A variable-structure stabilizer for wind turbine generators

A variable-structure stabilizer for improving the dynamic stability of a wind turbine generator supplying an infinite bus through a transmission line under widely varying loading conditions is presented. A state space formulation of the linearized system model is developed and used in the design of the stabilizer. The inputs to the stabilizer are restricted to accessible states which renders its implementation practical. Digital simulation of the dynamic responses following pseudo-typical wind gusts for a conventional power system stabilizer and the proposed variable-structure stabilizer are included for comparative purposes. Whereas a conventional stabilizer design is based only on a particular operating point and its performance at other operating points is of necessity a compromise, it is shown that the main feature of the variable-structure stabilizer is its ability to maintain improved dynamic performance as operating conditions change.