Sensorless Stator Flux Oriented Control for Startup Gas Turbine

This paper introduces a novel hybrid rotor‐position estimation technique for wound‐field synchronous motors (WFSM) powered by load‐commutated inverters (LCI), operating continuously from standstill through turbine ignition speed. At low speeds, where signal‐injection techniques excel, a high‐frequency injection‐based estimator provides initial rotor‐angle information. As speed increases past this low‐speed region, a model‐based stator‐flux observer seamlessly takes over both position estimation and firing‐pulse generation for the thyristor bridge. By combining these two complementary estimation strategies, the proposed algorithm overcomes limitations inherent in each individual method—namely, poor low‐speed observability for flux observers and the energy losses associated with continuous injection at higher speeds. The result is reliable commutation of the load‐commutated inverter’s thyristors across the entire speed range, from zero to nominal. In addition, we present a new stator‐flux‐oriented control architecture tailored for LCI‐fed WFSMs. This structure enhances the motor’s power factor and yields a faster dynamic response in the speed controller, while simplifying the overall drive design to reduce manufacturing costs. The efficacy of the hybrid estimation algorithm and the novel control structure is demonstrated through detailed MATLAB/Simulink simulations. Results confirm seamless transition between estimation modes, robust commutation under varying operating conditions, improved power quality, and accelerated speed regulation—validating the approach as a practical, cost‐effective solution for high‐performance WFSM drives.

کلیدواژه ها:

load commutated inverter ، sensorless control ، stator flux oriented control ، wound field synchronous motor