HVDC technologies are widely acknowledged as one of solutions for the interconnection of renewable energy resources with the main electric power grid. The application of the latest modular multi-level converter (MMC) makes power conversion much more efficient. Due to the relatively low impedance in a DC system, DC fault currents may rise to an extremely high level in a short period of time, which can be very dangerous for HVDC converters. To improve the sustainability and security of electricity transmission, protection solutions for HVDC systems are being developed. Nevertheless, they have various drawbacks on fault signal detection and timely clearance. This paper proposes a protection method that provides a fast and reliable solution addressing those drawbacks. A protection algorithm based on travelling wave simulation and analysis is proposed to detect abrupt transient signals. The algorithm shows high efficiency, reliability, selectivity and has low sampling frequency requirements. The proposed protection method has been validated through a cyber-physical simulation platform, developed using a real-time digital simulator (RTDS) and IEC 61850 communication links. The obtained results show that the proposed method has good potential for practical applications.

中文翻译：

---

基于暂态信号检测的多端高压直流系统快速保护


高压直流技术被广泛认为是可再生能源与主电网互连的解决方案之一。最新模块化多电平转换器（MMC）的应用使功率转换更加高效。由于直流系统的阻抗相对较低，直流故障电流可能在短时间内升至极高水平，这对于高压直流换流器来说非常危险。为了提高电力传输的可持续性和安全性，正在开发高压直流系统的保护解决方案。然而，它们在故障信号检测和及时清除方面存在各种缺点。本文提出了一种保护方法，提供快速可靠的解决方案来解决这些缺点。提出了一种基于行波仿真和分析的保护算法来检测突发瞬态信号。该算法具有高效、可靠、选择性好、采样频率要求低等优点。所提出的保护方法已通过网络物理仿真平台进行了验证，该平台使用实时数字模拟器 (RTDS) 和 IEC 61850 通信链路开发。所得结果表明该方法具有良好的实际应用潜力。