The paper proposes the design of a sensorless control for driving a permanent magnet synchronous motor (PMSM). The drive is fed by a current source inverter (CSI) which adopts the paralleled configuration to increase the power level. The key is to design the interleaved operation and active damping to suppress the LC resonance and reduce the low order harmonics for motor voltages and currents. Thus, the better voltage and current waveforms could provide good performance for the extended Kalman filter (EKF) to estimate the PMSM rotor position. The proposed control scheme is designed, analyzed and compared with other methods available. It has been verified that the proposed drive system can offer good operating performance by computer simulation.