Design Of Centralized Control And Supervisal System Of A Water Basin

The paper was based on the scientific research, concentrated on building a centralized control and supervisal system.For the experiments in testing basin are expensive, the processes are complicated, the inveriment is humid, there is severe electromagnetic interference. So a high-performenc control and supervisal system is essential to the testing basin labrory. The research was concentrated on building a centralized control and supervisal system with high-reliability,real-time reaction,multiple and redundant operation methods,universal interface to expend,universal interface of hardware and software.First, The main frame of the centralized control and supervisal system was established based on the theory of distribute control system(DCS), the function of the testing basin and the demanding on electromagnetic interference and inveriment were analysed in detail. The supervisal function was centralized in the main monitor and control room, meantime the functions of control and data-access were decentralized, the risk of system failure was reduced. The function of subsystems and the data for communication were analysed.Then, The communication system was established based on dual-ring redundancy and switched network theory according to the damand of the system.The commom protocols and topologies used in control system were compared, the tolerance of common redundant topologies were compared. The communication system was highly reliable, high-speed in data transfer, full duplex,high-performance in anti-electromagnetic interference.The interface of communication was designed based on PROFINET Component Based Automation.The hardware, software, the expand interface and diagnosis of the communication system were also researched. The field communication system was designed based on profibus protocol, the hardware, software, the expansion interface and diagnosis of the field communication system were also researched.The impression of network delay was analysed,the synchronous clock system was established to reduce the impression of network delay.Then, design for system reliability was conducted on application, controller and programme based on the redundancy theory. The faults could happen were analysed based on fault tree analysis (FTA), the fault tree was developed for diagnosing. The main human-machine interface of the centralized control and supervisal, the alarm interface, the storage system and the field interface of subsystem were established for the operator to monitor and control the experiment.At last, the mathematical model of the communication system was established using OPnet, the capability and extension of the system were simulated and verified.The mathematical model of communication system under fault was established and simulated, the reliability of the system was verified. The system showed a great value with reliability in terrible environment, easy to maintenance, easy to expand and convenient human-machine interface and multiple and redundant operation methods.