a conventional PWM drive contains a frequency modulator. The motor is always excited by constructing a sinusoidal power signal (i.e. 50 Hz), by modulating the ON Time of pulses that are generated at the carrier frequency (typcially 2Khz to 8 Khz)
Inomax ACS580 direct torque control drive contains no frequency modulator. It functions by providing ON/OFF current control based upon torque requirement calculations as needed to achieve the required velocity. The torque or current requirements are calculated using a sophisticated algorithm that describes electro-mechanical characteristics of the motor and load. In this way, there will have better torque and the drive constantly tests the motor to determine the minimum magnetization flux required to meet the present speed and torque demands. By minimizing the magnetization flux, current consumption, hence power consumption, is further reduced.
Choose Inomax VFD means longer life time and lower electric cost.