針對大容量風電機組的中壓變換問題，本文研究一種基于多繞組發電機的模塊化級聯型變換器，通過模塊單元級聯實現中壓輸出，從而省去升壓變壓器。對模塊中發電機的兩個正交繞組經PFC整流后在直流母線上并聯，實現發電機單位功率因數運行，并保持饋入直流母線的瞬時功率恒定。利用發電機的電樞電感作為升壓電路的儲能電感，減小了系統的體積和成本，導出了電感取值的適用范圍。逆變側的H橋單元級聯電路采用矢量控制，獨立調節饋入電網的有功和無功功率。仿真和試驗結果驗證了該類變換器的拓撲結構和控制方法的有效性。
Abstract: This paper has presented a module-cascaded system for multi-coil direct-drive permanent magnet wind generator system with high voltage output, eliminating the grid-side step-up transformer. The generator coils with 90 degree phase shift are rectified through PFC circuit and connected in parallel to get unit power factor and stable dc-link power. The generator armature inductance is used for the AC-side PFC inductor, thus reducing the system size and cost. The required value of the inductor is derived based on the current ripple and zero-crossing distortion. The H-bridge inverters are cascaded to achieve high voltage output and the vector control scheme regulates the system active and reactive power output. Simulation and experimental results validate the proposed topology and control method.
關鍵詞：風力發電；永磁直驅；單元化模塊；H橋級聯
Key words: wind generation, direct-drive, modular approach, cascade H-bridge