Power turbine speed control of the GE T700 engine using the zero steady-state self-tuning regulator

This paper presents a new approach to the speed control of the T700 turboshaft engine using an adaptive controller of the self-tuning type for the power turbine. For the design of the SISO-STR, a SISO time-series model describing the relationship between the fuel flow as input and power turbine speed as output is used. The unknown parameters of this model can be updated recursively online by the recursive least squares estimation algorithm. An adaptive self-tuning type controller are then designed by minimizing the expected value of a quadratic criterion which also includes an integrating effect to remove the steady-state speed errors. Three linearized models characterizing turboshaft engine without and with load dynamics are used to test the robustness and performance specifications of the proposed self-tuning regulator in the digital simulation studies.