This option, which is also provided by some manufacturers of VFDs, uses the energy stored in the mechanical load to keep the DC bus voltage from dropping down to the trip level. This is accomplished by running the inverter section during a voltage sag at a frequency slightly below the motor frequency, causing the motor to act as a generator. Similar to the flying restart option, the motor speed will drop while it is acting as a generator,
however the advantage is that the motor is never disconnected from the drive. This option works best for those high-inertia loads .
In Altivar drives the similar function like Kinetic buffering function is availabe, the parameter named as control stop on power loss, attached is the extracted page of the programming manual has the details about the setting of Under V.prevention (StP) parameter. When selected StP=MMS, the stop mode uses the inertia to maintain the DC bus voltage as long as possible.
however the advantage is that the motor is never disconnected from the drive. This option works best for those high-inertia loads .
In Altivar drives the similar function like Kinetic buffering function is availabe, the parameter named as control stop on power loss, attached is the extracted page of the programming manual has the details about the setting of Under V.prevention (StP) parameter. When selected StP=MMS, the stop mode uses the inertia to maintain the DC bus voltage as long as possible.
Released for:Schneider Electric India
