| Abstract |
The low-frequency mode is an established operation mode for modular multilevel converters, which enables the converter operation with machines at low speeds. This paper analyzes the operation mode in frequency domain using a simplified harmonic model. Based on the frequency domain model, an extension for the operation mode is proposed, which significantly reduces the current loading of the modules' semiconductors without increasing the module capacitance requirements. The simplified frequency domain models and the effectiveness of the proposed extension are validated using simulations and experimentally using a downscaled converter prototype. |
