Design Of Digital Electro-hydraulic Control Equipment For Propulsive Steam Turbine Based On DSP

The control system is one of core parts for steam turbines, and the digital electro-hydraulic control is an important development direction in automation of marine propulsive steam turbine at present. It has the vital significance for safeguarding marine navigation, enhancing marine mobility and reducing the crew's labor intensity. Comparing with the conventional power plant steam turbine, marine propulsive steam turbine's operating mode changes frequently and the systematic inertia is big. Therefore, dynamic and static performance of the control system should ensure the steam turbine operating safely under different operating mode. This is extremely strict to the reliability and real-time of the control system.The control system of propulsive steam turbine controls steam turbine rotational speed and propeller rotational speed by adjusting steam rate of flow of the steam turbine .And ensure the marine navigate according to the speed of normal navigation. The control system accomplishes controlling forward and backward motion by a set of control device and two set of actuating mechanisms. The control system includes order sending implement, controller, electro-hydraulic servo valve, actuator, rotational speed measurement equipment of stern axis, displacement measurement equipment of actuator. Hydraulic oil of the control system is from special power oil resource. Controller receives input rotational speed signal, valve position signal and feedback signals of stern axis rotational speed and valve position. By the control law computing, controller sends control signals to the electro-hydraulic servo valve. And by regulating inlet and export of actuator, the electro-hydraulic servo valve can change the actuator displacement. Valve train of the steam turbine can regulate the inlet steam flow of steam turbine, and the eventual controller can realize rotational speed control of steam turbine and stern axis.Based on the analysis of work process and traditional control mode of the marine propulsive steam turbine, DSP-based electro-hydraulic systematic control equipment design is accomplished. The overall scheme design of the control equipment is proposed in the paper, and the systematic function is also ascertained. Furthermore, the hardware architecture schematic diagram, the software flow design, besides software and hardware preliminary debugging and test is completed, respectively.The control equipment hardware mainly constitutes by the PC/104 embedded industry computer and the DSP control card, which can realize off-line configuration, off-line simulation, and on-line movement monitor and so on. The control software and hardware card which based on TMS320F28335 DSP are designed. Every circuit function module's design principle picture of the control card is given, and the detailed introduction to the application software design method is introduced at the same time.The preliminary test experiment indicates that this equipment can realize the basic function which designed and verify the correctness that system principle designed. So it has laid the technology base for further the project application.