Active Front Ends becoming increasingly popular within the electrical motor drive industry, since they in comparison to traditional passive diode rectifier bridges, allow for bi‐directional power flow, provide reactive power and control/reduce the harmonic distortions.
The AFE consists out of a 3 phase 2 level Voltage Source Converter using SiC MOSFETS, which offers the possibility to increase the switching frequency and thus reduce the size of the line filter. The AFE controller is designed using MATLAB/SIMULINK and implemented on a low cost DSP platform from Texas Instruments using automatic code generation for embedded targets.
The video itself shows the difference of a passive diode rectifier and an Active Front End after the controller is activated. The high level of harmonic distortions of the line current using a passive diode rectifier can result, depending on the line impedance, in grid distortions affecting other loads and generators.
After the controller is activated the harmonic distortions of the current and thus voltage improve significantly to a “clean” sinusoidal shape.