Method for operating a drive train, and drive train

Patent metadata

Field	Value
Publication number	US-11945314-B2
Application number	US-201917311503-A
Country	US
Kind code	B2
Filing date	Nov 28, 2019
Priority date	Dec 6, 2018
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A method for operating a drive train includes supplying a motor voltage to an electric motor by a converter for achieving a torque setpoint value, determining an angular velocity actual value and an angular acceleration actual value from values of the angular position of the rotor, determining the torque setpoint value from a moment of inertia and an angular acceleration setpoint value, which is determined as an actuation variable, determining the moment of inertia as the sum of the moment of inertia of the drive train without a load and the moment of inertia of the load, and determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value.

First claim

The invention claimed is:

1. A method for operating a drive train, including an electric motor, a load driven by the electric motor and/or a gear unit driven by the electric motor, and a sensor for acquiring an angular position of a rotor of the electric motor, comprising:
supplying a motor voltage to the electric motor via a converter to achieve a torque setpoint value;
determining an angular velocity actual value and an angular acceleration actual value from acquired values of the angular position of the rotor;
determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference between the angular velocity actual value and an angular velocity setpoint value is supplied;
determining the total moment of inertia as a sum of a moment of inertia of the drive train without a load and a moment of inertia of the load;
determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train;
wherein the rpm control member includes a PI controller, having a proportional element and an integral element arranged in parallel with the proportional element, a proportionality constant of the proportional element is a function of the moment of inertia of the drive train and the total moment of inertia, and a time constant of the integral element is a function of the moment of inertia of the load and the total moment of inertia.

2. The method according to claim 1 , wherein the sensor is arranged on the electric motor.

3. The method according to claim 1 , wherein the motor voltage is supplied to the electric motor via a motor control device of the converter.

4. The method according to claim 1 , wherein the angular velocity actual value and the angular acceleration actual value are determined recurrently over time.

5. The method according to claim 1 , wherein the torque actual value is determined from a motor current, acquired by a current sensor, and from the acquired values of the angular position of the rotor.

6. The method according to claim 1 , wherein the torque actual value is determined from a motor current acquired by a current sensor and from an acquired motor voltage and/or from the acquired values of the angular position of the rotor.

7. The method according to claim 1 , wherein the moment of inertia of the drive train without a load is predefined as a parameter.

8. The method according to claim 1 , wherein the torque setpoint value is formed as a product of the total moment of inertia and the angular acceleration setpoint value.

9. The method according to claim 1 , wherein the moment of inertia of the load is determined as a quotient, of the torque actual value and the angular acceleration actual value, reduced by the moment of inertia of the drive train.

10. A method, comprising:
supplying a motor voltage to the electric motor via a converter to achieve a torque setpoint value;
determining an angular velocity actual value and an angular acceleration actual value from acquired values of the angular position of the rotor;
determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference between the angular velocity actual value and an angular velocity setpoint value is supplied;
determining the total moment of inertia as a sum of a moment of inertia of the drive train without a load and a moment of inertia of the load;
determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train;
wherein the rpm control member includes a PI controller, having a proportional element and an integral element arranged in parallel with the proportional element, a proportionality constant of the proportional element is a function of the moment of inertia of the load and the total moment of inertia, and a time constant of the integral element is a function of the moment of inertia of the drive train and the total moment of inertia.

11. A method, comprising:
supplying a motor voltage to the electric motor via a converter to achieve a torque setpoint value;
determining an angular velocity actual value and an angular acceleration actual value from acquired values of the angular position of the rotor;
determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference between the angular velocity actual value and an angular velocity setpoint value is supplied;
determining the total moment of inertia as a sum of a moment of inertia of the drive train without a load and a moment of inertia of the load;
determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train;
wherein the rpm control member includes a PI controller, having a proportional element and an integral element arranged in parallel with the proportional element; and
wherein a proportionality constant of the proportional element is a function of a product of the moment of inertia of the drive train and the moment of inertia of the load, and/or a time constant of the integral element is a function of a product of the moment of inertia of the drive train and the moment of inertia of the load.

12. A method, comprising:
supplying a motor voltage to the electric motor via a converter to achieve a torque setpoint value;
determining an angular velocity actual value and an angular acceleration actual value from acquired values of the angular position of the rotor;
determining the torque setpoint value from a total moment of inertia and an angular acceleration setpoint value determined as an actuation variable by an rpm control member to which a difference between the angular velocity actual value and an angular velocity setpoint value is supplied;
determining the total moment of inertia as a sum of a moment of inertia of the drive train without a load and a moment of inertia of the load;
determining the moment of inertia of the load from a torque actual value and from the angular acceleration actual value, taking into account the moment of inertia of the drive train;
wherein at a first instant, the moment of inertia of the load is determined as a first quotient, reduced by the moment of inertia of the drive train, of the torque actual value and the angular acceleration actual value α_ist, and the angular acceleration actual value lies in a first value range;
wherein at a second instant after the first instant, the moment of inertia of the load is determined as a second quotient, reduced by the moment of inertia of the drive train, of the torque actual value and the angular acceleration actual value, and the angular acceleration actual value lies in a second value range; and
wherein an updated moment of inertia of the load is determined by adding to the previously determined value of the moment of inertia of the load a difference between the second quotient and the first quotient.

13. The method according to claim 12 , wherein the first value range is a value range of angular acceleration, and the second value range is a further value range of angular acceleration, and the two value ranges do not overlap but are spaced apart from each other.

14. The method according to claim 1

Assignees

• Sew Eurodrive Gmbh & Co Kg

Inventors

• Schuster Thomas

Classifications

• B60L15/20 Primary

  for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed · CPC title

• B60L3/12

  Recording operating variables {; Monitoring of operating variables} · CPC title

• B60L2240/421

  Speed · CPC title

• B60L2240/423

  Torque · CPC title

• B60L2240/427

  Voltage · CPC title