In this paper is proposed a new modulation technique for the modular multilevel converter, based on space vector theory. This technique is based on step-wave modulation (reduced switching frequency). Therefore, this technique performs a fast calculation of every pulse pattern of upper and lower arm three-phase voltages that will define the switching sequence, in this way becoming an attractive alternative. This technique generates N +1 levels at inverter output voltage/current with and low ripple on the submodules capacitors voltage. The simulation results show a good performance of the proposed modulation technique for any number of submodules.