Apparatus and method of driving a plurality of permanent magnet synchronous motors using single inverter

Patent metadata

Field	Value
Publication number	US-9768715-B2
Application number	US-201514624836-A
Country	US
Kind code	B2
Filing date	Feb 18, 2015
Priority date	Feb 17, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A motor driving apparatus and a method of driving a plurality of permanent magnet synchronous motor (PMSM) using a single inverter is described. The motor driving apparatus includes a single power conversion apparatus configured to supply power to a plurality of motors and a control apparatus configured to control the power conversion apparatus to adjust a phase current ratio supplied to the plurality of motors from the single power conversion apparatus according to a requirement of each of the plurality of motors.

First claim

What is claimed is:

1. A motor driving apparatus comprising:
a single power conversion apparatus configured to supply power to a plurality of motors including a single inverter configured to convert a provided Direct Current (DC) power to an Alternating Current (AC) power required by the plurality of motors and a DC link provided with a neutral point to provide the DC power to the single inverter; and
a control apparatus configured to control the single power conversion apparatus to adjust a phase current ratio supplied to the plurality of motors from the single power conversion apparatus according to an amount of current required by each of the plurality of motors,
wherein a first leg of the single inverter is connected to a first coil of a first motor of the plurality of motors, a second leg of the single inverter is connected to a second coil of the first motor, a third coil of the first motor is connected to a third coil of a second motor of the plurality of motors, and a third leg of the single inverter is connected to a first coil of the second motor, and the neutral point of the DC link is connected to a second coil of the second motor.

2. The motor driving apparatus of claim 1 , further comprising:
a first current sensor configured to detect current applied through connection between the first leg of the single inverter and the first coil of the first motor, a second current sensor configured to detect current applied through connection between the second leg of the single inverter and the second coil of the first motor, and a third current sensor configured to detect current applied through connection between the third leg of the single inverter and the first coil of the second motor.

3. The motor driving apparatus of claim 1 wherein:
the control apparatus is configured to generate a modified current command to control the power conversion apparatus to adjust the phase current ratio supplied to each of the plurality of motors from the single power conversion apparatus.

4. The motor driving apparatus of claim 3 wherein:
the generation of the modified current command comprises modifying the current command to adjust the phase current ratio applied to each of the plurality of motors according to the requirement by the plurality of motors so that an amount of current required by each of the plurality of motors is applied to the each of the plurality of motors.

5. The motor driving apparatus of claim 4 wherein:
voltage vA, vB, vC applied to the plurality of motors by the modified current command is expressed as below:
v A =( i* c2 k 1 +i* c1 k 2 +4 i* a1 +3 i* b1 +i* a2 +3 i* c2 ) Z   [Formula 1]

v B =(− i* c2 k 1 +i* c1 k 2 +3 i* a1 +4 i* b1 +i* a2 +4 i* c2 ) Z   [Formula 2]

v C =(0· k 1 +2 i* c1 k 2 +i* a1 +i* b1 +2 i* a2 +i* c2 ) Z   [Formula 3]

wherein in Formulas 1, 2, and 3, ia1*, ib1*, ic1*, ia2*, ib2*, ic2* represents the abc current command converted from the dq current command by coordinate transformation, k1 and k2 represents the phase current ratio applied to each of the plurality of motors, and Z represents stator impedance of the plurality of motors.

6. A motor driving apparatus comprising:
a single power conversion apparatus configured to supply power to a plurality of motors including a single inverter configured to convert a provided Direct Current (DC) power to an Alternating Current (AC) power required by the plurality of motors and a DC link provided with a neutral point to provide the DC power to the single inverter; and
a control apparatus configured to control the single power conversion apparatus to adjust a phase current ratio supplied from the single power conversion apparatus to each of the plurality of motors so that line voltage at least at one of a plurality of nodes at which the single power conversion apparatus and at least one of the plurality of motors are connected is at a minimum,
wherein a first leg of the single inverter is connected to a first coil of a first motor of the plurality of motors, a second leg of the single inverter is connected to a second coil of the first motor, a third coil of the first motor is connected to a third coil of a second motor of the plurality of motors, and a third leg of the single inverter is connected to a first coil of the second motor, and the neutral point of the DC link is connected to a second coil of the second motor.

7. The motor driving apparatus of claim 6 , further comprising:
a first current sensor configured to detect current applied through connection between the first leg of the single inverter and the first coil of the first motor, a second current sensor configured to detect current applied through connection between the second leg of the single inverter and the second coil of the first motor, and a third current sensor configured to detect current applied through connection between the third leg of the single inverter and the first coil of the second motor.

8. The motor driving apparatus of claim 6 wherein:
the control apparatus is configured to generate modified current command to control the power conversion apparatus to adjust the phase current ratio supplied to each of the plurality of motors from the single power conversion apparatus.

9. The motor driving apparatus of claim 8 wherein:
the generation of the modified current command comprises modifying the current command to adjust the phase current ratio applied to each of the plurality of motors according to the requirement by the plurality of motors so that an amount of current required by each of the plurality of motors is applied to the each of the plurality of motors.

10. The motor driving apparatus of claim 9 wherein:
voltage vA, vB, vC applied to the first leg, the second leg, and the third leg by the modified current command is expressed as below:
v A =( i* c2 k 1 +i* c1 k 2 +4 i* a1 +3 i* b1 +i* a2 +3 i* c2 ) Z   [Formula 1]

v B =(− i* c2 k 1 +i* c1 k 2 +3 i* a1 +4 i* b1 +i* a2 +4 i* c2 ) Z   [Formula 2]

v C =(0· k 1 +2 i* c1 k 2 +i* a1 +i* b1 +2 i* a2 +i* c2 ) Z   [Formula 3]

wherein in Formulas 1, 2, and 3, ia1*, ib1*, ic1*, ia2*, ib2*, ic2* represents the abc current command converted from the dq current command by coordinate transformation, k1 and k2 represents phase current ratio applied to each of the plurality of motors, and Z represents stator impedance of the plurality of motors.

11. The motor driving apparatus of claim 9 wherein:
voltage vA, vB, vC are represented as a time function expressed in Formulas 6, 7, and 8:

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Assignees

• Samsung Electronics Co Ltd
• Snu R&Db Foundation
• Samsung Electronics Co Ltd

Inventors

• Cho Je Hyung
• Ha Jung-Ik
• Bodrov Alexey
• Kim Youngnam

Classifications

• H02K15/00 Primary

  Processes or apparatus specially adapted for manufacturing, assembling, maintaining or repairing of dynamo-electric machines · CPC title

• H02P6/04 Primary

  Arrangements for controlling or regulating the speed or torque of more than one motor (H02P6/10 takes precedence) · CPC title

• H02K11/0073

  Electricity · mapped topic

• Y10T29/49009

  Dynamoelectric machine · CPC title

• H02P2006/045

  Control of current · CPC title