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With the development of the computer, communication and control technology, control system is developing towards the communication network based open system, Fieldbus and computer network technology has become more and more important in the industrial control field. Modbus fieldbus, an effective support for real-time distributed test control fieldbus, with good stability, high reliability, strong anti-jamming capability, low maintenance cost, has been given more and more attention. Virtual instrument technology as a new technology of measurement and control has been used more and more widely for its unique advantages in the system design, testing and maintenance, and leads the development direction of measurement and control technology. So it’s of great practical significance to reaearch the design and development of control system based on Modbus fieldbus and Virtual instrument.Gas turbine and its combined cycle power generation unit as a new type of power generation equipment, for the advantages of low cost, short period of construction, high power efficiency, and little pollution, gets more and more attention, research and application. So the research on the operation characteristics, fault detection and diagnosis technology is one of the important means to improve the gas turbine system working stability.This paper firstly analyses the research and development of the fault diagnosis technology, field bus technology and virtual instrument technology. And then the Modbus protocol and its realization in TCP / IP are researched, and the Modbus protocol based communication program is designed. Next, the gas turbine system mathematical model is studied, and the gas turbine UniSim simulation model is designed as well, thus a series of gas turbine normal states operating parameters are obtained. On the basis of this, the adaptive numerical filter for fault detection is applied, and the joint fault diagnosis algorithm is proposed for the two different system faults diagnosis. Finally, according to the system design requirements, the system software and hardware structure is built, the system database is designed with Access2003, and the gas turbine system monitoring program, the fault diagnosis program and the database management program are developed in the Labview2010 development platform. The HC900 controller is used for the communication between the mornitoring computer and the gas turbine UniSim simulation model, and the the gas turbine diagnosis system design and development is successfully implemented at last.This paper has provided a basic solution for the further design and development of the CCHP system optimization control.
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