الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Distributed control system, DCS is known as a computer control network which implement a modern technology. It is used to control the unified power system, generation power plants, airplanes, the production lines in factories and radar centers. This kind of technology give the facility of managing data aiming to realize the required function.
Digital controllers usually used as control device in the computer network. These controllers are connected with each other via communication cables and communication protocol used to direct the communication process. Data exchange could be done between controllers to serve the control process.
The controller load is divided to three parts, the base load, the static load and the dynamic load. The base load is used to cover the internal activities of the controller, the static load is the load due to the subjected scan time of the control program, but the dynamic load comes from the data base activity. The dynamic load of the controller is calculated using probability theorem. The calculated value is very close to that measured value to indicate the feasibility of the proposed method to calculate the dynamic load of he controller. This will enable the users to choose the suitable central processing unit (CPU).
Load estimation for the controller should be done firstly according to the data base capacity. Safety factor should be taken into consideration when we are going to choose the controller, keeping in mined that the controller load shouldn’t exceed 80%.
The distributed control system, DCS stability for the high dam power station is investigated and calculated. The proposed approach for investigation the DCS, stability approved successfully.
Performance of distributed control system mostly depends on from the communication network delay due to its components like filters, decoders, encoder, and modulation, demodulation devices.
The DCS performance is improved by converting the continuous loop to discrete loop via mathematical approach. Hence the DCS, delay time is improved.
The stability of the DCS network has been studied and investigated. The proposed approach proved that the controller capacity has been decreased, i.e. the system retain to stable mode. The execution time for the data at the controller is also obtained.