An Extended SFR Model With High Penetration Wind Power Considering Operating Regions and Wind Speed Disturbance

Qi Wang,Yuqiang Hou,Jianfeng Dai,Yi Tang,Ping Jiang

doi:10.1109/access.2019.2930807

Qi Wang, Yuqiang Hou + Show 3 more

Open Access

https://doi.org/10.1109/access.2019.2930807

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Journal: IEEE Access	Publication Date: Jan 1, 2019
Citations: 16	License type: CC BY 4.0

Affiliation: Southeast University, NARI Group (China)

Abstract

High-penetration wind power grid access requires wind turbine generators (WTGs) to provide frequency regulation, and an accurate system frequency response (SFR) model is required for frequency stability analysis. To overcome the limitations of conventional methods, different operational regions of WTGs and wind speed disturbances are fully taken into account and a frequency response model of wind power (WPFR) participating in primary frequency control is developed by employing small signal analysis theory. Then, the WPFR model is integrated into the conventional SFR model to obtain an extended SFR model, which is given in the form of a symbolic transfer function with two input variables and single output variable, and can clearly and intuitively show the specific parameters that determine the system frequency response. Finally, the accuracy and effectiveness of the extended SFR model are verified through comparisons of the detailed model, and the impacts of initial wind speed, wind speed disturbance, and the wind power's penetration level on the system frequency response characteristics are analyzed and discussed. Such extended SFR model significantly avoids the need for modeling complex transient process while preserving the frequency response fidelity in a satisfactory level.

Highlights

Variable-speed wind turbine generators (VSWTGs) have been widely used in recent years due to their good operating characteristics, flexible active and reactive power control, and small power converters [1], [2]
Taking into account different WTG operational regions and wind speed disturbances, the WPFR model is first developed by using small signal analysis
1) The low order extended system frequency response (SFR) model is presented in the form of a symbolic transfer function with two input variables and single output variable, which introduce load disturbances as one input variable and wind speed disturbances as another input variable

Summary

INTRODUCTION

Variable-speed wind turbine generators (VSWTGs) have been widely used in recent years due to their good operating characteristics, flexible active and reactive power control, and small power converters [1], [2]. As presented in the aforementioned studies, it is not clear how to derive an equivalent WPFR model if the adaptability of the frequency control method for WTGs in different wind speed regions and the impact of wind speed disturbance are taken into account. To fill the gaps in the present literature, this paper proposes a comprehensive equivalent method for deriving the extended frequency response model of a power system with a high penetration of wind power participating in primary frequency control. The main contributions of this paper are as follows: 1) the transfer function form of the WPFR model for different operational regions based on current wind speed is deduced by using the small signal analysis theory; 2) the wind speed disturbances are fully taken into account as input variables to accurately represent the SFR model; and 3) the impacts of the initial wind speed and wind speed disturbance on the SFR are analyzed.

EQUIVALENT SFR MODEL STRUCTURE

ZONE I

ZONE II

ZONE III

SIMULATION STUDY

CONCLUSION