A recognition of the mode of dynamic motions of a vertical-rotating wind turbine in wind power station for the fault detections by indirectly measuring in bearing

This paper illustrates a method to develop a system diagnosis according to a vertical-rotating turbine based on the operating principle of the Darrieus rotor and to compare the results with a horizontal wind turbine. It is not easy to timely righteously estimate and evaluate the states. But it is very important for the safe operation in time domain system. The synthesis of this problem presumes that all state variables are observable for the concerned system. But it seems that it is not always feasible to measure all of states directly. A practical way to solve these problems is the estimation of the state variables by the use of the observers which can estimate system characteristics of linear or nonlinear states and effects as a mode, so called, “Indirect measurement”. For this procedure, the mathematical model of the concerned physical system which consists of a vertical standing long shaft with two journal bearings at the ends of the rotor, is derived with the significant remarks such as friction, gravitation, and Coriolis force. This is a basic system. The concrete assignment is to design the observer that estimates the characteristics of the states and velocities based on the measurement vectors. The main artifice is to approximate the characteristics with a fictitious model that may describe the modes of system errors. As a practical and convenient fictitious model, the characteristics of nonlinear effects are assumed as approximately stepwise contact. An identity observer is obtained whose state variables are the estimate of the state variable of the corresponding “observer system”. It consists of a simulated model with a correction feedback of the estimation.