Controlling retarding torque in an electric drive system

• US 8,981,685 B2
• Filed: 12/21/2012
• Issued: 03/17/2015
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Nee, Brett M., Williams, Joshua M., Gottemoller, Benjamin P., Thaduvayi, Srikar
• Primary Examiner(s): Luo, David S
• Application Number:
  US13/723,288
• Publication Number:
  US 20130162182A1
• Time in Patent Office: 816 Days
• Field of Search: 318/380, 318/375, 318/273, 318/362
• US Class Current: 318/380
• CPC Class Codes: B60K 2007/0092 the motor axle being coaxial to the wheel axle
• CPC Class Codes: B60K 7/0007 the motor being electric
• CPC Class Codes: B60L 7/02 Dynamic electric resistor braking B60L7/22 takes precedence
• CPC Class Codes: B60Y 2200/142 Heavy duty trucks
• CPC Class Codes: H02P 15/00 Arrangements for controlling dynamo-electric brakes or clutches controlling speed of dynamo-electric motors by means of a separate brake H02P29/04, vector control H02P21/00 see provisionally also H02K49/00 and H02P29/0022

Abstract

The disclosure describes, in one aspect, a system for a machine having an electric drive configuration. The system includes an electric motor associated with at least one wheel and adapted to provide retarding torque to the wheel, and a controller configured to determine a power measurement of a retarding grid and control the retarding torque to the at least one wheel during retarding as a function of the power measurement.

Claims

1. A system for a machine having an electric drive configuration, comprising:

an electric motor associated with at least one wheel and adapted to provide retarding torque to the wheel; and

a controller configured to;

determine a power measurement of a retarding grid;

compare the power measurement to a power threshold;

determine a temperature measurement of a retarding grid; and

control the retarding torque during retarding as a function of the power measurement and the temperature measurement.

2. The system of claim 1, further comprising:

a first grid and a second grid; and

wherein the controller is further configured to;

determine a power measurement of a first grid and a second grid; and

control the retarding torque as a function of at least one of the first or the second grids.

3. The system of claim 2, wherein the controller is further configured to:

determine a power measurement of a first grid and a second grid; and

control the retarding torque as a function of the first and the second grids.

4. The system of claim 3, wherein controlling the retarding torque includes determining a statistical calculation of the first and the second grid power measurements.

5. The system of claim 3, wherein controlling the retarding torque includes determining at least one of an average or a sum of the first and the second grid power measurements.

6. The system of claim 1, wherein controlling the retarding torque includes decreasing a magnitude of retarding torque provided when the power measurement is above the power threshold.

7. A method for controlling retarding torque of a machine having an electric drive configuration including an electric motor and a retarding grid, comprising:

determining a power measurement of the retarding grid;

compare the power measurement to a power threshold;

determining a temperature measurement of a retarding grid; and

controlling the retarding torque during retarding as a function of the power measurement and the temperature measurement.

8. The method of claim 7, further comprising:

determining a power measurement of a first grid and a second grid; and

controlling the retarding torque as a function of at least one of the first or the second grids.

9. The method of claim 8, further comprising:

determining a power measurement of a first grid and a second grid; and

controlling the retarding torque as a function of the first and the second grids.

10. The method of claim 9, wherein controlling the retarding torque includes determining a statistical calculation of the first and the second grid power measurements.

11. The method of claim 9, wherein controlling the retarding torque includes determining at least one of an average or a sum of the first and the second grid power measurements.

12. The method of claim 7, wherein controlling the retarding torque includes decreasing a magnitude of retarding torque provided when the power measurement is above the power threshold.

13. An electric drive machine, comprising:

an electric motor adapted to provide retarding torque;

at least one wheel adapted to receive retarding torque from the electric motor;

a controller operatively connected to the motor, the controller configured to;

determine a power measurement of a retarding grid;

compare the power measurement to a power threshold;

determine a temperature measurement of a retarding grid; and

control the retarding torque during retarding as a function of the power measurement and the temperature measurement.

14. The machine of claim 13, wherein the controller is further configured to:

determine a power measurement of a first grid and a second grid; and

control the retarding torque as a function of the first and the second grids.