High efficiency of 3-level inverter embedding neutral point voltage shifting control

Recently renewable energy has attracted a lot of attention and solar power generation systems and wind power generation systems are widely used as public eco-awareness increases. Generally inverters are used in such power generation systems. They need high efficiency. Multi-level technique improves efficiency of inverters. We proposed neutral point voltage shifting control.(1)(2) for 2-level inverters to achieve high efficiency of the inverters before. It is difficult to apply our neutral point voltage shifting control to 3-level inverters. In this paper, we propose a new neutral point voltage shifting control for 3-level inverters.