The invention discloses a neutral point clamped
inverter topology for a three-phase three-level
diode of a
zero voltage switch and a modulation method for a neutral point clamped
inverter. The topology comprises a three-phase bridge arm consisting of 12 main switches connected in antiparallel with diodes and 6 diodes, an output
inductor connected between the output neutral point of the bridge arm and a load, and positive and negative
bus capacitors connected between the positive end and the negative end of a
direct current bus, and is characterized in that the main switches of the bridge arm is connected in parallel with a
capacitor; resonant inductors are respectively connected between the positive input end of the bridge arm and the positive
electrode of the positive
bus capacitor as well as between the negative input end of the bridge arm and the negative
electrode of the negative bus
capacitor; the two ends of the resonant inductors are bridged with a circuit formed by connecting auxiliary switches with antiparallel diodes with a clamped capacitor in series; the two ends of the auxiliary switches are connected in parallel with a capacitor; short-circuit switches are respectively connected between the positive input end of the bridge arm and the negative
electrode of the positive bus capacitor as well as between the negative input end of the bridge arm and the positive electrode of the negative bus capacitor. The modulation method is generating auxiliary switch and
short circuit switch signals according to a main switch driving
signal timing sequence of the three-phase bridge arm, so that
zero voltage on and off of all the switch devices can be realized.