Frequency Regulation and Coordinated Control for Complex Wind Power Systems

Delin Wang,Cheng Guo

doi:10.1155/2019/8525397

Abstract

With the development of complex renewable energy systems, the frequency control and regulation of the power grid powered by such renewable energies (e.g., wind turbine) are more critical, since the adopted different power generators can lead to frequency variations. To address the frequency regulation of such power grids, we will present a variable coefficient coordinated primary frequency regulation scheme for synchronous generator (SG) and doubly fed induction generator (DFIG). The variable adjustment coefficient of DFIG is defined according to the current reserve capacity, which can be applied to adjust different operation conditions to regulate the frequency variation within a predefined allowable range. Since the DFIG can make full use of the reserve wind power in the system frequency regulation, the proposed method can address both the frequency regulation response and the economic performance. Simulation results indicate that the proposed coordinated control scheme can achieve satisfactory frequency regulation response and lead to reduced demand for frequency regulation of SG.

Highlights

The wind power industry in all countries of the world is developing at a relatively fast speed
The aim of this paper is to develop a new control strategy for wind turbine generators (WTG) to participate in the primary frequency regulation, and the coordinated control strategy between synchronous generator (SG) and doubly fed induction generator- (DFIG) for primary frequency regulation is explored
We make the DFIG-based wind turbine whose load is reduced by 20% operate at the current wind speed, which is shown rinotaorresapAeeidnaFt itghuerecu3r.rIenntthwiisnfdigsupreee, dω,rPio󸀠sptthise corresponding the suboptimal power when the wind turbine’s load is reduced by 20%, Rω is the adjustment coefficient of the DFIG maximum power point tracking module, f is the real-time frequency of the system, fN is the rated frequency of the system, K1 is the gain value, ΔPω is the frequency regulation power of DFIGbased wind turbine corresponding to the system frequency variation, and PΣ is the sum of suboptimal power Po󸀠pt and frequency regulation power ΔPω

Summary

Introduction

The wind power industry in all countries of the world is developing at a relatively fast speed. In order to obtain better power grid response and frequency modulation ability, it is necessary to coordinate the frequency regulation outputs between the DFIGs and the synchronous generators, according to the adjustable frequency capacity of DFIG-based wind turbines under different wind speeds. This idea has been recognized as one of emerging research topics as it can improve the wind frequency regulation.

System Formulation and Problem Statement

E ΔPW fN Δf f1

Coordinated Control of Synchronous Generators and DFIG-Based Wind Turbines

Coordinated Strategy for Frequency Regulation

Simulations

Findings

Conclusions