Analytical model building for Type-3 wind farm subsynchronous oscillation analysis

Abstract

Many real-world scenarios confirmed insights developed based on the dq-frame nonlinear analytical model for doubly-fed induction generator (DFIG)-based type-3 wind subsynchronous resonance (SSR) study by the authors in 2010. A few real-world observations do not align with the simulation results from that model. In real-world scenarios, when a type-3 wind farm is radially connected to a series compensated line, even at a low compensation level, SSR occurs. This phenomenon has not been replicated by the nonlinear analytical model. In this paper, we revisited the analytical model by including phase-locked-loop (PLL). A modular modeling approach is presented in this paper. The inputs and outputs of each subsystem and the interconnections among subsystems are identified first. The overall system is then developed with all blocks integrated. The analytical model is capable of dealing with various transmission topologies, providing both large-signal time-domain simulation results and small-signal analysis. The new analytical model can successfully replicate the aforementioned phenomena and provide insights of type-3 wind SSR phenomena. The accompanying software package will be posted in the public domain.