WO2012066045A2

WO2012066045A2 - Charge system for charging a battery of a vehicle with a two-way charge controller

Info

Publication number: WO2012066045A2
Application number: PCT/EP2011/070268
Authority: WO
Inventors: Mathias Deiml
Original assignee: Avl Software And Functions Gmbh
Priority date: 2010-11-16
Filing date: 2011-11-16
Publication date: 2012-05-24
Also published as: WO2012066045A3; CN103328253B; DE102010051323A1; CN103328253A; DE102010051323B4; EP2640595A2

Abstract

The invention relates to a charge system for charging a battery of a vehicle, where in the charge system comprises at least one converter for converting an alternating voltage into a direct voltage when the battery is charged as well as for converting a direct voltage into an alternating voltage when an electric motor is operated by the battery, a power system charge connection for connecting an external power supply system to the converter and at least a first switching unit for disconnecting an electrically conductive connection between the converter and the electric motor, with the charge system also having a two-way charge controller which is directly connected to the battery in such a way that it can be disconnected by a third switching unit and has the purpose of stepping down an input charge voltage from the external power supply system during the charging process of the battery and on stepping up an input charge voltage from the battery for charging a capacitor which is connected in parallel between the two-way charge controller and the converter, wherein the two-way charge controller has a charge circuit which is independent of an operating circuit for operating the electric motor by the battery, comprising the battery for charging the battery and the capacitor, wherein the charging circuit comprises a first positive conductor and a negative conductor.

Description

Charging system for charging a battery of a vehicle with a two-way charge controller

description

The present invention relates to a charging system for charging a battery of a vehicle according to the preamble of claim 1.

Due to the progressive development with respect to the drives of a vehicle, electric motors are increasingly being used, either in hybrid drives, by one or more electric motors being drive-coupled with an internal combustion engine, or as sole drive motors for driving a purely electrically operated vehicle, such as a passenger car , a moped or moped or even a bicycle. Electric motors, which are preferably used in hybrid drives together or in addition to the internal combustion engines, are usually connected to a battery or a rechargeable battery, which, for example. be supplied by the brake power recovery and during operation of the internal combustion engine with electrical energy to charge accordingly. Consequently, it is not necessary to supply this battery via an external power supply network, e.g. while the vehicle is parked, in addition to charge.

The situation is different with purely electrically operated vehicles, in which only one or more electric motors take over the drive of the vehicle. It is understood borrowed that here the battery supplying the electric motor with electric power can also be supplied by electrical energy, for example, the brake force recovery, but this energy recovery is not sufficient to, for example, a To move a car over a longer distance. In addition, additional energy converters, such as the internal combustion engine in the hybrid drives omitted. Consequently, it is necessary to additionally charge the battery of this electric vehicle by means of, for example, external power grids.

The arranged in the vehicle charging system has for this purpose in addition to the battery and the electric motor to internal knowledge usually a converter for converting a DC voltage into an AC voltage when operating the electric motor and for converting an AC voltage into a DC voltage when charging the battery, a power grid charging port for connecting of the external power supply network and a voltage adjustment module for adapted charging of the battery according to the charging characteristic of the battery.

In most cases, especially the voltage adjustment module, which is used for example during charging of the battery, or its components are so highly dimensioned that both the useful power of the electric motor, which may be about 100KW, for example, is performed as well over the voltage adjustment module, as well Mains power of the external power supply network for charging the battery. Accordingly, it is the object of the present invention to provide a charging system for charging a battery of a vehicle having a two-way charge controller, which uses only small, needs-sized components due to its circuit arrangement, whereby the charging system is inexpensive and space to produce optimized , and which also has a reduced number of power semiconductors used in the construction of the charging system, thus simplifying the manufacture of the charging system.

This object is achieved by the present invention by means of a charging system for charging a battery of a vehicle according to claim 1.

Accordingly, a charging system for charging a battery of a vehicle is claimed, wherein the charging system has at least one converter for converting an AC voltage into a DC voltage when charging the battery and for converting a DC voltage into an AC voltage when operating an electric motor by the battery, a power grid charging port for connecting an external power supply network to the inverter, and at least one first switching unit for separating an electrically conductive connection between the inverter and the electric motor. In this case, the charging system according to the invention is characterized by a directly and by means of a third switching unit interruptible connected to the battery two-way charge controller for charge-subsetting an input voltage from the external power supply network during the charging of the battery and charge-boosting an input voltage from the battery Charge a capacitor connected in parallel between the two-way charge controller and the inverter. In addition, the two-way charge controller has a charging circuit independent of an operating circuit for operating the electric motor by the battery with the battery for charging the battery and the capacitor, wherein the charging circuit comprises a first positive conductor and a negative conductor. As a result, it is possible for the battery, for example via the charging circuit and in particular via the plus conductor, to conduct an electric current to the two-way charge controller, so that the latter, preferably in the form of a boost converter, converts the input voltage generated by the battery into a higher one Output voltage converts to charge the capacitor or the DC link capacitor.

The charging of the capacitor to a maximum voltage or to a voltage which is higher than the voltage of the external power supply network is especially important before plugging in the power supply socket to an external power grid to avoid inrush surges and consequently the battery, as well to protect the external power supply network itself against damage.

For example, the capacitor in an intermediate circuit, which also has the parallel to the capacitor connected two-way charge controller and the battery connected in parallel, arranged.

When the capacitor is charged, the two-way charge controller or the electrical components provided for it are dimensioned, for example, to approximately 50W only.

A second mode of operation of the two-way charge controller is the charge of the battery or the vehicle battery, in this case, the two-way charge controller as a buck converter or Down converter acts to charge the battery by means of a network performance of the external power supply network, which has the usual characteristics, such as 220 to 240V (single-phase AC mains) or about 400V (three-phase network). For this purpose, the two-way charge controller or the electrical components provided for this purpose, for example, to about 3 to 100kW, preferably to about 5 to 50kW and more preferably to about 10 to 25kW dimensioned to allow fast charging of the battery without damaging, overcharging or fully charging the battery, monitoring and, in particular, controlling and regulating the charging and discharging

Discharge currents from and to the battery is effected, for example, by means of a charge control element, which is preferably a component of the two-way charge controller, which prevents overcharging and / or incomplete charging of the battery by controlled monitoring of the charge characteristics of the battery.

Consequently, the two-way charge controller is also able to detect the charging characteristics of the battery to allow a tuned charging the battery, for example by adjusting the charging current or the charging voltage. Consequently, the two-way charge controller is dimensioned to a necessary charging power and therefore does not have to be designed for a maximum traction power, whereby additional components are saved in contrast to the conventional charging systems.

It should also be noted that in order to allow a charging of the battery, the line between the electric motor and the at least one inverter should be separated by means of, for example, the first switching unit, which consists of at least one electrical switch. This prevents that the electric motor electrical energy of the external power supply network is supplied, which could be driven. An additional locking of the vehicle during the charging of the battery is therefore not required.

The two-way charge controller itself is connected in a circuit independent of the operating circuit. That is, the operating circuit used for operating the electric motor by the battery, and thus comprising at least the battery, the electric motor and the inverter, regardless of the charging circuit, which for charging the battery and the capacitor is used and at least the battery, the two-way charge controller and the capacitor and / or the inverter comprises, is connected.

Thus, an electric current flow controlled by the two-way charge regulator flows only through the charging circuit, which has for this purpose a first positive conductor which is connected to the positive pole of the battery and a negative conductor which is connected to the negative pole of the battery.

In a preferred embodiment, the negative conductor of the charging circuit corresponds to the negative conductor of the operating circuit.

Accordingly, the operating circuit has a second positive conductor and a negative conductor common to the charging circuit, wherein the operating circuit is interruptible by means of a second switching unit connected to the second positive conductor.

However, it is also conceivable that the charging circuit has a negative conductor independent of the operating circuit, which runs from the negative pole of the battery, via the two-way charge controller to, for example, to the intermediate circuit capacitor. The operating circuit may preferably be interrupted by means of the second switching unit to allow charging of the capacitor or the battery by means of the charging circuit.

Wrd the second switching unit, which preferably consists of an electrical switch is activated so that an electric current can flow through the operating circuit (switch on), then takes place at a still switched charging circuit bridging this charging circuit, thereby discharging the battery via the operating circuit and consequently comes to the operation or drive of the electric motor. Consequently, this second switching unit serves as galvanic isolation of the battery from the electric motor.

The charging circuit can also be separated from the battery during the drive of the electric motor by the battery, for example by means of a third switching unit (switch of the third switching unit is open). In a preferred embodiment, the first positive conductor of the charging circuit has a first line section from the capacitor to the two-way charge controller and a second line section from the two-way charge controller to a positive pole of the battery, wherein the second switching unit between the charging circuit and the positive pole of the Battery is switched.

Consequently, the charging circuit "bypasses" the second switching unit and consequently can not be interrupted by it., For example, the converter and preferably the DC side of the converter are also connected to the positive conductor or to the first line section of the positive conductor.

It is also conceivable that, based on the arrangement of the first positive conductor of the two-way charge controller is connected to an independent of the operating circuit second negative conductor to the negative terminal of the battery. As a result, for example, this second negative conductor of the charging circuit would have a first line section from a negative terminal of the battery to the two-way charge controller and a second line section from the two-way charge controller to the condenser.

In a preferred embodiment, for example, the inverter and preferably the DC side of the inverter is connected to the negative conductor.

As a result, the two-way charge controller is preferably connected in parallel with the battery and / or preferably in parallel with the capacitor and / or with the converter.

In a further preferred embodiment, the two-way charge controller has at least two power switches as electronic components, each power switch each comprising a transistor in parallel with a diode.

This makes it possible, for example, to conduct a rectified electric current coming from the battery via a power switch to the capacitor in order to charge the latter. On the other hand, it is possible to transport an electric current rectified by the inverter and the capacitor via a power switch to the battery, thus charging the battery. Preferably, the two-way charge controller has at least one charge control element for charging power and control of the battery, which is preferably connected at least to the circuit breakers of the two-way charge controller and / or to the third switching unit of the two-way charge controller. It is also conceivable that the charging control element is connected to, for example, a precharging circuit, which preferably consists of a resistor and a switching unit, this precharging circuit preferably being a component of the two-way charge controller and, for example, during charging or before charging the intermediate - Circular capacitor is used to prevent damage to the DC link capacitor due to excessive power surges from the battery.

By means of the charge control element it is possible, for example, to determine the required charging power of the battery, e.g. to generate a defined voltage when charging the battery. This is necessary due to the fact that the battery itself, which z. B. for the drive of the electric motor about 100kW power available, but even with about 3 to 100kW, preferably with about 5 to 50kW and more preferably with about 10 to 25kW from the external power grid is loadable.

It should also be noted that the capacitor is not only used as a smoothing capacitor in the conversion of the alternating current into direct current, but is also used for temporary storage of electrical energy to avoid, for example inrush surges when plugging the power grid charging connection to the external power grid. For this, the capacitor is charged by means of electrical energy of the battery, which is transported by the two-way charge controller, so that ultimately the capacitor or the intermediate circuit has a higher voltage than the voltage of the external power supply network. In a further preferred embodiment, the inverter has at least two power switches per phase, each comprising a transistor in parallel with a diode, the two power switches being connected in series, and the power grid charging terminal being connected to a node between the two power switches. is closing.

Accordingly, the power grid charging terminal is preferably located on the AC side of the inverter to supply electrical power received from the external power grid to an inverter.

Furthermore, the converter preferably comprises three series circuits connected in parallel to each other, each comprising at least two power switches, wherein the series circuits are each connected in parallel to the capacitor. In a further preferred embodiment, the inverter is a double converter, which has a first and a second converter or inverter for converting the DC voltage of the battery into an AC voltage for the electric motor when operating the electric motor or an AC voltage of the external power supply network in a DC voltage for the battery during the charging of the battery, wherein the electric motor is connected in each case with the first and the second inverter.

In a further preferred embodiment, the first switching unit, for example, two switches or switching units, which are each connected between the first and the second inverter, so that these switching units can each separate a connection between the two converters.

It is also conceivable that the electric motor is a three-phase motor connected in a star connection, which is consequently connected between the two inverters or inverters of the double converter.

In addition, it is possible that the two-way charge controller is part of the battery and therefore not a separate electrical component. Further advantages, objects and characteristics of the present invention are explained with reference to the following description of the appended drawing, in which two circuits of embodiments of the charging system according to the invention are shown by way of example. Components which at least substantially coincide in the figures with respect to their function may in this case be identified by the same reference symbols, these components not having to be identified and explained in all figures.

In the figures show:

1 shows a circuit of a first embodiment of the charging system according to the invention with a double converter, and

2 shows a section of a circuit of a second embodiment of the charging system according to the invention.

In Fig. 1, a circuit of a first embodiment of the charging system 1 according to the invention with a double inverter 2, which consists of a first inverter 2a and first inverter 2a and a second inverter 2b and second inverter 2b, an electric motor 3, a DC link capacitor 4 or capacitor 4, a two-way charge controller 5 and a battery 6 shown.

The two inverters 2 a and 2 b each have three series circuits arranged parallel to one another, which are composed of two series-connected power switches 7. Each power switch consists of a diode 8, which is connected in parallel with a transistor 9.

The electric motor 3 is connected between the respective series-connected circuit breakers and consequently connected to both converters 2a and 2b. The capacitor 4 is connected in parallel to the converters 2a and 2b and to the two-way charge controller 5 and the battery 6.

The power grid charging terminal 10 is connected at a node between each of the two series-connected circuit breakers 7 of the first inverter 2 a and the motor 3. Before the charging process, the first switching unit, which consists of two switching units or switches 1 1a and 1 1 b shown in FIG. 1, switched such that an electrically conductive connection between the motor 3 and the power grid charging terminal 10 and the first inverter 2a is interrupted or disconnected (switch open). This positioning of the first switching unit 11 a, 11 b also remains during the entire charging process, so that during the charging of the battery 6 by means of electrical energy from an external power supply network (not shown here) no electric current to the motor 3 can flow. This avoids the risk of the engine 3 being driven during the charging process and the vehicle starting to move.

The two-way charge controller 5 is connected via a charging circuit which has a positive conductor 12 a, 12 b and a negative conductor 13 with the battery 6 and the DC link capacitor 4. The positive conductor 12a, 12b is composed of a first wiring harness or section 12a, which connects at least the capacitor 4 to the two-way charge controller 5, and a second line section 12b, which connects the two-way charge regulator 5 to the positive pole 6a of the battery 6 connects, together. The negative conductor 13 corresponds according to the Fig.1 the negative conductor of the operating circuit.

The charging circuit is preferably used either to charge the capacitor 4 by means of the electrical energy of the battery 6 or to charge the battery 6 by means of the electrical energy of the external power supply network.

In contrast, an independent of the charging circuit operating circuit with a second positive conductor 14 which is connected to the positive terminal 6a of the battery 6 and the negative conductor 13, which is connected to the negative terminal 6b of the battery 6 of the battery 6 from. In addition, the operating circuit has a second switching unit 15 which is connected to the positive conductor 14 and which, for example, interrupts the

Operating circuit causes when e.g. the capacitor 4 or the battery 6 is charged or should be.

If the switch 15 or the second switching unit 15 is closed and thus enables an electrically conductive operating circuit, the battery 6 is discharged to drive the electric motor 3. As a result, power is only supplied via the operating circuit when the electric motor 3 supplies electrical energy shall be. According to FIG. 1, the battery 6, the inverters 2 a, 2 b or the double converter 2 and the electric motor 3 are connected to this operating circuit.

It is conceivable that the two-way charging port 5 is a component of the battery 6.

2 shows a section of a circuit of a second embodiment of the charging system 1 according to the invention. Here, only one converter 2a is listed, but which shows the same construction as the converter 2a of FIG. 1 and accordingly should not be explained further here. Also, the DC link capacitor 4 is again connected in parallel to the two-way charge controller 5 and the battery 6.

The two-way charge controller 5 also has two power switches 7, each having a diode 8 connected in parallel with a transistor 9. In addition, between the two circuit breakers 7 of the two-way charge controller 5, a precharge circuit, which consists of a Wder- stand 23 and a to the Wderstand 23 in parallel fourth switching unit 24, connected.

Furthermore, an inductance 21 or coil 21 with a third switching unit 22 is connected in series with the positive pole 6a of the battery 6. As a result, it is possible for example during charging of the intermediate circuit capacitor 4 by the battery 6 to deactivate the second switching unit 15, which according to FIG. 2 consists of two switching units 15a and 15b or two switches 15a and 15b or the switches 15a and 15b 15 b open, so that no electric current can flow through the operating circuit, the third switching unit 22 is activated or closed. As a result, an electric current via the positive conductor of the charging circuit to the coil 21, which serves as a magnetic latch when charging the capacitor 4, and continue to flow to the precharge circuit.

If the fourth switching unit 24 is deactivated, i. opened, so the precharging of the capacitor 4 via the resistor 23, in order to avoid damage to the capacitor 4 due to, for example, power surges.

If the capacitor voltage reaches predetermined values or the values of the battery voltage, the fourth switching unit 24 is preferably activated or closed, whereby the electric current can flow unhindered via the corresponding power switch 7 to the capacitor 4, so that it is possible to increase the capacitor voltage he- heights that this ultimately exceeds the battery voltage. This corresponds to the operation of a boost converter or a boost converter.

The charging control element 20 is connected to the circuit breakers 7 of the two-way charge controller 5 and the third 22 and fourth switching unit 24 and controls or regulates, preferably the charging of the battery 6 so that it can not be overcharged or the charge of the Battery is not prematurely terminated, although this is not fully charged. In addition, it is possible that the charging control element 20 and the charging of the

DC link capacitor 4 controls and regulates, so that raising the

Capacitor voltage above the value of the battery voltage can be done without the capacitor is damaged during charging. Thus, it is up to the charge control element 20 to drive the power switches 7 of the two-way charge controller, respectively according to their function to be performed, to charge either the capacitor through the battery or the battery through an external power supply network. It should be noted that the third switching unit 22 is preferably a component of the two-way charge controller 5 and is not part of the battery 6,

The Applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided that they are novel individually or in combination with respect to the prior art.

LIST OF REFERENCE NUMBERS

1 charging system

2 double inverters

2a first inverter

2b second inverter

3 electric motor

4 DC link capacitor 5 two-way charge controller

6 battery

6a positive pole of the battery

6b negative pole of the battery

7 circuit breakers

8 diode

9 transistor

10 power supply charging port

11 a first switch of the first switching unit

11 b second switch of the first switching unit

12a first line section of the first positive conductor

12b second line section of the first positive conductor

13 negative conductor

14 second positive conductor

15 second switching unit

15a first switch of the second switching unit

15b second switch of the second switching unit

20 charging control element

21 inductance

22 third switching unit

23 resistance

24 fourth switching unit

Claims

claims

Charging system (1) for charging a battery (6) of a vehicle, the charging system (1) comprising:

at least one inverter for converting an AC voltage into a DC voltage when charging the battery (6) and for converting a DC voltage into an AC voltage when operating an electric motor (3) by the battery (6), a power supply charging port (10) for connecting an external Power supply network to the inverter,

and at least one first switching unit (11a, 11b) for separating an electrically conductive connection between the converter and the electric motor (3),

marked by

an immediately and by means of a third switching unit (22) interruptible connected to the battery (6) connected two-way charge controller (5) for charge-subsetting an input voltage from the external power supply network during the charging of the battery (6) and to load-boosting a Input voltage from the battery (6) for charging a between the two-way charge controller (5) and the inverter (2, 2a, 2b) connected in parallel capacitor (5), wherein the two-way charge controller (5) one of an operating circuit for operating the electric motor (3) by the battery (6) independent charging circuit with the battery (6) for charging the battery (6) and the capacitor (4), wherein the charging circuit, a first positive conductor (12a, 12b) and a negative conductor (13).

Charging system according to claim 1,

characterized in that

the operating circuit has a second positive conductor (14) and a negative conductor (13) common to the charging circuit, the operating circuit being interruptible by means of a second switching unit (15, 15a, 15b) arranged on the second positive conductor (14).

3. charging system according to one of claims 1 or 2,

characterized in that

the first positive conductor (12a, 12b) has a first line section (12a) from the condenser (4) to the two-way charge controller (5) and a second line section (12b) from the two-way charge controller (5) to a positive pole (6a) the battery (6), wherein the second switching unit (15) is connected between the charging circuit and the positive pole (6a) of the battery (6).

4. charging system according to one of the preceding claims,

characterized in that

the two-way charge controller (5) is connected in parallel to the battery (6).

5. charging system according to one of the preceding claims,

characterized in that

the two-way charge controller (5) comprises at least two power switches (7), each power switch (7) each comprising a transistor (9) in parallel with a diode (8).

6. charging system according to one of the preceding claims,

characterized in that

the two-way charge controller (5) has at least one charge control element (20) for charging power control and control of the battery (6).

7. charging system according to claim 6,

characterized in that

the charging control element (20) is connected at least to the power switch (7) and / or the third switching unit (22) of the two-way charge controller (5).

8. Charging system according to one of the preceding claims,

characterized in that

the capacitor (4) is used for temporary storage of electrical energy in order to avoid inrush current surges when plugging in the power supply charging connection (10) to the external power supply network.

9. charging system according to one of the preceding claims,

characterized in that

the inverter comprises at least two power switches (7), each comprising a transistor (9) in parallel with a diode (8), the two power switches (7) being connected in series, and the power supply charging terminal (10) a node between the two circuit breakers (7) is connected.

10. Charging system according to one of the preceding claims,

characterized in that

the converter comprises three series circuits connected in parallel to each other, each comprising at least two power switches (7), wherein the series circuits are connected in parallel to the capacitor (4).

11. Charging system according to one of the preceding claims,

characterized in that

the converter is a double converter (2) having a first (2a) and a second converter (2b) for converting the DC voltage of the battery (6) into an AC voltage for the electric motor (3) when operating the electric motor (3) or an AC voltage the external power supply network into a DC voltage for the battery (6) during the charging of the battery (6), wherein the electric motor (3) is connected to each of the first (2a) and the second converter (2b).

12. Charging system according to one of the preceding claims,

characterized in that

the two-way charge controller (5) is part of the battery (6).