# US 12,113,450 B2 · Power conversion device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,450 B2 - Document ID: US12113450B2 - Status: Granted - Kind: B2 - Application number: 17/679,084 - Filed: 2022-02-24 - Published: 2022-09-01 - Granted: 2024-10-08 - Earliest claimed: 2021-02-26 - Applicants: Kabushiki Kaisha Yaskawa Denki - Inventors: Keisei Inoki; Takahiro Saeki; Toshihiro Hanada; Kengo Nakahara; Hideaki Iura - Web page: https://patentgrep.com/patent/US12113450B2 ## CPC - H02M 5/458: using semiconductor devices only - H02P 21/05: specially adapted for damping motor oscillations, e.g. for reducing hunting - H02P 1/26: for starting an individual polyphase induction motor - H02P 21/22: Current control, e.g. using a current control loop - H02P 25/16: characterised by the circuit arrangement or by the kind of wiring - H02P 27/04: using variable-frequency supply voltage, e.g. inverter or converter supply voltage - H02P 29/028: the motor continuing operation despite the fault condition, e.g. eliminating, compensating for or remedying the fault - H02P 2207/01: Asynchronous machines - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract The power conversion device may include: power conversion circuitry configured to perform a power conversion for outputting a driving power to an induction motor; and control circuitry. The control circuitry may be configured to: receive a master command phase from a master power conversion device; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving a rotor of the induction motor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the induction motor, in synchronization with the master power conversion device, based on the rotation phase and the voltage command. ## Claims ### Claim 1 A power conversion device comprising: power conversion circuitry configured to perform a power conversion for outputting a driving power to an induction motor; a communication interface configured to receive one or more signals from a master power conversion device; and control circuitry configured to: receive a master command phase from the communication interface based, at least in part, on the one or more signals from the master power conversion device; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving a rotor of the induction motor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the induction motor, based on the rotation phase and the voltage command, so that the rotating magnetic field is in synchronization with a master rotating magnetic field generated by the master power conversion device. ### Claim 2 (depends on 1) The power conversion device according to claim 1, wherein the communication interface is further configured to receive one or more second signals from the master power conversion device, and wherein the control circuitry is further configured to: receive a master rotation phase from the communication interface based, at least in part, on the one or more second signals from the master power conversion device; calculate the rotation phase based on a rotation phase difference between the master rotation phase and the rotation phase to reduce the rotation phase difference if a coordinate rotation speed of the rotating coordinate system is less than a first threshold; and calculate the rotation phase based on the command phase difference if the coordinate rotation speed is greater than a second threshold that is equal to or higher than the first threshold. ### Claim 3 (depends on 2) The power conversion device according to claim 2, wherein the control circuitry is further configured to: calculate the rotation phase based on a weighted average value of the command phase difference and the rotation phase difference if the coordinate rotation speed is between the first threshold and the second threshold; and gradually decrease a weight of the rotation phase difference and gradually increase a weight of the command phase difference as the coordinate rotation speed approaches the second threshold from the first threshold. ### Claim 4 (depends on 2) The power conversion device according to claim 2, wherein the control circuitry is further configured to: calculate the rotation phase based on a torque target value, a rotor speed of the induction motor, and the rotation phase difference if the coordinate rotation speed is less than the first threshold; and calculate the rotation phase based on the torque target value, the rotor speed, and the command phase difference if the coordinate rotation speed is greater than the second threshold. ### Claim 5 (depends on 4) The power conversion device according to claim 4, wherein the control circuitry is further configured to: calculate an angular frequency command value of the rotating coordinate system based on the torque target value and the rotor speed; correct the angular frequency command value based on the rotation phase difference if the coordinate rotation speed is less than the first threshold; correct the angular frequency command value based on the command phase difference if the coordinate rotation speed is greater than the second threshold; and calculate the rotation phase by integrating the corrected angular frequency command value. ### Claim 6 (depends on 2) The power conversion device according to claim 2, wherein the one or more second signals received from the master power conversion device comprise a sine value of the master rotation phase and a cosine value of the master rotation phase, and wherein the control circuitry is further configured to calculate the rotation phase based on the sine value and the cosine value if the coordinate rotation speed is less than the first threshold. ### Claim 7 (depends on 6) The power conversion device according to claim 6, wherein the control circuitry is further configured to detect an abnormality of a communication for receiving the sine value and the cosine value based on a square sum of the sine value and the cosine value. ### Claim 8 (depends on 7) The power conversion device according to claim 7, wherein the control circuitry is further configured to detect an abnormality of a second communication for receiving the master command phase if the master command phase is smaller than a predetermined level. ### Claim 9 (depends on 2) The power conversion device according to claim 2, wherein the communication interface is further configured to receive one or more third signals from the master power conversion device, and wherein the control circuitry is further configured to: receive a master torque target value from the communication interface based, at least in part, on the one or more third signals from the master power conversion device; calculate the torque target value based on the master torque target value; and generate the voltage command based on the calculated torque target value. ### Claim 10 (depends on 7) The power conversion device according to claim 7, wherein the control circuitry is further configured to: detect an abnormality of the communication interface a based on the rotation phase difference if the coordinate rotation speed is less than the first threshold; and detect the abnormality of the communication based on the command phase difference if the coordinate rotation speed is greater than the second threshold. ### Claim 11 (depends on 1) The power conversion device according to claim 1, wherein the power conversion circuitry is a matrix converter circuitry configured to perform bidirectional AC-AC power conversion. ### Claim 12 (depends on 1) The power conversion device according to claim 1, wherein the control circuitry is further configured to calculate the rotation phase based on the torque target value, a rotor speed of the induction motor, and the command phase difference. ### Claim 13 (depends on 12) The power conversion device according to claim 12, wherein the control circuitry is further configured to: calculate an angular frequency command value of the rotating coordinate system based on the torque target value and the rotor speed of the induction motor; correct the angular frequency command value based on the command phase difference to reduce the command phase difference; and calculate the rotation phase by integrating the corrected angular frequency command value. ### Claim 14 (depends on 1) A power conversion device according to claim 1, wherein the power conversion device is configured to operate as the master power conversion device in a first mode, or as a second power conversion device in a second mode, based on a mode selection input, wherein the control circuitry, in the first mode, is configured to: generate a master voltage command having the master command phase in a master rotating coordinate system that rotates with the rotor; and control the power conversion circuitry to output a master driving power to the induction motor based on the master voltage command, and wherein the control circuitry, in the second mode, is configured to: generate the voltage command based on the torque target value; calculate the rotation phase based on the command phase difference to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the induction motor based on the rotation phase and the voltage command. ### Claim 15 (depends on 1) A control system comprising: the power conversion device according to claim 1; and the master power conversion device, wherein the master power conversion device comprises: a master communication interface communicatively coupled with the communication interface of the power conversion device; master power conversion circuitry configured to perform a master power conversion for outputting a master driving power to the induction motor; and master control circuitry configured to: generate a master voltage command having the master command phase in a master rotating coordinate system that rotates with the rotor; control the master power conversion circuitry to output the master driving power to the induction motor, based on the master voltage command; and cause the master communication interface to transmit the one or more signals to the communication interface of the power conversion device based, at least in part, on the master command phase of the master voltage command. ### Claim 16 (depends on 15) A drive system comprising: the control system according to claim 15; and the induction motor, wherein the induction motor includes a first group of primary coils and a second group of primary coils, wherein the master power conversion circuitry is configured to output the master driving power to the first group of primary coils, and wherein the power conversion circuitry is configured to output the driving power to the second group of primary coils. ### Claim 17 A power conversion method comprising: generating a first voltage command having a first command phase in a first rotating coordinate system based on a first torque target value, wherein a first rotating magnetic field for driving a rotor of an induction motor is generated to rotate with the first rotating coordinate system; calculating a first rotation phase of the first rotating coordinate system based on a first torque target value and a rotor speed of an induction motor; outputting a first driving power to the induction motor based on the first rotation phase and the first voltage command; generating a second voltage command having a command phase in a second rotating coordinate system based on a second torque target value, wherein a second rotating magnetic field for driving the rotor of the induction motor is generated to rotate with the second rotating coordinate system; calculating a second rotation phase of the second rotating coordinate system based on a command phase difference between the first command phase and the command phase to reduce the command phase difference; and outputting a second driving power to the induction motor, based on the second rotation phase and the second voltage command, so that the second rotating magnetic field is in synchronization with the first rotating magnetic field. ### Claim 18 (depends on 17) The power conversion method according to claim 17, further comprising calculating the second rotation phase based on a rotation phase difference between the first rotation phase and the second rotation phase to reduce the rotation phase difference if a coordinate rotation speed of the second rotating coordinate system is less than a first threshold, wherein the second rotation phase is calculated based on the command phase difference if the coordinate rotation speed is greater than a second threshold that is equal to or greater than the first threshold. ### Claim 19 A non-transitory memory device having instructions stored thereon that, in response to execution by a power conversion device, cause the power conversion device to perform operations comprising: receiving one or more signals from a master power conversion device; determining a master command phase from the one or more signals, wherein the master command phase indicates a phase of a master voltage command in a master rotating coordinating system of the master power conversion device; generating a voltage command having a command phase in a rotating coordinate system of the power conversion device based on a torque target value, wherein a rotating magnetic field for driving a rotor of an induction motor is generated to rotate with the rotating coordinate system; calculating a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and controlling a power conversion circuitry to output a driving power to the induction motor, based on the rotation phase and the voltage command, so that the rotating magnetic field is in synchronization with a master rotating magnetic field generated by the master power conversion device. ### Claim 20 (depends on 19) The non-transitory memory device according to claim 19, wherein the operations further comprise: receiving one or more second signals from the master power conversion device; determining a master rotation phase from the one or more second signals, wherein the master rotation phase indicates another phase in the master rotating coordinate system of the master power conversion device; and calculating the rotation phase based on a rotation phase difference between the master rotation phase and the rotation phase of the power conversion device to reduce the rotation phase difference if a coordinate rotation speed of the rotating coordinate system is less than a first threshold, and wherein the rotation phase is calculated based on the command phase difference if the coordinate rotation speed is greater than a second threshold that is equal to or greater than the first threshold.