DE102011006096A1 - Charging control system for traction battery cell assembly of motor vehicle, sets usual capacity of input and output of converter for same operation in respective operating mode by capacity of cell assembly and circuit capacitor - Google Patents

Abstract

The system (1) has an intermediate circuit capacitor (9) through which the traction battery cell assembly (2) is connected with the inverter (7). A direct current (DC)-DC regulator (10) works as high or low setting actuator in the direction of inverter of the traction battery cell assembly. The usual capacity of input and output of the DC-DC converter for same operation in the respective operating mode is set by the capacity of traction battery cell assembly and the intermediate circuit capacitor.

Description

The present invention relates to a charge control system for a traction battery cell assembly of a motor vehicle according to the preamble of claim 1. Such charge control systems find application in hybridized or electric drive systems, especially in connection with traction batteries in the form of high voltage batteries.

In the prior art it is known, for. B. from the document DE 196 52 950 A1 or the publication EP 0 849 112 A1 to charge a traction battery by means of the on-board drive system of a motor vehicle to an external AC or three-phase source. For this purpose, DC controllers can be used, which are suitably connected to the inverter. An arrangement of a DC adjuster to an inverter shows, for example, the document DE 10 2005 041 825 A1 ,

Starting from the known prior art, it is an object of the present invention to improve a charge control system for a traction battery cell assembly of a traction battery, in particular to reduce the manufacturing costs thereof.

This object is achieved by the features of claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

According to the invention, a charging control system for a traction battery cell assembly of a motor vehicle is proposed. Such a traction battery cell network, which is used to form a traction battery, comprises at least one battery cell, preferably a plurality of interconnected battery cells, which may be connected in series or in parallel. A traction battery formed by the traction battery cell assembly, also known as a traction battery, is used in hybridized or electric vehicle drive systems for powering electric drive assemblies, e.g. B. also to supply other consumers with electrical energy. A traction battery cell assembly is intended in particular for forming a high-voltage battery whose voltage can be several hundred volts.

In addition to the traction battery cell network, the charge control system further comprises an inverter or drive inverter, which is connected via an output, i. H. an output of the power unit, the supply side or the battery side is connected by means of a DC link capacitor to the traction battery cell network. The inverter is formed in the usual way by means of circuit breakers and control electronics.

In the context of the present invention, the charging control system has a DC converter, which can operate as a step-up or step-down converter in the direction from the inverter to the traction battery cell assembly. By using such a DC adjuster, the traction battery cell assembly can be charged in charging mode with a defined current. For this purpose, the charging voltage level is adjusted by means of the DC adjuster by clocking at least one switch of the DC adjuster to a designated charging voltage level.

According to the invention, the charge control system in this case has a DC converter, which can be realized in a simple manner and in particular cost-effectively. The usual capacity at the input and output of the DC adjuster, which are provided for operating the same in the respective mode boost converter or buck converter, are advantageously formed by the capacity of the traction battery cell network and the DC link capacitor, in particular exclusively. As a capacity of the traction battery cell network in this case, in particular those is referred to, which adjusts itself by the capacitor effect, due to the cell structure of the traction battery cell assembly - similar to that of plate capacitors on the traction battery cell assembly. Such a capacity is taken into account in the equivalent circuit diagram of the traction battery cell network in the context of the representation of the cells as RC elements.

The DC-DC converter of the charging control system formed by means of the capacitances of the DC link capacitor and the traction battery cell network advantageously consists of a few components. The DC-DC converter has, in addition to the above capacitors, an electrical circuit or a voltage regulating device with a first and a second diode, a first and a second switch and a coil, in particular a storage choke.

In an advantageous, easy-to-implement embodiment, the voltage control device is designed according to an H-bridge with a first and a second series circuit whose Mittenabgriffe are connected by a bridge branch. The first series connection of the circuit formed according to an H-bridge is in this case electrically connected in parallel to the output of the inverter, in particular to the DC link capacitor, and the second series circuit is electrically connected in parallel to the input of the traction battery cell network, i. e. parallel to the capacity or total capacity of the traction battery cell assembly.

Each of the series circuits in this case includes a switch and a diode, wherein the center taps of the series circuits via a coil, in particular a storage inductor in the bridge branch of the H-bridge, are connected. The switches are preferably formed by means of MOSFETs or IGBTs or generally as transistorized switches or power switches. The diodes are arranged in the respective series circuit such that their forward direction is in each case opposite to the voltage direction of the voltage or terminal voltage of the traction battery cell network at its input, ie the voltage direction at the input and output terminals of the respective series circuit is opposite to the forward direction of the respective diodes.

It is provided that the first series circuit, which is connected in parallel to the intermediate circuit capacitor, in the voltage direction of the voltage at the input of the traction battery cell assembly, a switch and a diode, the second series circuit, which is connected in parallel to the input of the traction battery cell assembly, in the voltage direction of the voltage at the input thereof has a diode and a switch. Further electronic components are advantageously not required for the voltage regulation device.

To the traction battery cell group, i. e. the battery cells of the same, to be able to load defined by means of the voltage regulating device is further provided to form the electrical connection of the inputs of the first and the second series circuit of the H-bridge selectively interruptible. Due to the interruption, the voltage regulation device can be activated for a charging process, in particular because the direct electrical connection between a connection of the intermediate circuit capacitor or the inverter output and a connection of the traction battery cell network is interrupted and current paths now occur within the voltage regulation device. For selective interruption, a battery contactor can advantageously be used, which as a rule is part of a traction battery formed by means of the traction battery cell assembly. Alternatively, an additional switch may be provided to selectively bypass the voltage regulation device. The outputs of the first and second series circuits are electrically connected.

In one embodiment, it is provided that the inverter on the drive side is selectively connectable to a single- or multi-phase designed, in particular external power supply device. The power supply device may, for. B. by means of a 110 V, 230 V or 400 V alternating or three-phase connection, which z. B. is provided by a public electric charging station. For selective connection, the charging control system may comprise at least one switch, in particular per phase, which makes it possible to connect the power supply device to drive-side power supply connections of the inverter. In this case, the inverter is designed in particular to charge the battery as a rectifier, preferably as a passive rectifier, in particular to provide connectable to the traction battery cell network output DC or DC power supplied by the power to the power supply connections. In this case, the output voltage of the inverter can be greater or smaller than the battery voltage of the traction battery cell network at the input thereof.

During the charging operation, the inverter can be selectively separated from an electric motor, preferably an induction motor, on the drive side. For separation at least a second switch is provided, in particular per strand winding, which interrupts the electrical connection of the winding strands of the electric motor to the inverter.

In an alternative embodiment, it is provided that the charging control system comprises a rectifier, in particular a passive rectifier, which is connected to the battery-side output of the inverter, in particular connected in parallel thereto, d. H. towards the traction battery after the DC link capacitor. When charging the battery, the electric machine is at a standstill and the inverter is not clocked.

In this case, the rectifier is preferably also advantageously designed for connection to an external, single-phase or multi-phase power supply device as described above, which can be provided by a charging station.

By means of the charge control system according to the invention can be easily formed onboard charger. The voltage regulation device can advantageously be integrated into a traction battery formed by means of the traction battery cell assembly or, alternatively, be accommodated, for example, at the inverter. In the latter case, isolating contactors are preferably likewise accommodated on the inverter, in particular in a common housing. Alternatively, it is also conceivable to integrate the voltage regulation device and / or the isolating contactors in a separate device.

Further features and advantages of the invention will become apparent from the following description of exemplary embodiments of the invention, with reference to the figures of the drawings which show essential to the invention, and from the claims. The individual features can be realized individually for themselves or for several in any combination in a variant of the invention.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

1 an example charging system, wherein the inverter can act as a rectifier and selectively separable with an electric motor and an external power supply device is connectable;

2 By way of example, a charge control system, wherein the voltage regulation device in contrast to 1 is integrated in the inverter;

3 an exemplary charge control system, wherein a rectifier is connected in parallel to the inverter; and

4 By way of example, a charge control system, wherein the voltage regulation device in contrast to 3 is integrated in the inverter.

In the following description of the figures, the same elements or functions are provided with the same reference numerals.

1 shows a charge control system 1 for a traction battery cell assembly 2 of a motor vehicle. The charge control system 1 is intended to be the traction battery cell assembly 2 to apply for a purpose of charging or during a charging operation with a defined voltage level or charging voltage level.

The traction battery cell network 2 has at least one battery cell 3 on which in the. Equivalent circuit 4 as an RC element 5 is shown, each battery cell due to their structure, a capacity and the totality of. Cells or the cell network 2 thus again provides or forms a capacity or total capacity. Interconnected battery cells 3 are in the equivalent circuit diagram 4 represented as RC elements in series connection. The traction battery cell network 2 has an entrance 6 on, which by means of terminals 6a and 6b is formed and to which a voltage in the arrow direction of the arrow A is applied. Here, the terminal forms 6a one positive pole, the terminal 6b a negative pole.

The charge control system 1 also has a drive inverter or inverter 7 with a power unit, which is formed by means of power semiconductor switches, in particular in the form of MOSFETs or IGBTs, and is controlled by control electronics. The battery-side or supply-side connection or output 8th of the inverter or its power unit is by means of an intermediate circuit capacitor 9 formed, which parallel to the terminals 8a and 8b of the inverter 7 is switched. About the exit 8th of the inverter 7 a DC voltage is provided for the charging operation, the terminal 8a a plus and a clamp 8b forms a negative pole. The voltage provided may be higher or lower than the voltage of the traction battery cell assembly 2 be. The inverter works to provide a DC voltage 7 in charging mode as a rectifier, in particular as a passive rectifier. For this purpose, the power electronics of the inverter 7 suitably controlled.

To a designated, defined charging voltage for the traction battery cell assembly 2 at its input terminals 6a and 6b to be able to adjust is by means of the capacitances of the DC link capacitor 9 and the traction battery cell assembly 2 a DC chopper 10 formed, wherein the DC adjuster 10 In particular, no additional capacitors has or need to be used. Thus, the DC chopper functionality can be realized easily and inexpensively. The capacities of the DC link capacitor 9 and the traction battery cell assembly 2 form insofar input or output capacitances of the DC adjuster 10 ,

The DC-DC converter 10 which operates as a step-up converter or alternatively as a step-down converter as a function of the intended charging voltage level in the charging mode, furthermore comprises an electrical circuit or voltage regulating device 11 with a first 12 and a second diode 13 , a first 14 and a second one 15 Switch and a coil 16 , in particular in the form of a storage throttle. Further electronic components have the voltage regulation device 11 besides not advantageous.

The tension control device 11 of the DC actuator 10 has a first series connection according to an H-bridge 17 pointing towards the traction battery cell assembly 2 parallel to the battery-side output 8th of the inverter 7 is connected, ie in particular parallel to the DC link capacitor 9 is switched. The first or input terminal 17a the series connection 17 is with the clamp 8a of the inverter 7 electrically connected, the second or output terminal 17b the series connection 17 is with the clamp 8b of the inverter 7 electrically connected. It should be noted that a tap is generally referred to as a terminal.

A second series connection 18 the voltage regulation device designed according to an H-bridge 11 is parallel to the entrance 6 of the traction battery cell assembly 2 switched, with the first or input terminal 18a the second series connection 18 with the clamp 6a , the second or output terminal 18b the second series connection 18 with the clamp 6b electrically connected. The center taps 17c . 18c the series connections 17 . 18 are via the coil 16 in the bridge branch 19 electrically connected. The first series connection 17 here has the first switch 14 and the first diode 12 on, the second series connection 18 the second switch 15 and the second diode 13 , The switches 14 . 15 are by means of MOSFETs or alternatively z. B. IGBTs formed and arranged such that, depending on their switching state, the electrical connection between the terminals 17a and 17b respectively. 18a and 18b is selectively interruptible and manufacturable. The output terminals 17b . 18b the series connections 17 . 18 are electrically connected.

Within the voltage regulator formed according to an H-bridge 11 are the diodes 12 respectively. 13 in the respective series connection 17 respectively. 18 arranged such that their forward direction according to the arrow direction of the arrow B respectively opposite to the voltage direction of the voltage of the traction battery cell assembly 2 at the entrance 6 according to arrow A. The arrangement of the components of the voltage control device 11 is here such that the first series circuit 17 in the voltage direction A of the traction battery cell assembly 2 the switch 14 and the diode 12 , the second series connection 18 in voltage direction A the diode 13 and the switch 15 in each case in this order.

The charge control system 1 is further configured such that the electrical connection of the inputs or terminals 17a and 18a the first 17 and the second 18 Series connection of the H-bridge is selectively interruptible. For selective interruption of the electrical connection between the terminals 17a and 18a indicates the charge control system 1 a switch 20 on which advantageous by a contactor of means of traction battery cell assembly 2 formed traction battery 2a is formed, which is the input terminal 6a of the traction battery cell assembly 2 is connected in series. The traction battery 2a has next to usual manner z. B. another contactor 21 on.

The inverter 7 of the charge control system 1 is the drive side with a multi-phase designed power supply device 22 selectively connectable, which alternatively or additionally z. B. can be designed single phase. For selective connection, the charge control system 1 Here, switches S1 ... S3 with associated connection lines, which are suitable, strand supply connections 23 for connection to the external power supply device 22 phase-correct electrical to the inverter 7 to energize the same on the drive side.

Furthermore, the charge control system 1 Switch S4 ... S6 along with associated connection lines, which are suitable for a charging operation, the connection of the inverter 7 with the electric motor 24 to interrupt selectively. For controlling the respective switches S1... S3 and S4... S6, the inverter control is advantageously used.

By means of the power supply device 22 supplied energy is the inverter 7 at the exit 8th in charging mode, ie with the switch open 20 , DC voltage available. Here is the e-machine 24 by means of switches S4 ... S6 from the inverter 7 disconnected, while the switches S1 ... S3 are each closed and thus the electrical connection to the power supply device 22 produce. After loading, the switches S1 ... S3 are opened, the electrical connection to the electric motor 24 can be made via the switches S4 ... S6.

2 shows an embodiment of the charge control system 1 wherein the tension control device 11 as well as the switches 20 . 21 at the inverter 7 are received, in particular in the housing 7a , Alternatively, the voltage regulation device 11 , as in 1 shown part of the traction battery 2a be.

3 shows an embodiment of a charge control system 1 , where the charge control system 1 in addition to the inverter 7 a rectifier 25 having. The inverter 7 forms here z. B. no own rectifier functionality. The rectifier 25 is in particular a passive rectifier 25 and the battery side output 8th of the inverter 7 switched on, ie the DC link capacitor 9 towards the traction battery cell assembly 2 connected in parallel and the voltage control device 11 connected in parallel. This is a connection line 25a of the rectifier 25 with the clamp 8a electrically connected, a second connecting line 25b is with the clamp 8b electrically connected.

The rectifier 25 is for connection to an external multi-phase power supply device 22 trained, z. B. by providing a suitable connector device. Alternatively or additionally, the rectifier for Connection with a single-phase power supply device 22 be educated.

4 shows an alternative embodiment of the charge control system 1 wherein the tension control device 11 at the inverter 7 is received or arranged, in particular in the housing 7a the same is integrated. The switches 20 and 21 are also on the inverter 7 added.

To operate in the 1 to 4 shown charge control system 1 will be the electrical connection between the terminals 6a and 8a interrupted, ie the switch 20 , in particular in the form of a battery contactor, opened. This will cause the voltage regulation device 11 activated, ie the DC for charging the traction battery cell group 2 is through the voltage regulation device 11 forced. After establishing the electrical connection to the external power supply device 22 Current now flows through the voltage control device 11 to the traction battery cell network 2 ,

Thus the DC-DC converter 10 or the voltage regulation device 11 in buck converter mode, the switch becomes 15 permanently open and the switch 14 clocked accordingly. The charging voltage for the traction battery cell network 2 is thus lowered. For working in boost converter operation, the switch 14 permanently closed while the switch 15 is clocked accordingly. The charging voltage for the traction battery cell network 2 can be raised. In both modes, the electrical energy in the storage choke 16 saved. The control of the switches 14 and 15 is done by a battery control of the traction battery 2a or alternatively by a controller of the inverter 7 , But it is also conceivable that the voltage regulation device 11 has its own controller.

After a loading, the switch 20 closed, ie the voltage control device 11 bridged and thus deactivated.

LIST OF REFERENCE NUMBERS

1

Charge Control System

2

Traction battery cell assembly

2a

traction battery

3

battery cell

4

Equivalent circuit

5

RC element

6

Entrance traction battery

6a, b

jam

7

inverter

7a

casing

8th

connection

8a, b

terminals

9

Link capacitor

10

DC chopper

11

Voltage control device

12

first diode

13

second diode

14

first switch

15

second switch

16

Power inductor

17

first series connection

17a, b

jam

17c

center tap

18

second series connection

18a, b

jam

18c

center tap

19

bridge branch

20

Switch (contactor)

21

contactor

22

Power supply device

23

Strand supply connections

24

E-machine

25

rectifier

25a, b

connecting line

A

Direction of voltage at the entrance traction battery

B

Forward direction diodes

S1 ... S3

switch

S4 ... S6

switch

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19652950 A1 [0002]
• EP 0849112 A1 [0002]
• DE 102005041825 A1 [0002]

Claims (11)

Charge control system ( 1 ) for a traction battery cell assembly ( 2 ) of a motor vehicle, comprising a traction battery cell network ( 2 ) and one with this via a DC link capacitor ( 9 ) connected inverters ( 7 ), the charge control system ( 1 ) a DC chopper ( 10 ), which as a step-up or step-down converter in the direction of the inverter ( 7 ) to the traction battery cell network ( 2 ), characterized in that the capacitances of the DC adjuster ( 10 ) for operating the same in the respective operating mode, in particular input and output capacities, by means of a connection to the traction battery cell network ( 2 ) adjusting capacity and the DC link capacitor ( 9 ) are formed, in particular exclusively. Charge control system ( 1 ) according to claim 1, characterized in that the means of the capacitors of the DC link capacitor ( 9 ) and the traction battery cell network ( 2 ) formed DC chopper ( 10 ) further comprises an electrical circuit ( 11 ) with a first ( 12 ) and a second ( 13 ) Diode, a first ( 14 ) and a second ( 15 ) Switch and a coil ( 16 ), in particular a storage throttle. Charge control system ( 1 ) according to one of the preceding claims, characterized in that the DC-DC converter ( 10 ) an electrical circuit ( 11 ) according to an H-bridge, wherein a first series circuit ( 17 ) of the H-bridge parallel to the battery-side output ( 8th ) of the inverter ( 7 ), in particular to the intermediate circuit capacitor ( 9 ), and a second series circuit ( 18 ) parallel to the entrance ( 6 ) of the traction battery cell network ( 2 ), the center taps ( 17c . 18c ) of the series circuits ( 17 . 18 ) via a coil ( 16 ), in particular a storage inductor, and wherein each series circuit ( 17 . 18 ) a switch ( 14 . 15 ) and a diode ( 12 . 13 ) having. Charge control system ( 1 ) according to claim 3, characterized in that the diodes ( 12 . 13 ) in the respective series circuit ( 17 . 18 ) are arranged such that their forward direction (B) in each case opposite to the voltage direction (A) of the voltage of the traction battery cell assembly ( 2 ) at the entrance ( 6 ). Charge control system ( 1 ) according to one of claims 3 or 4, characterized in that the first series circuit ( 17 ) in the voltage direction (A) of the voltage at the input ( 6 ) of the traction battery cell network ( 2 ) a switch ( 14 ) and a diode ( 12 ), the second series circuit ( 18 ) in the voltage direction (A) a diode ( 13 ) and a switch ( 15 ) in each case in this order. Charge control system ( 1 ) according to one of claims 3 to 5, characterized in that the electrical connection of the inputs ( 17a . 18a ) the first ( 17 ) and the second ( 18 ) Series connection of the H-bridge is selectively interruptible and the outputs ( 17b . 18b ) of the first and second series circuits are electrically connected. Charge control system ( 1 ) according to claim 6, characterized in that the electrical connection of the inputs ( 17a . 18a ) by means of a contactor ( 20 ), in particular a traction battery ( 2a ), is selectively interruptible. Charge control system ( 1 ) according to one of the preceding claims, characterized in that the inverter ( 7 ) on the drive side selectively with a single- or multi-phase designed power supply device ( 22 ) is connectable, in particular by means of at least one switch (S1 ... S3), wherein the inverter ( 7 ) is further adapted to charge the traction battery cell assembly ( 2 ) to act as a rectifier, in particular with the traction battery cell network ( 2 ) connectable output ( 8th ) To provide DC or DC by means of the supplied energy. Charge control system ( 1 ) according to one of the preceding claims, characterized in that the inverter ( 7 ) on the drive side selectively from an electric motor ( 24 ) is separable, in particular by means of at least one switch (S4 ... S6). Charge control system ( 1 ) according to one of claims 1 to 7, characterized in that the charge control system ( 1 ) a rectifier ( 25 ), in particular a passive rectifier ( 25 ), which is the battery-side output ( 8th ) of the inverter ( 7 ), in particular connected in parallel thereto. Charge control system ( 1 ) according to claim 10, characterized in that the rectifier ( 25 ) for connection to an external, single or multi-phase power supply device ( 22 ) is trained.

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