Control with regenerative braking

May 24, 2007
The PowerFlex 700l AC drive from Allen-Bradley, Milwaukee (, a div. of Rockwell Automation, can provide precise positioning with quick response times, continuous decelerations, and stop high-inertia loads, all while saving energy.

Instead of relying on resistor braking like most other controllers, the liquid-cooled 700L uses regenerative braking to generate electricity while braking. This electricity is put back into the system and used by other equipment.

A liquid-cooled heat sink transfers over 80% of the heat from the drive to the coolant, giving the unit the best drive power-to-size ratio in the market, according to the manufacturer. And it is about half the size of typical air-cooled controllers. The 700L also features an active converter and line-side filters so it will perform consistently despite power dips or other power-quality issues. It also sends 480 V to the motor even when operating on 380-Vac power lines.

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