Cascaded three-level inverter modulation strategies: a unifying point of view based on duty-cycle space vector approach

In this paper the problem of the modulation strategy of a cascaded three-level inverter is solved using the duty-cycle space vector approach, which is based on the space vector representation of the switch state. This approach simplifies the study of the modulation strategies and leads to a general solution of the problem, providing an intuitive graphical representation of the modulation properties. Furthermore, some well-known modulation strategies are briefly reviewed and then analyzed from this unitary point of view