Avoidance of nonlinear resonance jump in turbine governor positioning system using fuzzy controller

Abstract

The paper deals with analysis of turbine governor positioning system of hydroelectric power plant regarding nonlinear resonance jump. The term "resonance jump" is used in the case of a sudden jump of amplitude and/or frequency and/or phase of a periodic output signal of a nonlinear system. Resonance jump cannot occur if excitation is such that the response of the system is transient and cannot be defined by solving nonlinear differential equations. Resonance jumps can cause severe damage and the mechanical, hydraulic and electrical systems with the saturation should be analyzed with the respect to the possibility of occurrence of resonance jump. In the paper the analysis of the water turbine governor positioning system with the respect to the occurrence of resonance jump is described. Two methods of analyzing system with the respect to resonance jumps are described: the simulation method and the analytical method. When using the simulation method, the analysis of the variations of important parameters, including dead zone is performed and the simulation procedures are detailed. Then, the confirmation of the results of simulation is given by the analytical analysis method based on the describing function approach. At the end, the fuzzy regulator for avoidance of nonlinear resonance jump in turbine governor positioning system is involved.