This paper describes the vector control of a high capacity power slip-energy recovery induction machine drive below and above the synchronous speed. Using an x and y rotating reference frame with an x-axis coincides with the stator vector flux. The stator and rotor variables are transformed on to this reference frame first. The nonlinear equations of the drive system are derived based on the separate and stable control of active and reactive powers. To improve the drive system performance, a trapezoidal modulated current source inverter is used in the rotor circuit with a less varible power factor and lower harmonic pollution. This also helps to reduce the torque ripples and the torsional mode resonances especially for the generating modes of operation. A step by step computer program has been developed in order to simulate the drive system on PC. The simulation results are obtained for a high power capacity drive system in the motoring and generating modes of operation (below and above the synchronous speed).