An Adaptive Protection Scheme for Power Systems Considering the Effects of HVDC Interfaced Distributed Generations

Jipu Gao,Mingyong Xin,Xiaobo Li,Yang Yu,Changbao Xu

doi:10.1109/access.2022.3144638

Abstract

Distributed Generations are usually connected to the ac grid through HVDC transmission systems. However, due to the current injected by the grid-side voltage source converter (GVSC), the voltage drop after a short-circuit fault will be partly compensated. For this reason, the viewed impedance of distance relays will be affected, which is a challenge for the distance protection scheme. For this issue, this paper proposed an adaptive distance protection scheme for the system containing distributed generations. Firstly, the proposed scheme controls the current of the GSVC to be proportional to the current of the AC transmission line. Secondly, an adaptive distance protection criterion is proposed, which can obtain the impedance from the relay to the fault-point accurately. The effectiveness of the proposed approach was validated through simulation using MATLAB/Simulink.

Highlights

T HE distance protection of high voltage transmission systems is an essential safety measure and plays a vital role to ensure the stability and security of power systems [1]-[5]
When a short-circuit fault happened, the current injected by the distributed generation improved the voltage of the fault point, which produced an non-ignorable error in impedance measurement
To consider the effect of the distributed generation, a robust distance protection scheme based on μ synthesis analysis technique was proposed [10]

Summary

INTRODUCTION

T HE distance protection of high voltage transmission systems is an essential safety measure and plays a vital role to ensure the stability and security of power systems [1]-[5]. In the transmission system of a large-scale power system, the high-voltage long-distance transmission lines are irreplaceable. As the increase of the distance, the probability of short-circuit failure is increasing. Once a short-circuit fault occurs, it will cause great safety hazards and economic losses. Distance relay is important to protect the high-voltage transmission system [6]-[10]

DRAWBACKS OF THE TRADITIONAL DISTANCE PROTECTION ALGORITHM