# US 2014/0197771 A1 · Motor control apparatus and motor control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197771 A1 - Document ID: US20140197771A1 - Status: Published application - Kind: A1 - Application number: 13/895,361 - Filed: 2013-05-16 - Published: 2014-07-17 - Earliest claimed: 2013-01-17 - Assignees: Kabushiki Kaisha Yaskawa Denki - Applicants: Kabushiki Kaisha Yaskawa Denki - Inventors: Zhenning CHEN; Tomohiro KAWACHI; Kenji TOMOHARA; Koji HIGASHIKAWA; Masashi TAKENOUCHI - Web page: https://patentgrep.com/patent/US20140197771A1 ## CPC - H02P 25/18: with arrangements for switching the windings, e.g. with mechanical switches or relays - H02P 21/0089: {using field weakening} - Y02P 80/10: Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A winding switching signal generator is configured to obtain information indicating a degree of field weakening from at least one of a current command calculator and a constant output controller, and to generate a winding switching signal for switching from a low speed rotation state to a high speed rotation state when the degree of the field weakening exceeds a predetermined condition in the low speed rotation state. ## Claims ### Claim 1 A motor control apparatus comprising: a d-axis current command value corrector configured to decrease a d-axis current command value as a command value of an exciting current component of a current flowing in an AC motor to perform field weakening; a field weakening information obtaining section configured to obtain information indicating a degree of the field weakening; and a switch command generator configured to generate a switch command from a first state to a second state when the degree of the field weakening exceeds a predetermined condition in the first state, wherein in the first state power is supplied to a coil of a first winding number arranged in the AC motor, and wherein in the second state power is supplied to a coil of a second winding number that is smaller than the first winding number. ### Claim 2 (depends on 1) The motor control apparatus according to claim 1, wherein the information indicating the degree of the field weakening indicates a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed; and the switch command generator configured to generate the switch command when the constant output amount is a predetermined threshold value or larger in the first state. ### Claim 3 (depends on 1) The motor control apparatus according to claim 1, wherein the information indicating the degree of the field weakening indicates an inclination of a combined vector of a q-axis current command value as a command value of a torque current component of the current flowing in the AC motor and the d-axis current command value from a q-axis to a d-axis in a negative direction; and the switch command generator is configured to generate the switch command when the inclination is a predetermined threshold value or larger in the first state. ### Claim 4 (depends on 1) The motor control apparatus according to claim 1, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by the d-axis current command value; and the switch command generator is configured to generate the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 5 (depends on 1) The motor control apparatus according to claim 1, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by a magnitude of a combined vector of a q-axis current command value as a command value of a torque current component of the current flowing in the AC motor and the d-axis current command value; and the switch command generator is configured to generate the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 6 (depends on 1) The motor control apparatus according to claim 1, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by the reference value; and the switch command generator is configured to generate the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 7 (depends on 1) The motor control apparatus according to claim 1, further comprising a constant output amount calculator configured to calculate a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed, based on a q-axis voltage command value as a command value of a torque voltage component of a voltage applied to the AC motor, a d-axis voltage command value as a command value of an exciting voltage component of the voltage, and a detected output voltage value of a power supply apparatus for supplying power to the AC motor. ### Claim 8 A motor control method comprising: decreasing a d-axis current command value as a command value of an exciting current component of a current flowing in an AC motor to perform field weakening; obtaining information indicating a degree of the field weakening; and generating a switch command from a first state to a second state when the degree of the field weakening exceeds a predetermined condition in the first state, wherein in the first state power is supplied to a coil of a first winding number arranged in the AC motor, and wherein in the second state power is supplied to a coil of a second winding number that is smaller than the first winding number. ### Claim 9 A motor control apparatus comprising: a d-axis current command value correcting means for decreasing a d-axis current command value as a command value of an exciting current component of a current flowing in an AC motor to perform field weakening; a field weakening information obtaining means for obtaining information indicating a degree of the field weakening; and a switch command generating means for generating a switch command from a first state to a second state when the degree of the field weakening exceeds a predetermined condition in the first state, wherein in the first state power is supplied to a coil of a first winding number arranged in the AC motor, and wherein in the second state power is supplied to a coil of a second winding number that is smaller than the first winding number. ### Claim 10 (depends on 9) The motor control apparatus according to claim 9, wherein the information indicating the degree of the field weakening indicates a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed; and the switch command generating means generates the switch command when the constant output amount is a predetermined threshold value or larger in the first state. ### Claim 11 (depends on 9) The motor control apparatus according to claim 9, wherein the information indicating the degree of the field weakening indicates an inclination of a combined vector of a q-axis current command value as a command value of a torque current component of the current flowing in the AC motor and the d-axis current command value from a q-axis to a d-axis in a negative direction; and the switch command generating means generates the switch command when the inclination is a predetermined threshold value or larger in the first state. ### Claim 12 (depends on 9) The motor control apparatus according to claim 9, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by the d-axis current command value; and the switch command generating means generates the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 13 (depends on 9) The motor control apparatus according to claim 9, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by a magnitude of a combined vector of a q-axis current command value as a command value of a torque current component of the current flowing in the AC motor and the d-axis current command value; and the switch command generating means generates the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 14 (depends on 9) The motor control apparatus according to claim 9, wherein the information indicating the degree of the field weakening indicates a quotient obtained by dividing a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed by the reference value; and the switch command generating means generates the switch command when the quotient is a predetermined threshold value or larger in the first state. ### Claim 15 (depends on 9) The motor control apparatus according to claim 9, further comprising a constant output amount calculating means for calculating a constant output amount as an amount of decreasing the d-axis current command value from a reference value determined for a case in which the field weakening is not performed, based on a q-axis voltage command value as a command value of a torque voltage component of a voltage applied to the AC motor, a d-axis voltage command value as a command value of an exciting voltage component of the voltage, and a detected output voltage value of a power supply apparatus for supplying power to the AC motor.