Modular multilevel converter-based high voltage direct current (MMC-HVDC) has a broad application prospect in renewable energy transmission. With the development of converter capacity, the transmission capacity calculation for MMC-HVDC grids becomes important for power dispatching. The existing method depends on manual work and is suitable for a simple grid. However, as the grid structure and operation modes become more and more complex, it becomes difficult to calculate the transmission capacity of different operation modes for an MMC-HVDC grid. This paper analyzed and simplified affecting factors and basic topologies. On this basis, a topology-based MMC-HVDC grid transmission capacity calculation method is proposed. First, an MMC-HVDC grid is divided into sending end grid, transmission section lines, and receiving end grid. Then the power limits of these three parts are calculated. Finally, the transmission capacity is determined by analyzing the connection mode of these three parts. This method can be adapted to any kind of MMC-HVDC grid and can be easily programmed.

中文翻译：

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基于拓扑分析的MMC-HVDC电网输电容量计算方法

基于模块化多电平转换器的高压直流电（MMC-HVDC）在可再生能源传输中具有广阔的应用前景。随着变流器容量的发展，MMC-HVDC电网的输电容量计算对于电力调度变得尤为重要。现有方法取决于手动工作，并且适用于简单的网格。然而，随着电网结构和操作模式变得越来越复杂，对于MMC-HVDC电网，计算不同操作模式的传输容量变得困难。本文分析并简化了影响因素和基本拓扑。在此基础上，提出了一种基于拓扑的MMC-HVDC电网输电容量计算方法。首先，将MMC-HVDC网格划分为发送端网格，传输分段线和接收端网格。然后计算这三个部分的功率极限。最后，通过分析这三个部分的连接方式来确定传输容量。该方法可以适用于任何类型的MMC-HVDC电网，并且可以轻松地进行编程。