A Dual VSG-Based M3C Control Scheme for Frequency Regulation Support of a Remote AC Grid Via Low-Frequency AC Transmission System
A Dual VSG-Based M3C Control Scheme for Frequency Regulation Support of a Remote AC Grid Via Low-Frequency AC Transmission System
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DOI：
10.1109/access.2020.2985386
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发表时间：
2020-04
期刊：
影响因子：
3.9
通讯作者：
Mustafa Al-Tameemi;Jia Liu;H. Bevrani;T. Ise
中科院分区：
文献类型：
--
作者：
Mustafa Al-Tameemi;Jia Liu;H. Bevrani;T. Ise
本文提出了一种低频交流输电系统，能够提供频率调节支持的远程交流电网，旨在提高其频率稳定性。使用模块化多电平矩阵变换器（M3 C）进行直接交流-交流变换的LFAC传输系统作为长距离传输系统的替代解决方案而受到显著关注。其潜在的应用之一是大型交流电网和远程交流电网之间的系统连接，而后者通常由于缺乏惯性而遭受波动的频率。这项工作的核心是解决一种新的控制方案的远程交流电网侧M3 C，这使得与LFAC系统和远程交流电网的相互作用像一个同步发电机使用双虚拟同步发电机（VSG）控制方案。该控制方案可以提高远程交流电网的频率调节，这是现有控制方案所不能提供的。平均直流电容电压与有功功率（$V_{ave}$ -P）下垂控制提出了协调应用在M3 C两侧的VSG控制之间的功率流。为了证明现有的控制方案的问题，以及所提出的控制方案，瞬态性能，包括负载变化和故障事件在远程交流电网的EMTDC/PSCAD软件环境中的研究和检查提供的好处。
This paper proposes a low-frequency ac (LFAC) transmission system capable of providing frequency regulation support for a remote ac grid aiming at enhancing its frequency stability. The LFAC transmission system using modular multilevel matrix converters (M3Cs) for a direct ac-ac conversion is receiving noticeable attention as an alternative solution for a long-distance transmission system. One of its potential applications is the system connection between a large ac grid and a remote ac grid, whereas the latter usually suffers from a fluctuant frequency due to lack of inertia. The core of this work is addressing a novel control scheme of the remote ac grid-side M3C, which makes both interactions with the LFAC system and the remote ac grid behave like a synchronous generator using a dual virtual synchronous generator (VSG) control scheme. This control scheme can enhance the frequency regulation in the remote ac grid, which the existing control schemes cannot provide. Average dc capacitor voltage versus active power ( $V_{ave}$ -P) droop control is proposed to coordinate the power flow between the VSG controls applied in both sides of the M3C. To demonstrate the problem of the existing control scheme, as well as the benefits offered by the proposed control scheme, transient performance including load variation and fault events in the remote ac grid is studied and examined in the EMTDC/PSCAD software environment.