Control device and method for improving voltage utilization ratio of inverter for green car

Patent metadata

Field	Value
Publication number	US-9584057-B2
Application number	US-201414569655-A
Country	US
Kind code	B2
Filing date	Dec 13, 2014
Priority date	Jul 2, 2014
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A control device and a control method can improve a voltage utilization ratio of an inverter for a green car, in which an input DC voltage of the inverter is modulated by a maximum amount into an output AC voltage of the inverter by changing the output AC voltage incapable of being linearly output into a voltage capable of being linearly output. The control method includes steps of: generating a two-phase current command having two phases of a first current command and a second current command; generating a two-phase voltage command having two phases of a first voltage command and a second voltage command; generating a three-phase pole voltage command; modulating the three-phase pole voltage command into a linear output voltage capable of being linearly output; and calculating a voltage gain value, using the two-phase voltage command and an input DC voltage of the inverter.

First claim

What is claimed is:

1. A control device for improving a voltage utilization ratio of an inverter for a green car, the control device comprising:
a current command map unit configured to receive a torque command and a reverse magnetic flux value, input from a motor, to generate a two-phase current command (Idq_ref) having two phases of a first current command (D-axis current command) and a second current command (Q-axis current command);
a current controller configured to receive the two-phase current command (Idq_ref) and generate a two-phase voltage command (Vdqref) having two phases of a first voltage command and a second voltage command;
a command conversion unit configured to receive the two-phase voltage command (Vdqref) input from the current controller to generate a three-phase pole voltage command (Vabcn_ref);
a first over-modulator configured to modulate the three-phase pole voltage command (Vabcn_ref) input from the command conversion unit into a voltage capable of being linearly output;
a high gain calculator configured to receive the two-phase voltage command (Vdqref) of the current controller and an input DC voltage (VdcLPF) of the inverter to calculate a voltage gain value;
a multiplicator configured to multiply an output value of the first over-modulator by an output of the high gain calculator; and
a second over-modulator configured to receive an output value of the multiplicator to modulate the received output value into a voltage capable of being linearly output.

2. The control device of claim 1 , wherein, the output value of the multiplicator is a voltage incapable of being linearly output, the second over-modulator corrects the output value of the multiplicator as a final linear output voltage by changing the command voltage vector of the output value of the multiplicator into a predetermined vector.

3. The control device of claim 1 , wherein the command conversion unit includes:
a phase converter configured to receive the two-phase voltage command (Vdqref) input from the current controller to convert the received two-phase voltage command (Vdqref) into a three-phase phase voltage command (Vabcs_ref); and
a space vector modulator configured to convert the three-phase phase voltage command (Vabcs_ref) input from the phase converter into a three-phase pole voltage command (Vabcn_ref).

4. The control device of claim 3 , wherein, if the three-phase pole voltage command (Vabcn_ref) input from the space vector modulator is a voltage incapable of being linearly output, the first over-modulator corrects the three-phase pole voltage command (Vabcn_ref) as a linear output voltage capable of being linearly output by changing a command voltage vector of the three-phase pole voltage command (Vabcn_ref) input from the space vector modulator into a predetermined vector.

5. The control device of claim 1 , wherein the high gain calculator calculates a magnitude value (|Vdqref|) of the two-phase voltage command (Vdqref), calculates a difference value (VmagErr) between the magnitude value (|Vdqref|) of the two-phase voltage command and the input DC voltage (VdcLPF) of the inverter through

V
magErr

=



V
dqref



-

VdcLPF

3

,

and then calculates a voltage gain value by integrating the difference value (VmagErr).

6. A control method for improving a voltage utilization ratio of an inverter for a green car, the control method comprising:
receiving, by a current command map unit, a torque command and a reverse magnetic flux value, input from a motor, to generate a two-phase current command (Idq_ref) having two phases of a first current command and a second current command;
receiving, by a current controller, the two-phase current command (Idq_ref) to generate a two-phase voltage command (Vdqref) having two phases of a first voltage command and a second voltage command, using the two-phase current command (Idq_ref);
generating, by a command conversion unit, a three-phase pole voltage command (Vabcn_ref), using the two-phase voltage command (Vdqref);
modulating, by a first over-modulator, the three-phase pole voltage command (Vabcn_ref) into a linear output voltage capable of being linearly output;
calculating, by a high gain calculator, a voltage gain value, using the two-phase voltage command (Vdqref) and an input DC voltage (VdcLPF) of the inverter;
outputting, by a multiplicator, a multiplication value by multiplying the linear output voltage by the voltage gain value; and
receiving, by a second over-modulator, the multiplication value to modulate the received multiplication value into a final linear output voltage capable of being linearly output.

7. The control method of claim 6 , wherein, in the modulating of the multiplication value into the final linear output voltage, if it is recognized that the multiplication value is a voltage incapable of being linearly output, the multiplication value is corrected as a final linear output voltage capable of being linearly output by changing the command voltage vector of the multiplication value into a predetermined vector.

8. The control method of claim 6 , wherein the generating of the three-phase electrode voltage (Vabcn_ref) includes:
converting, by a phase converter, the two-phase voltage command (Vdqref) into a three-phase voltage command (Vabcs_ref); and
converting, by a space vector modulator, the three-phase phase voltage command (Vabcs_ref) into the three-phase pole voltage command (Vabcn_ref).

9. The control method of claim 6 , wherein, in the modulating of the three-phase pole voltage command (Vabcn_ref) into the linear output voltage, if it is recognized that the three-phase pole voltage command (Vabcn_ref) is a voltage incapable of being linearly output, the three-phase pole voltage command (Vabcn_ref) is corrected as a linear output voltage capable of being linearly output by changing a command voltage vector of the three-phase pole voltage command (Vabcn_ref) input from a space vector modulator into a predetermined vector.

10. The control method of claim 6 , wherein, in the calculating of the voltage gain value, a magnitude value (|Vdqref|) of the two-phase voltage command (Vdqref) is calculated, a difference value (VmagErr) between the magnitude value (|Vdqref|) of the two-phase voltage command and the input DC voltage (VdcLPF) of the inverter is calculated through

V
magErr

=



V
dqref



-

VdcLPF

3

,

and a voltage gain value is then calculated by integrating the difference value (VmagErr).

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Kim Sung Kyu
• Kwak Mu Shin
• Park Hong Geuk
• Bae Su Hyun

Classifications

• H02P21/22 Primary

  Current control, e.g. using a current control loop · CPC title

• Y02T10/7258

  Cross-Sectional Technologies · mapped topic

• B60L15/00

  Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles · CPC title

• Y02T10/644

  Cross-Sectional Technologies · mapped topic

• H02P27/08

  with pulse width modulation · CPC title