Basic concept and development process of integrate

The basic concept and development process of substation integrated automation

the substation integrated automation system uses advanced computer technology, modern electronic technology, communication technology and information processing technology to realize the re combination and optimization design of the functions of substation secondary equipment (including relay protection, control, measurement, signal, fault recording, automatic device and Telecontrol device), A comprehensive automation system that monitors, measures, controls and coordinates the operation of all equipment in a substation. Through the mutual exchange of information and data sharing among the equipment in the substation integrated automation system, the substation operation monitoring and control tasks are completed. The substation integrated automation replaces the conventional secondary equipment of the substation and simplifies the secondary wiring of the substation. Substation integrated automation is an important technical measure to improve the safe and stable operation level of substation, reduce operation and maintenance costs, improve economic benefits, and provide users with high-quality power

I. the necessity of developing substation integrated automation

as a node in the whole power system, substation is responsible for the monitoring, control and management of power transmission and distribution. Substation relay protection and monitoring automation system is the basis to ensure the completion of the above tasks. Under the unified command and coordination of electricity, each node of electricity (such as substation and power plant) implements and ensures the safe, stable and reliable operation of electricity. Therefore, substation automation is an important part of electric automation system. As a substation automation system, it shall ensure the following requirements:

(1) detect electrical faults and isolate the fault part as soon as possible

(2) collect real-time information of substation operation to monitor, measure and control substation operation

(3) collect primary equipment status data for reference of primary equipment maintenance

(4) realize local backup control and emergency control

(5) ensure communication requirements

therefore, it is required that the operation of the substation integrated automation system should enhance the basic research, utilization research and technology development cooperation, and be efficient, real-time and reliable, so as to uniformly monitor, manage, coordinate and control the equipment in the substation. At the same time, it is necessary to exchange and share real-time and effective information with the electric system, optimize the electric operation, improve the safe and stable operation level of electric power, improve economic benefits, and leave space for the further development of electric automation

in the traditional substation, its automation system has many shortcomings, which is difficult to meet the above requirements. For example:

(1) most traditional secondary equipment, relay protection, automatic and telecontrol devices adopt electromagnetic or small-scale integrated circuits, which lack self inspection and self diagnosis capabilities, and have complex structures and low reliability

(2) the secondary equipment mainly relies on a large number of cables to exchange information through contacts and analog signals, with small amount of information, poor flexibility and low reliability

(3) due to the above two reasons, the traditional substation covers a large area, uses many cables, bears heavy burden on voltage transformers and current transformers, and has many redundant configurations of secondary equipment

(4) the telecontrol function is not perfect, the amount of information provided to the dispatching control center is small, the accuracy is poor, and the automatic control and adjustment means in the substation are incomplete, lacking coordination and cooperation, which is difficult to meet the requirements of real-time electrical monitoring and control

(5) electromagnetic or small-scale integrated circuits have heavy commissioning and maintenance workload and low degree of automation. It is not possible to remotely modify the setting value of protection and automatic devices and check their working status. Some equipment are easily affected by the environment, such as transistor type secondary equipment, whose operating point will be affected by the ambient temperature

in the traditional secondary system, each equipment is configured according to the equipment function, and there is little correlation between them. It is difficult to coordinate with each other. It requires more intervention by the personnel on duty, and it is difficult to adapt to the control requirements of modern electricity. In addition, the equipment needs to be tested and repaired regularly. Even so, there is still the phenomenon that the equipment fault (abnormal operation) can not be found in time. Even this kind of regular maintenance may cause new problems, and failures caused by the fault of test personnel may occur

the necessity of developing substation integrated automation also reflects the following aspects: first, with the continuous expansion of power scale, a large number of new power plants and substations have been added, making the electrical structure more and more complex. This requires a large increase in the information mastered, managed and controlled by power dispatching personnel at all levels, but requires more rapid and accurate power fault handling and recovery; Second, the development of modern industrial technology, especially the development of electronic industry technology and the universal application of computer technology have put forward higher requirements for reliable power supply; Third, the development of market economy makes the whole society have higher requirements for environmental protection, which also puts forward many requirements for the construction, operation and management of electricity. For example, power enterprises are required to participate in market competition, reduce costs and improve economic benefits; Power plants and substations are required to reduce the floor area. To solve the above problems, it is obviously difficult to rely on the operators on duty at all levels of power dispatching. The development of modern control technology, the progress and development of computer technology, communication technology and electric power technology, and the application of electric automation system provide solutions to the above problems. These systems can actively launch the comprehensive application of experimental technology, resulting in the emergence and development of substation integrated automation system

II. Development process of substation integrated automation system

there are three forms of existing substations: the first is the traditional substation; The second one is the substation with certain automation level, which partially realizes microcomputer management; The third type is a comprehensive computerized integrated automation substation. The development of substation automation can be divided into the following three stages

1. automatic device stage composed of discrete components

before the 1970s, automatic devices with various functions produced by research units and manufacturers (such as automatic reclosing device, low-frequency automatic load shedding device, automatic input of standby power supply, DC power supply and various relay protection devices adopted by our company), mainly adopt analog circuits and are composed of discrete components such as transistors, It has played a certain role in improving the automation level of substations and power plants and ensuring the safe operation of the system. However, these automatic devices operate independently of each other and lack intelligence. Without the progress of plastic granulator technology, they are closely related to the development of the whole national economy. They have the ability of fault self diagnosis. If they fail during operation, they cannot provide alarm information, and some may even affect electrical safety. At the same time, the reliability of the device with discrete components is not high, the maintenance workload is large, and the device itself is large and uneconomical

2. intelligent automatic device stage with microprocessor as the core

with the development of China's reform and opening up, microprocessor technology began to be introduced into China and gradually applied to all walks of life. In substation automation, large-scale integrated circuits or microprocessors are used to replace the original automatic devices composed of discrete components such as relay transistors. Using the intelligence and computing power of microprocessors, new algorithms can be developed and applied to improve the accuracy and reliability of measurement; The ability to expand new functions, especially the fault self diagnosis function of the device itself, is of great significance to improve the reliability of the automatic device and shorten the maintenance time; In addition, because of the use of digital, unified digital signal level, reduced volume and so on, its advantages are obvious. As the hardware structure of these microcomputer based automatic devices is only replaced by microprocessors and their interface circuits, and some simple functions are expanded, although the ability and reliability of substation automatic control are improved, the original functions and logical relationships are basically maintained. In terms of working mode, most of them still operate independently and cannot communicate with each other and share resources, The problems existing in the design and operation of substations and power plants have not been fundamentally solved

3 development stage of substation integrated automation system

China began to develop substation automation technology in the 1960s. By the early 1970s, it had successively developed electric centralized control devices and devices integrating protection, control and signal. In the mid-1980s, the hydraulic universal testing machine in the 35kV substation market developed by Tsinghua University was equipped with many kinds of microcomputer protection and monitoring automation systems, which were put into operation in Weihai Wangdao substation. At the same time, Nanjing Jing Automation Research Institute has also developed a 220kV Meihekou substation integrated automation system. In addition, many domestic universities and scientific research institutions have also done a lot of work in this regard, launching some automation systems with different types and functions. It has played an effective role in promoting the development of substation automation technology in China. In the 1990s, substation integrated automation has become a hot topic. Research units and products have mushroomed. Representative companies and products include CSC 2000 series integrated automation system of Beijing Sifang company, bsj2200 computer monitoring system of Nanjing NARI Group Company, RCS 9000 series integrated automation system of Nanjing Nari Relay Protection Electric Co., Ltd, Shanghai Huian power comm 2000 substation automation monitoring system, Guodian Nanzi PS 6000 series integrated automation system, The cbz-8000 series integrated automation system of XJ electric company, etc. (later, we will focus on explaining the substation integrated automation systems we contact, such as Wuhan guoci gcsia substation integrated automation system, Nari urban and rural DSA substation integrated automation system, and the cbz-8000 series integrated automation system of XJ electric company). (end)