As I know it, a VSD alters the frequency to change the speed of a motor. I also understand that since the back emf of the rotor is directly proportional to the speed of the rotor, the slower the motor runs the higher the overall current there is going to be. Which explains why current is higher at starting of the motor, or at stand still altogether.
However, I've heard that the VSD can limit the current at starting of the motor whilst the motor accelerates from low speed to high speed. How is this possible? How does the VSD control the current of the motor whilst the motor is running slower than usual?