The small signal stability region in the power injection space for power systems with doubly-fed induction generators (DFIGs) is calculated. Results show that the boundary of the small signal stability region can be approximated by several hyper-planes in the scope of engineering application. Then the method is applied in probabilistic small signal stability analysis for power systems with DFIGs

instead of the traditional eigenvalue analysis method. Compared with the traditional method

the method presented has satisfactory computational precision and can effectively reduce the computational burden.