cyclogramRegeneration and cyclogram terms
The words of steps 5 and 6 — the braking energy and the drive that takes it, and the move as a bar on your cyclogram — each with what it means and what is typical. Try any of them in the calculator.
Energy the drive can absorb Bus capacitance Bus voltage Chopper threshold Regeneration efficiency The move back Time back Row name
Energy the drive can absorb
How much braking energy the drive's DC bus capacitors can take in before the voltage reaches the brake chopper's threshold.
- Unit
- J
- Typical
- 10 – 30 J for a small drive, 50 – 200 J for a large one
The drive's data sheet gives it, or work it out from the capacitance and the two voltages below.
Bus capacitance
The capacitance of the drive's DC bus.
- Unit
- µF
- Typical
- 500 – 2 000 µF for a small drive
With the bus voltage and the chopper threshold it gives the energy the bus can take: ½·C·(V_max² − V_bus²).
Bus voltage
The DC bus voltage while nothing is braking — the mains voltage rectified, √2 times its RMS value.
- Unit
- V
- Typical
- about 320 V on a 230 V supply, 565 V on 400 V
Chopper threshold
The bus voltage at which the drive switches the brake resistor in.
- Unit
- V
- Typical
- about 390 V on a 230 V supply, 760 V on 400 V
The capacitors absorb energy between the bus voltage and this threshold; beyond it the resistor must burn the rest.
Regeneration efficiency
The share of the braking work that reaches the DC bus; the motor's copper losses and the drive's losses take the rest.
- Typical
- 0.8 – 0.95
The move back
What the bar's ramp-down is: the same move in reverse, nothing (the bar stays up), or a time of your own.
- Typical
- the same move back for an axis that returns; none for an index that carries on
A cyclogram bar is travel: ramp-up out, body at the end position, ramp-down back.
Time back
How long the move back takes, when it is not the same as the move out.
- Unit
- s
- Typical
- the move time, or longer for a slower return
Row name
The name of the lane the move lands on in your cyclogram.
- Typical
- what the actuator is called on the machine: "Feeder X", "Lift Z"
Blank takes the calculation's name.