Discussion on computer monitoring system of Substa

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Abstract: This paper describes the composition, content, function and characteristics of the computer supervision and control system of the substation. In recent years, substation monitoring technology has developed rapidly and been widely used. However, due to the fact that the promotion work in China is in its infancy, the technology application is not mature, and the new operation and management mode is being explored, some problems have also been exposed in the operation

key words: Yan Ge, sales manager of Greater China in Lubrizol Life Sciences Department, computer monitoring system, telemetry, remote signaling, remote control, anti electromagnetic interference 1. Introduction power transformation and distribution substation is an important part of the power system and an important connecting part of the lines in power. Its role is to transform voltage, collect and distribute electric energy. The normal operation of the substation and distribution station is related to the stability and safety of the power system, so it is of great significance to monitor and protect the substation, some of which are - 40 ~ + 80 ℃. Substation computer monitoring technology is the combination of modern automation technology, electronic technology, communication technology, computer and network technology and power equipment, which organically integrates the monitoring, control, measurement of power distribution under normal and accident conditions and the work management of power supply departments. Complete the telemetry, remote signaling, remote control, and four remote functions of landing type remote adjustment at the dispatching end. Improve the quality of power supply, strive to supply the most safe, reliable, convenient, flexible and economical power, and make the management of transformation and distribution more effective, so as to improve the quality of power supply, improve the service level, and reduce the operation cost. In recent years, substation computer monitoring technology has developed rapidly, but in order to better ensure the safety, reliability and stability of computer monitoring system performance, we should also improve the anti electromagnetic interference ability of substation. 2. The computer monitoring system of power transformation and distribution substation is composed of acquisition and control modules with communication interfaces: multi-functional power integrated instrument, switching value acquisition module, current value acquisition module, analog value acquisition module, relay control output module, field management machine, 24V DC power supply and central management machine. The central management machine is the centralized management center of this system. It is generally placed in the general duty room with people on duty for real-time state display, parameter statistics, data analysis, historical records, fault alarm, control, report printing, etc. of the whole power transformation and distribution system. 3. System content 3.1 for the hardware part of the computer monitoring system of the substation, the power integrated instrument can be used for the main incoming and outgoing lines and busbars of the high-voltage central distribution station below 35KV to realize the functions of telemetry, remote signaling and remote control. The instrument is directly connected with CT and PT to collect high-precision AC signals. After discrete mathematical calculation, the electrical parameters of each circuit can be measured (the measurement accuracy is 0.5%). The instrument has eight switch inputs and four relay outputs. At the same time, it has self-test function, which can be used in conjunction with comprehensive relay protection devices. (1) Connect CT and Pt directly into the measuring circuit of power integrated instrument, and then the electrical parameters of the circuit can be measured. Realize the "telemetry" of the circuit; (2) The eight channel switch input of the instrument respectively collects the opening and closing state of the circuit breaker, the working position of the handcart, the energy storage state of the motor and the position of the grounding knife switch in the cabinet. At the same time, it collects and analyzes the fault tripping signal and internal fault in the integrated relay protection device, gives an alarm, and displays the fault type of the circuit. Realize the "remote signaling" of the circuit; (3) The relay output of the instrument is connected to the opening and closing coils of the circuit breaker respectively to realize the remote control of the circuit breaker, that is, the "remote control" of the circuit breaker. In the 0.4kV low-voltage main incoming and buscouple, the power integrated instrument is also used to realize the "three remote" function. The instrument is directly connected with CT and bus to collect high-precision AC signals, measure the actual power of the circuit, and realize telemetry. At the same time, it realizes telemetry for the closing and opening states of the circuit breaker of the main incoming and bus tie switches, the position of the frame switch and fault alarm, and realizes remote control of the circuit breaker. 3.1.1 remote signaling uses the switching value acquisition input module to collect the opening and closing status of each outgoing circuit switch, switch fault alarm signal, loss of voltage alarm signal, overvoltage alarm signal and the position of the frame switch according to Gao Lizhen, President of the Industrial Research Institute, and monitors the fan status, high temperature, ultra-high temperature signals and other switching values of the transformer. A single module can generally collect 16 channel switch status. 3.1.2 telemetry (1) collect the phase currents of each outgoing circuit through the current input acquisition module, and a single module can collect 16 circuit currents. For each circuit, the current of the circuit can be collected by the electric flow input module, and the actual power consumption of the circuit can be calculated according to the measured actual voltage, power factor, etc. (2) Collect the temperature signal, humidity signal, liquid level signal and other analog signals of the transformer through the analog input module (each analog signal needs to have 4-20mA or 0-5V output). 3.1.3 the remote control realizes the remote opening and closing function of the switch for each low-voltage outgoing circuit (switch with electric operating mechanism and voltage loss release) through the relay control output module. The field management machine is located between the central management machine and each module in this system. As the first level bottom control unit, it increases the reliability of the system. Its function is to carry out on-site debugging, use the on-site management mobility to set the on-site parameters of each module, independently complete the on-site display work, and send the signals to the central management machine through the communication line (ils485) after sorting, and accept the commands issued by the central management machine at the same time. It can be used as the backup of the central management machine, with display function and self-test function. 3.2 the software part of the computer monitoring system of the substation and distribution station the monitoring software installed in the computer monitoring system of the substation and distribution station is the special configuration software of the power system based on the windows environment, which can run on the Microsoft WindowsNT, 2000, XP platforms. It provides users with an all Chinese interface, simple picture design, flexible configuration mode, high-performance DDE driver, supports many industrial control products, and follows the open database connection (ODBC) standard. It is allowed to access the database of the system through a third party, such as Microsoft Access, SQL server, etc. 3.2.1 basic functional requirements of monitoring system: microcomputer monitoring system is the main way for users to master and control the operation status of equipment, especially the improvement of the reliability of protection equipment has simplified the functions of man-machine interface and local control, so it should have

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