List the reasons for using AC drives to control the speed of AC motors.Explain the methods of controlling the speed of an AC motor and identify which one is most effective. Describe the purpose of the following sections of an AC drive:

Operator Control               Drive Controller                         AC Motor

Explain the differences among volts/Hz, AC closed-loop vector, and sensorless vector control methods. Describe the operation of the following major sections of the VAC drive:

Converter     Intermediate               Circuit Inverter

Determine the V/H ratio when frequency changes and the voltage is constant.Describe the operation of the flux vector drive.