Apparatus for controlling rotation speed of motor

An apparatus for controlling the rotation speed of a motor, comprising:

• a first proportional integration (PI) controller for outputting reference torque component current for compensating for an error value obtained by comparing a reference speed of the motor with an estimated speed of the motor;
• a third PI controller for outputting a reference torque component voltage of the reference torque component current for compensating for the error value obtained by comparing the reference torque component current with real torque component current;
• a second PI controller for outputting a reference magnetic flux component voltage of reference magnetic flux component current for compensating for the error value obtained by comparing the reference magnetic flux component current with real magnetic flux component current;
• a synchronous/stationary coordinate converter for receiving the reference magnetic flux component voltage output from the second PI controller and the reference torque component voltage output from the third PI controller and outputting a reference voltage of the α axis in the stationary coordinate system and a reference voltage of the β axis in the stationary coordinate system;
• a three phase voltage generator for converting the reference voltage of the α axis in the stationary coordinate system and the reference voltage of the β axis in the stationary coordinate system output from the synchronous/stationary coordinate converter into three phase voltage;
• an inverter for applying the three phase voltage to the motor;
• a two phase current generator for converting the three phase current applied to the motor into two phase current;
• a speed/position estimation operator for outputting the estimated speed of the motor and the sine and cosine values sin θ and cos θ of the magnetic flux angle θ of a rotor of the motor on the basis of the reference voltage of the α axis, the reference voltage of the β axis, the two phase current, and the reference speed, wherein an induced voltage of a fundamental wave component from the current of the α axis and the current of the β axis is extracted;
• and
• a stationary/synchronous coordinate converter for receiving the two phase current and the sine and cosine values sin θ and cos θ, converting the two phase current and the sine and cosine values sin θ and cos θ into a stationary coordinate system, and outputting the real torque component current and the real magnetic flux component current.

An apparatus for controlling rotation speed of a motor, comprising:

• a first subtracter for comparing a reference speed of the motor with an estimated speed of the motor and outputting an error value according to the comparison result;
• a first PI controller for outputting reference torque component current for compensating for the error value;
• a third subtracter for comparing the reference torque component current with real torque component current and outputting an error value according to the comparison result;
• a third PI controller for outputting a reference torque component voltage of the reference torque component current for compensating for the error value output from the third subtracter;
• a second subtracter for comparing reference magnetic flux component current with real magnetic flux component current and outputting an error value according to the comparison result;
• a second PI controller for outputting a reference magnetic flux component voltage of the reference magnetic flux component current for compensating for the error value output from the second subtracter;
• a synchronous/stationary coordinate converter for receiving the reference magnetic flux component voltage output from the second PI controller and the reference torque component voltage output from the third PI controller and outputting a reference voltage of the α axis in the stationary coordinate system and a reference voltage of the β axis in the stationary coordinate system;
• a three phase voltage generator for converting the reference voltage of the α axis in the stationary coordinate system and the reference voltage of the β axis in the stationary coordinate system output from the synchronous/stationary coordinate converter into a three phase voltage and outputting the three phase voltage;
• an inverter for applying the three phase voltage generated by the three phase voltage generator to the motor;
• a two phase current generator for converting the three phase current applied to the motor into two phase current and outputting the two phase current;
• a speed/position estimation operator for receiving the reference voltage of the α axis, the reference voltage of the β axis, the two phase current, and the reference speed, wherein an induced voltage of a fundamental wave component from the current of the α axis and the current of the β axis is extracted, estimating a position and the speed of the motor, and outputting the estimated speed of the motor and a sine and cosine values of a magnetic flux angle of a rotor of the motor;
• and
• a stationary/synchronous coordinate converter for receiving the two phase current and the sine and cosine values, converting the two phase current and the sine and cosine values into a synchronous coordinate system, and outputting the real torque component current and the real magnetic flux component current.