FPGA-based control of modular multilevel converters: Modeling and experimental evaluation

In comparison with conventional two level converters, multilevel converters present lower switching losses, lower voltage stress on switching devices, lower common-mode voltages and better harmonic performance. Due to these remarkable features, nowadays the application of this technology covers a wide range, where high-quality voltages and currents are required. However, the multilevel converter requires a number of switching pulse width modulated (PWM) signals, which cannot be generated by using a single digital signal processor (DSP)/microcontroller because the available DSP at present only can provide about 12 PWM channels. In this instance, the field programmable gate array (FPGA) is the natural choice to develop the control circuit of multilevel converters. In addition, the most common software such as MATLAB/Simulink and Xilinx ISE Design Suite-based alternative design technique is used in this paper, which may reduce the developmental time and cost of the controller. The design and implementation of the switching controller, test platform, and experimental results are analyzed and discussed.