Long-distance high voltage alternating current (AC) submarine cables are widely used to connect offshore wind farms and land power grids. However, the transmission capacity of the submarine cable is limited by the capacitive charging current. This paper analyzes the impacts of reactive power compensation in different positions on the current distribution on long-distance submarine cable transmission lines, and tests the rationality of the existing reactive power compensation schemes based on electrothermal coordination (ETC). Research shows that compensation at the sending end has obvious impacts on current distribution along the cable, and the maximum current occurs at the sending or receiving end. Moreover, the reactive power compensation at sending end will reduce the current at receiving end of the line. On the contrary, it will increase the current at sending end. Compared with the directly buried laying method of the submarine cable in the landing section, the cable trench laying method can increase the cable ampacity of the landing section and reduce the reactive power compensation capacity at the sending end. The ampacity is the current representation of the thermal limits of the cable. ETC exploits the cable ampacity to coordinate current distribution on transmission lines under existing reactive power compensation schemes, thus optimizing the reactive power compensation schemes and avoiding the bottleneck point of cable ampacity.

中文翻译：

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考虑电热配合的海底长距离电缆无功补偿策略研究

长距离高压交流（AC）海底电缆广泛用于连接海上风电场和陆地电网。但是，海底电缆的传输容量受到电容充电电流的限制。本文分析了远距离海底电缆传输线上不同位置的无功补偿对电流分布的影响，并测试了基于电热协调（ETC）的现有无功补偿方案的合理性。研究表明，发送端的补偿对沿电缆的电流分配有明显影响，最大电流出现在发送或接收端。此外，发送端的无功功率补偿将减少线路接收端的电流。反之，它会增加发送端的电流。与海底电缆直接埋入敷设方式相比，该电缆沟敷设方法可以增加登陆区的电缆载流量，降低发送端的无功补偿能力。载流量是电缆热极限的当前表示。ETC利用电缆载流量来协调现有无功补偿方案下输电线路上的电流分配，从而优化了无功补偿方案并避免了电缆载流量的瓶颈点。电缆沟敷设方法会增加着陆段的电缆载流量，降低发送端的无功补偿能力。载流量是电缆热极限的当前表示。ETC利用电缆载流量来协调现有无功补偿方案下输电线路上的电流分配，从而优化了无功补偿方案并避免了电缆载流量的瓶颈点。电缆沟敷设方法会增加着陆段的电缆载流量，降低发送端的无功补偿能力。载流量是电缆热极限的当前表示。ETC利用电缆载流量来协调现有无功补偿方案下输电线路上的电流分配，从而优化了无功补偿方案并避免了电缆载流量的瓶颈点。