多機光伏并網逆變器的孤島檢測技術研究

摘要：隨著新能源發電的迅速發展，越來越多的可再生能源被轉化為電能通過并網逆變器輸送到電網。并網逆變器要求具備孤島檢測功能，目前對光伏并網逆變器的研究主要集中于單機，通常對其輸出施加一定的擾動以提高孤島檢測能力。本文從多機并網運行的角度對孤島檢測方法進行了研究。針對并網逆變器所常用的移頻與移相兩類主動孤島檢測技術在多逆變器并聯工作下的相互聯系及內在影響進行了深入分析。同時給出這兩類方法下的逆變器孤島檢測設計注意事項及孤島算法參數選取方法，從而為多機光伏并網逆變器孤島檢測提供了理論指導。 敘詞：并網逆變器 光伏 孤島檢測 移頻 移相 Abstract：Due to the development of distributed generation, grid-connected converters are widely employed for renewable energy sources utilization. The islanding detection is a mandatory function for such converters. It usually injects perturbations in the converters' output to improve islanding detection effectiveness. The current research is mainly focusing on the islanding detection of individual converter. This paper is dedicated to investigating the strategies for multiple PV grid-connected converters operation. The characteristics of normally used active frequency shift and active phase shift islanding detection methods in multiple converters system are explored. The design principle and parameters selection rule of the two strategies are also presented. It provides basic islanding detection design guidance for multiple PV grid-connected converters system. Keyword：Grid-connected converter, PV, Islanding detection, Frequency shift, Phase shift