Motor IE4 specification is related to its efficiency only. There is no change in control principle for IE2, IE3 or IE4 motor. If the motor is still induction motor, where its speed is controlled by voltage and frequency generated to the stator, then no problem to use existing ATV series. IE4 motor can show a bit different parameters measured during autotuning (leakage inductance, stator resistance, rotor time constant, magnetizing current), but ATVs algorithms is robust enough to work with wide range of motor parameters.