Study of two-cell immune feedback control for water level of boiler drum based on gray prediction
Due to the ‘false water level’ phenomenon in power station makes the traditional control strategy can't be a good solution to the problem, a two-cell immune feedback control strategy based on gray prediction for water level of boiler drum in power station is proposed, which using the function of gray prediction with strong self-adaptability and advanced control functions, and learning from bio-feedback mechanism of the immune system and regulating rule of response process. Through lots of simulation studies, it can achieve a more satisfied control quality with strong robustness and anti-jamming capability. Meanwhile, the structure and algorithm of the control strategy are simple and easy to engineering implementation.
Neural networks internal model control for water level of boiler drum in power station
Water level of boiler drum in power station is one of the main control parameters for turbine-generator unit, which reflects the balance of boiler load and feed-water indirectly. Aiming at the water level control in power station, an internal model control based on neural networks is presented in this paper. It adopts the steam flux signal to the internal model controller considering the influence of load changing, which has the ability of feed-forward compensation for steam flux disturbance and can avoid "false water level" phenomenon. At the same time, the whole input signal of controlled object is combined by NNC and a robust controller (RC), which make up of a changing robust controller to control the object. Thus, good regulating performance is guaranteed in the initial control stage, even when the controlled object varies later. Simulation results show that this strategy is more effective and practicable compared with general cascade PID control.
ANALYSIS OF SAUDI ARABIAN MARITIME TRANSPORTATION INDUSTRY
This paper analyses the past, present and future of the maritime transportation industry in the Kingdom of Saudi Arabia. Saudi Arabian seaborne trade and the shipping capacity are analysed for the past 15 years. Relationships between the declining Saudi shipping capacity and other economic measures are identified. Analysis of the Saudi Arabian maritime transportation is performed with respect to the world carrier fleets and models are developed to determine the theoretical shipping capacity required for transportation of the national seaborne cargo. Forecasts of the future shipping capacity requirement for the Kingdom are also presented. This paper illustrates the general approach for analysing a country's maritime industry and thus could help other researchers in that respect.