Application of Domestic DCS System in Thermal Control Transformation in Our Province

Abstract : This paper introduces the application of domestic distributed control system (DCS)-EDPF-2000 system developed by the Institute of Electrical Engineering in the thermal control reform of #10 furnace at Xigu Power Plant in our province.

I. Overview Gansu Power Grid is located at the center of the Northwest Power Grid. It is connected to Qinghai in the south, Ningxia in the north, Xinjiang in the west, and Shaanxi in the east. It plays a very important role in the power grid. As a point of power supply for the grid, the safety, reliability, and economic operation of power plants are particularly important. Due to the relatively unbalanced thermal control level of old and new thermal power units in our province, most of the new units use highly reliable DCS decentralized control systems, such as the WDPF system in Jingyuan Power Plant and the OVATION system in Pingliang Power Plant, and small and medium-sized units (100MW and below). Most of them use conventional instrumentation control systems, such as the Second Thermal Power Plant and Yongchang Power Plant. With the continuous development and deepening of the power industry reform in our province, as well as the separation of factories and networks, the continuous deepening of bidding for the Internet, how to adapt the small and medium-sized units to the new situation The continuous improvement of safety and economic development needs of the power grid will become the focus of future work. At present, the technological transformation of small and medium-sized generating units in our province is imminent, and how to choose a domestic DCS with high reliability, convenient configuration, flexible operation and high cost performance ratio is particularly critical.

Lanzhou Xigu Thermal Power Co., Ltd. #10 boiler is a boiler built in the late 1960s in China. The original thermal control system was a conventional instrument control system. At the end of 2001, it was approved by the provincial power company to open a public tender for technical transformation.

Through in-depth and detailed analysis and comparison of the reliability and cost-effectiveness of the DCS master control equipment, the EDPF-NT system developed by the China Electric Power Research Institute was eventually determined to be the DCS master control equipment, and the Modicon TSX Quantum product of Beijing Schneider Electric was the boiler FSSS master control equipment. .

II. Scope and system configuration of DCS reformation According to the "Tender Documents for the Computer Control System (DCS) Reconstruction Project of the #10 Oven of Lanzhou Xigu Thermal Power Co., Ltd. and the Bidding Document of the FSSS Reconstruction Project of the #10 Oven of Lanzhou Xigu Thermal Power Co., Ltd." Requirements, # 10 furnace thermal control system transformation is divided into FSSS (boiler fire protection system) and DCS (Distributed Control System) transformation of two parts. Among them, the FSSS system main control equipment selected the ModiconTSX Quantum series PLC of American Schneider Company, the system design total number is 160 points. The fire detection device is ZFDZ series intelligent fire detection device newly developed by Zhongneng Company. The main control equipment of DCS system has been selected independently by the China Electric Power Research Institute and has its own proprietary copyrighted EDPF-NT distributed control system. The total number of system design points is 356 points, of which the analog point is 164 points (including thermocouples and thermal resistances), 140 points are actually used; the switching points are 192 points, and 105 points are actually used (SOE total 56 points). The FSSS system and the DCS system are composed of different hardware. The FSSS and DCS systems are relatively independent and interrelated. There are two system configuration operators and one engineering station.

The FSSS system uses dual CPUs, dual power supplies, and important I/O point redundancy configurations. This configuration does not affect the normal operation of the system when any CPU, power supply, or critical I/O point is faulty.

For reliability reasons, the FSSS system retains the FSSS standby operating panel in addition to the operator station #1. Important operations and displays can also be implemented on the FSSS standby operating panel.

III. Functions and Features of DCS and FSSS EDPF-NT is a decentralized control system independently developed by the China Electric Power Research Institute and possessing its own copyright. The EDPF-NT system is a set of decentralized control systems designed and developed by drawing on the advanced ideas of many similar systems in the 1990s and fully integrating with China's national conditions. The EDPF-NT system is based on the rapid development of network communication technology, and is based on "stations" oriented to functions and objects. It is also equipped with a unique and dedicated distributed dynamic real-time database, plus a dedicated distributed control system. The high-performance, fully-decentralized intelligent monitoring and control subsystem designed and developed makes it an advanced system that combines modern design ideas with modern technology. Has the following characteristics.

1) High reliability and high availability All important equipment and links of the EDPF-NT system are designed with redundancy. All important functions are implemented using multiple fault tolerance methods to ensure system reliability.

Excellent maintainability EDPF-NT has a complete self-diagnosis function and provides self-diagnostic information in the form of a CRT screen. It can diagnose networks, stations, and modules until the I/O point. Through this information, users can be timely and accurate. Locate faults and minimize maintenance time.

2) With good adaptability, the application scale can be configured through configuration, and the wide adaptability from large-scale applications to small-scale applications can be realized. The system also allows the integration of the functions of multiple stations to be implemented in one station to meet special requirements. The need for engineering or micro-engineering.

3) With good performance and cost ratio The system cost is about 30% to 50% of the similar import system, and the maintenance cost after running is about 1/10; if considering the localization of service, maintenance and spare parts, Chinese interface and Chinese documents The ease of use of data and other factors will have greater advantages over foreign systems.

4) The system is safe and durable, with strong anti-interference ability and enhanced structural design. All I/O modules and power modules adopt a fully-enclosed structure, which is dust-proof, anti-static and electromagnetic interference resistant. I/O cards can adapt to harsh environments.

All input/output modules of the EDPF-NT system meet the requirements of the ANSI/IEEE 427 "Surge Voltage Tolerance Test Guideline (SCW)", and do not damage the system module when a 250V DC voltage or a peak-to-peak peak voltage is erroneously added. . It is worth mentioning that the input modules of the EDPF-NTDCS system are all equipped with a patented over-voltage protection circuit. The strong input will block the channel. After removing the strong signal, the channel will automatically resume operation. The 380 volt AC signal was added incorrectly without damaging the device.

5) The system design is simple and it strives to meet the complex application requirements with the smallest variety and dedicated design I/O card: 16 thermocouples, thermal resistance, voltage, transmitter and other signals can be connected to the same AI module, greatly benefiting the design And cable laying.

All DI inputs can be software defined as SOE with a resolution better than 1ms. For the important AO output, it can be used as a double redundant structure between channels to perform important analog output control. Two AO cards output hot backups and no interference switching.

6) The system has a fast processing cycle, high control accuracy, strong self-diagnosis capability, and meets the user's high requirements. The fastest system processing time is 30ms. The accuracy of each type of analog acquisition is better than 1 ‰. Analog output accuracy is also better than 1 ‰. Has a complete hierarchical self-diagnosis function that diagnoses network, station, and I/O cards up to I/O points.

7) The system configuration is convenient, easy to learn and easy to use, and the operation is convenient Chinese interface, the operating personnel can view the detailed information of any point on any operation screen without the need to specifically view the database.

IV. Conclusions The FSSS and DCS systems of the #10 boiler at Xigu Power Plant are both relatively independent and interconnected. The FSSS system and the DCS system are composed of different hardware. This structure maximizes the advantages of the Modicon TSX Quantum system and the EDPF-NT system. From the perspective of the application of the power industry, it can be said to be the most reliable and economical system configuration. The EDPF-NT system has a leading position in the application of domestically produced DCS for domestic 200MW and below units.

The tested EDPF-2000 indicators are in line with the quality standards of the "Geoelectric Power Plant Distributed Control System Technical Specifications" (G-RK-95-51) promulgated by the Ministry of Electric Power Planning.

Through this technical transformation, the reliability and economy of #10 furnace operation have been greatly improved, labor intensity of operators has been reduced, and the maintenance of maintenance personnel has been reduced.

The operation practice in the past two years after the transformation proves that there have been no protection misoperations or refusals, and the correct rate of protection actions is 100%. The automatic investment rate is 86%. The DAS investment rate is 100%. Reduces the number of abnormal shutdowns and saves fuel. Reduced production costs.

At present, the system has been applied in more than 130 domestic power industries, and the largest single-unit capacity has been upgraded to 300MW. After the transformation of #10 boiler from Xigu Thermal Power Co., Ltd. in our province, EDPF-NT was successfully applied in the DEH transformation of the second thermal power plant in Lanzhou (which I commissioned). Combining with the economic situation in our province, except for the #9 and #10 machines at Jingyuan Power Plant, Pingliang Power Plant, and Xigu Power Plant, the WDPF and OVATION decentralized control systems of the US Westinghouse Company are used, and Lanzhou No.2 Thermal Power Plant, Xigu Thermal Power Plant, and Yongchang Power Plant have been used. Liancheng Power Plant and other 100MW units are facing technological transformation. The successful transformation of the #10 furnace thermal control system at Xigu Power Plant has created new ideas for the future transformation of thermal control DCS in our province. It is believed that there will be broad promotion prospects.

V. Existing Problems and Improvement Objectives Because the configuration environment of LOOP and LADDER of EDPF-NT system is DOS environment and the configuration of database and screen is Windows NT, it needs to be switched during the configuration process, causing some inconvenience to the software configuration. Need to be perfect.

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