Research on Adjustable-Speed Asynchronous Condenser with AC Excitation and Its Excitation Control Strategy

In this paper, a speed-adjustable asynchronous condenser with AC excitation and its excitation control strategy are proposed. Through excitation control, the asynchronous condenser not only can adjust the voltage by reactive power output but also can adjust the speed to release rotational kinetic energy and increase the system inertia to smooth system frequency. In this paper, the model of the asynchronous condenser is established, and then a transiently improved control strategy for the asynchronous condenser considering the change of the stator excitation current, is proposed. It is verified by simulation that after the transient improvement control strategy is adopted, the asynchronous condenser can provide reactive power support and a certain frequency support capability to the system.