| The control and protection system is one of the most important control systems used in power plants. The current steam turbine control system has been developed into Digital Electro-Hydraulic (DEH) Control system. The main functions of DEH include complete acceleration, grid connection, load control and protection of turbines.This article mainly aims at control and protection system at the level of 1000MW ultra-supercritical turbine. In the thorough analysis of control and protection functions, the author designed the main control and protection system based on the actual 1000MW unit control object.The main contents of the thesis are as follows:a) Analyzed the main components of Digital Electro-Hydraulic Control system.b) Analyzed and designed the speed control of steam turbine, grid connection of steam turbines,load control of steam turbines etcc) Load rejection protection is one of the most important protections of steam turbine. This function is designed from two aspects emphatically: acceleration protection and power - load imbalance.d) Over speed protection of steam turbines aims at controlling the turbine to work in certain safe limits. Another important means of control is to quickly trip the system when the turbine is working in dangerous speed, which can put the turbine work in safe condition.e) vacuum lower protection, main steam pressure lower protection, main steam temperature lower protection and generator cool water loss protection are the characteristic protections of the 1000MW unit, which are designed and analyzed in this article. |
