Speed control apparatus for synchronous reluctance motor

Claim 2

A speed control apparatus for a synchronous reluctance motor comprising: a voltage detector for detecting a voltage applied to the synchronous reluctance motor; a first phase converter for receiving voltages in three phases outputted from the voltage detector based on the voltage detection thereof, and converting the three-phase voltages into equivalent voltages in two phases; a current detector for detecting a current applied to the synchronous reluctance motor; a second phase converter for receiving currents in three phases outputted from the current detector based on the current detection thereof, and converting the three-phase currents into equivalent currents in two phases; a rotor speed operator for receiving the two-phase voltages outputted from the first phase converter, thereby computing a speed of a rotor included in the synchronous reluctance motor; a speed controller for receiving a deviation between a speed command externally inputted and an output value from the rotor speed operator, thereby generating a torque-related current command; a current controller for receiving 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 receiving a deviation between the torque-related current command outputted from the speed controller and a torque-related one of the two-phase currents outputted from the second phase converter, thereby outputting a torque-related voltage command along with a magnetic-flux-related voltage command; a voltage generator for converting the two-phase voltage commands, outputted from the current controller, into voltages in three phase; and an inverter for conducting a pulse width modulation for the three-phase voltages outputted from the voltage generator, and applying the resultant voltages to the synchronous reluctance motor.

Claim 3

The speed control apparatus according to claim 1 , further comprising: a magnetic command generator for receiving the output value from the rotor speed operator, thereby detecting a positive torque range and a positive output range in accordance with a rotating speed of the synchronous reluctance motor, and outputting a magnetic-flux-related current command; a magnetic flux controller for receiving a deviation between the output signal from the magnetic command generator and a magnetic-flux-related one of the two-phase currents outputted from the second phase converter, thereby conducting a magnetic flux control for the current controller to generate the magnetic-flux-related voltage command; and a magnetic flux angle operator for receiving the output value from the rotor speed operator, thereby computing a magnetic flux angle for a coordinate conversion.

Claim 4

The speed control apparatus according to claim 1 , wherein the rotor speed operator comprises: an induced voltage operator for receiving respective outputs from the first and second phase converters, thereby calculating a voltage actually induced in the motor; an excited current operator for receiving the respective outputs from the first and second phase converters, thereby calculating an excited current in the motor; an induced voltage estimating operator for receiving the outputs from the second phase converter, thereby estimating a voltage induced in the motor; an excited current estimating operator for receiving an output from the induced voltage estimating operator, thereby estimating a current excited in the motor; a first proportional-integral controller for receiving a deviation between respective outputs from the induced voltage operator and the induced voltage estimating operator, thereby conducting a proportional-integral control; and a second proportional-integral controller for receiving a deviation between respective outputs from the excited current operator and the excited current estimating operator, thereby conducting a proportional-integral control.

Claim 5

The speed control apparatus according to claim 3 , wherein said first proportional-integral controller outputs an estimated speed value.

Claim 6

The speed control apparatus according to claim 4 , wherein said estimated speed value is outputted to the induced voltage estimating operator.

Claim 7

The speed control apparatus according to claim 3 , wherein said second proportional-integral controller outputs a resultant value from said proportional-integral control to the induced voltage estimating operator to achieve an inductance compensation depending on a load applied to said motor.

Claim 8

A speed control apparatus for a synchronous reluctance motor comprising: a voltage detector for detecting a voltage applied to the synchronous reluctance motor; a first phase converter for receiving voltages in three phases outputted from the voltage detector based on the voltage detection thereof, and converting the three-phase voltages into equivalent voltages in two phases; a current detector for detecting a current applied to the synchronous reluctance motor; a second phase converter for receiving currents in three phases outputted from the current detector based on the current detection thereof, and converting the three-phase currents into equivalent currents in two phases; a rotor speed operator for receiving the two-phase voltages outputted from the first phase converter, thereby computing a speed of a rotor included in the synchronous reluctance motor; a magnetic command generator for receiving the output value from the rotor speed operator, thereby detecting a positive torque range and a positive output range in accordance with a rotating speed of the synchronous reluctance motor, and outputting a magnetic-flux-related current command; a magnetic flux controller for receiving a deviation between the output signal from the magnetic command generator and a magnetic-flux-related one of the two-phase currents outputted from the second phase converter, thereby conducting a magnetic flux control for the current controller to generate the magnetic-flux-related voltage command; and a magnetic flux angle operator for receiving the output value from the rotor speed operator, thereby computing a magnetic flux angle for a coordinate conversion.

Claim 9

A speed control apparatus for a synchronous reluctance motor comprising: a voltage detector for detecting a voltage applied to the synchronous reluctance motor; a first phase converter for receiving voltages in three phases outputted from the voltage detector based on the voltage detection thereof, and converting the three-phase voltages into equivalent voltages in two phases; a current detector for detecting a current applied to the synchronous reluctance motor; a second phase converter for receiving currents in three phases outputted from the current detector based on the current detection thereof, and converting the three-phase currents into equivalent currents in two phases; a rotor speed operator for receiving the two-phase voltages outputted from the first phase converter, thereby computing a speed of a rotor included in the synchronous reluctance motor; a magnetic command generator for receiving the output value from the rotor speed operator, thereby detecting a positive torque range and a positive output range in accordance with a rotating speed of the synchronous reluctance motor, and outputting a magnetic-flux-related current command; a magnetic flux controller for receiving a deviation between the output signal from the magnetic command generator and a magnetic-flux-related one of the two-phase currents outputted from the second phase converter, thereby conducting a magnetic flux control for the current controller to generate the magnetic-flux-related voltage command; and a magnetic flux angle operator for receiving the output value from the rotor speed operator, thereby computing a magnetic flux angle for a coordinate conversion.

Claim 10

A speed control apparatus for a synchronous reluctance motor comprising: a voltage detector for detecting a voltage applied to the synchronous reluctance motor; a first phase converter for receiving voltages in three phases outputted from the voltage detector based on the voltage detection thereof, and converting the three-phase voltages into equivalent voltages in two phases; a current detector for detecting a current applied to the synchronous reluctance motor; a second phase converter for receiving currents in three phases outputted from the current detector based on the current detection thereof, and converting the three-phase currents into equivalent currents in two phases; and a rotor speed operator for receiving the two-phase voltages outputted from the first phase converter, thereby computing a speed of a rotor included in the synchronous reluctance motor; and wherein said rotor speed operatore further includes an induced voltage operator for receiving respective outputs from the first and second phase converters, thereby calculating a voltage actually induced in the motor; an excited current operator for receiving the respective outputs from the first and second phase converters, thereby calculating an excited current in the motor; an induced voltage estimating operator for receiving the outputs from the second phase converter, thereby estimating a voltage induced in the motor; an excited current estimating operator for receiving an output from the induced voltage estimating operator, thereby estimating a current excited in the motor; a first proportional-integral controller for receiving a deviation between respective outputs from the induced voltage operator and the induced voltage estimating operator, thereby conducting a proportional-integral control; and a second proportional-integral controller for receiving a deviation between respective outputs from the excited current operator and the excited current estimating operator, thereby conducting a proportional-integral control.

Claim 11

A speed control apparatus for a synchronous reluctance motor comprising: a voltage detector for detecting a voltage applied to the synchronous reluctance motor; a first phase converter for receiving voltages in three phases outputted from the voltage detector based on the voltage detection thereof, and converting the three-phase voltages into equivalent voltages in two phases; a current detector for detecting a current applied to the synchronous reluctance motor; a second phase converter for receiving currents in three phases outputted from the current detector based on the current detection thereof, and converting the three-phase currents into equivalent currents in two phases; and a rotor speed operator for receiving the two-phase voltages outputted from the first phase converter, thereby computing a speed of a rotor included in the synchronous reluctance motor; and wherein said rotor speed operatore further includes an induced voltage operator for receiving respective outputs from the first and second phase converters, thereby calculating a voltage actually induced in the motor; an excited current operator for receiving the respective outputs from the first and second phase converters, thereby calculating an excited current in the motor; an induced voltage estimating operator for receiving the outputs from the second phase converter, thereby estimating a voltage induced in the motor; an excited current estimating operator for receiving an output from the induced voltage estimating operator, thereby estimating a current excited in the motor; a first proportional-integral controller for receiving a deviation between respective outputs from the induced voltage operator and the induced voltage estimating operator, thereby conducting a proportional-integral control; and a second proportional-integral controller for receiving a deviation between respective outputs from the excited current operator and the excited current estimating operator, thereby conducting a proportional-integral control.

Claim 12

The speed control apparatus according to claim 8 , wherein said first proportional-integral controller outputs an estimated speed value.

Claim 13

The speed control apparatus according to claim 9 , wherein said estimated speed value is outputted to the induced voltage estimating operator.

Claim 14

The speed control apparatus according to claim 8 , wherein said second proportional-integral controller outputs a resultant value from said proportional-integral control to the induced voltage estimating operator to achieve an inductance compensation depending on a load applied to said motor.

Claim 17

The method according to claim 12 , further comprising the step of determining said estimated speed value based on a deviation between said induced voltage and an estimated induced voltage.

Claim 18

The method according to claim 13 , wherein proportional-integral control is used to determine said estimated speed value.