Francis turbine control with electrohydraulic inlet guide vane system dynamics

Francis turbine (FT) system dynamics include water flow nonlinearities, a generator, and an electrohydraulic inlet guide vane system making a complicated system. Most of the previous research did not include the dynamics of the electrohydraulic inlet guide vane (IGV) system and detailed flow analysis for FT system studies. The present work considers detailed dynamics of water flow through FT system, IGV and its actuation system. The velocity diagram approach has been considered based on Euler's equation of FT to capture water flow dynamics through the FT. The model integrated with the electrohydraulic inlet guide vane system dynamic model with the consideration of the effect of inlet guide vane angular position (IGVAP) on flow loss hence power loss. Further, the generator dynamics also has been integrated with the FT system model. The proposed model has been validated with the experimental result of a Lab. scale experimental setup. The controller design is based on the consideration of the IGV position error and FT speed error. A fuzzy feedforward-PID bias controller has been developed to control efficiently under various external disturbances. Performance comparison of PID, PID feedforward (PIDF), fuzzy PID feedforward (F-PIDF) and fuzzy PID feedforward bias (F-PIDFB) controllers have been studied for the FT system control application. The controller performances have been studied with water head disturbance with a sinusoidal signal