DE102011118716A1 - Storage system for e.g. supplying electrical energy for electric drive of electric car, has semiconductor switch connected in series with contactors and accumulator, and blocking in opened bidirectional manner - Google Patents

Abstract

The system (10) has two contactors (14, 15) connected with a positive terminal (12) and a negative terminal (13), respectively. An accumulator (16.1) is connected in series between the contactors. A semiconductor switch (23) e.g. MOSFET, conducts in a closed bidirectional manner and blocks in an opened bidirectional manner. The switch is connected in series with the contactors and the accumulator. The switch includes enhancement type n-channel power MOSFETs, which are connected so that a discharging current path (Ie) and a charging current path (Il) run through the respective MOSFETs. Independent claims are also included for the following: (1) a method for discharging a storage system for electrical energy (2) a method for charging a storage system for electrical energy.

Description

The invention relates to a storage system for electrical energy according to the preamble of claim 1, a method for unloading such a storage system and a method for loading such a storage system. Such storage systems are particularly suitable for use in electric vehicles.

In the prior art are electric vehicles, ie electric vehicles such as hybrid cars and pure electric cars, known to include traction batteries for the electrical power supply of the electric drive. These traction batteries are connected in series and form an electrical energy storage system which is connected to a high voltage vehicle electrical system and typically when discharging into this one current of over 100 A with a DC voltage of over 100 V and obtain when charging from this DC.

The publication DE 10 2009 020 178 A1 relates to a system for storing energy and forms the basis for the preamble of claim 1. This document discloses an energy storage system with a first energy storage and a second energy storage connected in series. Each of the two energy storage devices has a plurality of energy storage cells connected in series, which can be any desired electrochemical storage, such as lithium-ion battery cells. The first energy store has a first control unit for controlling the operation and monitoring of the state of the first energy store. To control the energy storage, the first control unit is connected via control lines with two shooters. By opening the contactors of the first energy storage can be separated from the energy storage system. The second energy store has a second control unit for controlling the operation and monitoring of the state of the second energy store. For controlling the second energy store, the second control unit is connected via control lines with two contactors. By opening the contactors of the second energy storage can be separated from the energy storage system. The energy supply from the energy storage system and the energy feed into the energy storage system via two power terminals, one of which is connected to one of the contactors of the first control unit and the other with one of the contactors of the second control unit. The other contactor of the first control unit is connected via a fuse with the other contactor of the second control unit.

If, for disconnecting the energy storage, which may be required, for example due to an emergency situation, the contactors under load, so must be opened with flowing current, the switching times of about 25 to 30 ms are very large.

The object of the invention is to enable a faster disconnection under load in a storage system according to the preamble of claim 1 and to provide a method for unloading such a storage system and a method for loading such a storage system.

This object is achieved by a memory system according to claim 1, a method for discharging an electrical energy storage system according to claim 7 and a method for charging an electrical energy storage system according to claim 12. Further embodiments are described in the subclaims.

• – Plusanschluss und einen einen Minusanschluss;
• – ein erstes Schütz, das mit dem Plusanschluss verbunden ist;
• – ein zweites Schütz, das mit dem Minusanschluss verbunden ist;
• – wenigstens einen Akkumulator, der in Reihe zwischen den beiden Schützen geschaltet ist;
• – einen Halbleiterschalter, der geschlossen bidirektional leitet und geöffnet bidirektional sperrt; wobei
• – der Halbleiterschalter in Reihe mit den Schützen und dem wenigstens einen Akkumulator geschaltet ist.

According to a first aspect, the invention proposes a storage system for electrical energy, in particular for an electric vehicle, comprising

• - plus connection and one a minus connection;
• A first contactor connected to the positive terminal;
• A second contactor connected to the negative terminal;
• - At least one accumulator, which is connected in series between the two shooters;
• - A semiconductor switch, the bidirectionally conducts closed and bi-directionally open locks; in which
• - The semiconductor switch is connected in series with the contactors and the at least one accumulator.

The contactors are used to galvanically isolate the accumulators of the proposed storage system from a load or power source connected to the positive and negative terminals. Since the semiconductor switch is connected in series with the contactors and the at least one accumulator and compared to the known shooters has significantly shorter switching times even under load, the proposed storage system allows in comparison to the DE 10 2009 020 178 A1 known storage system faster disconnection under load. This can be achieved, for example, by the semiconductor switch being actuated to open before or simultaneously with the contactors. In this case, the contactors can open without load or without current, which is significantly faster and significantly less wear compared to opening under load. In addition, cheaper contactors can be installed, since they no longer have to be designed for opening under load.

The proposed storage system may be formed as desired in any manner and include, for example, at least one further contactor and / or at least one further accumulator and / or at least one further semiconductor switch.

Each semiconductor switch may be formed as desired in any manner and include, for example, at least one MOSFET and / or at least one IGBT and / or at least one thyristor.

The position of the semiconductor switch in the series circuit with contactors and accumulators can be arbitrarily selected as needed. For example, the semiconductor switch can be located between the positive terminal and the first contactor or between the first contactor and a first accumulator or between two adjacent accumulators or between the first or the last accumulator and the second contactor or between the second contactor and the negative terminal.

• – der Halbleiterschalter einen ersten Transistor und einen zweiten Transistor umfasst;
• – die Transistoren derart geschaltet sind, dass ein Entladestrompfad, der zum Plusanschluss weist, zumindest durch den ersten Transistor und ein Ladestrompfad, der zum Minusanschluss weist, zumindest durch den zweiten Transistor verläuft.

It can be provided that

• - The semiconductor switch comprises a first transistor and a second transistor;
• - The transistors are connected such that a Entladestrompfad, which points to the positive terminal, at least through the first transistor and a charging current path, which points to the negative terminal, at least through the second transistor.

As a result, at least with the first transistor or with both transistors, a discharge current fed by the accumulators into a load connected to the positive terminal and the negative terminal, and at least to the second transistor or with both transistors, a charging current, the accumulators from one to the positive terminal Refer to the minus power supply connected electrical power source, quickly and low wear on and off. The load may be, for example, a high voltage electrical system of an electric vehicle having, for example, an electric motor, and the power source may be, for example, a high voltage electrical system of an electric vehicle having, for example, a generator and / or fuel cells.

The transistors may be formed and / or switched and / or driven as required in any desired manner. For example, the transistors can be designed and / or switched and / or driven such that the discharge current path passes through the first transistor but not through the second transistor, if the first transistor is closed and the second transistor is closed or opened, or Entladestrompfad passes through both the first transistor and the second transistor, if both transistors are closed. Alternatively or additionally, for example, the transistors may be designed and / or switched and / or driven such that the discharge current path is blocked if the first transistor is open and the second transistor is closed or opened. Alternatively or additionally, the transistors may for example be designed and / or switched and / or controlled such that the charging current path through the second transistor, but not through the first transistor, if the second transistor is closed and the first transistor is closed or opened, or that the charging current path extends through both the second transistor and the first transistor, if both transistors are closed. Alternatively or additionally, the transistors may for example be designed and / or switched and / or controlled such that the charging current path is blocked if the second transistor is opened and the first transistor is closed or opened.

The position of the transistors in the series circuit with contactors and accumulators can be arbitrarily selected as needed. For example, the first transistor may be between the positive terminal and the first contactor or between the first contactor and a first accumulator or between two adjacent accumulators or between the first or the last accumulator and the second contactor or between the second contactor and the negative terminal. Alternatively or additionally, for example, the second transistor may be between the positive terminal and the first contactor or between the first contactor and the first accumulator or between two adjacent accumulators or between the first or the last accumulator and the second contactor or between the second contactor and the negative terminal ,

Each transistor can be configured as desired, for example, as a MOSFET, in particular power MOSFET, or IGBT.

• – der Halbleiterschalter weiter eine erste Diode und eine zweite Diode umfasst;
• – die erste Diode gegensinnig zu dem ersten Transistor und die zweite Diode gegensinnig zu dem zweiten Transistor geschaltet ist.

It is preferably provided that

• - The semiconductor switch further comprises a first diode and a second diode;
• - The first diode in opposite directions to the first transistor and the second diode is connected in opposite directions to the second transistor.

The diodes thus represent freewheeling diodes, which prevent the respective transistor from being damaged during inverse operation.

Each diode may be formed as desired in any manner, for example, as a body diode of the MOSFET or as a Schottky diode.

It can be provided that the memory system further comprises at least one precharge resistor, which is connected in such a way that a precharge current path, which points to the positive terminal, runs through it, if the semiconductor switch blocks.

With the help of this pre-charging, for example, a pre-charge of an intermediate circuit capacitor, the load side is coupled to the positive terminal and the negative terminal, can be spared, the accumulators, but also the entire high-voltage electrical system including storage system and connected loads, energy sources and DC link capacitor, since the pre-charge the Limited pre-charging current, which is thus smaller than the discharge current.

The precharge resistor may be switched as desired in any manner, for example parallel to the first transistor or parallel to the first transistor and the second transistor. Alternatively or additionally, it can be integrated into the semiconductor switch as required or switched separately from it.

• – die Akkumulatoren in Reihe geschaltet sind;
• – die beiden Transistoren, falls die Anzahl der Akkumulatoren gerade ist, zwischen den beiden mittleren Akkumulatoren liegen oder, falls die Anzahl der Akkumulatoren ungerade ist, die beiden Transistoren an anderer Stelle liegen oder der mittlere Akkumulator zwischen den beiden Transistoren liegt.

It can be provided that the storage system further comprises at least one further accumulator, wherein

• - The accumulators are connected in series;
• - The two transistors, if the number of accumulators is even, between the two middle accumulators or, if the number of accumulators is odd, the two transistors are elsewhere or the middle accumulator between the two transistors.

As a result, a symmetrical arrangement is achieved. However, the two transistors can also be located elsewhere as required and in particular be arranged asymmetrically.

• – einen Plusanschluss und einen Minusanschluss;
• – ein erstes Schütz, das mit dem Plusanschluss verbunden ist;
• – ein zweites Schütz, das mit dem Minusanschluss verbunden ist;
• – wenigstens einen Akkumulator, der in Reihe zwischen den beiden Schützen geschaltet ist;
• – einen Halbleiterschalter, der geschlossen bidirektional leitet und geöffnet bidirektional sperrt; wobei
• – der Halbleiterschalter in Reihe mit den Schützen und dem wenigstens einen Akkumulator geschaltet ist;
• – in einem Schritt a) beide Schütze geschlossen werden oder geschlossen bleiben;
• – in einem Schritt b) der Halbleiterschalter geschlossen wird oder geschlossen bleibt.

According to a second aspect, the invention proposes a method for discharging an electrical energy storage system, the storage system comprising

• - a positive connection and a minus connection;
• A first contactor connected to the positive terminal;
• A second contactor connected to the negative terminal;
• - At least one accumulator, which is connected in series between the two shooters;
• - A semiconductor switch, the bidirectionally conducts closed and bi-directionally open locks; in which
• - The semiconductor switch is connected in series with the contactors and the at least one accumulator;
• - in a step a) both contactors are closed or remain closed;
• - In a step b) the semiconductor switch is closed or remains closed.

During discharging, the batteries feed a direct current into a load connected to the positive connection and the negative connection, which is, for example, a high-voltage onboard electrical system of an electric vehicle which has, for example, an electric motor. As a result, a discharge current flows from the negative terminal through the accumulators to the positive terminal in the storage system. Since the contactors and the semiconductor switch are connected in series, as soon as the contactors and the semiconductor switch are closed, the discharge current can flow through the contactors and the semiconductor switch.

The storage system may be, for example, one of the proposed storage systems.

The contactors can be closed sequentially or simultaneously as needed.

The order of steps a) and b) can be arbitrarily selected as needed. Thus, for example, step a) can be carried out before or simultaneously with or after step b). Advantageously, however, step a) is carried out before step b). As a result, the contactors are closed, as long as the semiconductor switch is still open, thus blocking the discharge, so then the closing of the contactors is de-energized.

If, at the beginning of the proposed method for discharging, the semiconductor switch should already be closed, then preferably before step a) in a step a ') the semiconductor switch can be opened.

• – der Halbleiterschalter einen ersten Transistor und einen zweiten Transistor umfasst;
• – die Transistoren derart geschaltet sind, dass ein Entladestrom, der zum Plusanschluss weist, durch den ersten Transistor fließt;
• – in dem Schritt b) zumindest der erste Transistor geschlossen wird oder geschlossen bleibt.

It can be provided that

• - The semiconductor switch comprises a first transistor and a second transistor;
• - The transistors are connected such that a discharge current, which points to the positive terminal, flows through the first transistor;
• - In step b) at least the first transistor is closed or remains closed.

• – in einem Schritt c) der Halbleiterschalter geöffnet wird;
• – in einem Schritt d) beide Schütze geöffnet werden.

It can be provided that for disconnecting the at least one accumulator from the plus terminal and the minus terminal

• - In a step c) the semiconductor switch is opened;
• - In a step d) both contactors are opened.

This disconnection may be required in particular due to an emergency situation, for example an accident or a defect, or a repair or maintenance or a too low state of charge of the accumulators. As soon as the contactors are open, the storage system or its accumulators are galvanically isolated from the positive connection and the negative connection.

The contactors can be opened one after the other or simultaneously as needed.

The order of steps c) and d) can be arbitrarily selected as needed. For example, step c) may be performed before or simultaneously with or after step d). Advantageously, however, step c) is carried out before step d). As a result, the semiconductor switch is opened, thus blocking the discharge current, as long as the contactors are still closed, so that then the opening of the contactor is de-energized.

• – der Halbleiterschalter einen ersten Transistor und einen zweiten Transistor umfasst;
• – die Transistoren derart geschaltet sind, dass ein Entladestrom, der zum Plusanschluss weist, durch den ersten Transistor fließt;
• – in dem Schritt e) zumindest der erste Transistor geöffnet wird.

It can preferably be provided that

• - The semiconductor switch comprises a first transistor and a second transistor;
• - The transistors are connected such that a discharge current, which points to the positive terminal, flows through the first transistor;
• - In step e) at least the first transistor is opened.

Since the discharge current flows through the first transistor and must also flow, it can be interrupted by opening the first transistor. But it is also possible to open both transistors.

• – wenigstens ein Vorladewiderstand derart geschaltet ist, dass durch ihn ein Vorladestrom, der zum Plusanschluss weist, fließt, falls der Halbleiterschalter sperrt;
• – in einem Schritt e) der Halbleiterschalter geöffnet wird oder geöffnet bleibt;
• – in einem Schritt f) beide Schütze geschlossen werden oder geschlossen bleiben.

It may be provided that for precharging a link capacitor, which is coupled to the positive terminal and the negative terminal,

• - At least one precharge resistor is connected such that flows through it a precharge, which has the positive terminal, if the semiconductor switch locks;
• In a step e) the semiconductor switch is opened or remains open;
• - in a step f) both contactors are closed or remain closed.

Such a link capacitor is usually coupled on the load side in parallel to a load to the positive terminal and the negative terminal and serves, for example, to buffer voltage fluctuations. If this DC link capacitor should be uncharged or only slightly charged, then steps a) and b) would cause an initially very large discharge current that could destroy the accumulators. This can be avoided in the proposed pre-charging using the pre-charging resistor.

If it is to be transferred from unloading to pre-loading, this can be done simply by step e) and by step f) in the second alternative, since in step b) both contactors have already been closed during unloading and now simply remain closed. Thus, as soon as the semiconductor switch is opened, the discharge current can no longer flow through the semiconductor switch, but only through the precharge resistor, so that now a precharge current flows with a current intensity corresponding to the electrical resistance or conductance of the precharge resistor in the storage system. The semiconductor switch thus not only has the function of switching the discharging on and off, but also the function of switching the pre-charging on and off.

The contactors can be closed sequentially or simultaneously as needed.

The order of steps e) and f) can be arbitrarily selected as needed. Thus, step e) may be carried out before or simultaneously with or after step f). Advantageously, however, step e) is carried out before step f) in the first alternative, since in step f) the contactors are normally closed in the first alternative.

• – einen Plusanschluss und einen Minusanschluss;
• – ein erstes Schütz, das mit dem Plusanschluss verbunden ist;
• – ein zweites Schütz, das mit dem Minusanschluss verbunden ist;
• – wenigstens einen Akkumulator, der in Reihe zwischen den beiden Schützen geschaltet ist;
• – einen Halbleiterschalter, der geschlossen bidirektional leitet und geöffnet bidirektional sperrt; wobei
• – der Halbleiterschalter in Reihe mit den Schützen und dem wenigstens einen Akkumulator geschaltet ist;
• – in einem Schritt g) beide Schütze geschlossen werden oder geschlossen bleiben;
• – in einem Schritt h) der Halbleiterschalter geschlossen wird oder geschlossen bleibt.

According to a third aspect, the invention proposes a method for charging an electrical energy storage system, the storage system comprising

• - a positive connection and a minus connection;
• A first contactor connected to the positive terminal;
• A second contactor connected to the negative terminal;
• - At least one accumulator, which is connected in series between the two shooters;
• - A semiconductor switch, the bidirectionally conducts closed and bi-directionally open locks; in which
• - The semiconductor switch is connected in series with the contactors and the at least one accumulator;
• - in a step g) both contactors are closed or remain closed;
• - In a step h) the semiconductor switch is closed or remains closed.

During charging, the accumulators draw a direct current from an electrical energy source connected to the positive connection and the negative connection, which is, for example, a high-voltage onboard electrical system of an electric vehicle which has, for example, a generator and / or fuel cells. As a result, a charging current flows from the positive terminal through the accumulators to the negative terminal in the storage system. Since the contactors and the semiconductor switch are connected in series, As soon as the contactors and the semiconductor switch are closed, the charging current can flow through the contactors and the semiconductor switch and charge the accumulators.

The storage system may be, for example, one of the proposed storage systems.

The contactors can be closed sequentially or simultaneously as needed.

The order of steps g) and h) can be chosen as desired. Thus, for example, step g) can be carried out before or simultaneously with or after step h). Advantageously, however, step g) is carried out before step h). As a result, the contactors are closed, as long as the semiconductor switch is still open and thus blocks the charging current, so that the closing of the contactors is de-energized.

If at the beginning of the proposed method for charging the semiconductor switches should already be closed, so preferably before step g) in a step g ') of the semiconductor switch can be opened.

• – der Halbleiterschalter einen ersten Transistor und einen zweiten Transistor umfasst;
• – die Transistoren derart geschaltet sind, dass ein Ladestrom, der zum Minusanschluss weist, durch den zweiten Transistor fließt;
• – in dem Schritt h) zumindest der zweite Transistor geschlossen wird oder geschlossen bleibt.

It can be provided that

• - The semiconductor switch comprises a first transistor and a second transistor;
• - The transistors are connected such that a charging current, which points to the negative terminal, flows through the second transistor;
• - In step h) at least the second transistor is closed or remains closed.

• – in einem Schritt i) der Halbleiterschalter geöffnet wird;
• – in einem Schritt j) beide Schütze geöffnet werden.

It can be provided that for disconnecting the at least one accumulator from the plus terminal and the minus terminal

• - In a step i) the semiconductor switch is opened;
• - in a step j) both contactors are opened.

This disconnection may be required in particular due to an emergency situation, for example an accident or a defect, or a repair or maintenance or a sufficiently high state of charge of the accumulators. As soon as the contactors are open, the storage system or its accumulators are galvanically isolated from the positive connection and the negative connection.

The contactors can be opened one after the other or simultaneously as needed.

The order of steps i) and j) can be chosen as desired. For example, step i) may be performed before or simultaneously with or after step j). Advantageously, however, step i) is carried out before step j). As a result, the semiconductor switch is opened and thus the charging current interrupted as long as the contactors are still closed, so that they can then be opened normally.

• – der Halbleiterschalter einen ersten Transistor und einen zweiten Transistor umfasst;
• – die Transistoren derart geschaltet sind, dass ein Ladestrom, der zum Minusanschluss weist, durch den zweiten Transistor fließt;
• – in dem Schritt i) zumindest der zweite Transistor geöffnet wird.

It can preferably be provided that

• - The semiconductor switch comprises a first transistor and a second transistor;
• - The transistors are connected such that a charging current, which points to the negative terminal, flows through the second transistor;
• - In the step i) at least the second transistor is opened.

Since the charging current flows through the second transistor and must also flow, it can be interrupted by opening the second transistor. But it is also possible to open both transistors.

The statements relating to one of the aspects of the invention, in particular to individual features of this aspect, also apply analogously to the other aspects of the invention.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings. However, the individual features resulting therefrom are not limited to the individual embodiments, but can be combined with individual features described above and / or with individual features of other embodiments. The details in the drawings are to be interpreted as illustrative, but not restrictive. The reference signs contained in the claims are not intended to limit the scope of the invention in any way, but merely refer to the embodiments shown in the drawings.

The drawings show in:

1 a circuit diagram of an electrical energy storage system in a first embodiment;

2 a circuit diagram of an electrical energy storage system in a second embodiment; and

3 a circuit diagram of an electrical energy storage system in a third embodiment.

In the 1 is a storage system 10 for electrical energy in a first embodiment for connection to a high voltage electrical system 11 an electric vehicle shown. This storage system 10 includes a positive connection 12 , one negative connection 13 , a first contactor 14 , a second contactor 15 , four accumulators 16.1 . 16.2 . 16.3 . 16.4 and a semiconductor switch 23 ,

To the positive connection 12 and the negative connection 13 is the high voltage on-board electrical system 11 connected, the one DC link capacitor 24 , an electric motor 25 that has a switch 25 ' in the high voltage on-board electrical system 11 can be coupled, and a fuel cell module 26 that has a switch 26 ' in the high voltage on-board electrical system 11 can be coupled. The DC link capacitor 24 , the electric motor 25 and the fuel cell module 26 are connected in parallel. The electric motor 25 provides an electrical load during engine operation and an electrical energy source for the storage system during generator operation 10 dar. Also the fuel cell module 26 can be an electrical energy source for the storage system 10 represent.

The first contactor 14 has a first main power contact connected to the positive terminal 12 is connected, and a second main current contact, to the positive pole of the first accumulator 16.1 connected. The first accumulator 16.1 is in series with the second accumulator 16.2 connected. The second contactor 15 has a first main power contact to the negative terminal 13 is connected, and a second main power contact, which is connected to the negative pole of the fourth accumulator 16.4 connected. The fourth accumulator 16.4 is in series with the third accumulator 16.3 connected.

The semiconductor switch 23 conducts bidirectionally in the closed state and bi-directionally locks in the open state, and it is connected in series to the negative pole of the second accumulator 16.2 and the positive pole of the third accumulator 16.3 connected. Consequently, he is in line with the shooters 14 . 15 and the accumulators 16 switched and also switched such that a discharge current path to the positive terminal 12 points, and a charging path leading to the negative terminal 13 points, passes through it, if it is closed and directs.

In this first embodiment, the number of accumulators 16 straight and lies the semiconductor switch 23 between the two middle accumulators 16.2 and 16.3 ,

In this first embodiment, the storage system includes 10 further a pre-charge resistance 21 , which is parallel to the semiconductor switch 23 is switched. It is thus switched such that a Vorladestrompfad, the positive terminal 12 points through it, if the semiconductor switch 23 is open and locks.

In this first embodiment, the storage system includes 10 further a control unit 22 , via dotted control lines with the shooter 14 . 15 and the semiconductor switch 23 is connected and connected to a central control unit, not shown, of the electric vehicle. The control unit 22 is configured to provide a method of unloading the memory system 10 and a method for loading the storage system 10 which will be described in more detail below.

When unloading, the storage system feeds 10 a discharge current I _E in the high voltage _{electrical system} 11 in this case, as an electrical load in the form of the motor-driven electric motor 25 by closing the switch 25 ' at the positive connection 12 and the minus connection 13 is applied. This discharge current I _E flows from the positive terminal 12 through the high voltage on-board electrical system 11 to the minus connection 13 and from this on in the storage system 10 back to the positive connection 12 ,

In the case of the control unit 22 If necessary, pre-charging of the DC link capacitor is carried out if necessary 24 with a through the pre-charge resistor 21 compared to the discharge current I _E reduced pre-charge current I _V and then the actual discharge with the not by the pre-charging resistor 21 reduced discharge current I _E. For pre-charging, first in a step e) the semiconductor switch 23 opened by a corresponding control signal so that it locks. Then in a step f) both shooters become 14 . 15 closed by appropriate control signals, which because of the opened semiconductor switch 23 Although not de-energized, but at the reduced compared to the discharge current I _E precharge I _V occurs. Now the accumulators can 16 to deliver the precharge current I _V coming from the storage system 10 from the positive connection 12 to the DC link capacitor 24 and from this to the negative terminal 13 and continue through the second contactor 15 , the fourth and the third accumulator 16.4 . 16.3 , the pre-charge resistance 21 , the second and the first accumulator 16.2 . 16.1 and the first contactor 14 back to the positive connection 12 flows.

If you want to skip the pre-load for unloading, for example, because the control unit 22 and / or the central control unit has a sufficiently high state of charge of the intermediate circuit capacitor 24 has determined and, for example, the switch 25 ' is closed, it is, omitting the step a), immediately in step b) of the semiconductor switch 23 closed by a corresponding control signal, which thus conducts and the precharge resistance 21 bridged. Consequently, the discharge current I _E as the precharge I _V from the storage system 10 to the high voltage on-board electrical system 11 flow, however, unlike the precharge current I _V , it flows in the memory system 10 from the third accumulator 16.3 through the now closed semiconductor switch 23 on pre-charge resistance 21 over to the second accumulator 16.2 ,

If this unloading or preloading is to be ended, for example because the control unit 22 and / or the central control unit a critically low state of charge of the accumulators 16 or has detected an accident of the electric vehicle, it is provided in the method for discharging that to disconnect the accumulators 16 from the positive connection 12 and the minus connection 13 first in a step c) of the semiconductor switch 23 is opened by a corresponding control signal so that it locks and the current path between the two middle accumulators 16.2 . 16.3 Although not completely interrupted, but by the Vorladewiderstand 21 to be led. Then in a step d) both shooters become 14 . 15 opened by appropriate control signals, which although not de-energized, but at the reduced compared to the discharge current I _E pre-charging current I _V happens because the semiconductor switch 23 is open.

If the unloading is to take place without previous precharging, it is provided in the method for discharging that initially in a step a ') the semiconductor switch 23 is opened by a corresponding control signal so that it locks and the current flow in the storage system 10 Although not completely interrupted, but by the Vorladewiderstand 21 to be led. Then in a step a) both shooters 14 . 15 closed by appropriate control signals. Although this is not currentless, but still in the reduced compared to the discharge current I _E precharge I _V , since the semiconductor switch 23 is open. Then, in a step b), the semiconductor switch 23 closed by a corresponding control signal, which thus conducts and the precharge resistance 21 bridged and one compared to the pre-charge resistance 21 lower resistance current path between the positive pole of the third accumulator 16.3 and the negative pole of the second accumulator 16.2 closes. The accumulators 16 can thus supply the discharge current I _E.

When loading the storage system 10 feeds the high voltage on-board electrical system 11 , which in this case now as an electrical energy source in the form of the electric motor operated as a generator 25 by closing the switch 25 ' and / or in the form of the fuel cell module 26 by closing the switch 26 ' to the positive connection 12 and the negative connection 13 is connected, a charging current I _L in the storage system 10 which flows opposite to the discharge current I _E.

In the case of the control unit 22 implemented method for charging is first in a step g '), the step a') corresponds to the discharge, the semiconductor switch 23 opened by a corresponding control signal. Then in a step g) both shooters become 14 . 15 closed by appropriate control signals. This may be due to the opened semiconductor switch 23 Although not de-energized, but still at a lower compared to the discharge current I _E current corresponding to the pre-charge 21 respectively. Then, in a step h), the semiconductor switch 23 closed by a corresponding control signal, so that he the pre-charge 21 bridged and the low-resistance connection between the negative terminal of the second accumulator 16.2 and the positive pole of the third accumulator 16.3 is made and the charging current I _L can flow.

If this loading is to be stopped, for example because the control unit 22 and / or the central control unit a critically or sufficiently high state of charge of the accumulators 16 or has detected an accident of the electric vehicle, it is provided in the method for charging that to disconnect the batteries 16 from the positive connection 12 and the minus connection 13 first in a step i) of the semiconductor switch 23 is opened by a corresponding control signal, so that the charging current I _L is not interrupted, but yet according to the pre-charge 21 is reduced. Then in a step h) both shooters become 14 . 15 opened by appropriate control signals. This is done because of the opened semiconductor switch 23 Although not de-energized, but still in accordance with the pre-charge resistance 21 reduced current.

In the 2 is a storage system 10 shown in a second embodiment. This second embodiment is similar to the first embodiment, so that only the differences will be described in more detail below.

In this second embodiment, the semiconductor switch comprises 23 a first transistor 17 , a second transistor 18 , a first diode 19 and a second diode 20 , The transistors 17 . 18 are each here as a self-blocking n-channel power MOSFET 17 . 18 formed and in series to the negative terminal of the second accumulator 16.2 and the positive pole of the third accumulator 16.3 connected, the first transistor 17 closer to the negative terminal 13 and the second transistor 18 closer to the positive connection 12 lies. They are oriented in opposite directions to each other, since the normal operating direction of the first transistor 17 opposite to the normal operating direction of the second transistor 18 has. Here is an example of the drain terminal of the first transistor 17 with the Positive pole of the third accumulator 16.3 connected, the source terminal of the first transistor 17 to the source terminal of the second transistor 18 and the drain terminal of the second transistor 18 with the negative terminal of the second accumulator 16.2 , Thus, the normal operation direction of the first transistor 17 to the positive connection 12 and thus in the direction of the discharge current I _E and the normal operating direction of the second transistor 18 to the minus connection 13 and thus in the direction of the charging current I _L. Consequently, the transistors are 17 . 18 in line with the shooters 14 . 15 and the accumulators 16 and also switched such that the discharge current path through the first transistor 17 and the charging current path through the second transistor 18 runs.

The first diode 19 is antiparallel to the first transistor 17 switched, since it is connected in parallel to him, but their forward direction opposite to its normal operating direction and thus in the Inwersbetriebsrichtung and has its reverse direction in its normal operating direction. The second diode 20 is antiparallel to the second transistor 18 is switched, since it is connected in parallel to him, but has its forward direction opposite to its normal operating direction and thus in its Inversbetriebsrichtung and their reverse direction in its normal operating direction. Every diode 19 . 20 is therefore opposite to the respective transistor 17 . 18 connected.

In this second embodiment, each diode 19 . 20 by a body diode of the respective transistor formed as a MOSFET 17 . 18 formed by that in the corresponding MOSFET, the source terminal is connected to the bulk terminal.

In this second embodiment, the gate terminals of the transistors 17 . 18 connected to each other and to the control unit 22 coupled.

In the case of the control unit 22 implemented methods for discharging are for pre-charging initially in step e) both transistors 17 . 18 opened by a corresponding control signal, so that the first transistor 17 and the reverse-connected first diode 19 the current path through the semiconductor switch 23 lock. Then in step f) both shooters become 14 . 15 closed by appropriate control signals. Now the precharge current I _V in the storage system 10 from the third accumulator 16.3 through the pre-charge resistor 21 at the semiconductor switch 23 over to the second accumulator 16.2 flow.

For subsequent discharge in step b) both transistors 17 . 18 closed by a corresponding control signal so that they conduct and the precharge resistance 21 bridged. The forward-biased second diode prevents this 20 an inverse operation in the second transistor 18 , Consequently, the discharge current I _E in the storage system 10 from the third accumulator 16.3 through the first transistor, which is now switched in the normal operating direction 17 and the second diode 20 on pre-charge resistance 21 over to the second accumulator 16.2 flow.

To disconnect the accumulators 16 from the positive connection 12 and the minus connection 13 are first in step c) both transistors 17 . 18 opened by a corresponding control signal, so that the first transistor 17 and the reverse-connected first diode 19 the current path through the semiconductor switch 23 lock and only the current path through the pre-charge resistor 21 remains. Then in step d) both shooters become 14 . 15 opened by appropriate control signals.

In the case of the control unit 22 implemented methods for charging are first in step g ') both transistors 17 . 18 opened by a corresponding control signal, so that the second transistor 18 and the reverse-connected second diode 20 the current path through the semiconductor switch 23 lock. Then in step g) both shooters become 14 . 15 closed by appropriate control signals. Then in step h) both transistors become 17 . 18 closed by a corresponding control signal so that they conduct and the precharge resistance 21 bridged. The forward-biased first diode prevents this 19 an inverse operation in the first transistor 17 , Consequently, the charging current I _L in the memory system 10 from the second accumulator 16.2 by the second transistor, which is now connected in the normal operating direction 18 and the first diode 19 on pre-charge resistance 21 over to the third accumulator 16.3 flow.

To disconnect the accumulators 16 from the positive connection 12 and the minus connection 13 be first in step i) both transistors 17 . 18 opened by a corresponding control signal, so that the second transistor 18 and the reverse-connected second diode 20 the current path through the semiconductor switch 23 lock and only the current path through the pre-charge resistor 21 remains. Then in step h) both shooters become 14 . 15 opened by appropriate control signals.

In the 3 is a storage system 10 shown in a third embodiment. This third embodiment is similar to the second embodiment, so that only the differences will be described in more detail below.

In this third embodiment, the storage system 10 three accumulators 16.1 . 16.2 . 16.3 on that between the two transistors 17 . 18 are arranged. Consequently, the number of accumulators 16 odd and lies the middle accumulator 16.2 between the two transistors 17 . 18 ,

In this third embodiment, the two transistors 17 . 18 interchanged, so now the first transistor 17 closer to the positive connection 12 and the second transistor 18 closer to the negative terminal 13 lies, but still in opposite directions. Here is an example of the drain terminal of the first transistor 17 with the plus pole of the first accumulator 16.1 connected, the source terminal of the first transistor 17 with the second main current contact of the first contactor 14 , the drain terminal of the second transistor 18 with the negative pole of the third accumulator 16.3 and the source terminal of the second transistor 18 with the second main current contact of the second contactor 15 ,

Thus, as in the second embodiment, the normal operation direction of the first transistor 17 to the positive connection 12 and thus in the direction of the discharge current I _E and the normal operating direction of the second transistor 18 to the minus connection 13 and thus in the direction of the charging current I _L. Consequently, the transistors are 17 . 18 in line with the shooters 14 . 15 and the accumulators 16 and also switched such that the discharge current path through the first transistor 17 and the charging current path through the second transistor 18 runs.

In this third embodiment, the gate terminals of the two transistors 17 . 18 not connected to each other, but each separately to the control unit 22 coupled so that they can be individually controlled independently.

In this third embodiment, each diode becomes 19 . 20 not by a body diode of the respective formed as a MOSFET transistor 17 . 18 is formed, since in the corresponding MOSFET, the source terminal is not connected to the bulk terminal, but by a Schottky diode.

In the case of the control unit 22 implemented method for discharging is to precharge first in step e) the first transistor 17 opened by a corresponding control signal, so that he and the reverse-connected first diode 19 the current path through the semiconductor switch 23 lock. Then in step f) both shooters become 14 . 15 closed by appropriate control signals. Now the precharge current I _V in the storage system 10 from the second contactor 15 through the second diode connected in the forward direction 20 , the accumulators 16.3 . 16.2 . 16.1 and the precharge resistance 21 at the first transistor 17 over to the first contactor 14 flow.

For subsequent discharge in step b) the first transistor 17 closed by a corresponding control signal, so that it conducts and the precharge resistance 21 bridged. Consequently, the discharge current I _E in the storage system 10 from the second contactor 15 through the second diode connected in the forward direction 20 , the accumulators 16.3 . 16.2 . 16.1 and the now in the normal operating direction connected first transistor 17 on pre-charge resistance 21 over to the first contactor 14 flow.

To disconnect the accumulators 16 from the positive connection 12 and the minus connection 13 is first in step a), the first transistor 17 opened by a corresponding control signal, so that he and the reverse-connected first diode 19 the current path through the semiconductor switch 23 lock and only the current path through the pre-charge resistor 21 remains. Then in step d) both shooters become 14 . 15 opened by appropriate control signals.

In the case of the control unit 22 implemented method for charging is first in step g '), the second transistor 18 opened by a corresponding control signal, so that he and the reverse-connected second diode 20 the current path through the semiconductor switch 23 lock. Then in step g) both shooters become 14 . 15 closed by appropriate control signals. Then, in step h), the second transistor 18 closed by a corresponding control signal, so that he directs. Consequently, the charging current I _L in the memory system 10 from the first contactor 14 through the first diode connected in the forward direction 19 on pre-charge resistance 21 over, the accumulators 16.1 . 16.2 . 16.3 and the second transistor now connected in the normal operating direction 18 to the second contactor 15 flow.

To disconnect the accumulators 16 from the positive connection 12 and the minus connection 13 First, in step i), the second transistor 18 opened by a corresponding control signal, so that he and the reverse-connected second diode 20 the current path through the semiconductor switch 23 lock. Then in step h) both shooters become 14 . 15 opened by appropriate control signals.

This is done because of the opened second transistor 18 not de-energized.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102009020178 A1 [0003, 0008]

Claims (15)

Storage system ( 10 ) for electrical energy, in particular for an electric vehicle, comprising - a positive terminal ( 12 ) and a negative terminal ( 13 ); - a first contactor ( 14 ) connected to the positive terminal ( 12 ) connected is; - a second contactor ( 15 ) connected to the negative terminal ( 13 ) connected is; - at least one accumulator ( 16.1 ) in series between the two shooters ( 14 . 15 ) is switched; characterized by - a semiconductor switch ( 23 ), which conducts bidirectionally closed and bi-directionally open locks; wherein - the semiconductor switch ( 23 ) in series with the shooters ( 14 . 15 ) and the at least one accumulator ( 16.1 ) is switched. Storage system ( 10 ) according to claim 1, wherein - the semiconductor switch ( 23 ) a first transistor ( 17 ) and a second transistor ( 18 ); - the transistors ( 17 . 18 ) are connected such that a discharge current path (I _E ) to the positive terminal ( 12 ), at least through the first transistor ( 17 ) and a charging current path (I _L ), which leads to the negative terminal ( 13 ), at least through the second transistor ( 18 ), Storage system ( 10 ) according to claim 2, wherein - the semiconductor switch ( 23 ) a first diode ( 19 ) and a second diode ( 20 ); The first diode ( 19 ) in the opposite direction to the first transistor ( 17 ) and the second diode ( 20 ) in the opposite direction to the second transistor ( 18 ) is switched. Storage system ( 10 ) according to one of the preceding claims, further comprising - at least one precharging resistor ( 21 ), which is connected such that a precharge current path (I _V ), which leads to the positive terminal ( 12 ), passes through it, if the semiconductor switch ( 23 ) locks. Storage system ( 10 ) according to claim 4 and one of claims 2 to 3, wherein - the precharge resistance ( 21 ) parallel to the first transistor ( 17 ) or parallel to the first transistor ( 17 ) and second transistor ( 18 ) is switched. Storage system ( 10 ) according to one of claims 2 to 5, further comprising - at least one further accumulator ( 16.2 . 16.3 . 16.4 ); in which - the accumulators ( 16 ) are connected in series; The two transistors ( 17 . 18 ), if the number of accumulators ( 16 ) is just between the two middle accumulators ( 16.2 . 16.3 ), or, if the number of accumulators ( 16 ) is odd, the two transistors are elsewhere or the middle accumulator ( 16.2 ) between the two transistors ( 17 . 18 ) lies. Method for unloading a storage system ( 10 ) for electrical energy, the storage system ( 10 ) - a positive connection ( 12 ) and a negative terminal ( 13 ); - a first contactor ( 14 ) connected to the positive terminal ( 12 ) connected is; - a second contactor ( 15 ) connected to the negative terminal ( 13 ) connected is; - at least one accumulator ( 16.1 ) in series between the two shooters ( 14 . 15 ) is switched; A semiconductor switch ( 23 ), which conducts bidirectionally closed and bi-directionally open locks; wherein - the semiconductor switch ( 23 ) in series with the shooters ( 14 . 15 ) and the at least one accumulator ( 16.1 ) is switched; - in a step a) both contactors ( 14 . 15 ) getting closed; In a step b) of the semiconductor switch ( 23 ) is closed. Method according to claim 7, wherein - the semiconductor switch ( 23 ) a first transistor ( 17 ) and a second transistor ( 18 ); - the transistors ( 17 . 18 ) are connected such that a discharge current (I _E ) to the positive terminal ( 12 ), by the first transistor ( 17 ) flows; In step b) at least the first transistor ( 17 ) is closed. Method according to claim 7 or 8, wherein for separating the at least one rechargeable battery ( 16.1 ) from the positive terminal ( 12 ) and the negative terminal ( 13 ) - in a step c) of the semiconductor switch ( 23 ) is opened; - in a step d) both shooters ( 14 . 15 ). Method according to claim 9, wherein - the semiconductor switch ( 23 ) a first transistor ( 17 ) and a second transistor ( 18 ); - the transistors ( 17 . 18 ) are connected such that a discharge current (I _E ) to the positive terminal ( 12 ), by the first transistor ( 17 ) flows; In step c) at least the first transistor ( 17 ) is opened. Method according to one of claims 7 to 10, wherein for precharging a DC link capacitor ( 24 ) connected to the positive terminal ( 12 ) and the negative terminal ( 13 ) is coupled, At least one precharge resistor ( 21 ) is switched such that by him a pre-charge current (I _V ) to the positive terminal ( 12 ) flows, if the semiconductor switch ( 23 ) locks; In a step e) of the semiconductor switches ( 23 ) is opened; - in a step f) both shooters ( 14 . 15 ) getting closed. Method for loading a storage system ( 10 ) for electrical energy, the storage system ( 10 ) - a positive connection ( 12 ) and a negative terminal ( 13 ); - a first contactor ( 14 ) connected to the positive terminal ( 12 ) connected is; - a second contactor ( 15 ) connected to the negative terminal ( 13 ) connected is; - at least one accumulator ( 16.1 ) in series between the two shooters ( 14 . 15 ) is switched; A semiconductor switch ( 23 ), which conducts bidirectionally closed and bi-directionally open locks; wherein - the semiconductor switch ( 23 ) in series with the shooters ( 14 . 15 ) and the at least one accumulator ( 16.1 ) is switched; - in a step g) both shooters ( 14 . 15 ) getting closed; In a step h) of the semiconductor switches ( 23 ) is closed. The method of claim 12, wherein - the semiconductor switch ( 23 ) a first transistor ( 17 ) and a second transistor ( 18 ); - the transistors ( 17 . 18 ) are connected such that a charging current (I _L ) to the negative terminal ( 13 ), through the second transistor ( 18 ) flows; In step h) at least the second transistor ( 18 ) is closed. The method of claim 12 or 13, wherein for separating the at least one accumulator ( 16.1 ) from the positive terminal ( 12 ) and the negative terminal ( 13 ) - in a step i) the semiconductor switch ( 23 ) is opened; - in a step j) both contactors ( 14 . 15 ). The method of claim 14, wherein - the semiconductor switch ( 23 ) a first transistor ( 17 ) and a second transistor ( 18 ); - the transistors ( 17 . 18 ) are connected such that a charging current (I _L ) to the negative terminal ( 13 ); through the second transistor ( 18 ) flows; In step i) at least the second transistor ( 18 ) is opened.

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