An Effective Dynamic Equivalent Model of Wind Farm Connected to Power System Network

Abstract

A large scale Wind Farm (WF) usually consists of hundreds of interconnected Wind Turbines (WTs) and other related power components. This makes the detailed modeling of a WF a complex and oppressive process. A suitable equivalent model of WF, on the other hand, plays a vital role in studying the interaction of WF and the power system network. Hence, this paper proposes a slip based clustering method for Doubly Fed Induction Generator (DFIG) to evaluate the equivalent model of the complete WF. The proposed method is focused on the dynamic behavior of DFIGs. Based on the proposed method, a multi-machine equivalent model of a WF test system of 32MW capacity is obtained and its dynamic behavior is observed. Test cases like sudden wind speed change and short-circuit fault are simulated on MATLAB Simulink and DigSILENT. The transients in active and reactive power output of the multi-machine model of WF are compared with the single-machine and the detailed model. For the reliability assessment, the IEEE 14 bus system is modified by augmenting the WF test system and its dynamic response during network fault is compared with the detailed model of WF. The simulation results for different test cases show that the multi-machine model is a much closer approximation of detailed model without any considerable compromise with the simulation time.