Evaluation of quasi-resonant dc-link technique on generalized three-level inverter

This paper presents a combination of a quasiresonant dc-link (QRDCL) inverter and a generalized three-level inverter. QRDCL inverter can decrease the dc-link voltage to zero in order to provide a zero voltage condition for the power devices. The voltage stresses of the power devices can be released and the switching losses of the inverter can be reduced under zero-voltage switching (ZVS). Generalized multilevel inverter topology provides an alternative way in high level inverter implementation. The generalized multilevel inverter is constructed by several basic cells which enable a higher flexibility in extending the levels of inverter, and moreover it gives the inverter a self voltage balancing ability without any assistance from extra circuits. Control strategy of a generalized three-level QRDCL inverter is proposed. Switching losses of the inverters are also presented to prove the feasibility of a generalized three-level QRDCL inverter.