An Active Power Filter Using a Sensorless Muticell Inverter

Unlike traditional inverters, multicell inverters have the following advantages: lower switching frequency, high number of output levels and less voltage constraints on the IGBT's. Significant performances are provided with this structure which is constituted with flying capacitors. This paper deals with a predictive and direct control applied to the multicell inverter. To perform the capabilities of multicell active filter, a voltage control method of flying capacitor, based on the use of a switching table, is added. Flying capacitor voltages are kept on a fixed interval and precise voltage sensors are not necessary. The association of predictive control and voltage balancing increases considerably the bandwidth of active filter.