GUIDE TO THE
REGENERATIVE APPLICATION
SINUS PENTA
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3.6.
Dimensioning the Regenerative Drive
The correct match between the regenerative drive and the motor drive is given
—in most cases—in the
application tables in the previous sections. If a special application is not included in the tables, you need to
check the regenerative drive dimensioning.
The same dimensioning must be worked out when the application comprises multiple motor drives.
Basically, the power exchanged with the mains
—both in continuous operation and when the drive is
overloaded
—must be lower than or equal to the drive rated power and peak power respectively.
a) Continuous Operation
The power exchanged with the mains in continuous operation (Pconrgn) is as follows:
Pconrgn= Pmot + motor drive regenerative drive losses.
- Pmot is the electric power absorbed by the motor;
- Loss values are given in the tables containing the drive specifications (the motor drive losses are supposed
to be the same as the regenerative drive losses).
The electric power absorbed by the motor can be calculated as follows:
Pmot= Mechanical power/motor efficiency
or
Pmot=1.73*Vmot*Imot*power factor
where:
Vmot: rated motor voltage
Imot: rated motor current
power factor: rated motor power factor
b) Overload
The power obtained when the drive is overloaded (Polrgn) is as follows:
Polrgn= overloaded motor drive overloaded regenerative drive losses
The electric power required when the motor is overloaded is as follows:
Polmot=1.73*Vmot*Ilim*power factor
where Ilim is the limit current for the drive controlling the motor.
Loss values are given in the tables containing the drive specifications (the motor drive losses are supposed
to be the same as the regenerative drive losses) and should be increased by the ratio between the overload
current and the rated current (Ilim/Imot).