Method for controlling operating speed and torque of electric motor

Patent metadata

Field	Value
Publication number	US-2016355103-A1
Application number	US-201615243061-A
Country	US
Kind code	A1
Filing date	Aug 22, 2016
Priority date	Mar 16, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Systems and methods for controlling the operating speed and the torque of an electric motor using an operational model are described. An operational model for the electric motor, including a plot of engine performance parameters, is used for reference, and a most efficient output path, which may pass through an optimal operation region in the operational model, is selected. The most efficient output path may be determined, for example, according to locations of a current output state and a to-be-reached target state in the operational model, enabling the operating state of the motor to reach the target state from the current operating state. By selecting a more efficient output path, the operating efficiency of the motor may be optimized, the life of a battery improved and/or the operating mileage of the vehicle may be increased, without significantly reducing the driving experience.

First claim

What is claimed is:

1 . An electric vehicle motor controller, comprising:
a processor; and a storage device including an operational model stored thereon, the operational model including a plurality of operation positions and an optimal operation region of an electric motor, each operation position corresponding to a speed parameter, a torque parameter and an operating efficiency parameter of the electric motor; wherein the processor is configured to:
detect a current speed parameter and a current torque parameter of the electric motor;
determine a current operation position of the electric motor in the operational model based on the current speed parameter and the current torque parameter;
determine a target speed parameter and a target torque parameter corresponding to a target operation position of the electric motor in the operational model;
calculate power requirements for two transition paths connecting the current operation position and the target operation position in the operational model, the two transition paths including a first path consisting of one vector, and a second path consisting of two vectors; and
select one of the two transition paths for controlling the electric motor based at least in part on the calculated power requirements.

2 . The controller of claim 1 , wherein the processor is further configured to select an optimal intermediate operation position in the optimal operation region as a vertex of the second path.

3 . The controller of claim 2 , wherein:
the optimal intermediate operation position is selected as a position having a shortest linear distance from the optimal operation region to the current operation position.

4 . The controller of claim 1 , wherein the electric motor is controlled according to the first or second path by changing at least one of the driving voltage and the driving current applied to the electric motor such that the current operation position at any time during the transition to the target operation position is on the selected transition path in the operational model.

5 . The controller of claim 1 , wherein the processor is further configured to:
amend an efficiency parameter on a selected position in the operational model according to a calculated efficiency parameter on the target operation position.

6 . The controller of claim 5 , wherein the processor is further configured to:
amend the efficiency parameter on a selected position in the operational model according to the calculated efficiency parameter on the target operation position comprises: detect the input voltage and current of the motor at the target operation position; calculate the actual operating efficiency of the motor at the target operation position according to the torque and the speed of the motor at the target operation position and the detected input voltage and current at the target operation position; calculate a correction coefficient according to the operating efficiency corresponding to the target operation position in the operational model and the calculated actual operation efficiency of the motor at the target operation position; select at least one position to be corrected close to the target operation position; calculate the distance between the target operation position and the position to be corrected; calculate a correction quantity according to the calculated correction coefficient calculated and the calculated distance; and correct the position of the position to be corrected in the operational model according to the correction quantity.

7 . A method for implementing an electric vehicle motor controller, the method comprising:
detecting, by an operational model which includes a plurality of operation positions and an optimal operation region of an electric motor, each operation position corresponding to a speed parameter, a torque parameter and an operating efficiency parameter of the electric motor, a current speed parameter and a current torque parameter of the electric motor; determining a current operation position of the electric motor in the operational model based on the current speed parameter and the current torque parameter; determining a target speed parameter and a target torque parameter corresponding to a target operation position of the electric motor in the operational model; calculating power requirements for two transition paths connecting the current operation position and the target operation position in the operational model, the two transition paths including a first path consisting of one vector, and a second path consisting of two vectors; and selecting one of the two transition paths for controlling the electric motor based at least in part on the calculated power requirements.

8 . The method of claim 7 , further comprising selecting an optimal intermediate operation position in the optimal operation region as a vertex of the second path.

9 . The method of claim 8 , wherein the optimal intermediate operation position is selected as a position having a shortest linear distance from the optimal operation region to the current operation position.

10 . The method of claim 7 , further comprising controlling the electric motor according to the first or second path by changing at least one of the driving voltage and the driving current applied to the electric motor such that the current operation position at any time during the transition to the target operation position is on the selected transition path in the operational model.

11 . The method of claim 7 , further comprising amending an efficiency parameter on a selected position in the operational model according to a calculated efficiency parameter on the target operation position.

12 . The method of claim 11 , further comprising:
amending the efficiency parameter on a selected position in the operational model according to the calculated efficiency parameter on the target operation position comprises: detecting the input voltage and current of the motor at the target operation position; calculating the actual operating efficiency of the motor at the target operation position according to the torque and the speed of the motor at the target operation position and the detected input voltage and current at the target operation position; calculating a correction coefficient according to the operating efficiency corresponding to the target operation position in the operational model and the calculated actual operation efficiency of the motor at the target operation position; selecting at least one position to be corrected close to the target operation position; calculating the distance between the target operation position and the position to be corrected; calculating a correction quantity according to the calculated correction coefficient calculated and the calculated distance; and correcting the position of the position to be corrected in the operational model according to the correction quantity.

13 . An electric vehicle comprising:
an electric motor; a motor controller in communication with the electric motor; a processor in communication with the motor controller; and a storage device including an operational model stored thereon, the operational model including a plurality of operation positions and an optimal operation region of an electric motor, each operation position corresponding to a speed parameter, a torque parameter and an operating efficiency parameter of the electric motor; wherein the processor is configured to:
detect a current speed parameter and a current torque parameter of the electric motor;
determine a current operation position of the electric mo

Assignees

• Thunder Power Hong Kong Ltd

Inventors

• Lai Sheng-Fu

Classifications

• B60L50/60

  using power supplied by batteries (in combination with fuel cells B60L50/75) · CPC title

• H02P31/00

  Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00 · CPC title

• B60L2260/44

  by parameter estimation · CPC title

• Y02T10/72

  Electric energy management in electromobility · CPC title

• H02P7/285

  controlling armature supply only · CPC title