Digital control of grid-connected converters

During the last decades, the amount of power electronic converters connected to the grid has increased rapidly. Since regulations such as EN-61000-3-2 limit the amount of harmonics in the input current of these converters, many converters use power factor correction (PFC). This means that a low harmonic distortion of the input current and a low phase shift between the input current and the grid voltage are obtained. In many cases, the control algorithms for PFC are still implemented as analogue circuits. However, with the advent of fast digital signal processors (DSP) embedding control peripherals such as PWM generation units, AD converters, etc. new and more complicated control algorithms become feasible. In EELAB the consequences of going towards a digital control have been investigated and new control algorithms have been developed.

• Digital control of a boost PFC converter in a wide power range
  
  
• Converters for grid connection of distributed generation units