Research on Turbine Speed Control Method Based on Flow Characteristics of Governing Valve

Abstract

Studies show that there are inherent lower rotor time constants at high-parameter and large-capacity thermal power units, which leads to poor rotational speed stability under traditional control methods in complicated power grid structures and operating conditions. Moreover, it is prone to induce various safety accidents. Based on the current development trend of steam turbines in China, this paper analyzes the theories of rotational speed instability under special conditions as the incompatibility between the unit’s inherent characteristics and the commonly used control idea. In this regard, a series of speed control ideas are proposed based on the flow characteristic of governing valve. Through analysis and comparison of several typical operating conditions and events, theoretical modeling, practical tests, and simulation identification, the theoretical analysis was verified. Flow characteristic curves of the governing valve and optimized strategies such as targeted control strategies and optimized operating procedures were adopted, and promising results were achieved in terms of safety and economy.