A new method of control for multilevel converter implemented on FPGA

This paper proposes a strategy of control for multilevel converter that uses capacitors as auxiliary power source. Though this paper emphasis on the inverter control, the method has been proved effective for rectifier as well. In multi-level converter, the regulation of the capacitor is done on different switching state. Depending of the ratio between output and input voltage, two different mode of regulation are used. For a smaller ratio, less levels are necessary and a simple hysteresis is sufficient to achieve regulation. For a larger ratio, the drifting PWM is used, which allow a slight variation in the switching state so regulation can be achieve. Case study where both methods are required is simulated and then tested on a fast prototyping development board, to prove their reliability. Once fully functional, it is implemented on an FPGA board, making the embedded system more affordable. Using this method the output voltage should follow its reference, even when the input voltage changes.