Method for generating a setpoint current value for a load-dependent current-generating system

• US 20020163320A1
• Filed: 04/19/2002
• Published: 11/07/2002
• Est. Priority Date: 04/21/2001
• Status: Active Grant

• Current Assignee: Mind Fusion, LLC (Ascend Innovation Management, LLC)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Buck, Michael
• Granted Patent: US 6,859,017 B2
• Time in Patent Office: Days
• US Class Current: 322/27
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A method for operating a load dependent current-generating system which supplies at least one electric drive motor with electrical energy. A power request is made to the electric drive motor, and a dynamic parameter of the current generating system and/or a simulation model, which characterizes the behaviour of the current generating system, is used for calculating the setpoint current value for the current generating system.

Claims

1. A method for generating a setpoint current value for a load-dependent current-generating system which supplies an electric drive motor with electrical energy, said method comprising the steps of:

providing a power request (LA) to the electric drive motor;

providing at least one of a dynamic parameter of the current-generating system and a simulation model which characterizes behaviour of the current-generating system; and

calculating a setpoint current value (I_setp) as a function of said at least one of a dynamic parameter of the corresponding system and a simulation model.

2. The method according to claim 1, wherein dynamics of the rotational speed (Δ

n) of the electric drive motor at a given time are additionally used for calculating the setpoint current value (I_setp) of the current-generating system.

3. The method according to claim 1, wherein a rotational speed (n) of the electric drive motor at a given time and a torque (M) of the electric drive motor are additionally used for calculating the setpoint current value (I_setp) of the current-generating system.

4. The method according to claim 3, wherein the setpoint current value (I_setp) for the current generating system is determined from the torque (M) of the electric drive motor and from the sum of the rotational speed (n) of the electric drive motor at a given time and a predictive rotational speed difference (Δ

n_pre).

5. The method according to claim 1, wherein a time constant, scaled with a timing clock (Δ

T), of the current-generating system (T_SE-scal) is used as a dynamic parameter.

6. The method according to claim 2, wherein the dynamics of the rotational speed (Δ

n) of the electric drive motor at a given time are determined by the differentiation of the rotational speed (n) of the electric drive motor at said given time.

7. The method according to claim 4, the predictive rotational speed difference (Δ

n_pre) is generated from said at least the dynamic parameter and the simulation model of the current-generating system and from the dynamics of the rotational speed (Δ

n) of the electric drive motor at a given time.

8. The method according to claim 4, wherein the predictive rotational speed difference (Δ

n_pre) is generated from the dynamic parameter of the current generating system and the dynamics of the rotational speed (Δ

n) of the electric drive motor at a given time by means of multiplication.

9. The method according to claim 3, wherein one of instantaneous torque at a given time or a setpoint torque of the electric drive motor is used as torque (M).

10. The method according to claim 1, wherein the current-generating system is a fuel cell system.

11. A method of compensating for the dynamic behaviour of a current-generating system, comprising the steps of:

scaling a dynamic parameter of the current-generating system by dividing the dynamic parameter by a number of time units; and

subsequently taking a measured value of a variable in order to ensure a time reference frame for all variables to be used.

12. The method according to claim 11, wherein said dynamic parameter is a time constant.

13. The method according to claim 11, wherein said dynamic parameter is one of a dead time, a mathematical simulation model of the current-generating system and a physical simulation model of the current-generating system.

14. The method according to claim 13, wherein one of said mathematical and physical simulation model is a differential equation.