Study On The Steady-state Model And Grid-connected Problems Of Wind Turbine With Synchronous Generator

Different from it in variable-speed double-fed generator system, Gearbox is no more needed in synchronous generator directly driven by wind turbine, which makes synchronous system more efficient, reliable and power controllable with less noise. As the cost of generation devices decreases and the control technique of synchronous generator applied in wind power develops, synchronous generator directly driven by wind turbine will become more and more competitive. In order to ensure the stability of power system including variable-speed wind turbine equipped with synchronous generator, the interrelated problems of grid-connected wind turbine with synchronous generator have become a problem demanding prompt research. The main contents on the new task are as follow:1. The theory and the control strategies of directly driven wind turbine with permanent magnet synchronous generators are studied. It's the elements of D-PMSG model and D-PMSG treated methods in load flow calculation in power systems.2. Dynamic model of directly driven wind turbine with permanent magnet synchronous generators (D-PMSG) are studied. Wind speed model, aerodynamic model, shaft system model, pitch controller model and PMSG model are analyzed. The overall models of D-PMSG are given.3. The steady-state model of D-PMSG is proposed in the paper used in the grid-connected analysis . New methods are put forward witch are used to treat D-PMSG wind farms node in load flow calculation in power systems, and the entire algorithms are realized through MATLAB programs. The methods are used to calculate example system load flow and the results indicate that they are veracious and efficacious: the amount of calculation is reduced and the computing speed is increased in the premise of guarantee calculation precision. In a word, the methods are practical.4. Transient stability of power system including wind power is studied. By investigating the dynamic behavior of fixed induction wind turbines, doubly-fed induction wind turbines and directly driven permanent magnet synchronous generators on power grid, conclusive the effect of different wind turbines on power grid transient stability.