Method for controlling the power supply of an electric motor

• US 9,184,692 B2
• Filed: 07/04/2011
• Issued: 11/10/2015
• Est. Priority Date: 07/02/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmidt, Alexander
• Primary Examiner(s): GLASS, ERICK DAVID
• Application Number:
  US13/807,652
• Publication Number:
  US 20130200824A1
• Time in Patent Office: 1,590 Days
• Field of Search: 318/139, 701/29.1
• US Class Current: 1/1
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/27 by heating
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/613 Cooling or keeping cold
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/6567 Liquids
• CPC Class Codes: H01M 10/6571 Resistive heaters arrangements for heating the battery by its resistance to the internal current H01M10/637
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02P 31/00 Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method and electrical system for controlling the power supply of an electric motor, in particular the electric motor of a vehicle that can be electrically driven, includes a control device that controls the power supply of the electric motor by an energy store. The energy store comprises a plurality of modules that are exposed to stress due to repeated charging and/or discharging and undergo an aging process as a result of said stress. In order to decouple the service life of the energy store from the service life of a vehicle, for example, the control device controls the charging and/or discharging of at least two modules differently such that said modules exhibit a stress difference so as to selectively reduce the aging process of the module being exposed to less stress.

Claims

1. A method for controlling a power supply of an electric motor, comprising:

controlling the power supply of the electric motor with a control device, the power supply having an energy store including a plurality of modules electrically connected together in parallel and configured to provide a current to the electric motor, each module having an average current during at least one of charging and discharging; and

controlling the at least one of charging and discharging of at least two modules with the control device such that the average currents of the at least two modules are different, the controlling of the at least one of charging and discharging further comprising;

modifying a resistance value of at least one variable resistor of the power supply, the at least one variable resistor being configured to control the average current of at least one of the at least two modules.

2. The method as claimed in claim 1, the modifying further comprising:

modifying the resistance value of the at least one variable resistor such that the difference between the average currents of the at least two modules does not exceed a value of 20%.

3. The method as claimed in claim 1, further comprising:

measuring the difference in the average currents of the at least two modules with the control device via at least one of an ammeter and a voltage measurement.

4. The method as claimed in claim 3, the controlling of the at least one of charging and discharging further comprising:

modifying a resistance value of at least one variable resistor of the power supply based on the measured difference in the average currents of the at least two modules, the at least one variable resistor being configured to control the average current of at least one of the at least two modules.

5. The method as claimed in claim 1, the controlling of the at least one of charging and discharging further comprising:

evaluating at least one of a capacity and an inner resistance of the at least two modules,

controlling the at least one of charging and discharging of at least two modules with reference to the at least one of the capacity and the inner resistance.

6. The method as claimed in claim 5, the evaluating further comprising:

measuring at least one of a voltage, a temperature, and a current of the at least two modules to determine the at least one of the capacity and the inner resistance.

7. The method as claimed in claim 1, wherein the at least two modules have the same nominal voltage.

8. The method as claimed in claim 1, wherein the electric motor is an electric motor of a vehicle configured to be electrically driven.