Implementation of a single space vector control strategy for a seven-level inverter

Recent advances in power have made multilevel converters suitable for high-power and medium voltage applications; there are many modulation techniques available to control their operation. In this paper, the Space Vector Pulse Width Modulation (SVPWM) technique to control a multilevel inverter is described. The inverter produces seven-level SVPWM three-phase voltage waveforms using twelve transistors and a delta-star transformer. The control strategy is implemented on a DSPIC and requires only the modulation index as an input to obtain the voltage amplitude required in the three-phase output. A description of the SVPWM algorithm, the improvement of the control signals to reduce the switching losses in the power semiconductor devices and the implementation are presented along with a discussion of simulation and experimental results obtained with a 1 kW prototype.