Control strategy of a three phases current inverter dedicated to static loads, taking into account forced and natural commutations in order to minimize semiconductors losses

This paper deals with a current inverter which is the output stage of a static load for a generator or DC supply. The energy is fed back through this inverter to the 3-phase mains. The main constraint is to limit the perturbation of the mains by this device, and particularly to reduce as much as possible the low-frequency current harmonics. A PWM strategy allows this reduction. It is also necessary to avoid the appearance of reactive energy in the system. The inverter can be controlled so that the fundamental of the current of each phase is in phase with the corresponding voltage