A motor driving apparatus comprising: an inverter to convert a direct current, DC, voltage into an alternating current, AC, voltage and to output the AC voltage to a motor; an output current detector to detect output current flowing in the motor; a first analog filter to pass a first output current corresponding to high-frequency signal injection of the detected output current; a second analog filter to block the first output current of the detected output current and to pass a second output current of the detected output current; and an inverter controller to control the inverter, wherein the inverter controller is configured to: inject a high-frequency voltage command value at the output side of a voltage command generator; output an inverter switching control signal based on said high-frequency signal injection, estimate a position and a rotator speed of a rotator of the motor based on the output current filtered by the first analog filter and a delay compensation value for compensating for delay of the first analog filter, generate a current command value based on the estimated rotator speed and a speed command value, generate a voltage command value based on the current command value and the second output current filtered by the second analog filter, and output the inverter switching control signal based on the voltage command value and on the high-frequency voltage command value. an inverter to convert a direct current, DC, voltage into an alternating current, AC, voltage and to output the AC voltage to a motor; an output current detector to detect output current flowing in the motor; a first analog filter to pass a first output current corresponding to high-frequency signal injection of the detected output current; a second analog filter to block the first output current of the detected output current and to pass a second output current of the detected output current; and an inverter controller to control the inverter, wherein the inverter controller is configured to: inject a high-frequency voltage command value at the output side of a voltage command generator; output an inverter switching control signal based on said high-frequency signal injection, estimate a position and a rotator speed of a rotator of the motor based on the output current filtered by the first analog filter and a delay compensation value for compensating for delay of the first analog filter, generate a current command value based on the estimated rotator speed and a speed command value, generate a voltage command value based on the current command value and the second output current filtered by the second analog filter, and output the inverter switching control signal based on the voltage command value and on the high-frequency voltage command value. inject a high-frequency voltage command value at the output side of a voltage command generator; output an inverter switching control signal based on said high-frequency signal injection, estimate a position and a rotator speed of a rotator of the motor based on the output current filtered by the first analog filter and a delay compensation value for compensating for delay of the first analog filter, generate a current command value based on the estimated rotator speed and a speed command value, generate a voltage command value based on the current command value and the second output current filtered by the second analog filter, and output the inverter switching control signal based on the voltage command value and on the high-frequency voltage command value.