An investigation of the dynamics of a wind power unit equipped with synchronous generators with permanent magnets

Abstract

Sudden gusts of wind exert significant forces on the blades of a wind power unit (WPU), creating a torque jump on the shaft of the unit. When operating a wind power unit on the grid, such a regime threatens to distort the dynamic stability of the system. A change in wind speed that is close to real fluctograms, structure of the wind velocity model that allows one to set the difference speed value rise and fall of the wind flow, the maximum value of a gust of wind, and the wind speed before and after a gust of wind are suggested. The system of equations constituting a mathematical model of a synchronous generator with permanent magnets, which is an electromechanical transducer in wind turbines were shown. Research that is carried out on these models determine the conditions under which the system is dynamically stable for different values and forms of perturbing actions of internal constant and electromagnetic coupling of stator and rotor generator circuits. The study allowed us to find the influence of the magnetic energy of a permanent magnet synchronous generator of a wind turbine on the dynamic stability. It is revealed that a larger value of the magnetic energy of permanent magnets per unit volume at constant values of generators active power will increase its dynamic stability. It was also revealed that the most effective way to improve the dynamic stability of a synchronous generator with a wind turbine’s permanent magnet is rapid frequency decrease of the generator stator current during a gust of wind to a certain value, with a further frequency increase to its original value after a gust of wind speed.