Compound control method for gas turbine power turbine speed based on SMC-PID

To address the issues of large overshoot, response lag, and insufficient anti-interference capability of traditional PID controllers for gas turbines under variable load conditions, which arise from the gas turbine's strong nonlinearity, multivariable coupling, and time-varying parameters, a compound controller combining Sliding Mode Control (SMC) and PID control was designed. Specifically, the sliding mode controller takes torque error as input and outputs a compensation amount for the control variable. This compensation amount is combined with the output of the PID controller to form the final control variable, thereby realizing the control of the gas turbine power turbine speed. Finally, simulation verification was conducted on the gas turbine's load rejection and emergency loading processes. The results show that compared with traditional PID control, the SMC-PID compound controller reduces both the overshoot and drop of the power turbine speed by more than 10%, while significantly decreasing the speed fluctuation amplitude and achieving better anti-interference capability. This provides an effective solution for the stable operation of gas turbines under complex working conditions.