Battery system comprising a hybrid battery and an NPC inverter which is connected at the input end to the battery, and method for operating an NPC inverter which is connected at the input end to a hybrid battery

Patent metadata

Field	Value
Publication number	US-10075094-B2
Application number	US-201515529540-A
Country	US
Kind code	B2
Filing date	Oct 20, 2015
Priority date	Nov 28, 2014
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

The present invention relates to a battery system which has a hybrid battery which comprises a first energy storage source having a plurality of first energy storage cells and comprises a second energy storage source which is connected in series with the first energy storage source and has a plurality of second energy storage cells which are different from the first energy storage cells. Furthermore, the battery system has an inverter which is connected at the input end to the battery and is designed to convert a DC voltage which is supplied to the input end into an, in particular polyphase, AC voltage which is produced at the output end. The battery system also has a control unit which is designed to operate the inverter in a first functional mode or in a second functional mode or in a third functional mode by controlling a plurality of semiconductor switches of the inverter. In the first functional mode, the inverter converts a DC voltage which is provided by the first energy storage source and is supplied to the input end into the AC voltage which is produced at the output end. In the second functional mode, the inverter converts a DC voltage which is provided by the second energy storage source and is supplied to the input end into the AC voltage which is produced at the output end. In the third functional mode, the inverter converts a DC voltage which is provided by a series circuit comprising the first energy storage source and the second energy storage source and is supplied at the input end into the AC voltage which is produced at the output end.

First claim

The invention claimed is:

1. A battery system ( 10 ; 100 ) having a hybrid battery ( 20 ), which comprises a first energy storage source ( 30 ) having first energy storage cells ( 35 ) and a second energy storage source ( 40 ) which is connected in series with the first energy storage source ( 30 ) and has a plurality of second energy storage cells ( 45 ) which are different from the first energy cells ( 35 ), and an inverter ( 50 ; 150 ) which is connected at the input end to the battery ( 20 ) and configured to convert a DC voltage (GS 1 , GS 2 , GS 3 ) applied to the input end into an AC voltage applied to the output end, characterized by
a control unit configured to operate the inverter ( 50 ; 150 ) in a first functional mode, in which the inverter converts a DC voltage (GS 1 ) applied to the input end and provided by the first energy storage source ( 30 ) into the AC voltage applied to the output end, and to operate the inverter ( 50 ; 150 ) in a second functional mode, in which it converts a DC voltage (GS 2 ) applied to the input end and provided by the second energy storage source ( 40 ) into the AC voltage applied to the output end, and to operate the inverter ( 50 ; 150 ) in a third functional mode, in which it converts a DC voltage (GS 3 ) applied to the input end and provided by a series circuit of the first energy storage source ( 30 ) and the second energy storage source ( 40 ) into the AC voltage applied to the output end, by controlling a plurality of semiconductor switches (M 1 , . . . , M 12 ; T 1 , . . . , T 12 , M 1 , . . . , M 12 ) of the inverter ( 50 ; 150 ); and
wherein, if an electric motor ( 60 ) is connected at the output end to the inverter ( 50 ; 150 ), the electric motor ( 60 ) provides a torque (M), the torque values of which are between zero and a maximum torque value (Mm), and the electric motor ( 60 ) c is operated at a speed (N), the speed values of which are between zero and a maximum speed value (Nm), wherein, in the first functional mode, the torque values assumed by the torque (M) are in a range of torque values between a positive first torque limit value (M 1 ) and the maximum torque value (Mm) and the speed values assumed by the speed (N) are in a range of speed values between zero and a positive first speed limit value (N 1 ), and, in the second functional mode, the torque values assumed by the torque (M) are in a range of torque values between zero and a positive second torque limit value (M 2 ) and the speed values assumed by the speed (N) are in a range of speed values between zero and a positive second speed limit value (N 2 ), and, in a third functional mode, the torque values assumed by the torque (M) are in a range of torque values between zero and the maximum torque value (Mm) and the speed values assumed by the speed (N) are in a range of speed values between a positive third speed limit value (N 3 ) and the maximum speed value (Nm).

2. The battery system ( 10 ; 100 ) as claimed in claim 1 , wherein a quotient between an internal resistance of each first energy storage cell ( 35 ) and a maximum amount of energy which can be stored in the latter is less than a quotient between an internal resistance of each second energy storage cell ( 45 ) and a maximum amount of energy which can be stored in the latter.

3. The battery system ( 10 ; 100 ) as claimed in claim 1 , wherein the inverter ( 50 ; 150 ) is an NPC inverter having three voltage levels.

4. The battery system ( 10 ; 100 ) as claimed in claim 1 , wherein the second torque limit value (M 2 ) is greater than the first torque limit value (M 1 ), and/or the second speed limit value (N 2 ) is greater than the first speed limit value (N 1 ), and/or the third speed limit value (N 3 ) is less than the second speed limit value (N 2 ) and/or less than the first speed limit value (N 1 ).

5. The battery system ( 100 ) as claimed in claim 1 , wherein the plurality of semiconductor switches (T 1 , . . . , T 12 , M 1 , . . . , M 12 ) are arranged in a first group of semiconductor switches having a plurality of first semiconductor switches (T 1 , . . . , T 12 ) each configured to switch a DC voltage in a first DC voltage range and/or in a second group of semiconductor switches having a plurality of second semiconductor switches (M 1 , . . . , M 12 ) each configured to switch a DC voltage in a second DC voltage range different from the first DC voltage range, wherein, in order to operate the inverter ( 150 ) in each functional mode, the control unit is configured to respectively convert the corresponding DC voltage (GS 1 , GS 2 , GS 3 ) applied to the input end into the AC voltage applied to the output end by the semiconductor switches in the group of semiconductor switches whose semiconductor switches are each configured to switch a DC voltage which is currently to be switched and is dependent on a current DC voltage value of the DC voltage (GS 1 , GS 2 , GS 3 ) to be converted.

6. The battery system ( 100 ) as claimed in claim 5 , wherein the first semiconductor switches (T 1 , . . . , T 12 ) convert the DC voltage (GS 1 ) applied to the inverter ( 150 ) at the input end and provided by the first energy storage source ( 30 ) into the AC voltage applied to the output end in the first functional mode, the second semiconductor switches (M 1 , . . . , M 12 ) convert the DC voltage (GS 2 ) applied to the inverter ( 150 ) at the input end and provided by the second energy storage source ( 40 ) into the AC voltage applied to the output end in the second functional mode, and the first semiconductor switches (T 1 , . . . , T 12 ) and/or the second semiconductor switches (M 1 , . . . , M 12 ) convert the DC voltage (GS 3 ) applied to the inverter ( 150 ) at the input end and provided by the series circuit of the first energy storage source ( 30 ) and the second energy storage source ( 40 ) into the AC voltage applied to the output end in the third functional mode.

7. The battery system ( 100 ) as claimed in claim 5 , wherein each first semiconductor switch (T 1 , . . . , T 12 ) is assigned a second semiconductor switch (M 1 , . . . , M 12 ) connected in parallel with it.

8. A vehicle having a battery system ( 10 ; 100 ) as claimed in claim 1 and having an electric motor ( 60 ), wherein the electric motor ( 60 ) is connected at the output end to the inverter ( 50 ; 150 ) of the battery system ( 10 ; 100 ) and operated using an AC voltage provided at the output end by the inverter ( 50 ; 150 ).

9. The vehicle as claimed in claim 8 , wherein the AC voltage is a polyphaser AC voltage.

10. The battery system ( 10 ; 100 ) as claimed in claim 1 , wherein the AC voltage is a polyphaser AC voltage.

11. A method for operating an inverter ( 50 ; 150 ) which is configured to convert a DC voltage (GS 1 , GS 2 , GS 3 ) applied to the input end into an AC voltage applied to the output end, wherein the inverter ( 50 ; 150 ) is connected at the input end to a hybrid battery ( 20 ) which comprises a first energy storage source ( 30 ) having a plurality of first energy storage cells ( 35 ) and a second energy storage source ( 40 ) which is connected in series with the first energy storage source ( 30 ) and has a plurality of second energy storage cells ( 45 ) from the first energy storage cells ( 35 ), characterized in that
the inverter ( 50 ; 150 ) is operated in a first functional mode, in which it converts a DC voltage (GS 1 ) applied to the input end and provided by the first energy storage source ( 30 ) into the AC voltage applied to the output end, and the inverter ( 50 ; 150 ) is operated in a second functional mode, in which it converts a DC voltage (GS 2 ) applied to the input end and provided by the second energy storage source ( 40

Assignees

• Bosch Gmbh Robert

Inventors

• Sahhary Waleed
• Woll Christoph
• Doege Volker

Classifications

• H02J7/52

  for charge balancing, e.g. equalisation of charge between batteries · CPC title

• H02M1/088

  for the simultaneous control of series or parallel connected semiconductor devices · CPC title

• B60L2210/42

  Voltage source inverters · CPC title

• H02J7/345

  using capacitors as storage or buffering devices · CPC title

• H02M7/487 Primary

  Neutral point clamped inverters · CPC title