Comparison of multiple stage braking circuits for wind driven generators

This paper presents multiple stage braking circuits for wind turbines with a permanent magnet synchronous generator. The system combines both passive converter circuit coupled to a resistive braking circuit. The second one is an over voltage protection when an emergency situation of no load is detected. The power converter control and braking are simulated and the output power/frequency graphics are derived. Three braking circuits are analyzed and compared. Design recommendations are formulated regarding the application of different topologies depending of the wind speed and the input assignments.