Fault Handling Methods and Comparison for Different DC Breaker Topologies and MMC Topologies of the HVDC System

Xu Jiang,Mark-M Bakran

doi:10.1155/2018/2719380

Abstract

The HVDC system has many significant benefits and is widely used around the world. The protection of HVDC system is always an issue, which should be solved. This paper presents the working principle of different protection schemes. The advantages and disadvantages of these protection schemes are also introduced. In order to solve the HVDC fault, two protection strategies are proposed. One design focusses on the topologies of the HVDC breaker in the HVDC line, such as all-solid HVDC breaker, resonant HVDC breaker, and hybrid HVDC breaker. The other design is from the viewpoint of converter topology, which has two types. One type generates the counter-emf in arms, such as full bridge MMC, hybrid MMC, and clamp-double MMC. The other type cuts off the current path from the AC side to the DC side, which is also introduced in this paper. Some performances of these topologies are compared, such as switching time and efficiency.

Highlights

The HVDC system became of more concern because it can increase power efficiency compared to the traditional AC transmission
This paper presents the working principle of different protection schemes
It is well known that half bridge modular multilevel converters (MMC) has many advantages, but one main disadvantage is that it has no ability to cut of the fault current

Summary

Introduction

The HVDC system became of more concern because it can increase power efficiency compared to the traditional AC transmission. The first way uses different circuit breakers in the HVDC line in order to cut off the fault current. The second way of HVDC protection is from the viewpoint of converter topologies. It is well known that half bridge MMC has many advantages, but one main disadvantage is that it has no ability to cut of the fault current. Because the modified SMs have more losses during normal operation, the hybrid MMC is considered [8] The second type is the topologies in [9, 10] These topologies cut off the energy flow between AC and DC sides and the rest energy is consumed in the designed loop. The new topology in [10] has good performance, which has lower loss than most topologies and short switching time

HVDC Breakers

S1 Thyristors

Modified MMC Topologies

Findings

Conclusion