A kind of fluid control system was designed using pressure compensation method for in-situ pH exploration of deep-sea hydrothermal fluid. In order to disclose dynamic characteristics of the fluid control system adopted pressure compensation method, power bond graphs were drawn by means of bond graph theory, and on this basis, mathematic models of the fluid control system were built, thus, the foundation for simulation was laid. The fluid control system was simulated by MATLAB/Simulink,and the simulation results show that dynamic process of the fluid control system is generally smooth when sucking in atmospheric pressure; pressure occurs sudden change when sucking in high pressure; pressure occurs slight fluctuation when draining in atmospheric pressure and high pressure. All of these explains that the system will occur sudden pressure changes and vibrations in high pressure environment in despite of the fluid control system can apply in deep-sea high pressure environment by means of pressure compensation method. Therefore,the solutions of avoiding open and close frequently in high pressure environment were put forward. The sea trial experiments indicate the fluid control system can work normally in high pressure environment on the seafloor. 

power bond graph, deep-sea hydrothermal fluid, fluid control system, dynamic characteristics

针对深海热液pH值的原位探测的需求，采用压力补偿的方式设计了一种流控系统。为了揭示该流控系统的动态性能，运用键合图理论绘制了其功率键合图，在此基础上，建立了流控系统的数学模型，从而为仿真研究奠定了基础。利用MATLAB/Simulink工具箱对流控系统进行了仿真，仿真结果表明：流控系统在常压下吸水时，其动态过程比较平稳;高压下吸水时,压力有突变;常压和高压下排水时都有轻微的压力波动。由此说明，通过压力补偿的流控系统尽管能用于深海高压环境，但在高压环境下，系统有压力突变并且会产生振动。针对此，提出了在高压环境下应尽量避免频繁开机与停机的应对措施。海试实验表明所设计的流控系统能在海底高压环境下正常工作。

功率键合图, 深海热液, 流控系统, 动态性能