Fault Detection and Localization Method for Modular Multilevel Converters

What is it about?

This paper presents a method for detecting and locating faults in modular multilevel converters (MMCs), which are used for medium- or high-power applications. The method uses a Kalman filter to compare the measured and estimated state variables of the MMC, and identifies the faulty submodules based on their failure characteristics. The method is fast, simple, and robust against multiple faults. The method is validated by simulations and experiments with a real-time controller.

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Photo by Marek Piwnicki on Unsplash

Photo by Marek Piwnicki on Unsplash

Why is it important?

The practical implications of this paper are that it proposes a fault detection and localization method for the MMC, which can effectively locate faulty SMs even in the case of multiple faults. This is important because the MMC has many sensors, making KF an attractive filter to optimally estimate its state. The proposed method detects faults by comparing measured inner difference current with estimated inner difference current through KF and analyzes failure characteristics thoroughly to reveal capacitor voltage increase in faulty SMs.

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