Regen Overview - Danfoss VLT HVAC Drive FC 102 Design Manual

Product Features
manner can reduce the need for external dynamic brake resistors, while also saving energy. The number of units
that can be connected in this way is infinite, as long as each unit has the same voltage rating. In addition,
depending on the size and number of units, it may be necessary to install DC reactors and DC fuses in the DC-link
connections, and AC reactors on the mains. Attempting such a configuration requires specific considerations.
•
The drive is powered exclusively from a DC source. This configuration requires:
- A DC source.
-
A means to soft charge the DC bus at power-up.

5.7 Regen Overview

Regen typically occurs in applications with continuous braking such as cranes/hoists, downhill conveyors, and centrifuges
where energy is pulled out of a decelerated motor.
The excess energy is removed from the drive using 1 of the following options:
•
Brake chopper allows the excess energy to be dissipated in the form of heat within the brake resistor coils.
•
Regen terminals allow a third-party regen unit to be connected to the drive, allowing the excess energy to be
returned to the power grid.
Returning excess energy back to the power grid is the most efficient use of regenerated energy in applications using
continuous braking.
MG16C302
Design Guide
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