Researching And Application Of Turbine-generator Set DEH Control System Based On Triple Modular Redundant PLC

Small and medium-sized turbo generator unit is used widely in our production enterprise. They mainly as plant power motive provide devices; some combined heat turbo generator units in addition to providing electrical power, but also provides heat power for production process. These units directly influence the running status of production device and stable operation of power grids, the parallel operation disturbance; also directly affect the stable running of the electrical power system.In view of the current widely used combined heat turbo generator units, this paper studied and design a turbine-generator unit digital electric hydraulic control system based on triple modular redundant PLC. It is high reliability, high security.Establishes mathematical models of each element of synchronous generators and steam turbine, researches their motion characteristics. According to the control object characteristics, work out relevant control procedures, adopt corresponding control strategy. This project adopts FBD language programming, realizing turbo generator speed, power, extraction steam pressure PID closed-loop control and realize the interlocking logic and turbo generator protection control.The unit there is a correlation between power load variable and heat load variable. It is the key how to eliminate the coupling effect for turbo generator unit stable running. This paper expounds the decoupling control theory, then according to working characteristic curve of the steam turbine unit worked out the corresponding decoupling coefficient, using a new type of decoupling control module program realization electrical power and heat load decoupling control.The study results showed that the static interferes between heat and electrical load can be eliminated because of the integral action of the PID governor of DEH control system, dynamic interferes between heat and electrical load are decreased. The system has better dynamic response characteristics than the system no decoupling control.this project significantly improved turbine working characteristic optimized the reliability and safety of the unit operation condition, greatly improves unit working efficiency. Adopting new decoupling control strategy, to avoid the heat load and electrical load between mutual interference, reduces the power grid disturbance.