DC-link / braking / regeneration

Unidrive DC Bus and Braking Path

Routes Over Volts evidence through line voltage, DC bus, load regeneration, deceleration ramp, brake resistor, brake chopper and feedback-induced instability.

Functional path

Input supply

Rectifier

DC-link capacitors

Brake chopper

Brake resistor

Regenerative load

Feedback loop

Diagnostic signals and checkpoints

Over VoltsDecel eventBrake resistor stateDC bus trendLine voltageLoad inertia

Technician notes

Deceleration overvoltage is not solved by repeatedly resetting the drive.
A noisy feedback loop can pump energy into the DC bus in closed-loop systems.