DE102022000676A1 - Energy storage device for an electrically powered vehicle - Google Patents

Abstract

The invention relates to an energy storage device (1) for a vehicle (2), having a first and a second energy storage (3, 4) for storing electrical energy; - an electrical connection (5) for charging the energy storage (3, 4) and/or to operate an electrical consumer; and- a semiconductor switching device (6) which has a plurality of semiconductor switching elements (S3, S4, S5) and by means of which the energy stores (3, 4) can be connected either in series or in parallel with one another; comprising:- a fifth semiconductor switching element (S5) of the semiconductor switching device (6) is electrically coupled to a positive pole of the first energy store (3) and a negative pole of the second energy store (4),- to the fifth semiconductor switching element (S5) the energy stores (3, 4 ) can be connected in series independently of the other semiconductor switching elements (S3, S4) of the semiconductor switching device (6), and- the fifth semiconductor switching element (S5) has a body diode (D5) which is connected in the reverse direction to the positive pole of the first energy store (3) is arranged to the negative pole of the second energy store (4).

Description

The invention relates to an energy storage device for a vehicle, the energy storage device having a first and a second energy storage device for storing electrical energy. Furthermore, the energy storage device has an electrical connection for charging the energy storage device and/or for operating an electrical consumer. The energy storage device also has a semiconductor switching device, which has a plurality of semiconductor switching elements and by means of which the energy storage devices can be connected either in series or in parallel with one another.

For example, electrically operated vehicles have a vehicle battery, in particular a high-voltage battery, with which an on-board network of the electrically operated vehicle can be supplied with electricity. Furthermore, the vehicle battery is used to supply an electric drive unit of the electrically operated vehicle. For this purpose, for example, the vehicle battery can have a voltage of 400 volts or 800 volts.

In order to be able to charge the vehicle battery at different electric charging stations and to use it in a wide variety of types or types of electric vehicles, the vehicle battery can be designed as a switchover battery. Due to the use of a changeover battery, different voltage levels can be present at an electrical connection of the changeover battery, depending on the requirement and/or the situation. For example, either 400 volts or 800 volts can be provided using the switchover battery. For example, in an electric vehicle with an 800-volt vehicle electrical system, 400-volt downward compatibility can be ensured by using a switchover battery. A switching matrix is used here in order to be able to vary between 400 volts and 800 volts.

Contactors are usually used in changeover batteries, which require a lot of space and weight, especially when high battery performance is required, e.g. in premium or sports vehicles with high drive power or "high performance charging".

For example, from the DE 10 2016 098 263 A1 a battery and a battery arrangement for a motor vehicle are known. This battery arrangement is implemented in accordance with the specifications for high-voltage safety.

Furthermore, from the DE 10 2016 008 052 A1 an energy storage device for a motor vehicle is known. The energy storage device has a first and a second energy store for storing electrical energy. The energy storage device is designed to be able to be operated with different voltages.

A disadvantage of using switching batteries in the prior art is that they require a lot of installation space and are heavy.

One object of the present invention is to create an energy storage device, in particular a changeover battery, that is more compact and less prone to errors for use in vehicles.

This object is achieved by an energy storage device according to claim 1. Useful further developments result from the dependent patent claims.

• - einem ersten und einem zweiten Energiespeicher zum Speichern von elektrischer Energie;
• - einem elektrischen Anschluss zum Laden der Energiespeicher und/oder zum Betreiben eines elektrischen Verbrauchers; und
• - einer Halbleiterschalteinrichtung, die mehrere Halbleiterschaltelemente aufweist, und mittels welcher die Energiespeicher wahlweise zueinander in Serie oder parallel schaltbar sind; aufweisend;
• - ein fünftes Halbleiterschaltelement der Halbleiterschalteinrichtung mit einem Pluspol des ersten Energiespeichers und einem Minuspol des zweiten Energiespeichers elektrisch gekoppelt ist,
• - mit dem fünften Halbleiterschaltelement die Energiespeicher unabhängig von den weiteren Halbleiterschaltelementen der Halbleiterschalteinrichtung in Serie schaltbar sind, und
• - das fünfte Halbleiterschaltelement eine Body-Diode aufweist, welche in Sperrrichtung von dem Pluspol des ersten Energiespeichers zum Minuspol des zweiten Energiespeichers angeordnet ist.

One aspect of the invention relates to an energy storage device for a vehicle, with

• - A first and a second energy store for storing electrical energy;
• - An electrical connection for charging the energy storage device and/or for operating an electrical consumer; and
• - A semiconductor switching device, which has a plurality of semiconductor switching elements, and by means of which the energy storage devices can be connected either in series or in parallel with one another; having;
• - a fifth semiconductor switching element of the semiconductor switching device is electrically coupled to a positive pole of the first energy store and a negative pole of the second energy store,
• - With the fifth semiconductor switching element, the energy stores can be connected in series independently of the other semiconductor switching elements of the semiconductor switching device, and
• - The fifth semiconductor switching element has a body diode, which is arranged in the reverse direction from the positive pole of the first energy store to the negative pole of the second energy store.

The proposed energy storage device can be used to create a changeover battery for a vehicle, in particular an electrically operated vehicle, which requires less installation space and is less prone to errors than the mechanical switching elements, in particular contactors. So can with Using the energy storage device according to the invention, a robust, efficient and improved switching battery for electrically operated vehicles can be provided or created. This is achieved in that the respective operation or operating mode of the energy storage device takes place using semiconductor elements instead of mechanical switching elements. For additional security or protection, the semiconductor elements or semiconductor switching elements have body diodes, by means of which no unwanted currents and/or short circuits can occur.

The energy storage device, which can be embodied as a switching battery, can have the at least first and second electrical energy storage device or a plurality of partial energy storage devices. For example, the first and second may be referred to as a sub-battery or a battery module. In particular, the two energy storage devices are part of the energy storage device designed as a switching battery. The energy storage device can thus be used, for example, as a high-voltage battery or vehicle battery in an electric vehicle.

With the help of the energy storage device, a DC voltage can be provided, for example, with which an on-board electrical system of the vehicle and/or an electric drive unit of the vehicle can be supplied with electricity.

The energy storage device has the electrical connection for this purpose. This can be used either as a charging connection or as a supply connection. Thus, with the help of this electrical connection, either the energy storage device can be charged or electrical loads, such as the on-board electrical system and/or the electrical drive unit, can be supplied with electrical energy.

In particular, the energy storage device can be used for an 800 volt vehicle in order to also be able to charge this 800 volt vehicle at a 400 volt charging station. This can be done by the mutually switchable energy stores by means of the semiconductor switching device. The semiconductor switching device can be referred to as a switching device, for example. As already described above, the energy storage device can be switched to different modes with this semiconductor switching device. This would be the case, for example, if the vehicle is a 400 volt vehicle. After controlling the semiconductor switching device, a 400 volt vehicle can also be charged at an 800 volt charging station. The energy storage device can thus be used universally in a wide variety of electrically operated vehicles.

For example, the vehicle can have the energy storage device.

A battery, in particular an electrical energy store, according to the invention comprises at least one and in particular a plurality of battery cells which are electrically conductively connected to one another, such a battery cell preferably providing a voltage in the range of 3.5 and 4.0 volts. Such a battery cell can be designed, for example, as a prismatic cell, a pouch cell or a round cell. The battery is preferably designed as a so-called high-voltage battery, which is set up to provide an electrical voltage in the range of more than 60 volts, in particular in the range of several 100 volts. Such a high-voltage battery can be arranged in a motor vehicle, where it can supply electrical energy to an electrical consumer, in particular a drive motor.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing(s). The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 eine schematische Darstellung eines Ausführungsbeispiels der erfindungsgemäßen Energiespeichereinrichtung;
• 2 eine schematische Darstellung der Energiespeichereinrichtung aus 1 in einem möglichen Betriebszustand;
• 3 eine schematische Darstellung der Energiespeichereinrichtung aus 1 in einem weiteren möglichen Betriebszustand; und
• 4 eine schematische Darstellung der Energiespeichereinrichtung aus 1 in einem weiteren möglichen Betriebszustand.

The following figures show in:

• 1 a schematic representation of an embodiment of the energy storage device according to the invention;
• 2 a schematic representation of the energy storage device 1 in a possible operating condition;
• 3 a schematic representation of the energy storage device 1 in another possible operating state; and
• 4 a schematic representation of the energy storage device 1 in another possible operating state.

Elements with the same function are provided with the same reference symbols in the figures.

the 1 shows an energy storage device 1 for a vehicle 2. In particular, the energy storage device 1 can be used as a switchable battery for an electrically operated vehicle, such as a plug-in vehicle or a hybrid vehicle or an electric vehicle. The energy storage device 1 can therefore be referred to as a high-voltage battery or vehicle battery or battery arrangement for electrically operated vehicles.

The energy storage device 1 can have a first and a second electrical energy storage device 3 , 4 . With these energy stores 3, 4, electrical energy, such as DC voltage, can be provided as battery voltage for the vehicle 2. With the help of the energy storage device 1, electrical consumers in the vehicle 2 can be supplied with electricity, such as an on-board network, a vehicle component or an electric drive unit. The two energy stores 3, 4 can be referred to as a partial battery or battery modules, for example. For example, the energy storage device 1 can have additional, that is to say several, energy storage devices.

In order to be able to charge the energy storage device 1 electrically or to be able to deliver electrical energy, the energy storage device 1 has an electrical connection 5 .

So that the energy storage device 1 can in particular provide different operating modes and thus different voltage levels, it has a semiconductor switching device 6 . The semiconductor switching device 6 has, for example, a multiplicity of semiconductor switching elements or semiconductor switches. In particular, the semiconductor switching device can have the semiconductor switching elements S3, S4 and S5. These semiconductor switching elements S3, S4, S5 can be in the form of metal-oxide-semiconductor field-effect transistors or bipolar transistors or transistors, for example. With the help of the semiconductor switching elements S3, S4, S5, the energy stores 3, 4 can be connected either in series or in parallel with one another. Thus, depending on the application, a voltage level of 800 volts or 400 volts can be made available, or again the energy storage device 1 can be charged with either 400 volts or 800 volts.

For the use of semiconductor switching elements S3, S4, S5 or semiconductor components, the energy storage device 1 can be reduced in terms of its space requirement and its weight. Particular attention should be paid to the fact that the semiconductor switching elements S3, S4, S5 have a body diode D3, D4, D5. This makes it possible to keep the semiconductor switching elements S3, S4, S5 conductive in a defined direction.

Since semiconductor components have to be considered specifically with regard to the blocking direction of their body diode, two antiparallel semiconductors, for example MOSFETs, are usually used in order to be able to block currents in both directions. In order to compensate for the doubled waste heat, the semiconductor surfaces of each of the two semiconductor elements can be doubled again, so that the anti-parallel circuit results in four times the number of components. The body diodes D3, D4, D5 of the energy storage device 1 according to the invention are therefore designed in such a way that no unwanted currents, in particular no short-circuit currents, can occur. This alignment of the semiconductor switching elements S3, S4, S5 makes it possible to dispense with the antiparallel connection of semiconductors, which means that, for example, 75% of the semiconductor area of the semiconductor switching elements S3, S4, S5 can be saved.

For example, the third semiconductor switching element S3 is arranged or connected between the positive pole of the electrical connection 5 and a positive pole of the first energy store 3 . An electrical connection or electrical wiring is arranged between the positive pole of the electrical connection 5 and the positive pole of the second energy store 4 . The positive pole of the first energy store 3 can be electrically decoupled from the electrical connection 5 , in particular from the positive pole of the electrical connection 5 , with the aid of the third semiconductor switching element S3 . The body diode D3 of the third semiconductor switching element S3 is arranged in the blocking direction from the electrical connection 5, in particular its positive pole, to the positive pole of the first energy store 3. A current flow from the positive pole of the electrical connection 5 to the positive pole of the first energy store 3 can thus be blocked or interrupted.

By means of a first switching element 1 coupled to the positive pole of the second energy store 4 and to the third switching element S3, the positive pole of the second energy store 4 and/or the third switching element S3 can be electrically decoupled from the electrical connection 5, in particular from the positive pole of the electrical connection 5 . The switching element S1 can be implemented or designed as a mechanical switching element, in particular as a protection.

By means of a coupled to the negative pole of the second energy store 4 fourth semiconductor switching element S4, the negative pole of the second energy store 4 can be electrically connected to the charging connection 5, in particular from the negative pole of the Charging connection 5, are electrically decoupled. The fourth semiconductor switching element S4 is thus arranged or connected between the negative pole of the connection 5 and the negative pole of the second energy store 4 . The body diode of the fourth semiconductor switching element S4 can be arranged in the reverse direction from the negative pole of the connection 5 to the negative pole of the connection 5 . An undesired flow of current from the second energy store 4 to the negative terminal 5 can thus be suppressed or prevented or blocked. There is wiring or an electrical connection between the negative pole of the connection 5 and the negative pole of the first energy store 3 .

A second switching element S3 is arranged between the negative pole of the connection 5 and the fourth semiconductor switching element S4 and thus also between the negative pole of the connection 5 and the negative pole of the electrical connection 3 . Thus, the fourth switching element S4 and the first energy store 3 can be electrically decoupled using the second switching element S2, which is designed, for example, as a contactor.

The fifth semiconductor switching element S5 is coupled or arranged between the positive pole of the first energy store 3 and the negative pole of the second energy store 4 . In particular, the fifth semiconductor switching element S5 can be connected in series with the energy store 4 independently of the other semiconductor switching elements S3, S4. For safety, the body diode D5 is arranged in the reverse direction from the positive pole of the first energy store 3 to the negative pole of the second energy store 4 .

For example, the switching elements S1, S2 can be referred to as the main contactors of the energy storage device 1. These are responsible for safely switching off the energy storage device 1 or the high-voltage battery of the vehicle and must therefore meet stringent requirements with regard to high-voltage safety. Therefore, these are specially designed as mechanical contactors.

Possible switch positions of the semiconductor switching device 6 and thus the possible operating modes of the energy storage device 1 are explained below, for example.

If S1 and S2 are open, S3, S4, S5 can be switched as required. However, S5 must not be closed at the same time as S3 or S4, otherwise a short circuit may occur. In this switch position, the energy storage device 1 is voltage-free at the connections 5 or terminals. This state or modes can be used to switch between the other states.

If S1 and S2 are closed and S3 and S4 are open and S5 is closed, energy storage device 1 can be operated with twice the battery voltage. In this case, for example, a voltage level of 800 volts can be provided. In this mode, the energy storage device 1, in particular the energy storage device 3, 4, can be charged and also discharged.

When S1 and S2 are closed and S3 and S4 are also closed and S5 is open, the energy storage device 1 can be operated in this mode or operation with a simple battery voltage of, for example, 400 volts. Both charging and discharging of the energy storage device 1 are conceivable in this mode.

If S1 and S2 are closed and S3, S4 and S5 are open, a discharge operation with a single battery voltage of 400 volts, for example, or a charging operation with double the battery voltage of 800 volts, for example, can be provided.

In the following 2 is a further schematic representation of the energy storage device 1 from FIG 1 shown. If charging with a simple battery voltage of 400 volts, for example, is not required, the semiconductor switching elements S3, S4 can be designed as simple diodes D3, D4. For this purpose, for example, the semiconductor switching elements S3, S4 can be switched or interconnected or driven accordingly.

In the 3 the operating mode is again shown when no discharging operation with double the battery voltage, i.e. 800 volts, is required. In this case, the fifth semiconductor switching element S5 can be regarded as a diode D5.

In the 4 is shown when no charging operation with a single battery voltage, for example 400 volts, and no discharging operation with double the battery voltage, for example 800 volts, is required. In this case, the semiconductor switching elements S3, S4, S5 can be interconnected or controlled in such a way that they are designed or work as diodes. This can be done with the help of the semiconductor switching device 6, for example.

Reference List

1

energy storage device

2

vehicle

3

First energy storage

4

Second energy storage

5

Electrical connection

6

semiconductor switching device

D3, D4, D5

body diodes

S1, S2

switching elements

S3, S4, S5

semiconductor switching elements

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• DE 102016098263 A1 [0005]
• DE 102016008052 A1 [0006]

Claims (6)

Energy storage device (1) for a vehicle (2), with - a first and a second energy store (3, 4) for storing electrical energy; - An electrical connection (5) for charging the energy store (3, 4) and/or for operating an electrical consumer; and - a semiconductor switching device (6) which has a plurality of semiconductor switching elements (S3, S4, S5) and by means of which the energy stores (3, 4) can be connected either in series or in parallel with one another; characterized in that - a fifth semiconductor switching element (S5) of the semiconductor switching device (6) is electrically coupled to a positive pole of the first energy store (3) and a negative pole of the second energy store (4), - to the fifth semiconductor switching element (S5) the energy stores (3 , 4) can be connected in series independently of the further semiconductor switching elements (S3, S4) of the semiconductor switching device (6), and - the fifth semiconductor switching element (S5) has a body diode (D5) which is connected in the reverse direction to the positive pole of the first energy store ( 3) is arranged to the negative pole of the second energy store (4). Energy storage device (1) after claim 1 , characterized in that the positive pole of the first energy store (3) can be electrically decoupled from the electrical connection (5) by means of a third semiconductor switching element (S3) coupled to the positive pole of the first energy store (3), the third semiconductor switching element being a body diode ( D3) which is arranged in the blocking direction from the electrical connection (5) to the positive pole of the first energy store (3). Energy storage device (1) after claim 1 or 2 , characterized in that the negative pole of the second energy store (4) can be electrically decoupled from the charging connection (5) by means of a fourth semiconductor switching element (S4) coupled to the negative pole of the second energy store (4), the fourth semiconductor switching element (S4) having a body Diode (D4), which is arranged in the reverse direction from the negative pole of the second energy store (4) to the electrical connection (5). Energy storage device (1) according to one of the preceding claims, characterized in that the positive pole of the second energy store (4) can be electrically decoupled from the electrical connection (5) by means of a first switching element (S1) coupled to the positive pole of the second energy store (4), in particular the first switching element (S1) is designed as a contactor. Energy storage device (1) according to one of the preceding claims, characterized in that the negative pole of the first energy store (3) can be electrically decoupled from the electrical connection (5) by means of a second switching element (S2) coupled to a negative pole of the first energy store (3), in particular the second switching element (S2) is designed as a contactor. Energy storage device (1) according to one of the preceding claims, characterized in that the plurality of semiconductor switching elements (S3, S4, S5) are in the form of metal-oxide-semiconductor field-effect transistors.

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