Coordinated Fuzzy-Based Low-Voltage Ride-Through Control for PMSG Wind Turbines and Energy Storage Systems

Chunghun Kim,Wonhee Kim

doi:10.1109/access.2020.3000247

Abstract

Coordinated control methods involving a wind turbine (WT) and an energy storage system (ESS) have been proposed to meet several objectives, such as smoothing wind power (WP) fluctuations, shaving peaks, enabling power scheduling, and allowing low-voltage ride-through (LVRT). LVRT requirement is defined by grid operators, and it should be satisfied whenever grid faults occur. Several methodologies have been proposed for the LVRT both with or without the use of an ESS. Furthermore, using an ESS is more advantageous for several WP applications. By using an ESS, WTs can be operated in a more economic and reliable way. However, the installation cost of an ESS is high and it has operation range constraints for charging and discharging. Moreover, the WT operation condition and ESS state-of-charge (SoC) can be different when a grid fault occurs. Therefore, it is necessary to coordinate both units, WT and ESS, for reliable and economic operation during a grid fault. Thus, we propose a coordinated fuzzy-based LVRT method that considers the different operation conditions of a WT and an ESS. From the proposed method, the effective reference powers of a WT and an ESS are evaluated by considering the rotor speed and SoC in the fuzzy control algorithm. The effectiveness of the proposed method is validated by considering two case studies on ESS SoC and WT rotor speed violations.

Highlights

As wind power (WP) increases in proportion to the total grid power, several issues related to the economic andThe associate editor coordinating the review of this manuscript and approving it for publication was Manoj Datta .reliable operation of an integrated power grid become apparent
Previous studies have focused on the energy storage system (ESS) low-voltage ride-through (LVRT) control for regulating the DC-link voltage during a grid fault
The LVRT control burden was divided between the wind turbine (WT) and ESS, as illustrated by the simulation results

Summary

INTRODUCTION

As wind power (WP) increases in proportion to the total grid power, several issues related to the economic and. Changing the roles of GSC and MSC in terms of DC-link regulation may be more advantageous In this case, the rotor speed can be increased by storing the remaining mechanical power as WT inertia, which is similar to that observed during grid fault. We propose a coordinated fuzzy-based LVRT method that considers the inertial response capability of a WT and an ESS SoC. Previous studies have focused on the ESS LVRT control method, which regulates DC-link voltage during a grid fault. When implementing the proposed method, the required reserve capacity of the ESS can be significantly reduced, because the inertial response of the WT is determined using the maximum rotor speed limit This inertial response capability differs according to the rotor speed at the time of a grid fault. PMSG WPS we discuss the mechanical power of the WT, MSC and GSC models, DC-link voltage and ESS dynamics

MECHANICAL POWER OF WTs

SIMULATION AND EXPERIMENTAL RESULTS

CASE 1

CASE 2

Findings

CONCLUSION