中文摘要：

该文提出了一种适用于多端口背靠背式直流–直流变换器（multiport front-to-front DC/DC,MF2F）及其构成的多端直流系统的功率自动平衡控制方法。该平衡控制包括“外部平衡控制”、“内部平衡控制”以及其它常规控制环节;设计了与MF2F相连的外部换流器的功率平衡控制。在一个由四端口MF2F组成的多端直流系统上对所提出的平衡控制做了仿真验证,测试了功率阶跃,交流故障等工况下平衡控制器的响应特性。仿真结果表明,文中设计的功率自动平衡控制器可以保证MF2F及其构成的多端直流系统在发生功率失衡事件时,无需人为干预即可自动保持功率平衡从而保证系统的运行安全性。所提出的平衡控制方法有助于推进多端口直流–直流换流器在直流电网中的应用。

英文摘要：

Automatic power balance control of a multi-terminal DC system （MTDC） constructed by a multiport front-to-front connected DC/DC converting system （MF2F） was proposed. To overcome the instability problem, a generic controller including a ＇normal control loop＇, an ＂inner balance loop＂ and an ＂external balance loop＂ is proposed for each port of the MF2F. Further power balance controllers installed at external MTDC terminals were also designed. The designed power balance controls were verified by a test four terminal MTDC system constructed by a 4-port MF2F. Simulations of un-balanced power orders, AC faults and DC faults verified the proposed power balance controllers. The proposed power balance controllers enable automatic power balance inside a MF2F and automatic power balance between a port and its externally connected DC terminal without relying on intervention from upper layer operators. The proposed controllers can be used as generic controllers for a MTDC or a MTDC including multiport DC/DC converters.