The Introduction and Future Development of EMS System Luohe Electric Power Bureau Li Quanhai Abstract: In this thesis, the developing process of Power Dispatch Automation System and the general situation of EMS have been presented briefly. The positive effects the system has on enterprises production control and operation management have also been expatiated according to the existing development and application of EMS in Luohe Electric Power Bureau. Simultaneously, the solution in conformity to future development trend and the Second Time Defending for safety which should be paid more attention to have been proposed through the analysis of existing problems in the application of EMS. All those above play an important role in the building of the power generation system and the power transmission system to some extent. 1 General Introduction Energy Management System is the integrated automatic system of the modern electric power system based on computer technique. Along with the scientific development, the Power Dispatch Automation System has developed from the simplex Remote Terminal Unit to the SCADA system and to the EMS system combining the SCADA system and several applications of PAS. To date, EMS software can be subcategorized into data-collection class, power-management class, network-analysis class and training-simulation class.
The Power Dispatch Automation System in Luohe electric power bureau has been traced back to the year 1989. In 1999, it was put into operation and in May 2001, there was an updating and the PAS was expanded in function. At present, this system comprises the following organic sessions and components: a set of Regional Dispatch Automation Primary Station System (SCADA + PAS function) a set of Centralization Control Center System (SCADA function) Supervisory and Control System covering all the transformer substation (or integrative automation system) Information transmission channels The situation of Primary Station System is as follows: Platform: trans-platform, UNIX/WINDOWS; Structure: Customer/Server mode, distributed structure, bi-grid and bi-machine redundancy collocation; SCADA: It provides us with telemeter, telesignal, telecontrol, teleadjusting and telepulse functions; fixed-value summoning function; WEB browsing function and report form, Stat. Analysis function; PAS: Network Topology, State Estimation, Current Calculation, Voltage Control/Reactive Power Optimization, Load Forecasting, and Network-lose Calculation function; Connecting substations: 20 sets. 2. Operational exertion state
At present, stable operation and perfect function exist in the Regional Dispatch Automation Primary Station System, Centralization Control Center System and Supervisory and Control System. The transformer substation adopting the S&C system has enormously upgraded the management level and the scientific quantity, enhanced the information accuracy as well as facilitated our personnel in operating and timely problem-judging. The quantity of information is ten times that of the general transformer substation. Transformer substation inspecting and controlled operation are realized by the local background system and centralization control center. Personnel on duty make it come true through remote controlling, which comprises Five Prevention Functions. It thus improves the operational speed, advances the safety factors. It saves our time by automatic report form generating. It is also made simple and clear in fixed value checking and protecting by the aid of fixed value summoning function. Various curves and stick graphs provide us with preconditions in data checking up at any moment. With the provision of convenient and direct Stat. Function and power-balance counting function, the labor intensity is reduced to a large extent. Advanced applications: After the hand over, dispatchers firstly, carry out a network topology and state estimation, take down the topology time, the eligible ratio of telemeter and the result of state evaluation. And then, for the sake of having a well-thought-out plan, dispatchers calculate the current before a series of operations. It provides us with effective approaches for the appropriate and economic operation of the electric network by means of forecasting the load in future and on holidays.
The AVQC system in our Bureau is based on the SCADA system. AVQC system makes analysis, counting and closedown logic inspection after receiving information from SCADA system in distant inspecting, distant signalizing and distant protecting. It then sends out commands and suggestions of correlative equipment and realizes close-loop disposal by sending distant controlling and distant adjusting commands to SCADA system. It enhances the voltage quality of the system and reduced the wire loses of the main network. The adopting of dispatcher current, load forecasting and other applications has triggered the transition of EMS system from the experience model to decision-making model. And it is of some help for the dispatchers in functioning mode arrangement, accident handling, establishing blue print for the summer, constituting scheme for electricity protecting etc. 3. Existing problems In the perspective of accuracy: The success ratio of certain transformer substations in automatic telecontrol is quite low; Distorted report Skipped report problem still exist. All these above have affected the entire effect of EMS system to some extent. On the aspect of channels: At present, Four wires MODEM mode with the assisting of RS232 low-speed data channels are adopted in the channels between powerhouse and centralization control center as well as the regional dispatch center, comprehensive controlling station, which does not come up to the net-joining requirement of EMS system due to its low speed and level.
On the aspect of interface stipulation: At present, the stipulation between powerhouse and centralization control center and the regional dispatch center are too simplex and its mode is circulating. It is of some disadvantages in function expanding and system capacity. It should be taken into account of shifting to the stipulation of international standard with interlocution mode. 4. The developing trend of EMS system 1. Establishing Dispatch Data Specific-network EMS system is a crucial approach in the scientific dispatch of modern power network. Its functions and system capacity is expanding day by day and the data specific-network is needed to meet the requirement of high-speed transmission. 2. EMS system faced to the power market With the coming up of electric power marketization, decision-making and the founding of exchange system of the power market rely on a large amount of real- time data, history data and forecasted data. The future EMS system should be the integrated system for the electric power market. The price of electricity should be taken into account in applying certain software such as load forecasting, current counting, reactive power optimization etc. And the trade and decision making in electric power market to a large extent base on SCADA. Thus, EMS system used in the electric power market is the inevitable trend. 3. Multimedia EMS system and hypermedia EMS system with Five Distant functions
With the technologic development, the EMS system is to be shifted to Five Distant system with the incoming of televideo function to the SCADA system. The incoming of televideo function to the SCADA system is not a simple addition, but an optimized combination. With the help of distant controlling inter-functions, operating equipment is traced, pictures can be easily shifted between the operating situation of the electric network and the equipment operation, and the remote operation and inspection can be realized. Finally, information and images come to a harmonious combination through the alarm-linkage function and the scouting-linkage function. 4. The trans-platform Intranet EMS system with international standard protocol and with plug and play supporting the third part. It is required by the founding of EMS inter-system and data specific- network on dispatch that the future EMS system should base on the network structure of TCP/IP with a large capacity of transmission and convenient expanding. The connecting of different systems will be enhanced if the international standard protocol is adopted among installations and systems. It is also required that integrative designing thought and software engineering stipulation of the system should be followed and the following up to date techniques should be adopted: computer technique, database technique, cluster technique, middleware technique, integration technique, object distributing technique, JAVA technique and Internet/XML technique and the IEC61970 CIM/CIS international standard should be conformed to. 5. The general employment of analyzing and decision-making applications
The EMS system is turned into analyzing and decision-making system through the application of AVQC, ACC, Static Security Assessment, Stabilization analysis, Safety restriction dispatch and the coming up realization of close- loop self-controlling operation. 6. The increasingly coming up safety problems calls for Second Time Defending With the rapid development of internet technique, it is required by the real- time EMS system that it should possess the function of credible, stable and efficient safety defending system which can resist virus, hikers and other hostile attacking and also focus on protecting real-time close-loop S&C system and guarding the dispatch data network. Therefore, according to the type of operation, the degree of safety and the demand of safety, the following requirements are what we need to deal with: a comprehensive use of physical insulationauthenticationinbreak inspectionfirewall as well as virus preventing and backup means, reinforcing and perfection of second time safety defending system. Thank you!