Wide area measurements based fault detection and location method for transmission lines

Wen Fan,Yuan Liao

doi:10.1186/s41601-019-0121-9

Abstract

Electric power grids are critical infrastructure for delivering energy from generation stations to load centers. To maximize utilization of assets, it is desirable to increase the power transferred over transmission systems. Reliable protection of transmission systems is essential for safeguarding the integrity and reliability of the power grid. Distance protection is the most widely used scheme for protecting transmission lines. Most existing protection systems use local measurements to make a decision while pilot protection is used in some circumstances. Distance protection may fail under stressed operating conditions, which could lead to cascading faults. This paper proposes a system integrity protection scheme by utilizing wide area measurements. The scheme partitions the system into subnetworks or protection zones and employs current measurements to derive a fault identification vector indicating the faulted zone. Then the fault location is pinpointed based on wide area measurements and network data. The proposed method is able to deal with multiple, simultaneous faults, and is applicable to both transposed and untransposed lines. Evaluation studies based on simulation studies are presented.

Highlights

The electric power is delivered from generation sources to distribution system through the transmission system
This paper focuses on proposing wide area monitoring based fault detection and location method, which can supplement back up distance protection to avoid catastrophic consequences
5 Conclusions Protection systems play a pivotal role in maintaining safety and reliability of electric power grids

Summary

Introduction

The electric power is delivered from generation sources to distribution system through the transmission system. This paper proposes an algorithm to locate simultaneous faults in the transmission system using wide area measurements. The measured voltages at each bus during the fault are functions of the relevant driving point impedances and transfer impedances. The transfer impedance and driving point impedance at fault nodes are: Zrri 1⁄4 4 ypr þ yqr 2 þ z−pr þ z−qr. . 6 for double-circuit lines will give all relevant driving point and transfer impedances related to fault nodes. As discussed in Section 3.1.1, it is revealed that these driving point and transfer impedances are functions of fault locations

Fault location algorithm

Fault zone identification for multiple simultaneous faults

Conclusions

Availability of data and materials None