What is minimum frequency that VFD can run?
A VFD (or VSD) can operate down to its minimum designed frequency, however the motor design and load characteristics determine the minimum PRACTICAL frequency. If the motor is force cooled and the variable frequency drive is operated in vector mode, as long as there is encoder feedback, and the load is not excessive, it is possible to achieve 100% torque at zero frequency.
Some manufacturers' variable frequency drives can provide 100% torque at Zero speed without an encoder. A properly rated and designed motor can be provided to operate at Zero speed, full torque (often called 1000:1 speed range motors). This is a very typical motor requirement for Paper Winders and Rewinders, and Steel Coilers and Uncoilers.
Some manufacturers' variable frequency drives can provide 100% torque at Zero speed without an encoder. A properly rated and designed motor can be provided to operate at Zero speed, full torque (often called 1000:1 speed range motors). This is a very typical motor requirement for Paper Winders and Rewinders, and Steel Coilers and Uncoilers.
