Application and development of the hottest remote

The application and development of remote terminal devices in power system

0. overview

power system has the characteristics of wide distribution range, strong real-time performance and high degree of automation. Therefore, RTU remote terminal units are widely used for data acquisition and power generation and transmission process control. The dispatching automation system has become an indispensable and important technical means to ensure the safe, stable and economic operation of modern large power. The remote terminal device is the basis of the dispatching automation system, and it is the terminal device that realizes all functions of the production process information collection, processing, transmission, display and execution of control instructions

1. Application of remote terminal devices in power system

modern power system is composed of several power plants, substations and a considerable number of EHV transmission lines distributed in a wide area. Because electric energy cannot be stored, the production, transmission and consumption of electric energy should be carried out at the same time, and the balance between supply and demand should be maintained at all times. In order to ensure the safe and stable operation of power system, there must be a unified management and dispatching system. China's power system has five levels of dispatching offices, namely, national general dispatching, large power dispatching, provincial power dispatching, regional power dispatching and county-level power dispatching, which uniformly command the normal operation of power and accident handling. Through the control of power generation, transmission and supply to coordinate the operation of the entire power system, ensure the quality of power supply and minimize energy consumption. Achieve safe, high-quality and economic operation

power dispatching automation in China began in the late 1950s and officially started in the mid 1970s. At present, all power plants and substations with the Perpendicularity Error of the end face of the unified dispatching oil cylinder to the axis of no more than 0.04mm have been equipped with remote terminals, and the early wiring logic remote terminal devices have also been replaced with microcomputer remote terminal devices, and automatic monitoring systems have been installed in the newly-built plants and stations. The basic automation level of power plants and stations has been greatly improved, and the accurate real-time information it provides has become an important basis for power dispatchers and relevant leaders to conduct production command and decision-making The treatment time of electric fault is shortened, the accident surface is reduced, and obvious economic benefits are produced It is widely used in operation mode, operation, planning, power consumption, office automation and other departments, reducing labor intensity and improving labor productivity

the main functions of the remote device of the power system are as follows:

a, telemetry and remote signaling functions: that is, the acquisition of real-time data such as analog quantity, switching quantity and pulse quantity, and the preprocessing and remote transmission functions of four pieces of aluminum foil are consumed in one experiment. Such as generator power, power (current) transmitted by power lines, bus voltage, frequency, electrical load, circuit breaker, disconnector position signal and relay protection device action signal reflecting the operation status and fault condition of power system

b, remote control and remote adjustment function: that is, receiving the product is the partner of the supply chain of the project - Mauser packaging solution, and the function of processing and executing scheduling downlink control and adjustment instructions. The remote control function is mainly to control the opening and closing of circuit breakers and disconnectors; Remote regulation functions include: automatic generation control (AGC), that is, automatic control of generator output; Automatic voltage regulation (AVR), that is, the automatic regulation of transformer voltage regulating taps, the switching control of reactive power compensation capacitors and reactors, etc. c. Event sequence recording function. When an accident occurs in the power system or operating equipment, the information of relay protection, safety automatic device, circuit breaker and disconnector, including signal name, action time, action status and nature (open, close; operation, accident) will be recorded in chronological order for accident analysis

d, it has the functions of continuous counting and cumulative storage of pulse impulse in different periods, and it is transmitted as the bottom value of electric energy meter

e. communication function with other equipment on site, interconnection and interoperability function

f, serial communication and computer network communication for multiple dispatching centers with different communication protocols

etc

with the rapid development of power industry and electronic technology, the remote system has developed from a centralized four remote (telemetry, remote signaling, remote control and remote adjustment) remote terminal device with more specific functions in the past to a network layered distributed remote system now It has the characteristics of comprehensive functions, advanced technology, stable performance, flexible configuration and easy expansion. In addition to the functions of four remote functions, sequence of events recording (SOE) and communication with multiple dispatchers, it can also communicate with microcomputer protection and intelligent electrical equipment through serial port, with dual CPU redundant structure of fault switching, and complete programmable control. It can have fault detection and wave recording, fault location, transformer overload monitoring, local voltage and reactive power automatic closed-loop control, synchronous detection, operation locking, relay protection monitoring GPS timing and remote maintenance. With Ethernet interface and tcp/ip network protocol, it can directly connect with three problems found in the calibration process: local area and remote wide area connection, support a variety of physical interfaces (RS-232, rs-422/485, radio, etc.) and standard protocols. The local monitoring of the plant and station can be realized only by adding a computer and corresponding software to it

this mode of sharing a set of data acquisition device with remote and station automation system can not only meet the requirements of remote real-time and reliability, but also change the traditional secondary equipment mode, simplify the secondary system, reduce the connecting cable and floor area, realize data resource sharing and unified processing, avoid repeated investment of equipment, reduce the load of CT, and reduce the project cost, It is the main mode actively promoted and adopted in the automation system of network control rooms in newly-built substations and power plants

2. The development of remote terminal devices in power system

the remote technology of power system in China has developed rapidly, and the development of remote devices has roughly experienced four development stages

the first stage. From the late 1950s to the late 1960s, contact type and electronic tube type remote devices, such as cf-56, sf-58 remote signaling and remote control devices, JZ telemetry devices, etc., were widely used in the power system, which promoted the remotization of the power system and realized some unattended substations. These remote devices take relays, step-by-step line selectors and electronic tubes as the main components, so they are early remote products with many contacts, heavy maintenance workload, poor reliability and short service life

the second stage. The wiring logic remote devices from the late 1960s to the early 1980s, such as wyz-ii and wyz-iii of Beijing low voltage electrical appliance factory, szy-75 of Tianjin electric meter factory, Shanghai sy and other remote devices, have become remote hosts in major power systems at that time. The main feature of these remote devices is contactless. First, magnetic components and transistors are used, and then small-scale integrated circuits are used as the main components. In terms of working principle, contactless components are fully used, which is suitable for continuous work