A Hybrid Modulation Technique for Operating Medium-Voltage High-Power CHB Converters Under Grid Voltage Disturbances

Power converters, and particularly multilevel converters, are key elements in the current energy scenario. Among them, cascaded H-bridge converters are a popular and versatile solution for many industrial applications. Technical literature provides multiple modulation techniques for its operation. Among them, hybrid pulsewidth modulation techniques provide a good tradeoff between switching loss and output voltage quality. In this article, a hybrid modulation technique is presented, which allows not only the fundamental block switching operation of some power cells but also a harmonic control over a specific harmonic distortion present in the grid. To validate the operation of the proposal, several experimental results have been reported to demonstrate the good behavior of the proposed modulation technique.