Drive unit for an electric motor

• US 9,203,336 B2
• Filed: 04/24/2012
• Issued: 12/01/2015
• Est. Priority Date: 05/06/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Samsung SDI Company Limited
• Original Assignee: Robert Bosch GmbH
• Inventors: Butzmann, Stefan, Fink, Holger
• Primary Examiner(s): Luo, David S
• Application Number:
  US14/114,225
• Publication Number:
  US 20140111123A1
• Time in Patent Office: 1,316 Days
• Field of Search: 318/139, 318/34, 318/558
• US Class Current: 1/1
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 7/483 Converters with outputs that each can have more than two voltages levels
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02P 23/00 Arrangements or methods for the control of AC motors characterised by a control method other than vector control
• CPC Class Codes: H02P 27/14 with three or more levels of voltage
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A drive unit for an electric motor comprises a multilevel inverter and a battery. The battery comprises at least one battery module train comprising a plurality of battery modules connected in series, each module having at least one battery cell and one coupling unit. The at least one battery cell is connected between a first input and a second input of the coupling unit. The coupling unit is designed to connect the at least one battery cell between two terminals of the battery module in response to on a first control signal and to connect the two terminals in response to a second control signal. Several center taps are arranged on the battery module train, by means of which a potential can be tapped at a connection between two battery modules respectively. Inputs of the multilevel inverter are connected to the taps.

Claims

1. A drive unit for an electric motor comprising:

a multilevel inverter; and

a battery having at least one battery module string including a plurality of series-connected battery modules,

wherein each battery module includes at least one battery cell and a coupling unit,

wherein the at least one battery cell is connected between a first input and a second input of the coupling unit and the coupling unit is configured to connect the at least one battery cell between a first terminal of the battery module and a second terminal of the battery module in response to a first control signal, and to connect the first terminal to the second terminal in response to a second control signal,

wherein a plurality of center taps are arranged at the battery module string and are configured to tap a potential at a connection between in each case two battery modules in the plurality of battery modules, and

wherein inverter inputs of the multilevel inverter are connected to the center taps.

2. The drive unit as claimed in claim 1, wherein:

the coupling unit has a coupling output and is configured to connect one of the first input and the second input to the coupling output in response to the first control signal, and

the coupling output is connected to one of the first terminal and the second terminal of the battery module.

3. The drive unit as claimed in claim 1, wherein a battery module in the plurality of battery modules is arranged between two adjacent center taps in the plurality of center taps.

4. The drive unit as claimed in claim 1, wherein two or more battery modules in the plurality of battery modules are arranged between two adjacent center taps in the plurality of center taps.

5. The drive unit as claimed in claim 4, wherein the two or more battery modules between the two adjacent center taps are combined to form an overall module.

6. The drive unit as claimed in claim 1, wherein the plurality of center taps divide the battery module string such that each division of the battery module string includes an equal number of battery modules.

7. The drive unit as claimed in claim 1, further comprising:

a control unit configured to output the first control signal to a first variable number of battery modules of the at least one battery module string, to output the second control signal to the remaining battery modules of the at least one battery module string and to output a third control signal to the multilevel inverter to variably adjust a potential at an inverter output of the multilevel inverter.

8. The drive unit as claimed in claim 7, wherein the control unit is configured to adjust a sinusoidal potential at the inverter output of the multilevel inverter.

9. The drive unit as claimed in claim 8, wherein the control unit is configured to adjust the sinusoidal potential at an adjustably predefinable frequency.

10. A battery comprising:

a multilevel inverter; and

at least one battery module string including a plurality of series-connected battery modules, each of which includes at least one battery cell and a coupling unit,

wherein the at least one battery cell is connected between a first input and a second input of the coupling unit and the coupling unit is configured to connect the at least one battery cell between a first terminal of the battery module and a second terminal of the battery module in response to a first control signal, and to connect the first terminal to the second terminal in response to a second control signal,

wherein a plurality of center taps are arranged at the battery module string and are configured to tap a potential at a connection between in each case two battery modules in the plurality of battery modules,

wherein inverter inputs of the multilevel inverter are connected to the center taps, and wherein the battery forms a drive unit.

11. A motor vehicle comprising:

an electric drive motor configured to drive the motor vehicle; and

a battery as claimed in claim 10 connected to the electric drive motor.

12. A motor vehicle comprising:

an electric drive motor configured to drive the motor vehicle; and

a drive unit connected to the electric drive motor,

wherein the drive unit includes a multilevel inverter and a battery having at least one battery module string including a plurality of series-connected battery modules,

wherein each battery module includes at least one battery cell and a coupling unit,

wherein the at least one battery cell is connected between a first input and a second input of the coupling unit and the coupling unit is configured to connect the at least one battery cell between a first terminal of the battery module and a second terminal of the battery module in response to a first control signal, and to connect the first terminal to the second terminal in response to a second control signal,

wherein a plurality of center taps are arranged at the battery module string and are configured to tap a potential at a connection between in each case two battery modules in the plurality of battery modules, and

wherein inverter inputs of the multilevel inverter are connected to the center taps.