DE102020116420A1 - Energy supply system for an electrically powered vehicle - Google Patents

Abstract

The invention relates to an energy supply system for an electrically driven vehicle with three high-voltage storage strings connected in parallel, each comprising a first and a second partial storage string (10, 40; 20, 50; 30, 60) connected in series. The high-voltage storage strings can be coupled in a ring between the partial storage strings via a first to third switchable connection (111-113). The energy supply system has a first connection point (101) and a second connection point (102). The second connection point (102) is via a fourth switchable connection (114) between the first and the second partial storage string (30, 60) with the third high-voltage storage string (30, 60), the second switchable connection (112) and the third switchable Connection (113) can be electrically coupled. The first connection point (101) can be electrically coupled to negative poles (13, 23, 33) of the first partial memory strands (10, 20, 30) via a fifth switchable connection (115). The second connection point (102) can be electrically coupled to positive poles (44, 54, 64) of the second partial storage strands (40, 50, 60) via a sixth switchable connection (116). The invention also relates to an electrically powered vehicle.

Description

The invention relates to a power supply system for an electrically drivable vehicle and an electrically drivable vehicle.

Electrically powered vehicles are increasingly attracting people's interest. In particular, land vehicles, including off-road and road vehicles such as passenger cars, buses, trucks and other commercial vehicles, rail vehicles (trains), but also watercraft (boats) and aircraft such as helicopters, multicopters, propeller-driven aircraft, jet aircraft, which at least have an electric motor used to propel the vehicle. Vehicles can be manned or unmanned. In addition to pure electric vehicles (BEV), the definition should also include, for example, hybrid electric vehicles (HEV), plug-in hybrids (PHEV) and fuel cell vehicles (FCHV).

The number of electrical safety, comfort and information systems is already considerable, depending on the vehicle category and equipment. It can be observed that more and more components of this type are being installed. Examples include drive-by-wire systems (electrical steering) and break-by-wire systems (electrical braking), for land vehicles an active chassis control, assistance systems and infotainment systems.

There is a constant need to increase the storage capacity of the energy storage, the efficiency of the electrical components, the system availability and failure safety, to shorten the charging time and to master the complexity in technology and production.

It is therefore an object of the invention to provide an energy supply system for an electrically drivable vehicle and a corresponding vehicle, which is improved with regard to the points mentioned.

The object is achieved by an energy supply system according to the invention for an electrically drivable vehicle. The energy supply system comprises three high-voltage storage strings connected in parallel, each with a first and a second partial storage string connected in series. The first high-voltage storage string and the second high-voltage storage string can be electrically coupled between the first and the second partial storage strings via a first switchable connection. The first high-voltage storage string and the third high-voltage storage string can be electrically coupled between the first and the second partial storage strings via a second switchable connection. The second high-voltage storage string and the third high-voltage storage string can be electrically coupled between the first and the second partial storage strings via a third switchable connection. The energy supply system has a first connection point, a second connection point and preferably a third connection point.

According to one aspect, the second connection point can be electrically coupled via a fourth switchable connection between the first and the second partial storage line to the third high-voltage storage line, the second switchable connection and the third switchable connection.

According to a further aspect, the first connection point can be electrically coupled to negative poles of the first partial storage strings via a fifth switchable connection.

Furthermore, the second connection point can be electrically coupled to positive poles of the second partial storage strings via a sixth switchable connection.

Due to the structure of the energy supply system described above, current flows can be diverted according to the situation. This allows a significantly increased availability of the high-voltage direct voltage in the event of cell errors in individual storage strings. The switchable connections can also be used to balance the charge between individual storage strands.

The partial storage strings each include at least one high-voltage direct voltage source. In the context of the disclosure, high-voltage direct voltages are characterized by a potential difference of at least 60 volts. In the present case, the high-voltage DC voltage of the high-voltage storage strings can be several hundred volts, e.g. B. 200 V, 400 V, 600 V, 800 V, 1200 V or voltage values between those mentioned. For example, the partial storage strings can be battery modules, each with a plurality of cells connected in series. A plurality of battery modules, possibly with further electronic components, can also be combined to form a battery pack and form a partial storage string.

Preferred embodiments of the invention are specified in the subclaims and the following description, which can each represent an aspect of the invention individually or in combination.

The energy supply system can advantageously have a third connection point. In this case, the third connection point is via the sixth switchable connection with the positive poles of the second partial storage strings can be electrically coupled.

The second connection point can preferably be electrically coupled to the sixth switchable connection via a seventh switchable connection in order to electrically couple the second connection point to the positive poles of the second partial storage strands.

Optionally, the first connection point can be electrically coupled via an eighth switchable connection between the first and the second partial storage line to the third high-voltage storage line, the second switchable connection and the third switchable connection.

According to a further aspect, the partial storage strings can each have a switch arranged in series with the high-voltage direct voltage source. A current flow in the first partial storage strings can be interrupted by the separating element.

Advantageously, through the selective coupling via the first to third switchable connection of the high-voltage storage strings, an active charge shift / charge reversal between the storage strings or the individual partial storage strings can be carried out.

The switchable connections have switchable isolating elements for this purpose. It can advantageously be a semiconductor switch, for example. Semiconductor switches hardly wear out. Furthermore, an active battery or cell management can be operated through targeted control, for example with pulse width modulation (PWM) or operation in the constriction area. For example, voltage differences can be compensated for by controlled charge shifts.

According to a further advantageous aspect, the high-voltage storage strings can be arranged in a battery housing and can preferably be removed individually. In this way, the high-voltage storage strings from the energy supply system can be serviced or replaced particularly easily.

The above aspects enable granular control of the current paths. In this way, current flows can be routed around defective components and short circuits can be electrically isolated.

Furthermore, an electrically drivable vehicle is provided with an energy supply system according to the invention and at least two electric drive trains, preferably with 800 V or 400 V.

• - 1 eine stark vereinfachte schematische Darstellung der elektrischen Schaltung eines Energieversorgungsystems mit drei Hochvolt-Speichersträngen, und
• - 2 eine stark vereinfachte schematische Darstellung einer Variante der elektrischen Schaltung des Energieversorgungssystems mit drei Hochvolt-Speichersträngen.

Further advantages and features of the invention emerge from the following descriptions and from the accompanying drawings, to which reference is made. Show it:

• - 1 a greatly simplified schematic representation of the electrical circuit of an energy supply system with three high-voltage storage strings, and
• - 2 a greatly simplified schematic representation of a variant of the electrical circuit of the energy supply system with three high-voltage storage strings.

The individual components are usually designated according to their function and, if necessary, summarized. Electrical couplings of the respective components in the electrical circuit are provided via direct or indirect connections. Features and functions that have already been described in connection with a figure are only repeated in the context of the other figures if this appears necessary for better understanding.

In 1 a greatly simplified schematic overview of the energy supply system is shown. The energy supply system comprises three high-voltage storage strings connected in parallel, each with a first and a second partial storage string connected in series 10 , 40 ; 20th , 50 ; 30th , 60 . The first high-voltage storage string 10 , 40 and the second high-voltage storage line 20th , 50 are between the first and the second partial storage strands 10 , 40 ; 20th , 50 via a first switchable connection 111 electrically connectable. The first high-voltage storage string 10 , 40 and the third high-voltage storage line 30th , 60 are between the first and the second partial storage strands 10 , 40 ; 30th , 60 via a second switchable connection 112 electrically connectable. The second high-voltage storage string 20th , 50 and the third high-voltage storage line 30th , 60 are between the first and the second partial storage strands 20th , 50 ; 30th , 60 via a third switchable connection 113 electrically connectable.

The energy supply system also has a first connection point 101 and a second connection point 102 on.

The second connection point 102 is via a fourth switchable connection 114 with the third high-voltage storage line 30th , 60 at the center tap and the second switchable connection 112 and the third switchable connection 113 electrically connectable.

The first connection point 101 is via a fifth switchable connection 115 with minus poles 13th , 23 , 33 of the first partial storage strands 10 , 20th , 30th electrically connectable.

The second connection point 102 is via a sixth switchable connection 116 with plus poles 44 , 54 , 64 of the second partial storage strands 40 , 50 , 60 electrically connectable.

The energy supply system has a third connection point 103 on. The third connection point is via the sixth switchable connection 116 with the plus poles 44 , 54 , 64 of the second partial storage strands 40 , 50 , 60 electrically connectable.

The second connection point 102 is via a seventh switchable connection 117 with the sixth switchable connection 116 electrically connectable to the second connection point 102 with the positive poles of the second partial storage strands 40 , 50 , 60 to couple electrically.

The first connection point 101 is via an optional eighth switchable connection 118 between the first and the second partial storage string 30th , 60 with the third high-voltage storage line 30th , 60 , the second switchable connection 112 and the third switchable connection 113 electrically connectable.

The partial storage strands 10 , 20th , 30th , 40 , 50 , 60 each have a switch 12th , 22nd , 32 , 42 , 52 , 62 between the energy storage 11 , 21 , 31 , 41 , 51 , 61 and the minus pole 13th , 23 , 33 , 43 , 53 , 63 on.

The switches of the first to third switchable connection 111-113 solid state switches are preferred. The remaining switches can also be semiconductor switches and / or conventional contactors. The switches of the switchable connections are particularly preferred 111 , 112 , 113 Executed bidirectionally in order to enable a charge equalization in both directions, for example as a break chopper switch.

The energy supply system comprises a connection unit 2 with a first connector 201 and a second connector 202 for connection to charging electronics 3 . The charging electronics 3 can charge with the full string voltage (e.g. 800 V) or the partial string voltage (e.g. 400 V).

The connection unit 2 further comprises a third connector 203 and a fourth connector 204 for connection to a first electric drive train 4th as well as a fifth connector 205 and a sixth connector 206 for connection to a second electric drive train 5 . The connection unit also includes a seventh connector 207 for electrical coupling with the first connection point 101 , an eighth connector 208 for electrical coupling with the second connection point 102 and a ninth connector 209 for electrical coupling with the third connection point 103 . The connectors and connection points can have the same structure. The different designations were made for better referencing.

The first connector 201 , the third connector 203 , the fifth connector 205 and the seventh connector 207 are electrically coupled. The second connector 202 and the eighth connector 208 are electrically coupled. The fourth connector 204 , the sixth connector 206 and the ninth connector 209 are electrically coupled.

When charging with the full string voltage, the switches are the fifth, sixth and seventh switchable connection 115 , 116 , 117 closed. The fourth (and possibly eighth) switchable connection 114 , 118 is opened. The switches 12th , 22nd , 32 , 42 , 52 , 62 in the storage strands 10-60 are normally closed. The first to third switchable connection 111-113 can optionally be closed or alternatively (possibly partially) opened. A charge / load distribution can take place via the control of the semiconductor switches.

Provided that a partial storage string is used when charging with the full string voltage 20th fails, the corresponding switch 22nd opened in this partial storage string. The first to third switchable connection 111-113 is closed to the respective other partial storage strand 50 to be able to continue charging and using the high-voltage storage string.

When charging with half the line voltage (e.g. 400 V), the fifth and fourth switchable connections 115 , 114 closed, the sixth, seventh switchable connection 116 , 117 open. The first to third switchable connection 111-113 can be open or closed. Only the first partial storage strings are then initially used 10-30 loaded. As soon as the first partial storage strings have been loaded, the fourth and fifth switchable connections are opened and the sixth, seventh switchable connections are closed. The second partial storage strands 40-60 are then made from the first partial storage strands 10-30 charged until a charge equalization has taken place. The process is repeated until all partial storage strings are sufficiently loaded. If a partial storage line fails - as already described - the still functional partial storage line is switched via the closed first to third switchable connection 111 , 113 loaded. Is the optional eighth switchable connection 118 present, the reloading process can be omitted and the first and second partial storage strings are charged directly one after the other / alternately with half the string voltage.

In the drive mode with full phase voltage, the fifth, sixth and seventh switchable connections 115 - 117 closed, the fourth and eighth switchable connection 114 , 118 open.

If one drive fails, the second drive is still available, even if there is a short circuit in the load.

In the event of a complete failure of the second partial storage strands 40-60 a drive with half the phase voltage is still possible by adding the first to fifth and seventh switchable connection 111 - 115 , 117 closed and the sixth and eighth switchable connection 116 , 118 be opened. Charging with half the string voltage (see above) is then still available.

In the event of a complete failure of the first partial storage strings 10-30 It is still possible to drive with half the phase voltage by adding the first to third, sixth and eighth switchable connections 111-113 , 116 , 118 closed and the fourth and seventh switchable connection 114 , 117 be opened. Charging with half the line voltage is then still available.

2 shows a greatly simplified schematic overview of the energy supply system in a variant with an alternative connection box. The first connector 201 , the third connector 203 and the seventh connector 207 are electrically coupled. Furthermore, there is the second connector 202 , the fourth connector 204 , the fifth connector 205 and the eighth connector 208 electrically coupled. There are also the sixth connector 206 and the ninth connector 209 electrically coupled.

While in 1 the powertrains 4th , 5 operated with the full line voltage (e.g. 800 V) is the connection unit 2 designed to run the drivetrains 4th , 5 only with half the string voltage or with the voltage of the storage strings 10-60 operate.

The rest of the structure of the energy supply system corresponds to that already described 1 .

When charging with the full string voltage, the switches are the fifth, sixth and seventh switchable connection 115 , 116 , 117 closed. The fourth (and possibly eighth) switchable connection 114 , 118 is opened. The switches 12th , 22nd , 32 , 42 , 52 , 62 in the storage strands 10-60 are normally closed. The first to third switchable connection 111-113 can optionally be closed or alternatively (possibly partially) opened. A charge / load distribution can take place via the control of the semiconductor switches.

Provided that a partial storage string is used when charging with the full string voltage 20th fails, the corresponding switch 22nd opened in this partial storage string. The first to third switchable connection 111-113 is closed to the respective other partial storage strand 50 in the high-voltage storage string with the defective storage string 20th to be able to continue to load and use.

When charging with half the line voltage (e.g. 400 V), the fifth and fourth switchable connections 115 , 114 closed, the sixth, seventh switchable connection 116 , 117 open. The first to third switchable connection 111-113 can be open or closed. Only the first partial storage strings are then initially used 10-30 loaded. As soon as the first partial storage strands have been loaded, the fifth switchable connection is opened and the sixth, seventh switchable connection is closed. The second partial storage strands 40-60 are then made from the first partial storage strands 10-30 charged until a charge equalization has taken place. The process is repeated until all partial storage strings are sufficiently loaded. If a partial storage line fails - as already described - the still functional partial storage line is switched via the closed first to third switchable connection 111 , 113 loaded. Is the optional eighth switchable connection 118 present, the reloading process can be omitted and the first and second partial storage strings are charged directly one after the other / alternately with half the string voltage.

In drive mode with driven first drive train 4th become the fifth and fourth switchable connection 115 , 114 closed.

In drive mode with driven second drive train 5 become the sixth switchable connection 116 closed and the seventh switchable connection 117 open.

If one drive fails, the second drive is still available, even if there is a short circuit in the load.

Claims (9)

Energy supply system for an electrically drivable vehicle, with three high-voltage storage lines connected in parallel, each comprising a first and a second series-connected partial storage line (10, 40; 20, 50; 30, 60), the first high-voltage storage line (10, 40) and the second high-voltage storage string (20, 50) can be electrically coupled between the first and the second partial storage strings (10, 40; 20, 50) via a first switchable connection (111), the first high-voltage storage string (10, 40) and the third high-voltage Storage string (30, 60) between the first and the second partial storage strings (10, 40; 30, 60) can be electrically coupled via a second switchable connection (112), and wherein the second high-voltage storage string (20, 50) and the third high-voltage - Storage string (30, 60) between the first and the second partial storage strings (20, 50; 30, 60) can be electrically coupled via a third switchable connection (113), the energy supply system having a first connection point (101) and a second connection point (102 ), wherein the second connection point (102) via a fourth switchable connection (114) between the first and the second partial storage string (30, 60) with the third high-voltage storage string (30, 60), the second switchable connection (112) and the third switchable connection (113) can be electrically coupled, the first connection point (101) having a fifth switchable connection (115) with negative poles (13, 23, 33) of the first partial storage strands (10, 20, 30) can be electrically coupled, and wherein the second connection point (102) can be electrically coupled to positive poles (44, 54, 64) of the second partial storage strings (40, 50, 60) via a sixth switchable connection (116). Energy supply system according to Claim 1 , wherein the energy supply system has a third connection point (103), wherein the third connection point can be electrically coupled to the positive poles (44, 54, 64) of the second partial storage strings (40, 50, 60) via the sixth switchable connection (116). Energy supply system according to Claim 2 , wherein the second connection point (102) can be electrically coupled to the sixth switchable connection (116) via a seventh switchable connection (117) in order to electrically connect the second connection point (102) to the positive poles of the second partial storage strands (40, 50, 60) couple. Energy supply system according to one of the preceding claims, wherein the first connection point (101) via an eighth switchable connection (118) between the first and the second partial storage string (30, 60) with the third high-voltage storage string (30, 60), the second switchable connection (112) and the third switchable connection (113) can be electrically coupled. Energy supply system according to one of the preceding claims, wherein the partial storage strings (10, 20, 30, 40, 50, 60) each have a switch (12, 22, 32, 42, 52, 62) between the energy storage (11, 21, 31, 41, 51, 61) and minus pole (13, 23, 33, 43, 53, 63). Energy supply system according to one of the preceding claims, comprising a connection unit with a first connector (201) and a second connector (202) for connection to charging electronics (3), a third connector (203) and a fourth connector (204) for connection to a first electrical drive train (4), a fifth connector (205) and a sixth connector (206) for connection to a second electrical drive train (5), and a seventh connector (207) for electrical coupling to the first connection point (101), a eighth connector (208) for electrical coupling with the second connection point (102) and preferably a ninth connector (209) for electrical coupling with the third connection point (103). Energy supply system according to Claim 6 wherein the first connector (201), the third connector (203), the fifth connector (205) and the seventh connector (207) are electrically coupled, wherein the second connector (202) and the eighth connector (208) are electrically coupled , and wherein the fourth connector (204), the sixth connector (206) and the ninth connector (209) are electrically coupled. Energy supply system according to Claim 6 , wherein the first connector (201), the third connector (203) and the seventh connector (207) are electrically coupled, the second connector (202), the fourth connector (204), the fifth connector (205) and the eighth Connectors (208) are electrically coupled, and wherein the sixth connector (206) and the ninth connector (209) are electrically coupled. Electrically drivable vehicle with an energy supply system according to one of the preceding claims.

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