Modeling And Simulation Of DEH1000MW Turbine System

Along with the improvement of power system automation level, the digital electro hydraulic control system is widely used on the control of large steam turbine in our country. It is a control system which can be for steam turbine control and protection and it is the most important part of the power plant automation system. In order to determine the advanced control strategy is feasible. And improve the operation personnel operation skills, according to the actual unit we design and developed a simulation model of1000MW steam turbine digital electro hydraulic control system. Its operation environment and operation mode is the same as the actual unit. Both can be run staff training, but also the control strategy will be optimized feasibility test.In this paper, we have made a in-depth analysis on the principles and features of speed control systems, load control systems, pressure control system and valve management, and so on. Use the EDPF-NT PLUS simulation support software to build the control model to achieve unit’s start, and network or load, frequency stability, speed restrictions and other major functions. Connect the DEH system to the model of boiler, turbine and electrical, conduct an overall start, full load, the valve test and over speed protection test. Then compared the simulation results with the actual curve after running the debugger, the results show that the control model designed, fully functional and meet the target of the field operation. In order to simulate the field operation better, this paper made a model for the thermal stress, limited the increased rate of speed and load, and monitoring of the temperature of various parts of the cylinder and rotor. In the simulation, we found some problems of control strategies, analysis of the reasons, optimize the control strategy, eliminate the integral saturation effect, achieve undisturbed switch with the DEH system and coordination control system and reduce the overshoot when the rising rate of speed raise to the rated value. Then make a restart run to ensure its viability.The digital electro hydraulic control system is becoming increasingly important in power system. Research should continue on its analysis to improve its function. Advanced control systems require staff with more solid theoretical foundation skills skillfully. Simulator provided a platform for the staff to familiar with on-site operation, understand the unit performance and exercise incident handling capability. The simulator will promote the development to digital electro hydraulic control system and automatic control level of turbine.