This paper proposes an improved sensorless matrix-converter IPMSM drive system using a high frequency injection method. By suitably choosing different virtual dc-bus voltages and compensating the duty cycle of the switching states, the estimated position error can be obviously reduced. A 32-bit digital signal processor, TMS-320LF-2407A, is used to execute the rotor position estimation and the whole control algorithm. Experimental results show that the estimated rotor position error is reduced from 10 to 5 electrical degrees when compared to the traditional sensorless matrix-converter. In addition, the total harmonic distortion (THD) of the output currents is reduced near 2%. As a result, the low speed responses of the proposed sensorless drive system is obviously enhanced. The adjustable speed of the sensorless IPMSM drive is from 25 r/min to 1800 r/min.