1. determination of the natural frequency of the drive train of a wind turbine
2. determination of the additional rotor voltage at the operating point of a doubly fed three-phase asynchronous generator
3. phase shifter operation of a doubly fed three-phase asynchronous generator with rotor voltage imprinting
4. analysis of the characteristic curve field of a doubly-fed asynchronous machine with rotor voltage injection
5. operation of a direct inverter, construction of the output voltage of a direct inverter
6. locus curve of the generator voltage of an alternative power generation system with different energy input and power factor
7. determination of the yaw moment of a three-blade rotor
