Effect of DFIG Under Droop Control on Center Migration of Out-of-Step Oscillation

As a high proportion of new energy is connected to the power system, the system stability will be profoundly affected. According to the output characteristics of doubly-fed-generator under virtual droop control, the out-of-step oscillation center migration is analyzed. Firstly, virtual control is added to improve the current source output control strategy of doubly-fed-generator. Secondly, when there is a small disturbance in the system frequency, the doubly-fed-generator will increase the power and improve the stability of the system. Then, in the out-of-step oscillation scenario, the external equivalent characteristic of the doubly-fed-generator under the control strategy are analyzed, and the influence of the control strategy on the out-of-step oscillation center migration characteristic is analyzed. The influence of the control strategy in this paper to the system stability is verified by a two-machine simulation built by Matlab /Simulink.