Method and system for controlling motor

A system for controlling a motor, comprising:

• a brushless direct-current (DC) motor including a plurality of stator coils having different phases;
• an inverter configured to provide currents having different phases to the stator coils of the brushless DC motor;
• a plurality of Hall effect sensors configured to detect a position of a rotor of the brushless DC motor;
• a counter electromotive force detector configured to detect a counter electromotive force of at least one of the stator coils having the different phases;
• and
• a motor controller configured to adjust a speed of the brushless DC motor based on the output from the Hall effect sensors in response to determining that no output error of the Hall effect sensors occurs, stopping adjustment of the speed of the brushless DC motor based on the output from the Hall effect sensors in response to detecting the output error from the Hall effect sensors, and adjusting the speed of the brushless DC motor based on the counter electromotive force detected by the counter electromotive force detector,
• wherein the counter electromotive force detector is configured to detect a counter electromotive force of a non-excited phase of the different phases of the stator coils, and the motor controller is configured to estimate counter electromotive forces of another of the stator coils using predetermined phase differences between the stator coil of which the counter electromotive force is detected and another of the stator coils, and operate the motor based on the counter electromotive force detected by the counter electromotive force detector and the estimated electromotive forces.