Sub-synchronous frequency domain-equivalent modeling for wind farms based on rotor equivalent resistance characteristics

Abstract

The equivalent simplification of large wind farms is essential for evaluating the safety of power systems. However, sub-synchronous oscillations can significantly affect the stability of power systems. Although detailed mathematical models of wind farms can help accurately analyze the oscillation mechanism, the solution process is complicated and may lead to problems such as the “dimensional disaster.” Therefore, this paper proposes a sub-synchronous frequency domain- equivalent modeling method for wind farms based on the nature of the equivalent resistance of the rotor, in order to analyze sub-synchronous oscillations accurately. To this end, Matlab/Simulink is used to simulate a detailed model, a single-unit model, and an equivalent model, considering a wind farm as an example. A simulation analysis is then performed under the sub-synchronous frequency to prove that the model is effective and that the wind farm equivalence model method is valid.

Keywords

• Wind farm
• Sub-synchronous frequency domain
• Dynamic equivalence
• Rotor equivalent resistance characteristics