DE102018124789A1 - Fast charging device and electric drive system with such a quick charging device - Google Patents

Abstract

The present invention relates to a charging device for charging a battery 7 of a motor vehicle designed with an electric drive motor 2, with an inductor, and a drive converter 3, which converts the DC voltage of the battery 7 for the electric drive motor 2 when the motor vehicle is being driven, the inductance together serves as a step-up converter with the drive converter 3 for charging the battery 7. With the aim of providing an improved and in particular more adaptable charging device, a switching unit 10 is provided in the charging device which is designed to connect a charge source 8, 12 to the battery 7 directly or via the step-up converter.

Description

The invention relates to a device for charging a battery of a motor vehicle equipped with an electric drive motor and to an electric drive system with such a charging device.

Different charging concepts are used to charge electric vehicles. Charging with alternating current via the house socket is available almost everywhere, but only has a low charging power of usually less than 5 kW. In contrast, much faster outputs (50 kW and above) are possible with fast charging at DC sources (DC charging), for example via special charging stations. However, this requires an adjustment of the voltage if the available voltage level of the charging station, typically 400 V DC , is lower than the voltage level of the vehicle battery, for example 800V DC .

Step-up converters, also known under the terms "step-up converter", "boost converter" or "step-up converter", can be used to adjust the voltage level.

DE 10 2016 209 905 A1 shows a quick charging unit for an electric vehicle, the drive converter of the traction motor in conjunction with the motor coils serving as a step-up converter.

DE 10 2009 052 680 A1 shows the one charging device for charging a battery, in which a drive converter serves as a step-up converter for charging the battery. To adapt to a desired charging voltage, the structure on board can be completed by connecting a step-down converter in front of the step-up converter to enable adaptation to almost any DC voltage provided by the infrastructure.

A disadvantage of these aforementioned solutions is that only one charging voltage can be used to charge the battery at a time.

It is an object of the present invention to provide an improved fast charging device for an electric vehicle, in particular a charge device that is more adaptable to charge sources.

To achieve this object, the present invention provides a charging device according to claim 1. The charging device is, in particular, a charging device for charging a battery of a motor vehicle designed with an electric drive motor, with an inductor, and a drive converter which converts the DC voltage of the battery for the electric drive motor when the motor vehicle is being driven, the inductance together with the drive converter serves as a step-up converter for charging the battery. In this case, a switching unit is additionally provided which is designed to connect a charge source to the battery directly or via the step-up converter.

Advantageous developments of the invention are shown in the subclaims. This has the advantage that the charging device can be easily connected to the charge source. The charging device adapts to the properties of the charge source and enables the vehicle battery to be charged effectively without additional settings. The charge source can thus provide a lower or the same high voltage as the vehicle battery, which is connected to the charging device and ultimately to the vehicle battery by means of the switching unit in such a way that the vehicle battery can be charged.

The switching unit is preferably designed to identify a connected charge source. This can be done by the switching unit measuring the voltage of the charge source in advance and / or certain data from the charge source, e.g. wired and / or wireless, reads out. Once the charge source has been identified, depending on the identification, the charge source with the battery is e.g. directly, via the step-up converter or a step-down converter of the charging device. As a result, the charging device is able to identify the connected charge source independently and without external control and to connect / connect it to the vehicle battery. Alternatively or additionally, the switching unit can receive data, e.g. from the charge source, which identifies the charge source and / or controls the switching unit in order to connect the charge source to the vehicle battery accordingly.

In a further advantageous embodiment, the drive converter is designed as a 2-level inverter or as a 3-level inverter. The 3-level inverter can in particular be designed as a neutral point clamped (NPC) or T-shape neutral point clamped (TNPC) inverter.

Furthermore, the drive converter can be designed for three voltage phases and each have a half bridge for supplying each winding of the electric motor.

For charging the battery, one to three half bridges with corresponding inductances are preferably each controlled and stepped up as step-up converters usable. The step-up converters can be used individually or simultaneously, in particular with or without phase shift. The more step-up converters in particular are operated at the same time, the higher the charging power available for the vehicle battery.

In order to save the number of components and thus the costs for the charging device, the inductance required for a step-up converter can be formed by at least one coil / wave winding of the electric motor. A plurality of inductors are preferably provided, all of which are more preferably designed as windings for exciting the drive motor in the form of coil or shaft windings.

The intermediate circuit capacitance of the drive converter can preferably be designed to be variable. This can be done, for example, by one or more additional capacitances which can be connected in parallel and / or in series. These can have switches for coupling and decoupling in charging mode. An intermediate circuit capacitance optimized for driving operation can also be set up, which is decoupled in charging operation and replaced by one or more intermediate circuit capacitances optimized for charging operation, which are connected in charging operation. As a result, the charging device can e.g. be optimized for a loading operation.

Furthermore, it has proven to be advantageous if the electric drive motor is designed to have at least one fluid such as e.g. To use oil and / or water for cooling and in particular to supply it to the at least one coil / shaft winding. This can be done by pumps and / or by appropriately trained inflow / outflow structures, e.g. gravity-driven work, are made possible. In addition, the drive motor can be designed to supply the at least one fluid to additional locations or spaces within or on the engine in charging operation in order to improve the cooling effect. As soon as the engine is put into driving mode, it can be provided that the fluid is removed to such an extent that it is only present at those points which become very hot during driving and / or require lubrication during rotation. This means that drag losses during driving can be minimized. In this respect, there is the possibility, e.g. To carry oil not only in the winding head space sealed with respect to the stator, but also in the stator interior of the electric motor, in particular in the air gap between the stator and rotor.

The charging device, in particular the step-up converter, preferably has at least one cooling system with two mutually independent circuits, a water circuit for the drive converter and an oil circuit for the inductance, in particular for a coil / shaft winding of the electric drive motor. The water circuit can also be designed to cool the stator in addition to the drive converter via a cooling jacket.

The drive motor preferably has a rotor which is cooled during the charging process. It can be provided to cool the rotor from the inside and / or outside with a cooling fluid. It can be provided to make the rotor hollow and flow through it with a cooling fluid. It is also conceivable and possible to flood the interior of the entire drive motor with cooling fluid. Even in the case of cooling the rotor, it is conceivable and possible to use an oil circuit for cooling, preferably the same circuit as for the inductances of the motor.

Furthermore, the oil circuit is preferably designed such that the waste heat from the inductor and / or rotor can be released to a fluid or oil circuit of the drive motor and / or a transmission. Here, the circuit of the drive motor and / or gearbox serves to lubricate and cool moving or rotating components of the drive motor and / or gearbox. This can be, in particular, the bearing lubrication of the engine. The goal of oil heating is to lower the oil viscosity and thus to improve the lubricating effect and the pump performance. The cooling circuit normally gives off its waste heat, i.e. during driving, via a heat exchanger to the water circuit. The charging device can thus additionally be designed to specifically prevent this heat exchanger function so that the oil reaches its target temperature and / or viscosity more quickly, and only then to couple the heat exchanger back in again.

The oil circuit of the cooling system of the charging device preferably forms at least part of the oil circuit of the drive motor and / or transmission or vice versa.

In a further advantageous embodiment, an intermediate circuit center of the drive converter is e.g. Connect or connect via a resistor to an input voltage of the charge source and / or the inductance by means of a compensating conductor. In this case, a switching element can be designed to interrupt the compensating conductor for driving and to close it for charging. Compensating currents can thus flow via the compensating conductor in order to maintain or stabilize the voltage of the intermediate circuit center and to ensure the predetermined function of the step-up converter. The switching element can e.g. act as a contactor, relay or semiconductor switch.

The switching unit is preferably integrated in the housing of an electrical drive system. The components of the switching unit are preferably integrated with the components of the drive system, in particular the drive converter. Common components, such as busbars and cooling devices, for example, are formed only once. As a result, the internal circuitry and the number of parts can be reduced. The integration of the switching unit also offers the advantage that the external circuit complexity can also be reduced.
Accordingly, the switching unit and the drive converter are preferably arranged in a common housing.

The switching unit preferably has an upstream and / or downstream filter unit, with the aid of which the electromagnetic compatibility ( EMC ) can be improved. Such filters can advantageously have chokes and capacitors. Chokes with number of turns 1 are to be preferred, as this eliminates the need to bend / wrap toroidal cores. The ring cores are made, for example, of ferrite, but particularly preferably of amorphous or nanocrystalline materials. This enables sufficiently high inductances to be achieved even with small numbers of turns in the chokes.

The switching unit and / or the drive converter further preferably comprises a circuit for adapting the power in order to optimally adapt the charge source to the step-up converter in combination with the battery. Resistors, capacitors and coils are also used here. It is even conceivable and possible to provide adjustable elements and controllable switches in order to optimize the power adjustment in each case.

A further filter unit can be provided between the step-up converter and the battery, which has a corresponding power adjustment and / or a corresponding improvement in EMC represents. It is conceivable and possible to provide only one or more or all of the filter units. It is also conceivable and possible to provide the circuit for power adjustment in the electrical drive system without an additional filter unit or with one or more of the filter units mentioned above.

The invention further relates to a motor vehicle, comprising a charging device as described above, as well as a battery and a charging connection, which is also referred to as a charging socket, the battery having exactly one power connection for connection to a power connection for the drive converter, and that exactly a connection for connecting the charging socket to the switching unit is provided, the connections for the drive converter and the connections for connecting to the charging socket being arranged on the housing. The charging socket is in turn intended to make electrical contact with the charge source.

In this way, an easily exchangeable drive unit or drive system is shown that manages with a few electrical connections, for example plug contacts. Only short cable paths are formed internally in the housing, which reduce the system's sensitivity to interference.

The present invention also provides an electric drive system with a charging device according to the invention.

The electric drive system is designed to drive one or more wheels. In particular, it can be an electric drive axle for driving two wheels with the same axis of rotation or an electric drive unit for driving exactly one wheel. The electric drive system preferably comprises the electric drive motor and the drive converter, which are integrated in a common housing. It can also include a transmission, which is also integrated in the common housing.

The figures described below relate to preferred exemplary embodiments of the charging device according to the invention, these figures not being used to restrict, but essentially to illustrate the invention.

• 1 eine schematische Darstellung einer ersten Ausführungsform der Erfindung;
• 2 eine schematische Darstellung einer zweiten Ausführungsform der Erfindung;
• 3 einen Schaltungsplan eines Antriebssystems einer dritten erfindungsgemässen Ausführungsform mit einem 2-Level-Wechselrichter als Antriebsumrichter und mit einer erfindungsgemäßen Ladevorrichtung in einem ersten Lademodus;
• 4 einen Schaltungsplan des Antriebssystems gemäß 3 in einem zweiten Lademodus;
• 5 einen Schaltungsplan eines Antriebssystems einer vierten erfindungsgemässen Ausführungsform mit einem 3-Level-Wechselrichter als Antriebsumrichter gemäß einem bevorzugten Ausführungsbeispiel in einem zweiten Lademodus;
• 6a bis 6c einen Schaltungsplan für verschiedene Ausführungsformen von Filtereinheiten; und
• 7 einen strukturellen Aufbau eines Elektromotors mit angeschlossenen Kühlkreisläufen.
• 8 eine weitere Ausführungsform der Erfindung analog zur Ausbildung in 3 und 4.

Show it

• 1 a schematic representation of a first embodiment of the invention;
• 2nd is a schematic representation of a second embodiment of the invention;
• 3rd a circuit diagram of a drive system of a third embodiment according to the invention with a 2-level inverter as a drive converter and with a charging device according to the invention in a first charging mode;
• 4th a circuit diagram of the drive system according to 3rd in a second charging mode;
• 5 a circuit diagram of a drive system of a fourth embodiment according to the invention with a 3-level inverter as a drive converter according to a preferred embodiment in a second charging mode;
• 6a to 6c a circuit diagram for various embodiments of filter units; and
• 7 a structural design of an electric motor with connected cooling circuits.
• 8th a further embodiment of the invention analogous to the training in 3rd and 4th .

1 shows a schematic representation of a drive system 1 with a loading device according to the invention. The drive system 1 has an electric motor 2nd , a drive converter 3rd as well as a transmission 20th on that in a common housing 13 are summarized.

A vehicle battery 7 is via a line between the battery connection 73 , 74 and a first connection 131 , 132 with the electric drive unit 2nd connected and feeds the drive converter in drive mode 3rd to drive the electric motor 2nd . The electric motor with rotor 201 drives in drive mode via a gearbox 20th the wheel 22 . In the example there is only one wheel 22 shown. The drive system can also be designed to drive two or more wheels.

A charging socket 6 , which can also be referred to as a charging connector, can have a positive and negative pole of a DC charge source 8th , 12th get connected. The charging socket 6 is via cable with a switching unit 10th connected, the switching unit directly or with the interposition of a step-up converter executed below 11 with the battery 7 is connectable. For this purpose, there are conductors between the switching unit 10th and battery with battery connection 71 , 72 as well as conductors between the switching unit 10th and electric drive system 1 with connection 133 , 134 educated.

Switching unit 10th and charging socket 6 are designed as structurally independent components that are not physically integrated in the electrical drive system.

The switching unit 10th has three switches S1 , S2 , S3 on which is a connected charge source 8th , 12th with the drive system 1 or the battery 7 can connect electrically.

In a first charging mode there are switches S1 and S3 closed so that a connected charge source 12th directly with the battery 7 connected is. The battery and charge source have a charge or target voltage of approx. 800V.

In a second charging mode there are switches S2 and S3 closed and connect the charge source 8th indirectly via the drive system equipped with step-up function 1 with the battery 7 . Charge source 8th and battery have different charging or target voltages of 400V or 800V. The charging voltage is via a step-up converter located in the drive system 11 raised to 800V, with the step-up converter driving the motor 2nd and the drive converter 3rd with a capacity includes.

The electric motor has inductors L1 , L2 and L3 in the form of coil and / or shaft windings, in the example with 3 phases. The inductors L1 , L2 and L3 are interconnected in a star connection; this means that the inductors have a common node / star point.

The phase outputs of the windings and the star point are connected to the inverter. The charging current is set to the boost position via the star point of the motor in the inductors L1 , L2 , L3 guided and raised via switching elements of the drive inverter in connection with a capacitance and flows through the connection 131 , 132 into the battery 7 .

For a concrete possibility of implementing such a step-up converter, reference is made to the explanations in the exemplary embodiments below.

According to 1 are all switches S1 , S2 , S3 the switching unit 10th opened and the drive system 1 ready for driving mode.
The drive converter is in drive mode 3rd driven to the rotor 201 of the electric motor 2nd to rotate. Via a transmission 20th becomes a drive wheel 22 of a motor vehicle driven.

2nd shows a schematic representation of the drive system 1 out 1 with comparable components in a second embodiment of the invention. In this case, the drive system is in drive mode and the switches S1 , S2 , S3 are open accordingly. In contrast to the execution according to the 1 are the switching unit 10th , the drive converter 3rd and the electric motor 2nd in a common housing 13 ' arranged.

The drive system 1 includes two electrical contact connections 101 , 102 for electrical contacting of a charging socket 6 with the switching unit 10th . The drive system also includes 1 two electrical contact connections 301 , 302 for electrical contacting of the battery 7 (Connection 75 , 76 ) with the drive inverter 3rd , as well as the switching unit and the drive converter.

The external wiring effort V to connect the battery 7 , the drive system 1 and the other electrical members are reduced compared to the embodiment 1 on just one harness. Due to the structural integration of the switching unit 10th internal wiring efforts for high current and low current (including sensor signals) can be reduced.

Furthermore, the control / logic of the interconnection unit 10th be integrated into the central control / logic of the electrical drive axis, for example on the same board, so that structurally separate control units can be omitted.

3rd and 4th show a schematic representation of a circuit diagram of a drive system 1 in a third embodiment of the invention in a first or second charging mode, which is similar to the embodiment of the 2nd is trained.

The drive system 1 is here as an electric drive axle with a housing 13 " for driving wheels 22 educated. As in the previous versions, it contains an integrated switching unit 10th , an engine 2nd with windings connected to a star point, which are the inductors L1 , L2 , L3 form the step-up converter, and a drive converter 3rd , which is designed as a 2-level inverter.

The 2-level inverter comprises a positive and a negative busbar, which are connected by half bridges 4a , 4b , 4c are connected. The half bridges 4a , 4b , 4c each include two transistors T1a , T2a T1b , T2b , Tic , T2c and a corresponding freewheeling diode for each transistor D1a , D2a , D1b , D2b The, D2c . There is also an intermediate circuit capacitor C1 intended. Various power switches, for example thyristors or in particular IGBTs, can be used as transistors.

According to 3rd the electric drive system is illustrated in a first charging mode. Via a charging socket 6 is an 800 V DC voltage source 12th with the electric drive system 1 connected. Because the vehicle battery 7 used a voltage of 800 V, are the switches of the switching unit 10th switched such that the voltage source 12th over the switches S1 and S3 directly at the poles of the vehicle battery 7 lie. That means in particular that the first switch S1 and the third switch S3 are closed and the second switch S2 is open. Accordingly, the battery is charged directly from the DC voltage source 12th . In particular, the charging current does not flow through the motor windings, so that the charging resistance is low.

In the switching unit 10th Corresponding charge control mechanisms can be provided to control the charging of the battery.

There is also a filter in the example fa shown between the charging port 6 and the switching unit 10th is arranged, which filters out interference signals and EMC improved. A second filter Col is between the switching unit 10th and the boost converter 11 is arranged. This filter adjusts the filtering accordingly to the electrical properties of the step-up converter in order to filter out interference signals. Whether one or both filters are actually installed in real use must be decided according to the requirements.

The filter units can be designed in one or more stages and can be designed in such a way that legal regulations relating to emissions and immunity can be achieved.

Examples of the formation of such filters are in the 6a , 6b and 6c shown.

4th shows the arrangement according to 3rd in a second charging mode.
In this case, a DC voltage source 8th with a lower charging voltage, in the example 400V, to the drive system 1 connected. Thus the transformation of the lower charging voltage to that for charging the battery 7 required charging voltage, in the example 800V, is made possible, the charging current via the closed switch S2 in the as a boost converter 11 out of the windings L1 , L2 , L3 and the half bridges, as well as the capacitor C1 of the drive inverter 3rd is formed, directed. To do this, the switch S1 be open and the switch S3 be closed.

By controlling the transistors accordingly T1a to T2c the desired step-up function is generated.
For example, the periodically switched transistor forms a step-up converter in the narrower sense T2a in connection with the freewheeling diodes slide and D2a in the half bridge 4a , Inductance L1 and capacity C1 . The transistor T1a remains locked for the step-up position. The other half bridges form accordingly 4b , 4c with the inductors L2 , L3 further step-up converters. The step-up converters can be operated individually or together (eg by operating only two of the three step-up converters), out of phase or in phase (eg by switching cycles of the step-up converters shifted in time). Together they form the step-up converter 11 out.

To optimize the electronic adaptation of the electrical control in the drive converter 3rd , which is intended to drive the electric motor once while driving and to cooperate in the step-up position in charging operation, an additional adaptation element Fc can be provided, as is shown in FIG 8th is illustrated. In this adapter, inductors and / or capacitances and / or electrical resistances are provided which ensure corresponding electronic optimizations. A power adjustment can thus be represented, as stated above. Next is in 8th a filter element Fd shown that an adjustment of the output of the step-up converter 11 or an adjustment of the charging port 301 , 302 to the battery 7 enables.

5 shows a circuit diagram of an electric drive system 1 which is similar to the embodiment of the 3rd , 4th is trained. Accordingly, components with comparable functions are given the same reference numerals.

In contrast to the drive system 1 out 3rd , 4th , is the drive inverter 3rd in 5 trained as three 3-level inverters.

The 3-level inverter is designed here as an NPC converter (neutral-point-clamped) familiar to the person skilled in the art. In principle, other types of 3-level converters could also be used.

The 3-level inverter comprises a positive and a negative busbar, the 3 by half bridges 41a , 41b , 41c are connected. The half bridges 41a , 41b , 41c each comprise four transistors connected in series T1a to T4c with appropriate freewheeling diodes slide to D4c . They also have two intermediate diodes D5a to D6c on that with a DC link center 5 of the drive inverter 3rd are connected. The DC link center 5 lies between the two DC link capacities C1 and C2 that are parallel to the three half bridges 4a , 4b and 4c are arranged.

To over-voltage the capacitor during charging C2 or to prevent the permissible breakdown voltage of the diodes from being exceeded, the intermediate circuit center is via a compensating conductor 9 a switchable connection is provided with the star point of the motor winding. It can be a switch S4 be provided, which separates the compensating conductor for driving, in order to avoid unnecessary compensating currents, for example due to voltage fluctuations in the star point. In addition there is a resistance R1 , in particular a PTC resistor (positive temperature coefficient) arranged for decoupling purposes in the compensating conductor. An additional inductance can also be provided in the compensating conductor.

6a-c show exemplary filter structures for the filters fa , Col and Fd .

6a shows a filter F1 with an LC-LC element. 6b shows a filter unit F2 with parallel connected R and C element. 6c shows a filter unit F3 , in particular a preferred form of the filter unit fa . This has two times two ring cores (with L referred to). In order to avoid bending / wrapping the ring cores with the conductors / busbars, the busbar pairs are simply passed through the ring cores. In each case together with the grounded capacitors or the ungrounded capacitor, the chokes form a multi-stage circuit with common mode and differential mode properties, which represents a simple and inexpensive filter unit. It also includes a passive discharge circuit, consisting of four resistors R .

7 shows an embodiment of a cooling system, which is used for cooling a charging device according to the invention. A longitudinal section through an electric motor is shown 50 with a connected oil circuit 40 (especially for cooling / lubricating the electric motor and a gearbox 20th ) and a connected water circuit 42 (especially for cooling the electric motor 50 and a drive converter 26 ). The electric motor 50 can be part of a drive system according to the present invention (e.g. according to 1 ) be used. The motor 50 has a rotor 30th on whose shaft by means of storage facilities 32 is rotatably mounted. These storage facilities 32 are through the oil circuit 40 lubricated. The rotor is designed as a hollow shaft and is used to cool the oil circuit 40 connected. Next to the rotor 30th and the storage facilities 32 are the windings 36 for magnetic field generation and in a motor housing 34 housed. For cooling the engine 50 is on the motor housing 34 a stator jacket 28 arranged by the water cycle 42 is supplied with water and thereby the engine 50 cools. The oil circuit 40 assigns a pump 48 and one with the water cycle 42 connected heat exchanger 38 The oil circuit is, for example, an oil circuit located within a drive unit. The water cycle 42 has its own pump 24th and also a radiator / heat exchanger 44 to reduce the water temperature. The water cycle 42 is used to cool the drive inverter 26 (also as a drive converter 3rd out 1 described) and the stator sheath 28 . The water cycle can be a vehicle-side cooling system which is not completely located in the drive unit / drive system.

In charging operation, the heat generated in the rotor is dissipated by the flow of oil or other fluids through the hollow rotor shaft, so that the charging capacity can be increased. Furthermore, the motor interior is flooded so that oil penetrates the air gap between the rotor and stator and the rotor core is additionally cooled from the outside. At the same time, the flooding also effectively cools the stator winding. The oil circulates during the charging process.

The water flow to the stator jacket 28 can be prevented during charging in order to prevent or reduce heat dissipation from the oil circuit in order to heat the oil more quickly.
Also a water flow to the heat exchanger 38 , which in this example is in series with the water flow through the stator jacket 28 can be prevented for analog reasons. The vehicle or its drive system can thus be prepared for driving by an advantageous oil temperature.

Reference list

Electric drive system

2nd

Electric motor / electric drive motor

3rd

Drive converter

4a, b, c

Half bridges

5

DC link center

6

Charging socket / charging connection

7

Vehicle battery / traction battery

8th

Charging source or charging station 400V DC

9

Compensating ladder

10th

Switching unit

11

Boost converter

12th

Charging source or charging station 800V DC

13

Electric drive unit housing

13 '

Electric drive unit housing

13 "

Electric drive unit housing

20th

transmission

22

Vehicle wheel

24th

water pump

26

Drive converter

28

Stator jacket

30th

rotor

32

Storage facility for rotor

34

Motor housing

36

Windings or winding head of the motor

38

Heat exchanger between the oil circuit and water circuit

40

Oil circuit

41a, b, c

Half bridges

42

Water cycle

44

Radiator / heat exchanger for water cycle

46

Switchable inflow to the stator jacket

48

Oil pump

50

Electric motor

71.72

Charging connection of the battery

73.74

Charging and supply connection of the battery

75.76

Charging / supply connection of the battery

101, 102

Electric drive unit charging connector

131.132

Power connection of the electric drive unit

133.134

Electric drive unit charging connector

301, 302

Charging / supply connection of the electric drive unit

L1, L2, L3

Inductors / motor windings

C1

First capacitor

C2

Second capacitor

T_ij

transistor

D_ij

diode

R1

Decoupling resistance

S1-3

Switch unit switch 10th

S4

Charging switch

V

(external) interconnection effort

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102016209905 A1 [0004]
• DE 102009052680 A1 [0005]

Claims (17)

Charging device for charging a battery (7) of a motor vehicle designed with an electric drive motor (2), with - an inductor, - a drive converter (3) which, when the motor vehicle is in operation, the DC voltage of the battery (7) for the electric drive motor (2) converts, the inductance together with the drive converter (3) for charging operation of the battery (7) serves as a step-up converter, characterized in that a switching unit (10) is provided which is designed to charge or charge a charge source (8; 12) to interconnect the step-up converter with the battery (7). Loading device after Claim 1 , characterized in that the switching unit (10) is designed to detect and measure a charge source (8; 12) and its voltage and, depending on this, to be connected directly to the battery (7) or via the step-up converter. Loading device after Claim 1 or 2nd , characterized in that the drive converter (3) is designed as a 2-level inverter or as a 3-level inverter, the 3-level inverter being in particular in the form of an NPC or TNPC inverter. Loading device according to one of the Claims 1 to 3rd , characterized in that the drive converter (3) for three voltage phases each has a half bridge (4a; 4b; 4c), which is each connected to one of the three coil windings (L1; L2; L3) of the electric drive motor (2). Loading device after Claim 4 , characterized in that one to three half bridges (4a; 4b; 4c) for the step-up converter can be controlled and used to charge the battery. Loading device according to one of the Claims 1 to 5 , characterized in that the inductance (L1) is formed by at least one coil / shaft winding of the electric drive motor (2). Loading device after Claim 6 , characterized in that the electric drive motor (2) is designed such that oil can be pumped to the at least one coil / shaft winding for cooling during the charging process. Loading device according to one of the preceding claims, characterized in that the drive motor (2) has a rotor which is cooled during the charging process. Loading device according to one of the Claims 1 to 8th , characterized in that the step-up converter has at least one cooling system with two independent circuits. Loading device after Claim 9 , characterized in that the oil circuit is designed to deliver the waste heat of the inductance to an oil circuit of the drive motor and / or a transmission, the oil circuit of the drive motor and / or transmission being used to lubricate moving or rotating components of the drive motor and / or transmission . Loading device after Claim 10 , characterized in that the oil circuit of the cooling system forms at least part of the oil circuit of the drive motor and / or transmission or vice versa. Loading device according to one of the Claims 1 to 11 , characterized in that an intermediate circuit center point (5) of the drive converter is connected and / or interconnectable via a resistor (R1) to an input voltage of the charge source (8) and / or the inductance (L1) by means of a compensating conductor (9). Loading device according to one of the Claims 1 to 12th , characterized in that an intermediate circuit capacitance of the inverter is designed to be variable for the charging operation. Charging device according to one of the preceding claims, characterized in that the switching unit (10) and the drive converter (3) are arranged in a common housing (13). Charging device according to one of the preceding claims, characterized in that the switching unit (10), the drive converter (3) and the drive motor (2) are arranged in a common housing (13). Motor vehicle, comprising a charging device according to one of the preceding claims, in particular according to Claim 14 or 15 , a battery (7) and a charging socket (6), characterized in that the battery (7) has exactly one power connection (75, 76) for connection to a power connection (301, 302) for the drive converter (3) Exactly one connection (101, 102) is provided for the electrical connection of the charging socket (6) to the switching unit (10), the connections (301, 302) for the drive converter (3) and the connections (101, 102) for the electrical connection with the charging socket (6) on the housing (13 ', 13 ") are arranged. Electric drive system (1) with a charging device according to one of the preceding Claims 1 to 16 .

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