Realization of Localization of DCS System for Ultra Supercritical Units

Guodian Zhishen adopted a three-step strategy of digesting, innovating, and advancing the major goal of realizing the localization of the DCS system of 1000MW ultra-supercritical units. It is the Beilun project service of Taizhou, the laying foundation of Longshan Zhuanghe, and the realization of localization of the Shubi project. .

First, digest, innovate, and advance three-step strategy

Guodian Zhishen Company adopted a three-step strategy in realizing the major goal of domesticizing DCS system for 1000MW ultra-supercritical units, namely, Beilun project service in Taizhou, laying foundation for Longshan Zhuanghe, and localization of Shubi project. Specifically, by undertaking the DCS system engineering and technical services for 1000MW ultra-supercritical units in Taizhou and Beilun Power Plants, the control object characteristics and control technology of the ultra-supercritical units were studied in depth to understand the performance indicators, functions, and scales of the ultra-supercritical units for the DCS system. At the same time, the use of autonomous DCS system to achieve the control of Longshan 600MW subcritical direct air-cooled units and Zhuanghe 600MW supercritical units, thus laying a solid foundation for the localization of ultra-supercritical unit DCS system on the system platform; Finally, the localization of the DCS system for the ultra-supercritical thermal power unit was realized on the 1000MW ultra-supercritical unit.

At present, Unit 1 of Taizhou Power Plant has been put into commercial operation; Unit 2 is about to complete the 168-hour trial run; Beilun Project has started on-site commissioning; Longshan 600MW direct air-cooled subcritical unit using the DCS system of Guodian Zhishen has been in operation in 2007. Put into operation in the month and become the first domestic DCS system successfully used on 600 MW units; the National Development and Reform Commission’s “Eleventh Five-Year” National Technological Progress Demonstration Project using the State Power Zhishen Autonomous DCS System – Zhuanghe 600 MW Supercritical Unit was in 2007 Successfully put into operation in August of the year, and achieved a historic breakthrough in the domestically produced DCS on the 600MW supercritical unit; the cooperation agreement of the DCS system project for the 1000MW ultra-supercritical unit in Shubi has been signed, and was listed as the national 863 project “Key Project Automation Automation Set Control for Thermal Power Industry”. System" demonstration project. It can be said that Guodian Zhishen has successfully crossed the first two steps in achieving the strategic goal of localization of the DCS system for the 1000MW ultra-supercritical unit, and is beginning to enter the most critical third step.

(A) One million ultra-supercritical unit engineering services

1. Taizhou 1000MW Ultra Supercritical Unit DCS System Engineering Services

Guodian Taizhou Power Plant 2×1000MW ultra-supercritical unit boiler adopts transformer operation of Harbin Boiler Works with the introduction of Mitsubishi technology from Japan, vertical coiled ring wall water-cooled DC furnace with intermediate mixing header, octagonal double flame tangential combustion, steam turbine and generator It was jointly designed and manufactured by Harbin Steam Turbine Works and Generator Works and Toshiba Corporation of Japan. The DCS system uses Emerson's OVATION system. The DEH system uses Toshiba's TOSMAP-DS/W500 system. The State Power Zhishen Company is responsible for the engineering and technical service of the DCS system.

. 34 pairs of controllers were configured for the unit unit and the public system. The functions included DAS, FSSS, SCS, MCS, ECS, MEH, METS, and BPS. The number of I/O measuring points of the unit and public system reached 12452, and the control equipment 1105 One (motor 229, electric door / solenoid valve 771, electrical switch 105), control loop 127 sets. The function of the controller is assigned using the principle of combining the functions of the process.

The project was started in 2006. Unit 1 passed the 168-hour full-load trial run on December 4, 2007, and all performance indicators reached a higher level.

2. Beilun 1000MW Ultra Supercritical Unit DCS System Engineering Services

The boiler of 1000MW ultra-supercritical unit in Zhejiang Beilun Power Plant adopts variable pressure operation and spiral coil ring water wall DC furnace with Dongfang Boiler Works imported from Japan Hitachi. The front and back wall hedging combustion method is adopted. The turbine and generator are both Shanghai Turbine Works and generators. The factory introduced Siemens technology manufacturing. The DCS system of the main plant and auxiliary workshop adopts the American Emerson OVATION system. It covers the extended scope of the SCS function at the machine side. The DEH system adopts the T3000 hardware from Siemens, and Guodian Zhishen is responsible for the entire main and auxiliary DCS. System engineering and technical service work.

The unit unit of this project is equipped with 28 pairs of controllers, including DAS, FSSS, SCS, MCS, ECS, MEH, METS, and BPS. The number of I/O measuring points for unit units and public systems is 12464 points, and the number of control devices is 1411 (motors). 198, 1117 electric door/solenoid valves, 96 electric switches, and 147 control loops. The function of the controller is assigned using the principle of combining the functions of the process.

The project was launched in 2007 and factory testing and acceptance was carried out in December 2007. Field commissioning has now begun.

3, Taizhou Beilun project service summary

1. Analyze and study the process flow and operation mode of the 1000MW ultra-supercritical unit.

2. Through data digestion and absorption, engineering design and on-site commissioning, a more in-depth understanding of the static and dynamic characteristics of the object of the 1000 MW ultra-supercritical unit has been obtained, and a certain implementation of the control strategy has been optimized.

3. The research and implementation of the principle of DCS system controller function allocation for 1000MW ultra-supercritical units.

4. Based on the careful digestion and absorption of technical data from domestic and foreign equipment manufacturers and design institutes, in conjunction with the actual needs of power plant production and operation, and design units, equipment manufacturers, commissioning units and power plants to fully discuss, for the 1000MW ultra-supercritical units The functional design of DCS system application software has been studied and practiced, and it has been continuously improved and optimized in the on-site debugging and commissioning process.

5. A more in-depth understanding of the DCS system requirements for the 1000MW ultra-supercritical unit.

1 The system is larger

The number of I/O measuring points for DCS system unit and public system of 1000MW ultra-supercritical unit reaches 12000 points, while the number of I/O measuring points for DCS system unit and public system of 600MW unit is generally around 8000~9000; control equipment The number of 1000 MW ultra-supercritical units DCS systems reached 1100 to 1400, while the 600 MW units DCS systems were 750 to 900; there was no significant difference between the number of analog control loops and 600 MW units.

2 rapid control, fast protection

The 1000MW ultra-supercritical unit can only adopt the direct current boiler. In the once-through boiler, the total mass of the circulating working medium drops, the circulation speed increases, and the process characteristics are accelerated. Because the unit uses supercritical parameters, the fluctuation range requirements are more stringent, further strengthening the requirements for rapid control.

In order to meet the requirements of rapid control and rapid protection of the unit, the real-time performance of the control system needs to be comprehensively improved, including fast and reliable network communication, fast and stable controller cycles, fast I/O processing, and high-precision SOE. These have always been DCS improvements. And perfect difficulties.

3 higher reliability requirements

The thermal system of ultra-supercritical units is complicated and more thermal protection projects are set up to avoid major equipment damage caused by operational errors. At the same time, due to the large capacity of the supercritical units, the safe operation of the units is also critical to the safety of the entire power grid. This requires the entire automation system to have higher safety and reliability.

4 more intelligent requirements

The safety and economical operation of the 1000MW ultra-supercritical unit is very important to the stability of the power grid. Compared to the 600MW and 300MW units, the 1000MW ultra-supercritical unit must rely more on the automation system, and manual operation is unthinkable. The increase in the degree of intelligence in control methods, accident alarms, and operation guidance can better improve the safety and economical operation of the 1000MW ultra-supercritical units.

(II) Laying the Foundation for the Autonomization of Longshan Zhuanghe 600MW Units

1. Domestic DCS system of Longshan 600MW subcritical direct air cooling unit

In 2005, Guodian Zhishen undertook the DCS system project of Hebei Longshan 2×600MW subcritical direct air-cooling unit, and used the self-made domestic DCS system to realize the integrated control of 600MW unit machines, furnaces and electricity. The functions include DAS, FSSS, and MCS. The SCS, ECS, ACC, and BPS systems are divided into #1, #2, and 3 common system domains. The unit units use 26 pairs of controllers. The number of I/O measurement points is up to 8320 points. The public system uses 4 pairs of controllers. The number of I/O measuring points is 1276 points, and the number of units and public total measuring points is 9596 points, which is close to the scale of the control system of 1000 MW units. There are 1097 control devices (including 248 motors (including 56 air coolers), 647 electric gates/solenoid valves, 202 electrical switches) and 147 control loops.

After full system research and development and project preparation, the project was officially launched in December 2005. In June 2006, China Guodian Corporation’s Engineering Department organized well-known domestic experts to conduct a factory acceptance review meeting. The participating experts agreed that Beijing Guodian Zhishen Control Technology The performance, function and quality of the EDPF-NT system comply with the application requirements of the 600MW unit of Longshan Power Plant and can be applied to the 600MW unit of Longshan Power Plant. Unit #1 was formally put into operation on January 16, 2007, and unit #2 was put into production on July 24, 2007. In June 2007, it passed the technical appraisal organized by the China Institute of Electrical Engineering and was highly praised by well-known experts in China. The review commented that “the overall technology of the project is at the international advanced level, and the DCS of China’s independent intellectual property rights is on the large-scale generator set. Widely used, with important demonstration and promotion."

Since the commissioning of the 600MW unit of Longshan Power Plant, the DCS system has been operating stably and reliably, the unit protection investment rate is 100%, the correct rate of protection actions is 100%, the MCS control circuit input rate is 100%, and the unit coordination control has been put into and successfully implemented the AGC control during the 168 period. The control accuracy of the main parameters, such as load and main steam pressure, has reached a relatively high level. The EDPF-NT system has never been affected by the safe operation of the unit and has been highly evaluated by the power plant.

2. Zhuanghe 2×600MW Supercritical Unit Domestic DCS System

In 2006, 2×600MW domestic supercritical units in Dalian Zhuanghe Power Plant Phase I decided to adopt the EDPF-NT decentralized control system of Guodian Zhishen’s independent intellectual property to achieve the control of the main and auxiliary control systems. This is the first domestic use of domestic self- The 600 MW supercritical unit project of the DCS system is also the first project in China to adopt an integrated system platform to achieve the master control and auxiliary workshop control of a 600 MW supercritical unit. As the first self-contained control system project applied to 600 MW supercritical units, the project was identified by the National Development and Reform Commission in April 2006 as the first demonstration project for the implementation of the “State Council’s opinions on accelerating the revitalization of the equipment manufacturing industry”. .

Zhuanghe Power Plant's main control EDPF-NT system functions include DAS, FSSS, SCS, ECS, MCS, DEH, ETS, MEH, METS and BPS, etc. Boiler soot blowing is realized by PLC and is operated in DCS system through communication. The system realizes the control and protection of the boiler, turbine, feed pump turbine and turbine bypass and the control of the electric switch. It can be said that the main control system of the thermal power plant adopts a single set of DCS to realize one of the most complete functions. The domestic DCS system put into operation has the most functions, and it has truly realized the integrated control of the host. The number of I/O measuring points for unit crews and public systems reached 8200 points. There are 776 control devices (of which 160 are motors, 495 electric valves/solenoid valves, 121 electric switches), and 137 analog control loops. The unit unit is configured with 29 pairs of controllers (2 DEH controllers and 2 MEH controllers) and 2 pairs of public system controllers.

The auxiliary workshop control system (auxiliary control system) of Zhuanghe Power Plant also uses the EDPF-NT distributed control system, in which the flue gas desulphurization control DCS system adopts an independent network structure, and the rest of the auxiliary control system adopts an integrated network structure. The integrated auxiliary control system covers the water, coal, ash, fuel oil, HVAC, and air compressor systems. Among them, program control for coal transmission, electric dedusting, start-up of boilers, hydrogen production, and chlorine production are controlled by PLC and accessed through communication. Auxiliary control DCS system realizes centralized monitoring and operation of the auxiliary workshop of the whole plant in the centralized control room.

The project was formally launched on February 26, 2006. On November 29, 2006, the Engineering Department of China Guodian Group organized a factory acceptance review meeting attended by well-known domestic experts. The participating experts agreed that “the system configuration is reasonable, the technology is advanced, and the functions are complete. The quality is reliable, meets the technical specification request, agrees to pass the factory acceptance, can apply on the 600MW supercritical unit". After intense on-site commissioning work, on August 6, 2007, #1 unit of Zhuanghe Power Plant successfully passed the 168-hour full-load trial operation, and #2 unit passed the 168-hour full-load trial operation on November 5, supporting the auxiliary control system. Put into operation, centralized monitoring of the main and auxiliary control systems in the central control room was realized. During the 168-hour full-load test run, the automatic investment rate is 95%.

The protection investment rate is 100%, and the correct rate of protection actions is 100%. The coordinated control of the unit has been put into and successfully implemented the AGC control. The control accuracy of the main parameters such as load, main steam pressure and main steam temperature all meet or exceed the power industry standards.

3, Longshan Zhuanghe domestic DCS summary

1. We must adhere to independent research and development and master the technical route of the core technology. In the R&D of Longshan and Zhuanghe EDPF-NT systems, we insist on independently researching and developing and fully mastering the technical route of the core technology, independently developing core hardware and software, and achieving the maximum degree The autonomy and success.

2. Complete implementation of supercritical unit control using domestic DCS system The control of the main plant and auxiliary workshop of Zhuanghe Project adopts the domestic DCS system of Zhishen Zhishen, and it is also the first time that the domestically produced DCS system has been applied to 600MW supercritical units. Integrated Control of 600 MW Supercritical Units and Integrated Control of Auxiliary Workshops .

3. The adoption of domestic DCS system has realized the control strategy of the supercritical unit, which has a new understanding and improvement of the object characteristics and control optimization of the supercritical unit.

4. The performance of various aspects of domestic DCS system has been further improved

1 The system scale has taken a big step forward

Compared to the scale of more than 6,000 I/O measuring points for 300 MW unit and utility systems, the number of I/O measuring points for Longshan Project reached 9,596. It can be said that the scale of the 12,000 I/O points for the 1000 MW ultra supercritical unit has taken a big step forward. step.

2 System reliability has been improved and tested

Through the improvement of the system network, system hardware and software performance, and the reliability of engineering design, the reliability of the entire system has been greatly improved. During the commissioning and formal operation of the Longshan and Zhuanghe projects, the system has been operating steadily, the correct rate of protection actions is 100%, and there has never been any misoperation or refusal to move.

3 system rapidity has been tested

By ensuring that the controller load rate is within the normal range and accelerating the control processing cycle, adopting the algorithm's embedded constraint conditions to quickly return technology, optimizing the man-machine interface program, and implementing high-precision SOE and other technical measures, the system's rapidity has been greatly improved. It has been fully tested on Zhuanghe supercritical units (the Zhehe project DEH system and ETS system have all been implemented using domestic DCS systems independently developed by Guodian Zhishen).

4 enriches the control algorithm for supercritical DC furnaces

According to the needs of the control of the supercritical DC furnace, new control algorithms such as the enthalpy value were added.

(III) Qianbai million ultra-supercritical projects actively promote localization

State Power Zhishen summarized the experience of Taizhou engineering design and commissioning, Beilun engineering design experience, and based on the autonomous DCS system of Zhuanghe 600MW supercritical unit, it started to develop a self-contained DCS system for 1000MW ultra-supercritical units and successfully declared the country. The key project of the 863 Plan “The key project automation control system of the thermal power industry takes the DCS system of Guodian Jianbi Power Plant 1000MW ultra-supercritical unit as a demonstration project. This project has been started and is scheduled to be put into operation in 2010. It will adopt the autonomous power of Zhidian Zhishen The domestically produced DCS controls the 1000MW ultra-supercritical unit and achieves the goal of localization of the 1000MW ultra-supercritical unit automatic control system.

In order to ensure the success of the domestic DCS project of the 1000MW ultra-supercritical unit in Jianbi, we have formulated the following technical route measures:

1. Deepen the demand for 1000 MW ultra supercritical unit DCS

Analyze and research and develop a DCS system platform suitable for control of 1000MW ultra supercritical units.

2. Based on domestic and foreign research, data digestion and absorption,

Design and Implementation of Control System for 1000MW Ultra Supercritical Generating Unit in Bengbu,.

3. Simulate simulation as an important research method at each stage to improve research results and identify problems as early as possible.

4. In the DCS project of Jianbi 1000MW ultra-supercritical unit, the operation characteristics of the ultra-supercritical unit have been further understood, and the autonomous DCS system for the ultra-supercritical unit developed by the project has been applied and engineered as soon as possible.

5. Implement strict and efficient project management. From the organizational structure, project management, product manufacturing and system integration, engineering design, system configuration and factory testing, factory inspection, field service, research and development support, personnel training, etc., we have formulated a comprehensive and practical implementation plan and effective quality management. Measures shall be strictly implemented during the implementation of the project to ensure that the Shubi project becomes a quality project.

Second, (1) 1000MW ultra-supercritical unit analog control system design

The general understanding of the ultra (super)critical units is that the unit's heat storage capacity is small and the parameters affect each other seriously. Therefore, when the unit operating conditions change, the main parameters have poor stability and are difficult to control. But on the other hand, the small thermal storage capacity of the unit will greatly reduce the inertia of the dynamic response of the main steam pressure or unit power when the boiler combustion rate changes, provided that the control strategy of the control system is properly designed and the main control volume of the unit is statically matched. The dynamic matching is appropriate. Under the rapid combustion rate control, the main steam pressure and unit power dynamic response will be better, the dynamic and static adjustment quality of the main parameters will be significantly improved, and it can meet the requirements of continuous sliding pressure operation.

Because there is no work-piece buffer and heat storage buffer for the super (super)critical unit HR boiler, the balance between the combustion rate and the water supply directly represents the heat balance between the boiler heat absorption and the steam consumption of the turbine. In the process of variable load, as long as the heat balance relationship between the water supply and the combustion rate is statically matched and the dynamic match is ensured, the superheat or the ratio at the middle point will remain stable at all times, and the furnace will be under coordinated and stable control. status.

Based on the above analysis, in order to improve the influence of the coupling between the control variables and adapt to the unit's continuous variable pressure operation requirements, the basic idea of ​​the control system design is:

Maintain the basic matching and balance between the control variables in the dynamic and static process, accelerate the response of the corresponding loop in the process of variable load, and use variable gain and nonlinear links to improve the control characteristics. The essence of this design idea is to thoroughly analyze the operation mechanism of the unit and the equipment, and to fully utilize the characteristic parameters of the unit and the equipment to design the control system. This is especially important for such complex objects as the ultra (super)critical unit.

(2) Main protection design for 1000MW ultra-supercritical unit boiler

The ultra-supercritical units adopt high-parameter, large-capacity DC furnaces, whose safety is of vital importance, and the main protection of the boilers has also become safe production.

The most important thing. This concludes the requirements and characteristics of main boiler protection for two 1000MW ultra-supercritical projects of State Power Taizhou and Guodian Beilun Power Plant. The main fuel trip is the most important part of the FSSS. When certain dangerous situations occur in the boiler, the fuel entering the furnace will be completely cut off from both hard and soft sides. The "soft" aspect refers to the shutdown of related fuel equipment through logic. The "hard" aspect refers to using the MFT trip relay contacts and either serially in the device drive circuit to stop these devices.

III. Technology Development of Guodian Zhishen EDPF-NT System

The EDPF-NT decentralized control system is a new generation of control system developed by Beijing Guodian Zhishen Control Technology Co., Ltd. for the application needs of large-scale generating units of 600MW and above.

(1) EDPF-NT mainly has the following features:

1. Graphical project manager and control configuration tool

The integration of engineering management and graphical configuration tools forms an easy-to-use work environment, which greatly facilitates system-level configuration and management. The integrated engineering management environment integrates the core work of the control system engineering into an application platform: creating a project, establishing a domain, creating a node, a database, a logic diagram, a process screen, and the like.

The integrated engineering management environment is similar to the software development IDE (Integrated Development Environment), integrating the core work into a unified interface. Here, you can complete the system's overall planning, DPU card distribution, IO point allocation and establishment, bulk import and export, graphical configuration, compile download. Simulation debugging.

Fully-free, SAMA-style, graphical control configuration software. It has reached the same level of international mainstream DCS.

2. Support multi-domain network communication environment

The DCS communication system based on the TCP/IP protocol is called "distributed computing environment". Adopt a comprehensive approach to object design and implementation. Not only is it 100% portable between the Windows platform and the Linux platform, but it can also smoothly transition to IPv6 in the future. With multi-domain communication management, it can work on any network topology and can meet current and future engineering applications. The request.

1) Three types of isolation between domains

a. Use a Layer 3 switch

b, use ACL

c. Use a special safety isolation device

2) Multiple working modes of dual networks

a, A, B network completely isolated

b, A, B network single point is connected

c, A, B network is more connected

d, topology can use ring network or ordinary tree

3, efficient and reliable controller software

The DPU uses a real-time Linux kernel. All DPU software uses C/C programming, 100% portable between Windows platform and Linux platform. Under the new architecture, the DPU system software and algorithm modules are separate and can be upgraded independently. New algorithms can be added online. Simplified system upgrade procedures, increased the flexibility of DCS system configuration, and laid the foundation for the further development of dedicated control devices.

4, efficient history and reporting procedures

The historical station adopts binary compression and exceptional report storage, with superior performance, stable work, and fast data retrieval. Through the "volume" management function, with the help of external storage media, you can save historical data for a long time and provide quick queries.

The report station can generate regular, single and conditionally triggered reports, using Excel to create report templates, easy to learn and use. The report program requests data from the history station and obtains statistics such as instantaneous values ​​or average values, maximum values, and minimum values. Use Report Manager to manage reports, and daemons automatically generate and print reports.

5, man-machine interface software contains a series of new features

More stable and reliable process screen display.

The screen adds flicker function.

New light card program.

(2) In conjunction with the 863 key projects of the Ministry of Science and Technology, the State Power Zhishen Company is further improving and improving NT. mainly include:

1. Integrated platform

An integrated platform refers to a unified hardware and software operating environment that enables control, simulation, and optimization of operations.

The current domestic thermal power plant integrated automation system adopts an architecture in which the systems of different manufacturers are connected as a whole through a communication interface. Due to the large differences in the software and hardware environments of the functional systems, the database generation, screen configuration and other tasks need to be repeated. Larger.

The concept of domain is introduced in the architecture of the integrated platform, which constitutes a system that divides functions and cooperates according to functions. The functional systems of DCS, SIS and SIM adopt a unified software and hardware operating environment, simplifying the system structure and improving safety and reliability. Using a unified communication protocol to avoid the communication interface problem; using a unified data description method to ensure the consistency of the data flow; using a unified core engineer configuration software and engineering management tools, database and screen generated only once, the display screen completely Consistent, greatly reduce the workload of project implementation and system maintenance.

2. The technical foundation of the integrated platform (DCE, DROP, APP three-tier structure)

1) Hierarchical network structure

The system adopts a hierarchical network structure and is divided into three layers, namely the field I/O layer, the EIO layer, and the MCN layer of the control and control network. The MCN layer is logically divided into multiple "domains." Domains can be directly interconnected through full-duplex switches. They can also use VLAN technology or proprietary security isolation devices independently developed for security isolation.

2) Unified device description information

A unified method is used to describe the information required by the three systems of DCS, SIS, and SIM. The public information only needs to be described once. Information on the same device can be used in all systems.

3) Consistent software core

The core of the software is the Drop module. Drop is an abstract concept that represents the core functionality of a MCN node and is responsible for maintaining various data from this node and remotely.

4) A consistent software platform

The DCE based on the TCP/IP protocol is designed and implemented in a comprehensive approach to objects, taking into account the portability of the communication system and meeting the requirements of current and future engineering applications. The communication core of each system software platform is based on this module.

3, control network MCN

The network is an industrial real-time Ethernet managed using multi-domain technologies. DPUs, operator stations, historical stations, engineering stations and other access MCNs constitute the control domain. Value-added networks such as SIS and SIM are also MCN domains. They are isolated through optional safety isolation devices. DCS and SIS and SIM pass through MCN. For direct data exchange, there is no problem of communication protocol conversion between systems.

4, the bottom control network EIO

EIO is an industrial real-time Ethernet network and protocol developed by Guosen Zhishen. The protocol is compatible with industrial Ethernet protocols such as HSE and EPA. Pure digital fieldbus information and conventional I/O signals are converted to EIO information through their respective protocol conversion modules. One or more controllers can be connected to an EIO network to form a distributed control unit (DPU). When accessing remote I/O, the protocol conversion module can be placed in the local I/O cabinet.

5, control configuration and man-machine interface support WINDOWS and LINUX platform at the same time.

You can choose a convenient and familiar Windows environment, and you can also choose a safe and efficient Linux environment.

6, real-time operating system

The DPU operating system adopts an improved real-time Linux. In order to better meet the further requirements of the capacity and performance of the controllers of millions of kilowatts of ultra-supercritical units, further researches and improvements will be made in the following aspects:

(1) The clock granularity is further refined

(2) further optimization of the scheduling strategy

(3) Research on the mutual exclusion mechanism of forced binary semaphores, threading of interrupt processing, preemption of kernels, and other technologies to improve task execution efficiency.

Highly emphasizing the portability of the controller software. While self-researching real-time Linux systems, it is compatible with mature domestic and foreign real-time operating systems.

7, field bus interface

(1) Research on seamless integration of DCS and fieldbus

(2) Development of a variety of fieldbus protocol conversion modules

(3) Research on intelligent and non-intelligent equipment integrated management software based on field bus

8, control configuration through XML-based standard control language, to achieve the separation of the configuration and compilation process

Through the separation of configuration and compiling functions, the control configuration can be performed interactively in the integrated configuration environment, and can also be automatically completed in batches automatically according to scripts. Conveniently realize bulk copy and modification between projects and projects.

9, compatible with international standards

With the XML-based standard control language and a specially-customized compiler, it is easy to be compatible with the five configurations of IEC1131.

10, develop fault-tolerant control technology

Through system detection and fault diagnosis and other measures, equipment hidden dangers are discovered in advance, and active protection measures such as system redundancy and fault tolerance control technologies are adopted to automatically limit the scope of the fault, change the control strategy and control system structure, so that the system can continue to work and improve. Large-scale thermal power plant control and protection provide strong technical support.

IV. Conclusion

In recent years, Beijing Guodian Zhishen Control Technology Co., Ltd. has carried out relatively comprehensive and in-depth research on the control and protection strategies of supercritical units and superordinated decentralized control systems, and has achieved a series of results. At the same time, we are also soberly aware that there are still many problems in this field that deserve our further study and exploration.

1. In-depth study of the thermodynamic characteristics and operating modes of the super (super)critical units:

Due to the characteristics of the once-through passage of the boilers used in the ultra (super)critical units in the soda process, the coupling relationship between the variables of the controlled object is complex and constitutes a three-input three-output system. Because the heat storage capacity is significantly reduced, the heat storage capacity is only 1/4-1/3 of the drum furnace, and the heat storage capacity of the unit is inversely proportional to the steam pressure, that is, the higher the steam pressure, the smaller the heat storage capacity, and the control strategy. Should overcome the adverse effects of small heat storage capacity and play its favorable factors. At the same time, because the unit mainly adopts the sliding pressure operation mode, how the control strategy should adapt to the requirements of the large-scale sliding pressure operation, what kind of coordinated control system approach (cooking of the furnace with the stove or machine-to-furnace coordination) is more suitable.

In actual operation, there are often problems such as the change of burning coal, the start-stop of the coal mill in the process of large load changes, and the back grinding caused by the maintenance of the coal mill. How the control system compensates and corrects.

2. Experimental study on strengthening the control characteristics of super (super)critical units

Due to the short operating time of domestic super (super)critical unit units, the control characteristics of the unit still lacks more actual operation and dynamic characteristic data, which has become an important factor restricting the design and optimization of the control system. It is necessary to carry out experiments and analytical studies on typical super (super)critical units as soon as possible.

3, to further realize the standard design of super (ultra) supercritical unit control system

With the commissioning of the first batch of super (super) units, Guodian Zhishen has already familiarized with and mastered the basic control strategies of the domestically introduced control systems for different types of super (super)critical units and matching of different boilers. It can be seen that the control strategies provided by many foreign host manufacturers also have their own characteristics, but most of them are not implemented using DCS. How to target the actual situation in the country and the current level of DCS technology, targeted development of standardized design to better meet the needs of power plant operation monitoring, to ensure the integrity of the control strategy design in the case of the unit's infrastructure construction and commissioning time is tight, and better Achieve higher levels of automation and protection including APS and FCB.