Modeling of doubly-fed adjustable-speed machine for analytical studies on long-term dynamics of power system

This paper gives some considerations concerning modeling of doubly-fed machines for analytical studies, especially on long term dynamics of a power system in the time range of beyond 10 seconds in which the doubly-fed machines are operating and being controlled. The mathematical models are briefly presented first for short-term analysis (transient stability and dynamic stability analyses, up to 10 seconds) and then for long term analysis (frequency control analysis). The possible two control schemes of doubly-fed machine for long term analysis are presented and discussed. The dynamic simulations were performed to show the behavior of doubly-fed machines in a power system during pumping operation