SSR Analysis of DFIG-Based Wind Farm With VSM Control Strategy

Kanghui Gu,Haiqiang Zhou,Jianing Li,Ping Ju,Jiajie Luo,Xiao-Ping Zhang,Feng Wu

doi:10.1109/access.2019.2936872

Kanghui Gu, Haiqiang Zhou + Show 5 more

Open Access

https://doi.org/10.1109/access.2019.2936872

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Journal: IEEE Access	Publication Date: Jan 1, 2019
Citations: 29	License type: CC BY 4.0

Affiliation: University of Birmingham, Hohai University

Abstract

The wind turbine is usually integrated into the power grid via back to back converter, and the inertia is decreased. Virtual synchronous machine (VSM) control was proposed to improve inertia of the wind farm. While for the doubly-fed induction generator (DFIG)–based wind farm with traditional control strategy, sub-synchronous resonance (SSR) has become a significant problem when it is connected to series compensation transmission lines. Therefore, the impacts of VSM control strategy for DFIG on SSR need to be investigated. In this paper, a detailed small-signal stability analysis model of the VSM control strategy is first established and eigenvalue analysis is then carried out. SSR in the wind farm with the VSM control under different series compensation levels, controller parameters and wind speeds is analyzed, and it is also compared to that in the wind farm with the conventional vector control strategy (VC). Simulations are performed in PSCAD/EMTDC to verify the result of SSR analysis.

Highlights

Wind power generation develops quickly in recent years with global installation of 591 GW by the end of 2018
DIFFERENCES BETWEEN THESE TWO CONTROL STRATEGIES 1) REFERENCE FRAME OF THE CONTROL Different to the fact that vector control strategy (VC) is established on the rotating d-q reference frame using the phaselocked loop (PLL), Virtual synchronous machine (VSM) has no oriented vector control
It is found that the VSM controller has its own mode, which is related to the state variables x2s, x3s according to participating factor analysis

Summary

INTRODUCTION

Wind power generation develops quickly in recent years with global installation of 591 GW by the end of 2018. K. Gu et al.: SSR Analysis of DFIG-Based Wind Farm With VSM Control Strategy energy storage systems, and the transient stability of power systems was successfully enhanced. Mechanism analysis and mitigation solutions on SSR in DFIG-based wind farms have been carried out in [17]–[24] These observed oscillations were found similar to induction generator effect (IGE) of thermal power generators [17], which will be triggered when the negative rotor equivalent resistance exceeds the total system resistance under sub-synchronous frequency. This kind of IGE can be affected by different factors, such as series compensation level of transmission lines, wind speed [18], network topology [19] and spatial distribution of wind farms [20]. The parameters of the wind farm system can be found in Table 3 in Appendix

VIRTUAL SYNCHRONOUS MACHINE CONTROL

SMALL SIGNAL STABILITY ANALYSIS

UNDER DIFFERENT SERIES COMPENSATION LEVELS

UNDER DIFFERENT CONTROLLER PARAMETERS

Findings

CONCLUSION