Component-based Modeling and Analysis for Variable-pitch Wind Turbine Systems

In recent years, the modern power generation systems with complicated structure have witnessed rapid development and their working principles are of great variety and different properties. For most of the power generation forms, the switching of multiple operation modes exists in the whole working range, such as the wind turbine generation system, whose operating states are divided into four modes (i. e. park, startup, generating and break) to adapt to the varied wind speed and different working conditions. In this paper, a component-based multi-mode modeling and analysis methodology is proposed. The power generation system is divided into several components. Each component is relatively independent in physical structure and function. There are energy flow and information flow among the components under any operation mode. With the switch of the operation modes, the working status and connection relationship of components will change accordingly. Based on the component conception, the control systems can be designed separately for each operation mode, and the quantitative analysis of switching process will be carried out easily. As a kind of representative application, a multi-mode modeling and critical timing analysis for a variable-pitch wind turbine generator under four operation modes are given. The corresponding analytical results can also be applied to fault diagnosis, performance monitoring and system optimization.