Power conditions and control of a regenerative brake

Braking capability is typically accomplished by adding a dynamic/resistive brake (DB) module to a standard drive. Regenerating energy is dissipated in the braking resistor creating heat and decreasing the overall efficiency of the drive. To overcome the shortcomings of the DB solution, a regenerative brake (RB) was developed. The RB is a stand-alone, add-on unit to the drive. It operates with single or multiple drives sharing common DC and AC buses. The power rating of the brake is usually smaller than power rating of the drive(s). A robust and simple solution of control of RB with analysis of power conditions is provided in the paper. The total harmonic distortion (THD) of the current during regeneration of the drive is comparable with the THD of current during motoring. The theoretical results of the analysis are experimentally verified.