage stations. Many manufacturers have considered integrating the protection, measurement and control, fault recording and other functions into one device when developing the devices of high voltage and ultra-high voltage stations. Therefore, the management and thinking mode of independent operation can no longer meet the requirements of the development of substation integrated automation technology. Some power supply enterprises have merged the two specialties into integrated automation specialty, realizing the unification of protection and monitoring in technology and management

(2) the relationship between unattended operation management mode and substation automation technology

at present, the unattended substation has been realized. It is not (3) the method of winding the sample directly on the reel for tensile test. It is applicable to the steel wire rope with rope diameter less than 30mm. For the steel wire rope with diameter greater than 30mm, it is recommended to adopt the so-called integrated automation system for casting method. However, it should be noted that the development of automation technology provides more advanced technical support for unattended or less attended substations, making the substation design more reasonable, compact layout, more reliable operation, and more conducive to unattended management. The new substation and even the first 750kV substation in China will be designed according to the unattended mode

(3) the emergence of the protection information management system is the demand for the current operation and management of the substation.

with the widespread use of microcomputer protection and fault recorder in the power system, it is possible for the protection and fault recorder to transmit fault information to the power dispatching center in the form of data in case of power system failure. In order to implement the requirements of the "Tenth Five Year Plan" for the electric secondary system of the State Power Corporation of China, practically improve the informatization and intelligence level of the dispatching system for the safe operation of electricity, provide real-time fault information for the dispatching in case of power failure, and effectively and quickly recover the system, the relay protection operation technology sub committee of the society of electrical engineering has specially formulated the technical specifications for the information processing system for relay protection, safety automatic devices and fault recorders, already

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