KR20050041341A - Algorithm for the power system restorative training and its system - Google Patents

Abstract

The present invention provides an analysis and training method for any system operation and develops a system of a computer environment to develop a system of a computer environment in order to explore the improvement of the manager's ability to deal with a crisis in the event of a large power outage of a domestic transmission network. It is about.

That is, the present invention performs static characteristics analysis on transmission system of 154kV or more to determine bus overvoltage and line overload, and through this, the system operator can be trained for optimal failure recovery and can perform quick and accurate recovery in case of large power failure. It provides a database construction and management method that can convert data of PSS / E, which is widely used as a domestic system analysis tool, linkage, and move to all stages of the simulation to secure versatility, and has a graphical user interface. Can be implemented as a computer system. The present invention enables efficient recovery training for any control of the operator to memorize recovery training for large-scale blackouts, which was made based on the empirical knowledge of the conventional operators, and the operator's fast and accurate coping ability through pre-simulation training. There is a reduction in social disruption and economic loss when the actual situation occurs.

Description

Algorithm for the power system restorative training and its system

The present invention implements a training method for analyzing an operator's arbitrary system operation for a large power outage of a power system and a computer system, and especially for generator, transformer, line, and load control of a 154kV transmission system for recovery in the event of a power failure. The database management function and the user graphic interface are provided to develop the education and training algorithms for power system operators to find the optimal fault recovery method by analyzing the system, and to judge the line flow, overload and bus overvoltage. Training system in a computer Windows environment.

In modern industrial society, power dependence is very high. The recent regional outage in the eastern United States is a good example of the importance of the national grid. Even small breakdowns such as lightning strikes have a serious impact on finance, industry, and the economy and spread to emergencies throughout the country. Even if the ground fault of the ungrounded system with very low fault current occurs, the system operator should immediately identify the failure of the line and establish an appropriate countermeasure to stabilize the system.

However, the power system structure and facilities of Korea are very high compared to the developed countries, so the probability of actual power failure is very small, but the opportunities for operators to exhibit their ability to deal with emergencies are gradually decreasing.

In general, the system simulation training system based on the unit substation is used for the power system failure recovery training method in Korea, but it is difficult to maintain and expand the system, and it is impossible for the operator to control and various recovery simulations. Have.

In addition, large-scale power outages are being trained to allow the operator to memorize by writing a huge amount of case-by-case troubleshooting procedures reviewed using a system analysis program.

Accordingly, the present invention has been made in view of the above-described circumstances, and provides an algorithm capable of failure recovery training for any system control of a power system operator and a power system failure recovery education and training system as a system of a computer environment. There is a purpose.

Therefore, the present invention intends to develop a fault recovery education algorithm and a computer training system for finding a crisis response ability of the operator in the event of a large power outage.

The power system fault recovery education and training algorithm of the present invention aims to proceed the recovery work by any control of the operator from any system initial condition in a timely manner, and supply the bus overvoltage or line overload, generator reactive power during the training. If an excess occurs, it can take the form of returning to its previous state and attempting a new recovery operation.

According to the present invention, the power system failure recovery education and training algorithm calculates the active power of each line, the reactive power, and the voltage and phase angle of the bus line in transporting the power generation of the generator obtained from the economic power supply plan to the load point. It consists of a database management system that manages the power current calculation and data and system analysis results thereof, and can be implemented as an education and training system provided with a graphical user interface (GUI) for operating the algorithm of the present invention in a computer environment.

This invention will be described in more detail based on the accompanying drawings.

First, the power flow calculation can use the Per Phase analysis method as it considers the three-phase balanced system operation limited. The power current calculation based on the complex power S _i flowing into the grid from each bus is given by the complex power produced by a certain bus as S _Gi and the complex power consumed by S _Di as the complex power S _i of the bus. It can be defined as follows.

(One)

S _ik is the complex power flowing from bus i to bus k , and using the property of complex power conservation,

(2)

By Kirchhoff's current law,

(3)

Because of,

(4)

Now, using the equation (4) to calculate the complex power of the bus i is as follows.

(5)

(6)

Using the equations (5) and (6), the complex power at bus i is:

(7)

Real power of complex power in bus line i of equation (7) Imaginary part reactive power Then, the following equation can be obtained.

(8)

The power flow calculation takes into account the grid operation, so the generator bus is fixed with the active power P _i = P _Gi -P _Di and the absolute value ┃ V _i │ at the given value, and the load bus is complex power S _i, ie P _Di and Q _Di. Fix it. At this time, if the loss of the system is ignored, the sum of II of all buses becomes zero. However, in real systems where losses are present, the sum of II It is equal to the loss of. The problem is that it is not possible to know exactly how much this loss is before algae calculation. Therefore, instead of selecting a generator that will be responsible for this loss, the voltage and phase angle of the voltage are determined without specifying II at the bus. This bus is called the slack bus.

In the present invention, if the user does not specify a slack bus bar is connected to the power transmission system of 154kV or more to search all generators supplying power to designate the power generation bus with the largest power generation capacity as the slack bus bar, and more than one slack bus bar In this case, the calculation confusing causes the Slack bus automatic selection and search algorithm to search and inform the user.

In order to solve the algae calculation of the nonlinear equation of Equation (8), the present invention uses the Newton method and the Gaussian method, and the Newton method shows convergence characteristics sensitive to initial values since the transmission network applied to the present invention corresponds to a large scale system of 1000 buses or more. The initial value of the Gaussian method is obtained before the iterative calculation is performed, and the result shows good results even in the case of the relatively large RX Ratio which is difficult to converge by the Newton method alone.

If the generator reactive power, bus voltage, and phase angle are found through tidal flow calculation, the overload and overvoltage of the restored power system should be determined based on this. 1 is a track model for algae calculation and the process for determining the system state of the present invention is as follows.

Where V _p : p bus voltage, I _p : current flowing through the bus, a : transformer turns ratio, Y _series : linear admittance connected to the pq line, Y _shunt : line charge capacity, V _q : q bus voltage, I _q : q Each of the currents flowing through the bus is shown.

In the line circuit shown in FIG. 1, the relationship between voltage and current is as follows.

(9)

In order to find the current flowing in the line, I _p and I _q in Eq. (9)

10

(11)

Calculate the amount of power flowing in the track using equations (10) and (11).

(12)

(13)

Equation (12) and (13) are compared with the MVA of the corresponding line stored in the database to determine whether the line is overloaded, and it is determined whether the bus voltage calculated by the tide calculation is above the set overvoltage standard. To judge. In addition, it is determined whether the generator reactive power exceeds the reference value in the same manner, and the present invention transmits the abnormality of the system generated during the recovery education training to the user.

2 shows a data flow diagram between the algorithm of the present invention and the database management system 20 of the system.

Database (DB) of the present invention is converted into PSS / E data through the PSS / E data unit 40 most commonly used as a system analysis tool in the country is built with the SAV and CAS extensions 30 of the data format of the present invention , Database (15) is a static DB (11), which contains the system constants and status information of generators, transformers, lines, buses, and bus voltages, phase angles, generators, It is designed and managed as a dynamic DB 12 composed of active power and reactive power of the load.

3 is a flow chart of the UNDO function back to the previous stage of simulation of the present invention. When the power system fault recovery training and training algorithm is started (100), the present invention stores the connection information and data of the current transmission system as a UNDO file and designates a flag (false) (false) (110). When the system is operated by the user (120), the value of the flag is determined (130). If the value is true, a new UNDO file is generated and stored, and then the flag is changed to false. (110), and change the database (DB) according to the system operation (140), and if the failure (false) only changes the database according to the system operation.

In the next step, if the system operation for fault recovery is continuously performed, the above process is repeatedly repeated.In this case, when the tide calculation is performed (150), the flag is placed in the true position and the calculation result is stored in the database. After storing in (DB) (160), it moves to the step of system operation again. Through such a UNDO function, the present invention can return to the previous stage and attempt a new recovery task if any abnormality of the system occurs at any stage of the fault recovery training.

Figure 4 is a flow chart showing a process for performing a failure recovery training through the system development system of a computer environment to which the power system failure recovery training algorithm of the present invention is applied.

The present invention provides a user graphic interface (GUI: 210) that allows the user to operate the system on a graphic basis, and through the user graphic interface (GUI), the schematic diagram production, database management and troubleshooting for the recovery procedure in the order shown in Can be performed. Here, reference numeral 220 denotes a printer.

When training is started through the user graphic interface (GUI), the system is operated on a line on / off, generator output adjustment, and load input system (120). At this time, if there is a power failure command for a transmission network of 154 kV or more (230). Before operating the system, the system trips all breakers (P, Q, V, T = 0) and sets the active power, reactive power, voltage, and phase angle of all buses to zero (240). Upon completion of the grid operation, the system performs an analysis module to construct the Y-matrix for all grids from the database (250), after performing algae calculations (150), overloading the generator reactive power supply, bus line overvoltage and line overload. Determining (260), and graphically delivered to the user through the user graphic interface (GUI) (210). Once the power system analysis is complete, the system is again ready for the user's grid recovery operation, when a grid connection command is issued to the system (270). The current live power system data is stored in a CAS file, which is a grid-connected storage format (280). The present invention provides a system linkage simulation for performing a region-specific recovery simulation during a large power outage and calling two or more CASes stored in the CAS file 280 of FIG.

The algorithm and system of the present invention not only enable the user's arbitrary control function, but also the fault recovery simulation within a proper time, and use the PSS / E data as initial data for ease of input data creation and continuous use. It can be designed and implemented as a GUI-based system for the operator's convenience.

The present invention can be used not only for the simulation training to improve the crisis management ability of the power system operators, but also for the support of the decision-making of the operators in the event of a large-scale power outage. It is expected to have a great effect on.

1 is a track model for bird calculation,

2 is a configuration diagram of a database for explaining a power system failure recovery training system of the present invention;

3 is a flow chart of a pre-simulation step movement function,

Figure 4 is a flow chart of the configuration and training algorithm of the power system fault recovery training system of the present invention.

* Explanation of symbols for main parts of the drawings

11: static DB 12: dynamic DB

15: Database 20: Database Management System

30: SAU, CAS extension 40: PSS / E data part

210: user graphical interface 220: printer

Claims (4)

In performing tidal current calculation for power system fault recovery education and training algorithm, (a) If there is no slack bus designated for tide calculation, search all generators that are connected to the power transmission system over 154kV and designate the power generation bus with the largest generation capacity as the slack bus, and specify more than one slack bus. Providing a slack busbar automatic selection and search algorithm that detects and informs users if (b) The process of improving the convergence of algae, which obtains the approximate initial value using the Gaussian method, before the Newton method iteratively calculates the convergence characteristic sensitive to the initial value for a large transmission system of 1000 buses or more. , (c) By comparing the amount of power flowing in the line with the MVA of the corresponding line stored in the database, it is judged whether the line is overloaded or not, and whether the bus voltage calculated by the tide calculation is above the set overvoltage standard and the generator reactive power is the reference value. Power system failure recovery education and training system, characterized in that it has a process of determining whether exceeds. According to claim 1, wherein the amount of power flowing to the line , Power system failure recovery training system characterized in that calculated by the equation. In the correlation between the algorithm and the database management system of the system, A database is constructed by converting PSS / E data into SAV and CAS extensions 30, which are data formats; The database consists of a static DB that contains the system constants and status information of the generator, transformer, line, bus, and a dynamic DB consisting of bus voltage, phase angle, active power and reactive power of the generator and bus load. ; Power system fault recovery education and training system, characterized in that to perform the UNDO function to go back to the previous step and attempt a new recovery task if any abnormality of the system occurs at any stage of the fault recovery training. In the system development system of computer environment to which power system failure recovery education and training algorithm is applied, (a) a graphical user interface (GUI) capable of producing schematics, database management, and troubleshooting training; (b) the process of tripping all breakers and setting the active power, reactive power, voltage, and phase angle of all buses to zero for simulating power failure for grids above 154 kV, (c) the process of constructing the Y-matrix for all power grids from the system operation to the database, determining the tidal current calculation, the generator reactive power supply excess, the bus overvoltage, the line overload, and delivering it graphically to the user through the GUI; (d) A power system fault recovery education and training system comprising a process of performing a region-specific recovery simulation in case of a large power outage and linking two or more CASes stored in a CAS file and linking the linking points.