Open Access

ARTICLE

A Novel Control-Protection Coordination Strategy of Power Lines Connected with Inverter-Based Resources

Sumei Liu^1,*, Jizeng Wu¹, Yinghong Zhang², Ran Zheng³

1 College of Engineering, Beijing Forestry University, Beijing, China
2 Tianshui Power Supply Company, State Grid Gansu Electric Power Company, Tianshui, China
3 Jinhua Power Supply Company, State Grid Zhejiang Electric Power Company, Jinhua, China

* Corresponding Author: Sumei Liu. Email:

Energy Engineering 2026, 123(6), 2 https://doi.org/10.32604/ee.2026.081082

Received 23 February 2026; Accepted 02 April 2026; Issue published 27 May 2026

Abstract

The unique fault current characteristics of inverter-based resources (IBRs) result in a variable angle of the additional impedance for conventional distance protection, causing failure to operate for internal faults and maloperation for external faults. To address this issue, a novel control-protection coordinated strategy is proposed. The positive-sequence current references of IBRs’ inverter control strategy are reset, based on the relationship between the current on the high-voltage side of the transformer and that of the fault-point current. Under such control, the additional impedance angle can be effectively maintained at a constant value. On this basis, a single-ended protection principle immune to the additional impedance is developed. The proposed control-protection coordinated strategy can effectively identify internal and external faults under high-penetration IBRs integration, without substantially modifying the existing inverter control and protection framework. Compared with existing control-protection coordinated strategies, the proposed improved control strategy will not affect the stability of inverter control, nor will it generate additional harmonics. The proposed protection strategy still adopts conventional power-frequency voltage and current quantities for fault identification, facilitating its implementation.

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Keywords

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