A 3-phase 50Hz 2-pole 440V (L-L rms) induction motor drive has a rated speed of 2955 rpm and rated torque of 35 Nm. This motor drives a load with a torque characteristic that increases linearly with speed such that it equals the load torque at the rated speed. It draws a current of 3.8 A(rms) per phase at the rated voltage at a power factor of 0.85 (lagging). The stator resistance Rs = 1.9 ohms. At the rated operating speed, calculate the frequency (fbraking) of the phase voltage (Va, braking) needed produce a regenerative braking torque that is 1.4 times the rated torque in magnitude.