Simulation of the speed control for gas turbines using vibrating reed regulators

This paper describes a vibrating reed regulator used to control the speed of a gas turbine driving an alternator. The vibrating reed is excited by a pulsed jet of air at a frequency near to its resonant frequency. The edge of the reed is displaced opposite a fuel pipe, therefore the center section varies as the amplitude of vibrations varies. This amplitude is dependent on the frequency of excitation of the jet and is a function, through the intermediate member to the detector and the acoustic wheel, of the rotational speed of the exit shaft. This regulator is connected to the gas turbine and the entire study of the cycle is studied analogically. However, it must be specified that the study of this control system using a vibrating reed as speed sensor and fuel regulator is a simplified linearized analogical study. The paper presents the theoretical and experimental results concerning the characteristics of the regulator and the performance in a closed loop of the studied system.