Abstract: Energy management system is an indispensable means of modern large power grid operation, but the practical degree of energy management application software of power companies in China is still very low. Recently, the State Power Company has put forward practical requirements and assessment standards for EM S of various dispatching departments, and all dispatching departments are working hard for this goal. Because most provincial power dispatching centers in China use foreign EM S, which has no evaluation and statistical function, the author studies and implements Hubei EM S evaluation and monitoring management system according to the actual demand put forward by the National Power Dispatching Center. The system goes deep into the core of EM S, combines with external software programming, manually sets the running parameters of EM S, and evaluates, counts and controls the running status and results of EM S application software in real time. The system carries out all-round, automatic and uninterrupted standardized inspection and monitoring of the application software of EM S, which lays a solid foundation for the practical application of EM S.
Keywords: EM S；; Monitoring system; electric power system
China Library Classification Number: TM 734 Document Identification Number: A.
1 Introduction
Driven by the national power grid interconnection and power market, in order to coordinate and optimize the safety, high quality, economic operation, environmental protection and benefit of large power grids, the energy management system will have greater development and will become an indispensable means for the operation of contemporary large power grids. However, at present, there is not a comprehensive and fully functional power system security assessment and monitoring management system in China's power grid. The management, maintenance, evaluation and monitoring of EM S are mainly completed by operators, with low automation, reliability and accuracy. The use of EM S application software and the quality of the system have yet to be tested. In order to further promote the practical application of the basic functions of EM S application software, give full play to its role in the safe, high-quality and economic operation of power grid, and cooperate with domestic first-class power grid dispatching institutions to standardize and guide the acceptance of basic functions, the National Electric Power Dispatching and Communication Center has formulated the Practical Requirements and Acceptance Rules for the Basic Functions of EM S Application Software [1], which requires that the practical work of EM S be highly valued. According to the document number. [1998] 126 Notice on Printing and Distributing Functional Requirements and Basic Conditions for Implementing Energy Management System (EM S) and its annexes, with the document number of National Dispatching Center [1999] 207 "Practical Requirements and Acceptance Rules for Basic Functions of EM S Application Software". And the Functional Specification of Power System Safety Inspection, Monitoring and Management System formulated by the Automation Department of Hubei Electric Power Dispatching and Communication Bureau. Taking the practical improvement and assessment management of Hubei power grid safety management system as the subject, the assessment monitoring management system of safety management system is designed and established.
On the basis of improving the functions of EM S application software, the evaluation monitoring management system can monitor the running status and results of EM S application software in real time, and automatically calculate and generate evaluation indicators and reports of EM S operation. The invention can obviously reduce the analysis and calculation workload of operators, free the operators from a large number of complicated and tedious data retrieval and calculation work, and improve the work efficiency and accuracy. By monitoring the running module of EM S, the running performance of EM S is effectively improved. The system can also publish the real-time running status, intermediate calculation information and calculation results of EM S on the Internet, and realize unattended and remote monitoring and fault diagnosis of the system, which has practical value. The successful development of the system laid a solid foundation for the practical application of EM S, and gave full play to the role of EM S in the safe, high-quality and economic operation of power grid.
Principle and structure of environmental management system evaluation monitoring management system
The hardware of evaluation monitoring management system mainly includes evaluation monitoring computer, network adapter and laser report printer. Its hardware configuration is shown in figure 1. The evaluation and monitoring computer is respectively connected with the environmental management system and the management information system through dual networks. When a network fails, it will not affect the normal operation of the system, that is, it has the ability to switch between two networks.
The hardware of figure1hardware structure diagram of EMS assessment management system 1 Superv is the inventory control system of EMS.
The evaluation and monitoring management system software includes three parts: EM S automatic evaluation and monitoring software, evaluation index statistics management software and online information release system. The flow chart is shown in Figure 2.
The inspection, monitoring and management system obtains real-time data and running status information from EM S, and transmits these real-time data and running status information to the EM S automatic inspection, monitoring and management computer through standard network data communication interface. Through the data format conversion software, the special real-time database of the assessment management system is established on the local computer to complete the calculation, statistics, analysis and processing of data, generate assessment monitoring results such as reports and curves, and refresh the local real-time database of the assessment management system. Share data with management information system (M IS) ***, publish relevant information online, and send letters to electronic attendant as required.
Figure 2 schematic block diagram of EMS evaluation management monitoring system Figure 2 block diagram of EMS monitoring system
The first step of the flow chart is to complete the necessary source program modification and programming on EM S, which is specially designed for Hubei EM S system (ABB S. P. I. D. E. R system). Because under the existing EM S operating conditions and output conditions of Hubei power grid, it is impossible to obtain some statistical information of EM S assessment indicators. Therefore, the source program of EM S has been modified and expanded. The setting of EM S control parameters and the output of calculation results are increased.
3 main functions of the system
EM S evaluation monitoring management system has the following specific functions:
3. Real-time monitoring of1EMS calculation data
3. 1. 1 bus balance monitoring
Calculate the algebraic value and net value of real-time data of bus incoming and outgoing lines and transformers' active power and reactive power. Compare the net value with the threshold value, and screen out the stations with unbalanced buses. By sorting, according to the deviation of net value, the station name, net value and its measurement components of each plant and station are displayed. Normal stations are displayed in green; When the net deviation exceeds 3. 0%, which will be displayed in yellow. When the net deviation exceeds 5. 0%, which will be displayed in red. At the same time, the net deviation of each station can be displayed by curve method respectively. The curve density is 1 point per real-time database data refresh cycle (currently set to 1 min), and the storage time is 3 days. The horizontal and vertical coordinates of the curve can be modified online. And monitor the update of the net value. If the net value continuously exceeds 30 m in and has not been updated, it can be considered that the RTU of this road is out of service, and the events of RTU shutdown and resumption of operation are recorded. The event is saved for 2 months. If all RTUs are not updated, the operator will be prompted that the EM S system is broken or the network communication between the EM S evaluation and monitoring management system and EM S is interrupted, and this full stop information will be sent to the electronic attendant for alarm.
3. 1.2 line loss monitoring
Calculate the difference of real-time data of active power on both sides of the line. And compare the difference with the threshold to screen out the lines with abnormal line loss. By sorting, according to the deviation of net value, the station name, net value and its measurement components of each plant and station are displayed. Normal data is displayed in green; When the net deviation exceeds 3. 0%, which will be displayed in yellow. When the net deviation exceeds 5. 0%, which will be displayed in red.
3. 1.3 loss monitoring
Calculate the difference of real-time data of active power between two sides and three sides of transformer. Comparing the difference with the threshold, the transformer with abnormal loss is selected. The output result is similar to the line loss output result.
3. 1.4 voltage rationality monitoring
Calculate the difference of real-time bus voltage data of each section of multi-bus. And compare the difference with the threshold, and screen out the bus with abnormal voltage. The output result is similar to the line loss output result.
3. 1.5 Telecom. Consistency monitoring of telemetry
According to the principle that the switch state is consistent with the line power flow value, the switch with abnormal position is screened out. That is to say, switches with non-zero telemetry and remote signal position disconnected and switches with zero telemetry and remote signal position closed. The name and actual state of the switch with abnormal output position.
3. 1.6 Remote signal counter monitoring
Defining monitoring switch by remote signal inversion in real-time system.
The name and actual state of the output inversion switch.
3.2 EMS module running status monitoring
3.2. 1 module running state monitoring
The application software of EM S in Hubei Power Grid includes real-time data snapshot module (SN P), state and analog correction module (SAR), network topology and model building module (NMB), bus planning module (BSK), state estimation module (SE), network parameter updating module (N PU), security analysis module (SA), network sensitivity analysis module (N S) and dispatcher power flow module (DPF). EM S evaluation and monitoring management system can monitor the running state and control mode of each module of EM S in real time, distinguish the running state and exit state of each module of em s, and send the information that the module is not running to the electronic attendant for alarm when necessary. Various control modes of EM S can be divided into: real-time state estimation, real-time dispatcher power flow, research state estimation and research dispatcher power flow. The changes of the running state and control mode of each module of EM S are recorded as time-stamped events, and the storage time is 2 years.
3.2.2 Monitoring of the running state of the module
Monitor the running status of each functional module of EM S in real time. The closed state, initialization state, startup preparation state, request execution state, being executed state, timeout state, lock state, execution completion state, error state and stop state of each module of EM S can be distinguished, and the running state of each module is indicated on the flow chart of EM S application monitor. The change of the running state of each module is recorded as an event with a time stamp, and the storage time is 2 years. Count the number of times each module has been in an error state continuously. And set the limit of the number of consecutive error states for each module. If this limit is exceeded, an error message will be sent to the electronic attendant for alarm.
3.2.3 Analysis of Intermediate Results of Module Calculation
You can check the abnormal situation in the running process of the software of each functional module of EM S, check the causes of the abnormal situation, and obtain the information in the running process of the software of each functional module of EM S. Publish it on the web page to allow operators to monitor and diagnose faults through remote Internet.
3.2.4 Monitoring of module calculation results
It can monitor the calculation results of various functional modules of EM S in real time, including the iterative process and convergence of state estimation (SE) and dispatcher power flow (DPF) application modules. The convergence and non-convergence data of SE and DPF software are counted monthly, and the statistical data are kept for 2 years.
3.3 Control and management of module operation
The control mode of the module can be set online, and the iterative process of module calculation and the control of calculation convergence accuracy can be carried out. This is to reform the source program, screen and database of EM S application software, adjust and change the control parameters of related algorithms, so that operators can directly control the calculation process and convergence accuracy of state estimation and dispatcher power flow module on the screen of EM S monitor.
3.4 Statistical analysis of EMS calculation results
The calculation results of SE and DPF modules are statistically analyzed. According to the reference values of different voltage level measurement types, the deviation between the estimated value of state estimation and the calculated value of dispatcher power flow is calculated, and the unqualified calculation points are automatically found, and the qualified rate index of EM S state estimation and the qualified rate index of dispatcher power flow calculation are obtained. The calculation results and analysis results form a report output.
3.5 Management of assessment indicators of environmental management system
Establish an EM S assessment management database, and automatically calculate the EM S operation assessment indicators one by one according to the EM S database and statistical operation history data, including: ① state estimation coverage; ② Monthly availability rate of state estimation; ③ Telemetry estimation qualification rate; ④ Calculation time of single state estimation; (5) Monthly qualified rate of dispatcher's tidal current; ⑥ Error of dispatcher's power flow calculation result; ⑦ Calculation time of single power flow; ⑧ Monthly operation rate of load forecast; Pet-name ruby accuracy of monthly load forecasting; Bk monthly maximum (low) load forecasting accuracy.
3.6 Environmental management system assessment management information release system
EM S evaluation management information publishing system consists of evaluation information consulting management software on local computer and online information publishing system. By establishing the homepage of environmental management system assessment monitoring management system, assessment management information will be published online. In this way, operators can not only view the information of EM S evaluation monitoring management system on the local computer, but also view it online through the network, which is convenient for operators and managers to view.
On the basis of realizing the above main functions, the EM S evaluation monitoring management system integrates the existing statistical functions of GC as a subsystem of the EM S evaluation monitoring management system.
4 system characteristics
Practical transformation of (1) EM S function
EM S evaluation monitoring management system has a wide range of evaluation management, comprehensive functions and strong practicability. Its evaluation and management scope includes all functional modules of EM S application software. Its functions include: real-time monitoring of EM S calculation data, monitoring of EM S module operation state, control and management of EM S module operation, statistical analysis of EM S calculation results, management of EM S assessment indicators and online information release of EM S assessment management. Some of these functions can not be realized under the operation and output conditions of existing EM S in Hubei Power Grid. Therefore, the author analyzes the source program of EM S in detail, and modifies and expands the functions of related modules. The statistical results of calculation times and convergence times of EM S state estimation (SE) and dispatcher power flow calculation (DPF) are increased, and the tuning function of SE and DPF control parameters is increased.
(2) Fully automatic manual online maintenance
Considering that with the continuous expansion of the power system, the components and equipment of the power system managed by EM S will continue to increase. If the operator is required to manually maintain the EM S evaluation and monitoring management system, it will inevitably increase the workload of the operator, improve the requirements for the operator and reduce the automation, practicality and reliability of the EM S evaluation and monitoring management system. Therefore, this EM S evaluation and monitoring management system adopts the way of automatically tracking the changes of EM S components and equipment parameters, and EM S can automatically add and monitor telemetry and telecommunications of newly added lines, transformers, generators, buses and stations. This enables operators to operate the system skillfully without knowing, learning and mastering the data structure and data content of EM S, which meets the requirements of practicality and universality and improves the reliability of EM S evaluation and monitoring management system.
(3) Automatic and uninterrupted operation of the system and error monitoring.
EM S evaluation monitoring management system can monitor the running status of EM S server, automatically identify the online and standby status of EM S server, and automatically synchronize with EM S server after switching. When the stand-alone server of EM S is running, it will automatically switch from the normal working mode of connecting the standby server of EM S to the host server of EM S, and continue to evaluate and monitor EM S. The evaluation and monitoring management system of EM S has a self-running monitoring software module, which can be automatically reset once the evaluation and monitoring management system is found abnormal, and can continuously monitor EM S (if the hardware environment conditions permit).
5 concluding remarks
After the design and implementation of the environmental management S assessment monitoring management system in early August 2000, the system has been fully tested and put into trial operation. The test and trial operation results show that all the functions of the EM S evaluation monitoring management system have been realized, and the calculation results are accurate and reliable. EM S evaluation monitoring management system can automatically find the abnormal data of the calculated data of EM S system and the error state of each module. It can control the calculation process and results of the state estimation module of EM S and the dispatcher power flow calculation module. EM S assessment monitoring management system meets the needs of EM S operation managers for data analysis, operation state monitoring, calculation process and result analysis and statistical calculation of EM S assessment indicators and reports. It can replace the operator's complicated data retrieval and calculation, ensure the reliability and accuracy of calculation, automatically generate EM S assessment indicators and reports, reduce the subjective factors and possible errors that form EM S assessment indicators and reports, greatly save time and improve work efficiency. The system lays a solid foundation for the practical application of EM S, and helps EM S to give full play to its benefits in the safe, high-quality and economic operation of power grid.
The hardware equipment of EM S evaluation monitoring management system includes evaluation monitoring computer, network adapter and laser report printer. The evaluation monitoring computer can be realized by a high-performance commercial computer or an industrial computer. The hardware configuration of the whole system is economical and cost-effective. In the software part of the system, except for modifying some application software of Hubei power grid EM S (ABB SP IDER system) and data format conversion, other functional modules are all of universal standardized design, which is suitable for other types of EM S. Therefore, the EM S evaluation monitoring management system has high popularization and application value.
References:
[1] Notice on Printing and Distributing the Practical Requirements and Acceptance Rules for the Basic Functions of EM S Application Software [Z].
[2] Spider Operator Manual [Z]. Date of receipt: 200212204; Revision date: 200 12022 14.