[0029] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation modes and specific operating procedures are given, but the scope of protection of the present invention is not limited to the following Mentioned examples.
[0030] As shown in Figure 1, the system of this embodiment is located in a dispatch center or a centralized control center, and the control of the capacitor banks and transformer taps of the substation is realized through the SCADA system.
[0031] As shown in Figure 2, when this embodiment is applied, two servers and three workstations are used, where the servers use the UNIX operating system, and the workstations use the NT operating system.
[0032]As shown in Figure 3, this embodiment is composed of a database module, a communication module, an analysis and calculation module, a graphic display module, a report management module, system management and other modules. The database module saves the data required by the entire system and provides a sharing mechanism. It mainly interacts with the communication module and also with the analysis and calculation module; the communication module is the middle link of the entire system, and the various data of the system Transfer between modules. Therefore, the communication module has an interface with all other modules; the analysis and calculation module forms a reactive voltage control strategy, receives data through the communication module and sends the control results, and at the same time saves the calculation result data through the database module; the graphic display module displays the grid wiring diagram As well as monitoring data, these data are forwarded through the communication module; the report management module forms various reports required for reactive voltage management, interfaces with the communication module, and exchanges data; the system management module manages the system, and the same The communication module interfaces. The above-mentioned modules are respectively located on a server using UNIX operating system and a workstation using NT operating system.
[0033] 1. The database module is mainly to store and share various data required by the system. These include equipment attribute and type data, graphics data, network topology data, telemetry and telesignal data, control result data, including commercial databases and local databases For the interface with real-time database, commercial database and local database, as shown in Figure 4, ADO technology is used to access various commercial databases; for the local database, a dynamic connection library is designed to encapsulate, forming the same database access interface as ADO.
[0034] 1) The commercial database is located on the server, storing all the various data required by the system. As shown in Figure 2, the databases of the two servers are standby for each other. When one system fails, the other server will be switched immediately;
[0035] 2) The real-time database is also located on the server, and the remote signal values and remotely measured values received from the SCADA system are directly written into a resident real-time database. The database only retains the data at the latest time, that is, when receiving the remote signal value and remote measurement value at the new time, all the old data will be cleared, and only the data at the latest time will be saved. The real-time database uses file mapping memory sharing the way;
[0036] 3) The local database is located on the control workstation, which also saves various types of data, except that the saved data is on a time section, and the old data is replaced with new data.
[0037] 2. The communication module includes two parts: the communication with the SCADA system and the communication between the workstation and the server. Because it is a cross-platform operation, the realization of the communication interface adopts the way of socket (SORKET).
[0038] 1) The uplink data of the communication sub-module of the SCADA system is connected to the real-time database and commercial database, and the telemetry and telesignal data of the power grid are transmitted to the system. On the one hand, it is stored in the commercial database, and on the other hand, it is sent to the real-time database (such as As shown in Figure 5), to prepare for analysis and calculation; the downlink data is connected to the analysis and calculation module, and the control strategy obtained after analysis and calculation is issued through the SCADA system with remote control and remote adjustment commands. The communication protocol is mainly used by the SCADA system;
[0039] 2) The communication sub-module between the workstation and the server exchanges data with the commercial database on the one hand, and on the other hand sends the calculation and analysis results to the report management, graphic display and system management modules;
[0040] 3. As shown in Figure 6, the analysis and calculation modules include state estimation, topology analysis, load forecasting, reactive power optimization and expert system sub-modules. After state estimation, the data forwarded by the SCADA system is subjected to topology analysis and short-term load distribution prediction. On the basis of meeting the requirements of the switching times of the capacitor bank, the gradient optimal power flow algorithm is used to optimize the reactive power to form the optimal control of the capacitor bank The strategy is issued by the SCADA system; the expert system technology is the backup technology of the optimization technology. When the optimization fails, the expert system sub-module is activated to form the control strategy of the capacitor bank. The adjustment strategy of the on-load tapping tap is also realized through expert system technology.
[0041] 1) The topology analysis sub-module performs dynamic topology analysis based on the remote signaling data transmitted from the SCADA system, determines the uncharged part, and forms the network data required for the calculation;
[0042] 2) The state estimation sub-module firstly distinguishes and processes the wrong data based on the multi-point data, and then derives the parameters of the line, including resistance, reactance and admittance to ground based on the remote measurement at both ends of the line, such as current, voltage and power, and finally forms Data required for calculation;
[0043] 3) The load forecasting sub-module adopts linear regression and neural network algorithms to forecast the short-term load distribution. The result of the forecast is to provide the load peak, trough and average time period and load forecast value of the next day;
[0044] 4) The reactive power optimization sub-module adopts the gradient optimal power flow algorithm, and the technology of node type conversion and optimal step length setting to optimize the switching of the capacitor bank;
[0045] 5) The sub-module of the expert system is used to form a rule base. The rule base is divided into two parts: general rule base and special rule base. The general rule base describes the general rules required for reactive voltage control, while the special rule base describes Specific equipment, rules adopted according to the operation of the equipment;
[0046] 4. The graphic display module mainly displays the principle wiring diagram of the power grid. It can input graphic data, equipment attributes and type data, and automatically generate topology data; it can also search and locate equipment;
[0047] 5. The report management module is mainly for statistics, analysis and query of some reactive voltage control results;
[0048] 6. The system management module monitors and manages the entire system.
[0049] When this embodiment is working, the communication sub-module of the communication module and the SCADA system receives the measured data forwarded by the SCADA system, sends it to the calculation analysis module, and saves it in the commercial database at the same time, the analysis calculation module performs analysis and calculation to form a reactive voltage The control strategy is then issued through the communication sub-module of the SCADA system, and at the same time is transmitted to the graphic display module through the communication sub-module between the workstation and the server to display the results of calculation, analysis and control.
[0050] The graphical operation interface in this embodiment can intuitively display the network connection status of each district of the regional power grid, the status of related equipment and the data uploaded by the SCADA system. Operators can add lines, transformers, capacitors and other equipment graphic elements by themselves as needed, and then the system automatically completes the topology search and forms all the basic data required for subsequent calculations, without manual operation by the operators.
[0051] For regional power grids, if the network is large and there are more 220kV substations, the method of district control should be adopted. The principle of zoning is to use the power supply area of the 220kV substation as a basic unit to perform reactive power analysis and control separately, and the reactive power flow between the tie lines between each zone is required to be as small as possible.
[0052] Taking into account the safety and stability of system operation and the operating habits of field operators, the AVC system described in this embodiment adopts the NT-UNIX cross-platform structure, that is, the entire system adopts a workstation-server model, and the background database is placed on the server. And install the UNIX operating system on the server to make full use of the characteristics of the UNIX operating system's reliable operation and high network security; and the analysis and calculation module, system management module and report management module are placed on the workstations to form a monitoring workstation and a maintenance workstation. And the report workstation, and install the windowsNT operating system, which can make full use of the various operating functions of the NT platform and conform to the operating habits of the on-site operators, which is beneficial for the operators to learn and master the operating functions of the system of the present invention as soon as possible.
[0053] This embodiment adopts the method of district display and district management to coordinate and manage the voltage and reactive power situation of the regional power grid. The power supply area of the 220kV substation is used as a basic unit to perform reactive power analysis and control separately, and the tie line between each district is required Reactive power flow is as small as possible; graphics-model integration technology is widely used, and topology search and subsequent related calculations are automatically completed according to the network connection status displayed on the graphical interface, without manual intervention by the operator; NT-UNIX cross-platform is adopted Structure, the back-end database is placed on the server with UNIX operating system, making full use of the security and reliability of the UNIX operating system to ensure the unity and security of the underlying data. At the same time, monitoring workstations, maintenance workstations and report workstations are set up according to the function, and installed on the workstations The Windows NT operating system can not only provide operators with a better graphical interface, but also facilitate the operators to quickly grasp the various operating functions of the present invention.
