A new computer setting calculation scheme for the

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Abstract: according to the changes of 110 kV power and the development of computer technology, a new scheme of 0 kV power computer setting calculation, quasi expert system mode, is proposed when 11 samples are broken outside the marking line. The overall design, implementation conditions and functions of each module of the scheme are introduced, and simple mathematical model, friendly user interface Flexible input and output is the development direction of 110 kV computer setting calculation software

key words: 110kV electric computer setting calculation software Untitled Document 110kV electric relay protection setting calculation is a very complex technical work. It requires a lot of repeated setting calculation, comparison and screening based on the calculation of electrical short-circuit current according to certain setting calculation principles, and the workload is very large. Therefore, how to liberate the setting calculation personnel from the complicated calculation has become the goal pursued by many experts, scholars and technicians. The rapid development of computer technology has provided technical support to achieve this goal

since the late 1970s, the development of computer setting calculation has begun. Because the theoretical basis of short-circuit current calculation is strong and the mathematical model is mature, the use of computers for short-circuit current calculation has been popularized in the 1980s. Then, on the basis of short-circuit current calculation, using the basic mode of network node method, some setting calculation software has been developed. These software have some successful experience in the application of some 220 kV power, but for 110 kV power, so far, there is no relatively mature software. This is mainly due to the electrical structure specification of 220 kV and above voltage levels, and the corresponding relay protection setting calculation can be described by standard mathematical methods; The structure of 110 kV power is not standardized, such as short line group, T-connection, small power supply, etc., so in the setting calculation of 110 kV power, there are not only deterministic problems described by mathematical methods, but also a lot of problems that need to be solved by human experience. To solve these problems, we need to use some basic methods of expert system to establish a modifiable rule base. The setter uses these rules according to the specific situation of the setting and establishes a certain logical relationship. Once the logical relationship is established, the setting calculation may be completed automatically regardless of how other parameters of the system change. Since the establishment of its logical relationship requires some manual intervention, we call this method computer setting calculation of quasi expert system mode

1 conditions for setting calculation

when the previous setting calculation software was developed, most of China's 110 kV power systems were still in ring operation. These software fully considered the "impact" of the existence of electromagnetic ring between 220 kV power and 110 kV ring on protection setting, and therefore increased the complexity of the software and reduced its flexibility. These software do not pay attention to the problems of nonstandard setting, many mismatch points and many unconventional setting of 110 kV electric protection, which greatly reduces the practical value of the calculated results. In addition, due to the limitation of software development platform, developers consider less about the convenience of human-computer interface, which makes manual intervention very cumbersome, time-consuming and laborious, and has to be abandoned

The computer setting calculation of quasi expert system mode can solve the problems encountered when the previous software is applied to 110 kV power, which is mainly based on two points: the change of 110 kV power structure and the development of computer technology

1.1110 kV electricity forms the radiation structure of a single power supply, simplifying the setting calculation

with the formation of the 220 kV main transmission network, the original 110 kV ring can be released for operation, thus forming a zoning network with the radiation structure with the 220 kV substation as the central power supply, which greatly simplifies the 110 kV electrical structure. Since the electromagnetic ring is no longer considered, the development idea of the setting calculation software for 110 kV power has changed significantly. After de looping operation, the scale of the partitioned network has a high-speed and accurate data processing capacity of 56mips; The accuracy is above level 0.5. The measurement and control system can carry out various physical and mechanical experiments such as stretching, tightening, bending, peeling, tearing, shearing, puncturing, indentation hardness, low cycle fatigue, etc. the protection coordination relationship between power components has become very simple. If the method of node equation is still used for setting calculation, on the one hand, the simple problem will be complicated, on the other hand, the short line group, t wiring The problem of small power supply. Quasi expert mode is to summarize all the setting coordination relations of power components into corresponding rules expressed by calculation formulas (because there is no electromagnetic ring, the number and complexity of these rules are greatly reduced), and then the setting rules of the set power components are selected by the setter. If this mode is simple, the batch of joints will be judged as unqualified products and intuitive, and the whole process of setting calculation can be effectively controlled

1.2 the development of computer technology provides strong technical support for new models

the earliest development of setting calculation software was about in the 1970s and 1980s. The technical level of computer software and hardware is not comparable with that at that time. At that time, the running speed of the software and the storage capacity of data should be considered first, followed by the user interface. With the current level of computer technology, the calculation speed and data storage capacity of this scale of software can be ignored, so the focus should be on a good user interface. The quasi expert system mode completely completes the input of parameter data, the control of calculation process and the output of calculation results on the primary graphical interface of the system, which greatly reduces the difficulty for users to master the software and can be used conveniently without training

2 implementation scheme of setting calculation

2.1 overall design of the scheme

the scheme is composed of the following modules: Electrical topology drawing module, parameter data input module, short-circuit current calculation module, setting calculation rule module, setting calculation module, ODBC interface module

the whole process of setting calculation is completed under the primary graphical interface of the system, and the user is not required to operate the bottom layer. Under the special electrical topology drawing module, once the primary diagram is drawn, the topology structure of the network data is built, and each unit in the structure corresponds to each component of the system one by one. This correspondence is completed by software without manual intervention; Parameter database, short-circuit current database and rule database are the data sources of setting calculation. Among them, parameter database and short-circuit current database are closely related to the primary structure of the system. When the primary structure of the system changes, the contents of these two databases are modified accordingly. The setting rule base is completely independent, and its modification, supplement and other operations are carried out separately

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