Research On Variable Condition Control Strategy Of The Gas Steam Combined Cycle Device With Compressor Load

With the rapid development of gas steam combined cycle device in the world industry, a higher requirement for the control system of the combined cycle device is also put forward. Adopting the reasonable control strategy and control method to achieve the fast, stable and efficient control purposes, has a very important significance.The typical combined cycle device is composed of three parts, which are gas turbine, exhaust heat boiler and steam turbine. In the combined cycle of this paper, the exhaust heat boiler doesn’t supply combustion, the heat it absorbs depends entirely on the waste heat of the gas turbine. In order to maximize the use of waste heat, the steam turbine sliding pressure operation doesn’t regulate its power. The power it produces follows the change of the working condition of the gas turbine. Therefore, it can be supposed that the combined cycle device regulates its output power by regulating the operating condition of gas turbine.This paper takes a gas steam combined cycle device as the research object. Based on its working principle and operating characteristics, research and develop its control strategy. In order to meet the changing needs of load condition, the power turbine speed regulating system for gas turbine regulates the fuel flow into the gas turbine to control gas turbine power turbine speed and the output power of the combined cycle device. On the basis of establishing the mathematical model of each component of the device, based on the thought of modularization, build the simulation model on the Matlab/Simulink platform. Then according to the control strategy, utilize conventional PID control algorithm and fuzzy adaptive PID algorithm separately to control the device. Through the simulation research of the steady state and dynamic characteristics of the combined cycle device, analysis and study the operation characteristics of the variable working condition and the control characteristics when the device changes its load condition.By studying the simulation results, according to the control strategy we research, the control effects of the two control algorithms are analyzed and compared. The results show that the fuzzy adaptive PID algorithm has better control parameters and control effect compared to conventional PID control algorithm. The advantages are obvious especially when the load change is larger. The fuzzy adaptive PID algorithm can meet the control requirements of the device better. In this paper, the research on control strategy and simulation characteristics when load condition changes in a combined cycle device is expected to provide some references for the related field work in the future.