多分区异步互联电网的直流频率限制器协调控制策略研究

Coordination Strategy of Frequency Limit Control on Multi-area HVDCs Under Asynchronous Interconnection

大型同步电网异步分区运行是构建新型电力系统发展的重要探索方向,直流频率限制器(frequency limit control,FLC)在保障弱系统的频率稳定方面发挥着重要作用。在广东东西组团构网结构下,系统故障可能导致广东东西分片运行,出现多分区异步互联的网架形态,原有的仅送端弱系统配置单侧FLC的策略难以适应电网发展需要。针对弱送端、弱受端共存的特性,该文提出双侧FLC的数学模型,在不同场景下详细分析其控制特性。在此基础上,建立了一套面向多分区异步互联电网的FLC协调控制策略。通过广东东西异步运行后的典型方式和故障校核,验证了双侧FLC的功率支援效果以及所述协调控制策略的合理性。

The multi-area asynchronous operation of large synchronous grids is a key concern in the new power systems.The HVDC frequency limit control(FLC)plays an important role in the frequency stability control of the weak systems.Under the cluster structure of the eastern and weastern Guangdong province,the faults may cause the asynchronous operations of the two areas and lead to a multi-area asynchronous network frame.It is difficult for the existing one-side FLC at the weak sending end to meet the requirement of the system development.Aiming at the coexistence of the weak sending and the receiving ends,this paper proposes a mathematical model of the dual-side FLC and analyzes its control characteristics in detail under different scenarios.An optimization scheme on the coordination strategy of the FLCs in the asynchronously interconnected areas is established.Based on a typical operation condition and the faults after the asynchronous interconnection in the Guangdong grid,we verify the power support effect of the dual-side FLC and the rationality of the optimization scheme.