Speed control apparatus for synchronous reluctance motor

A speed control apparatus for a synchronous reluctance motor is disclosed. The speed control apparatus includes a voltage detector for detecting a voltage applied to the motor, a first phase converter for receiving voltages in three phases from the voltage detector and converting the three-phase voltages into equivalent voltages in two phases, a current detector for detecting a current applied to the motor, a second phase converter for receiving currents in three phases from the current detector and converting the three-phase currents into equivalent currents in two phases, and a rotor speed operator for receiving the two-phase voltages thereby computing a speed of a rotor included in the motor. A speed controller for receiving a deviation between a speed command externally inputted and an output value from the rotor speed operator is provided for generating a torque-related current command. A current controller receives a deviation between a torque current command externally inputted and an output value from the rotor speed operator thereby outputting a torque-related current command. A current controller for receives a deviation between the torque-related current command and a torque-related current outputted from the second phase converter, thereby outputting a torque-related voltage command along with a magnetic-flux-related voltage command.