In this paper, the authors propose a solution to unbalance problem of the input DC voltages of the five-level NPC-VSI used in a three-level PWM current rectifier – Five-level NPC VSI – PMSM cascade. The three-level rectifier is controlled by Lyapunov function and the speed control of the permanent magnet synchronous machine is realised using sliding mode control. The five-level NPC-VSI control is based on a pulse width modulation using four bipolar carriers. This study shows particularly the problem of the stability of the DC voltages of the inverter and its consequence on the performances of the PMSM speed control. Then, we propose a solution to the problem of four capacitance voltages instability by employed an inductive circuit to stabilise the four DC input voltages of the Five-level NPC-VSI.