Circulating Current Suppressing Control?s Impact on Arm Inductance Selection for Modular Multilevel Converter [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 621.3 Electrical, magnetic, optical, communications, computer engineering; electronics, lighting
• Thông tin xuất bản: Oak Ridge, Tenn. : Oak Ridge, Tenn. : Oak Ridge National Laboratory ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2016
• Mô tả vật lý: Size: 182-188 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 255934
• Chủ đề: 1. 30 direct energy conversion; 2. Arm inductance selection; 3. Circulating current suppression control; 4. Modular multilevel converter (mmc)

Tóm tắt

Arm inductor in a modular multilevel converter (MMC) is used to limit the circulating current and dc short circuit fault current. The circulating current in MMC is dominated by second-order harmonic, which can be largely reduced with circulating current suppressing control. By analyzing the mechanism of the circulating current suppressing control, it is found that the circulating current at switching frequency becomes the main harmonic when suppression control is implemented. Unlike the second-order harmonic that circulates only within the three phases, switching frequency harmonic also flows through the dc side and may further cause high-frequency dc voltage harmonic. This article develops the theoretical relationship between the arm inductance and switching frequency circulating current, which can be used to guide the arm inductance selection. The experimental results with a downscaled MMC prototype verify the existence of the switching frequency circulating current and its relationship with arm inductance.