Fault Ride through Capability Augmentation of a DFIG-Based Wind Integrated VSC-HVDC System with Non-Superconducting Fault Current Limiter

Md Alam,Ibrahim El-Amin,Alaa Hussein,Mohammad Abido

doi:10.3390/su11051232

Abstract

This paper proposes a non-superconducting bridge-type fault current limiter (BFCL) as a potential solution to the fault problems of doubly fed induction generator (DFIG) integrated voltage source converter high-voltage DC (VSC-HVDC) transmission systems. As the VSC-HVDC and DFIG systems are vulnerable to AC/DC faults, a BFCL controller is developed to insert sizeable impedance during the inception of system disturbances. In the proposed control scheme, constant capacitor voltage is maintained by the stator VSC (SVSC) controller, while current extraction or injection is achieved by rotor VSC (RVSC) controller. Current control mode-based active and reactive power controllers for an HVDC system are developed. Balanced and different unbalanced faults are applied in the system to show the effectiveness of the proposed BFCL solution. A DFIG wind-based VSC-HVDC system, BFCL, and their controllers are implemented in a real time digital simulator (RTDS). The performance of the proposed BFCL control strategy in DFIG-based VSC-HVDC system is compared with a series dynamic braking resistor (SDBR). Comparative RTDS implementation results show that the proposed BFCL control strategy is very efficient in improving system fault ride through (FRT) capability and outperforms SDBR in all cases considered.

Highlights

Due to the continuous depletion of fossil fuels as well as the perpetual escalation of energy demands, research on renewable energy resources has been a hot topic in recent years
This study proposes bridge-type fault current limiter (BFCL)-based control for reducing the fault current, improving the fault ride through capability, and enhancing the transient stability of doubly fed induction generator (DFIG) wind integrated voltage source converter (VSC)-HVDC systems
Unlike other methods presented in the literature, the proposed BFCL-based protection scheme is superior for augmenting the fault ride through (FRT) capability of DFIG wind farms integrated with VSC-HVDC systems

Summary

Introduction

Due to the continuous depletion of fossil fuels as well as the perpetual escalation of energy demands, research on renewable energy resources has been a hot topic in recent years. The non-superconducting bridge-type fault current limiter (BFCL) is a novel technology having promising competency to improve the dynamic stability of wind farms and power grids by inserting sizeable impedance during the inception of disturbances in the system [40,41,42,43,44,45]. There is gap in current studies examining and implementing low-cost BFCLs that needs to be filled by designing proper impedance as a prospective solution for fault impact mitigation of DFIG wind integrated HVDC systems. This study proposes BFCL-based control for reducing the fault current, improving the fault ride through capability, and enhancing the transient stability of DFIG wind integrated VSC-HVDC systems. Unlike other methods presented in the literature, the proposed BFCL-based protection scheme is superior for augmenting the FRT capability of DFIG wind farms integrated with VSC-HVDC systems. (a) Excessive DC link voltage fluctuation (b) High fault current and oscillation in DFIG speed and active power (c) Improper size of BFCL impedance for DFIG-based HVDC systems

Bridge-Type Fault Current Limiter

Controller Parameter Design

RTDS Implementation

BFCL Implementation Feasibility

Conclusions