Voltage control method for an electric motor control system

• US 6,047,787 A
• Filed: 02/03/1998
• Issued: 04/11/2000
• Est. Priority Date: 02/03/1998
• Status: Expired due to Term

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Ecostar Electric Drive Systems, LLC
• Inventors: Kambouris, Christos Aristotles, Deng, Doug D., Harmon, Kent Michael
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US09/017,934
• Time in Patent Office: 798 Days
• Field of Search: 180/165, 180/65.1, 180/65.2, 180/65.3, 180/65.4, 180/65.6, 180/65.7, 180/65.8, 318/139, 318/140, 318/141, 290/9, 290/10, 290/11, 290/14, 290/16, 290/17, 290/45, 477/2, 477/3, 477/4
• US Class Current: 180/165
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 7/16 for vehicles comprising converters between the power source and the motor

Abstract

A method for controlling regenerative energy in a system having an motor and having a power converter for converting regenerative energy from the motor for supply as electrical current to a receiving apparatus includes estimating a resistance to electrical current flow between the electrical power converter and the receiving apparatus and measuring a first voltage at the receiving apparatus. The method further comprises controlling a regenerative current from the power converter to the receiving apparatus in view of the resistance and the first voltage to limit a second voltage at the power converter.

Claims

1. A method for controlling regenerative energy in an electrically-propelled vehicle having a motor and having a power converter for converting regenerative energy from said motor for supply to a battery, said method comprising the steps of:

(a) estimating a resistance to electrical current flow between said electrical power converter and said battery;

(b) measuring a terminal voltage of said battery;

(c) controlling a regenerative current from said power converter to said battery in view of said resistance and said terminal voltage to limit a voltage at said power converter.

2. A method as recited in claim 1, wherein estimating a resistance to electrical current flow further comprises:

measuring a voltage V₁ at said power converter at a first time;

measuring a current I₁ between said power converter and said battery at said first time;

measuring a voltage V₂ at said power converter at a second time;

measuring a current I₂ between said power converter and said battery at said second time; and

calculating said resistance as a difference between V₂ and V₁, divided by a difference between I₂ and I₁.

3. A method as recited in claim 2, wherein estimating a resistance further comprises employing an initial resistance estimate at an initial time, said initial estimate representing a nominal internal resistance of said battery as a function of a state of charge of said battery at said initial time.

4. A method as recited in claim 2, wherein estimating a resistance further comprises employing an initial resistance estimate at an initial time, said initial estimate representing a nominal internal resistance of said battery as a function of a temperature of said battery at said initial time.

5. A method as recited in claim 2, wherein estimating a resistance further comprises employing an initial resistance estimate at an initial time, said initial estimate representing a nominal internal resistance of said battery as a function of a state of charge and a temperature of said battery at said initial time.

6. A method as recited in claim 1, wherein said step of controlling a regenerative current comprises limiting said regenerative current to maintain said voltage at said power converter below a predetermined threshold.

7. A method as recited in claim 2, wherein said step of controlling a regenerative current comprises limiting said regenerative current to maintain said voltage at said power converter below a predetermined threshold.

8. A method as recited in claim 5, wherein said step of controlling a regenerative current comprises limiting said regenerative current to maintain said voltage at said power converter below a predetermined threshold.

9. A method for controlling regenerative energy in a system having an motor and having a power converter for converting regenerative energy from said motor for supply as electrical current to a receiving apparatus, said method comprising the steps of:

(a) estimating a resistance to electrical current flow between said electrical power converter and said receiving apparatus;

(b) measuring a first voltage at said receiving apparatus;

(c) controlling a regenerative current from said power converter to said receiving apparatus in view of said resistance and said first voltage to limit a second voltage at said power converter.

10. A method as recited in claim 9, wherein estimating a resistance to electrical current flow further comprises:

measuring a voltage V₁ at said power converter at a first time;

measuring a current I₁ between said power converter and said receiving apparatus at said first time;

measuring a voltage V₂ at said power converter at a second time;

measuring a current I₂ between said power converter and said receiving apparatus at said second time; and

calculating said resistance as a difference between V₂ and V₁, divided by a difference between I₂ and I₁.

11. A method as recited in claim 9, wherein said step of controlling a regenerative current comprises limiting said regenerative current to maintain said voltage at said power converter below a predetermined threshold.

12. A method as recited in claim 10, wherein said step of controlling a regenerative current comprises limiting said regenerative current to maintain said voltage at said power converter below a predetermined threshold.