| Nuclear power is an important part of electric power industry. Because of the high radiativity of the nuclear fuel, nuclear power units ask for a higher security level than conventional thermal power units and hydropower units. As the proportion is increasing,nuclear power units are demanded to participate in peak shaving in the future, in order to ensure the safety of the grid. Therefore, both in terms of steam turbine running safety or regulation, the improvement of the stability and reliability is a top issue to nuclear power plants.As the power unit, the hydraulic control system receives adjustment instruction of fast close, start-stop and load regulation from the governing system(GFR). Therefore,further study on dynamic characteristics of hydraulic oil system and its influencing factors is of great significance in a nuclear power unit. First of all, this paper analyzed the feature and the working principle of the Electro-hydraulic proportional control system.According to fundamental principles of hydraulic transmission and hydraulic control, the mathematical model of EH oil supply system, Electro-hydraulic amplifier system,hydraulic servo-motor, location control system was set up, based on hydraulic fluid mechanics and kinetic theory. Since hydraulic system is an MIMO time-varying system,this paper takes differential equation to analyze dynamic characteristics of hydraulic oil system in the time domain. Based on the mathematical model, the whole simulation model of hydraulic oil system was established, with the help of integrated simulation support platform(Gensystem), and working parameters, such as pressure, flow and speed was studied in the dynamic process. The model can analyze the influence on the dynamic characteristic, brought by different structural parameters and input parameters. The results show that the model can be used to study the dynamic characteristics of the hydraulic system, which provides references for fault diagnosis, system design,parameter optimization, etc. |
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