Asymmetric Switching Angle Modulation for Cascaded Multilevel Power Inverters for Different Grid Support Functionalities

Symmetric switching angle modulation has been widely applied to multilevel inverters in the last decade. Most of the published techniques on this topic are to eliminate harmonics and generate sinusoidal voltages. This paper presents a new asymmetric switching angle modulation (ASAM) technique to utilize the harmonics of the staircase voltage waveforms generated by multilevel inverters for various grid support and energy storage charging. This technique can efficiently compensate reactive power and individual harmonics, balance unbalanced load and control bidirectional power flow between the grid and the energy storage. Simulations and experiments are conducted to validate the proposed technique.