基于PSCAD的海上特高压柔性直流线路保护的故障处理方法

Protection of Offshore UHV Flexible DC Lines Based on PSCAD

摘要:

柔性直流输电技术迅速发展,但其所面对的问题也越来越多,一个典型的问题是直流输电线路出现故障时,其迅速变化的故障电流会对其可靠性产生影响,因此,如何在最短的时间内切断故障电流,保证电网的安全运行,研究符合要求的快速、可靠的柔性直流输电(FDC, flexible direct current)保护机制显得尤为重要；本文首先对FDC系统保护机理的研究现状进行了综述分析,对故障特点进行了探讨,针对直流输电线路的新原理、新的布线方式进行了创新,提出了一种既能满足各种需求又能保证其正常运行的高效的直流线路保护方案；仿真试验和工程应用证明：该方案能够迅速地识别和隔离故障,对于保证FDC系统的安全、稳定运行有着十分重要的作用。

Abstract:

The flexible DC transmission technology is developing rapidly, but it faces more and more problems. A typical problem is that when a DC transmission line fails, its rapidly changing fault current will affect reliability. Therefore, how to cut off the fault current in the shortest time and ensure the safe operation of the power grid, it is particularly important to study the fast and reliable flexible direct current (FDC) protection mechanism that meets the requirements. In this paper, the research status of the protection mechanism of the FDC system is summarized and analyzed, and the characteristics of the fault are discussed. The new principle and new wiring method of the DC transmission line are innovated. An efficient DC line protection scheme that can meet various needs and ensure its normal operation is proposed. The simulation test and engineering application show that the scheme can quickly identify and isolate faults, which plays an important role in ensuring the safe and stable operation of the FDC system.