Equipment-Level Locating of Low Frequency Oscillating Source in Power System With DFIG Integration Based on Dynamic Energy Flow

Abstract

In view of the complex correlation between Doubly Fed Induction Generator (DFIG) internal components and control links which makes it difficult to locate the oscillating source in the equipment level, a DFIG equipment-level oscillating source locating method based on dynamic energy flow is proposed. Firstly, the energy correlation topology network of DFIG internal components and control links is constructed. On this basis, the analytical expressions of dynamic energy flows of DFIG internal components and control links are derived. And then, through Partial Directional Coherence (PDC) analysis, the values of causality between dynamic energy flows of DFIG internal components and control links are calculated, and the diagram of DFIG internal oscillation transmission causality is depicted. Thus according to the distribution pattern of causality values in the causality diagram, the oscillation transmission route is identified and the oscillating source is located. Finally, simulation tests in Real Time Digital Simulator (RTDS) of IEEE 10-machine 39-bus system verify that, the proposed method can quantitatively describe the intensity of interaction between dynamic energy flows of DFIG internal components and accurately identify the oscillation transmission route and the oscillating source in the equipment level. The proposed method can accurately track the original control link/physical component that causes the system to oscillate. Therefore, this paper will facilitate research on DFIG parameter tuning and oscillation suppression measures for low-frequency oscillation in power system.