What is a variable frequency drive, and how does it work? A variable frequency drive controls the speed of an AC motor by varying the frequency and voltage supplied to the motor. They work by taking ...

AC motor drives can also be classified based on types of control functions (e.g. integral motion controllers, variable speed drives, motor speed controllers, etc.). There are a wide range of design ...

When the Washington State Ferry System selected a synchronous, variable-speed AC motor with a cycloconverter drive for the propulsion system on its three new Jumbo Mark II ferries, the ships ...