Review of protection and fault handling for a flexible DC grid

Jinghan He,Keao Chen,Meng Li,Yiping Luo,Chenguang Liang,Yin Xu

doi:10.1186/s41601-020-00157-9

Jinghan He, Keao Chen + Show 4 more

Open Access

https://doi.org/10.1186/s41601-020-00157-9

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Abstract

With the development of power electronics technology, the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid. It is immune to commutation failure and has high flexibility in power control and renewable energy grid integration. However, the protection and fault handling technology for a flexible DC grid is a big challenge because of the limited overcurrent capability of the converters. This paper summarizes the development of the flexible DC grid, and analyzes the fault characteristics in detail. Next, the applicability, advantages and disadvantages of the existing protection principle, fault isolation and recovery schemes are reviewed. Finally, the key problems and development trend of the future flexible DC grid are pointed out and forecasted respectively.

Highlights

With the depletion of fossil energy, the worsening environmental pollution, and the occurrence of extreme climate events, large-scale development of renewable energy has become a significant trend around the world [1]
The results show that the low reliability of the DC circuit breaker is one of the main reasons for the low reliability of the DC distribution network [98, 100], and it should be further studied
Providing the power electronic devices are in their safe operating region, it can ensure the normal operation of non-faulty lines without blocking the converter, solving the problem of DC fault clearing and isolation in flexible DC systems and improving system availability

Summary

Introduction

With the depletion of fossil energy, the worsening environmental pollution, and the occurrence of extreme climate events, large-scale development of renewable energy has become a significant trend around the world [1]. The protection methods of flexible DC grids can be roughly divided into several schemes of fault detection and identification such as traveling wave protection, voltage and current protection, boundary protection, pilot protection, and protection-control coordination protection.

Results

Conclusion