WO2011057849A1

WO2011057849A1 - Energy transfer system for an energy accumulator system

Info

Publication number: WO2011057849A1
Application number: PCT/EP2010/064004
Authority: WO
Inventors: Stefan Butzmann; Holger Fink
Original assignee: Robert Bosch Gmbh
Priority date: 2009-11-11
Filing date: 2010-09-23
Publication date: 2011-05-19
Also published as: DE102009046605A1

Abstract

The invention relates to an energy transfer system (20) for an energy accumulator system (10), in particular a battery system, having a plurality of direct current regulator modules (22; 24; 26) each having a direct current regulator (22, 24, 26) and/or an output-side series connection of a plurality of direct current regulators (22, 24, 26; 50, 52, 54) each having a first and a second module output (46, 48), wherein each of the direct current regulators (22, 24, 26; 50, 52, 54) has a first and a second input (34, 36) for connecting an energy accumulator module (12, 14, 16) of the energy accumulator system (10) and the direct current regulator modules (22; 24; 26) are connected in parallel on the output side. The invention further relates to an energy accumulator system having a corresponding energy transfer system and a motor vehicle having an energy accumulator system.

Description

description

title

Energy transfer systems for an energy storage system

The invention relates to an energy transfer system for an energy storage system, in particular a battery system, with a plurality of DC converter modules. The invention further relates to an energy storage system with a corresponding energy transfer system and a motor vehicle having such an energy storage system.

State of the art

An energy transfer system for an energy storage system is z. B. from wind turbines, emergency power systems, but also known from vehicles with electric or hybrid drive. In such systems, a converter module with at least one DC-DC converter (DC / DC converter) between the energy storage modules of the energy storage system on the one hand and an electrical machine designed as an electric motor or alternator on the other hand interposed. The energy storage modules are designed as battery modules with rechargeable battery cells.

There is a growing demand for energy storage systems to be used in such stationary applications as wind turbines and emergency power systems or in vehicles. All of these applications place high demands on the reliability and reliability of the energy storage system. The reason for this is that a complete failure of the power supply by the energy storage system can lead to failure of an entire system. In wind turbines, batteries are used to adjust the rotor blades in strong wind to protect the system from excessive mechanical stresses that can damage or even destroy the wind turbine. In case of failure of the battery rie (module) of an electric or hybrid vehicle, this would become unfit for driving. In turn, an emergency power system should ensure uninterrupted operation, for example in a hospital, and should therefore not fail as far as possible.

In order to be able to provide the power and supply voltage required for the respective application, individual battery cells are connected in series and sometimes additionally in parallel. This z. B. a plurality of battery cells connected in series to achieve the required for example in a car (passenger cars) for the drive motor operating voltage. The operating voltage can be decoupled by output-side switches from the following non-illustrated power electronic components, such as inverters. Since the entire output current of the energy storage module flows due to the series connection of the battery cells in each of the battery cells, the failure of a single battery cell in an extreme case, the entire energy storage system no electricity and thus can no longer provide electrical energy. In order to be able to detect an imminent failure of a battery cell in good time, a so-called battery management system is usually used, which is connected to both poles of each of the battery cells and at regular or selectable intervals operating parameters such as voltage and temperature of each of the cells and the resulting state of charge (SoC : State of charge and / or SoH: State of Health). This means a lot of effort with low flexibility of the electrical operating data of the energy storage system.

Disclosure of the invention

The inventive energy transfer system the features mentioned in claim 1 offers the advantage that on the input side a large number of energy storage modules with each freely selectable for feeding electrical energy

Reference potential can be connected, each having a significantly lower clamping voltage than a corresponding combination of series and parallel connection of these energy storage modules, as resulting from the interconnection at the output of the energy storage modules. According to the invention, the energy transfer system has a plurality of DC converter modules (DC / DC converter modules) each having a DC controller (DC / DC converter) and / or an output-side series circuit of a plurality "

DC-DC converter and each having a first and a second module output, wherein each of the DC controllers has a first and a second input for connecting an energy storage module and the DC-controller modules are connected in parallel on the output side. The output side parallel circuit of the DC actuator modules takes place by electrically conductive connection of the first module outputs with each other and the second module outputs with each other.

Due to the resulting low clamping voltage between the first and 10 the second input of each of the DC controllers is not on any primary side

Connecting a voltage that would require a special handling of the energy storage when replacing individual energy storage modules or energy storage cells. By the outputs of the DC actuator modules are connected in parallel, the output side, a desired high Gei s total current as the sum of the output currents generated by the individual DC actuator modules. Due to the series connection of the DC-DC converter within the DC-controller modules, a preselectable high total voltage results at the same time on the output side as the sum of the output voltages generated by the individual DC-DC controllers. The structure of the converter modules 20 allows the choice of a suitable total voltage depending on the operating situation, since the output voltage of the individual DC choppers can be set in a known manner. In addition, the output voltage, regardless of the number of primary side connected energy storage cells. As a result, the design of the energy storage system can be based purely on energy and Leistungskri- 25 series, regardless of the total voltage required for the particular application. Another advantage is that expensive circuit breakers (contactors) can be omitted for separating the energy storage of the load and connections to the load, because the high voltage can be switched off at the energy storage output by switching off the DC chopper in a simple manner. The (total) voltage of each of the energy storage modules is preferably in the range 0.1 V <X <120 V, particularly preferably in the range 0.2 V <X <50 V.

Under an electrical energy storage in the context of the present invention 35 is an energy storage to understand the either electrical energy can be removed or fed and removed. The electrical energy store is used as charge storage and / or as magnetic energy. formed giespeicher and / or electrochemical energy storage. An electrochemical energy store is in particular a rechargeable battery or an accumulator. A DC chopper is to be understood in particular as a bidirectional DC chopper (DC / DC converter).

According to a preferred embodiment of the invention, at least one of the DC choppers has a first and a second coil, which are coupled together to form a power transformer and / or storage transformer. This variant of the DC-DC converter allows galvanic decoupling of the outputs of the DC-DC converter from their inputs, so that a series connection of the outputs of the DC-DC converter with a subsequent parallel connection of the outputs of DC-DC converter modules is easily combined.

According to an advantageous embodiment of the invention, it is provided that the DC-DC converter can be designed as a fly-back converter, as a forward converter, push-pull converter, half-bridge converter and full-bridge converter, and as a resonant converter. The aforementioned converters are known

DC chopper.

In an advantageous embodiment of the energy exchanger according to the invention, the first inputs or the second inputs of each of a DC-DC converter of each of the DC actuator modules are connected to ground. In particular, the first inputs or the second inputs of each DC chopper of each of the DC chiller modules are connected to ground.

According to a further preferred embodiment of the invention, it is provided that at least one of the DC choppers has a freewheeling diode, wherein in each case one anode of the freewheeling diode is electrically connected to a second output of the DC adjuster and a cathode of the freewheeling diode is electrically connected to a first output of the DC adjuster. Particularly preferably, each of the DC controllers has a freewheeling diode.

Alternatively or additionally, at least one of the DC controllers has a first control input for a first control signal and is configured to -.

upon receipt of the first control signal, electrically connecting a first output of the DC adjuster to a second output of the DC adjuster. In particular, it is provided that each of the DC controllers has a first control input for a first control signal and is designed to receive the first output of the first control signal

DC actuator to be electrically connected to the second output of the DC adjuster.

In a continuation of the two last-mentioned embodiments, at least one of the DC controllers has a second control input for a second control signal and is designed to increase a voltage between the first and the second output of the DC adjuster upon receipt of the second control signal. It is preferably provided that each of the DC controllers has such a control input. Thus, it is possible to counteract a decrease in the total voltage of a converter module by the already described failure or the shutdown of a single DC adjuster, so that further provided at least approximately unchanged total voltage of the reduced number of DC-controllers within the DC adjuster module.

The invention further relates to an energy storage system with an aforementioned energy transfer system. It is provided that the energy storage system comprises a plurality of energy storage modules each having a memory cell and a first and a second pole, wherein the poles with corresponding first and second inputs of the DC chopper of

Energy transfer system are electrically connected. This compound is preferably a releasable connection. The memory cells of the energy storage modules are preferably battery cells of battery modules, the poles corresponding to battery poles.

The invention further relates to a motor vehicle with an energy storage system mentioned above. According to a preferred embodiment of the invention, it is provided that the energy storage system is designed as an energy storage system for supplying an electric drive system of the motor vehicle. The drive system has at least one electrical machine designed as an electric motor and / or generator. The invention will be explained in more detail below with reference to the figures of exemplary embodiments. Show it:

1 is a circuit diagram of a first embodiment of an energy storage system with energy transfer system,

FIG. 2 shows a circuit diagram of a second exemplary embodiment of an energy storage system with energy transfer system; FIG. and FIG. 3 is a circuit diagram of a DC-DC regulator with a storage transformer.

1 shows a circuit diagram of a battery system designed as an energy storage system 10 having a plurality of rechargeable battery modules designed as electrical energy storage modules.

An electrical energy store in the sense of the present invention is to be understood as meaning an energy store to which electrical energy can be taken or can be supplied and removed. The electrical energy storage is designed as a charge storage and / or as a magnetic energy storage and / or electrochemical energy storage. Modular units of the energy storage are the electrical energy storage modules.

In Fig. 1, only three of a plurality of energy storage modules 12, 14, 16, each with a memory cell 18 are shown. In real applications, the number of energy storage modules or battery modules can be significantly higher. The

Energy storage system 10 further includes an energy transfer system 20, which in turn comprises a plurality of DC-DC converter modules 22, 24, 26, wherein each of the DC actuator modules 22, 24, 26 each have a DC / DC converter 28, 30, 32. Each of the DC controllers 22, 24, 26 has a first input 34 and a second input 36. Each of the first inputs 34 having an associated first battery pole 38 of a DC storage device 28, 30, 32 associated energy storage module 12, 14, 16 and each second input 36 of the DC choppers 28, 30, 32 with a second pole 40 of an associated energy storage module of the energy storage modules 12th , 14, 16 releasably electrically connected. Each of the DC controllers 28, 30, 32 has a first output 42 and a second output 44. Because each of the DC actuator modules 22, 24, 26 each have a DC controller 28, 30, 32, the respective first output corresponds to a first module output 46 and the respective second output 44 to a second module output 48 of the respective DC actuator module 22, 24, 26. Die Gleichstellstellermodule 22 , 24, 26 are connected in parallel to one another on the output side by short-circuiting the respective first module outputs 46 with each other and the second module outputs 48. At a first output contact (-) of the energy transmission system 18, which is electrically connected to the first outputs 42, and to a second output contact (+) connected to the second outputs 44, a consumer (not shown), in particular an electrical machine, can be connected. in the

Embodiment of FIG. 1, each of the actuator modules 22, 24, 26 exactly one DC-DC converter 28, 30, 32 and each of the energy storage modules 12, 14, 16 is connected to one of its poles 38, 40 connected to ground.

FIG. 2 shows a circuit diagram of a second exemplary embodiment of the energy storage system 10 with energy transfer system 20. The energy storage system 10 shown in FIG. 2 substantially corresponds to the energy storage system 10 of FIG. 1, so that only the differences are discussed here. The power transmission system 20 of FIG. 2 includes two DC chopper modules 22, 24, each DC chopper module 22, 24 each having three DC choppers 28, 30, 32; 50, 52, 54. The three DC choppers 28, 30, 32 of the first DC chopper module 22 are connected on the output side, that is via their outputs 42, 44, connected in series and the input side each with an associated energy storage module 12, 14, 16 electrically connected. The second DC-DC converter module 24 likewise has three DC-DC converters 50, 52, 54, which are connected in series on the output side and are each electrically connected on the input side to an associated energy storage module 56, 58, 60. The first module outputs 46 and the second module outputs 48 are electrically connected to each other and to a first output contact (-), respectively. The second module outputs 48 are electrically connected to each other and to a second output contact (+).

Such an arrangement has the advantage that the primary side a plurality of energy storage modules 12, 14, 16; 56, 58, 60 can be connected in parallel, wherein each of the DC-DC converter 28, 30, 32, 50, 52, 54 each present a significantly lower clamping voltage than in a series connection of all these energy storage modules 12, 14, 16, 56, 58th , 60 on a single _n

electronic device, such as an inverter. Therefore, there is no primary-side connection - that is to say none of the first and the second inputs 34, 36 of the DC-DC converter 28, 30, 32; 50, 52, 54 - a voltage, the special handling of the (preferably designed as a battery) th energy storage when replacing energy storage modules 12, 14, 16;

56, 58, 60 or individual memory cells 18 would be required. By the outputs of the DC choppers 28, 30, 32; 50, 52, 54, however, are connected in series, results - with respect to each of the DC actuator modules 22, 24 - a desired high total voltage as the sum of the individual DC actuators 28, 30, 32; 50, 52, 54 generated output voltages.

As a result of the direct current actuator modules 22, 24, which are connected to the energy transfer system 20 on the output side, correspondingly high currents result. The output voltage is thus independent of the number of primary side connected memory cells 18. This allows the design of the energy storage system 10 purely on energy and performance criteria, regardless of the required for the particular application total voltage. The DC controllers 28, 30, 32, 50, 52, 54 are preferably as fly-back converter, forward converter, push-pull converter, half-bridge converter, full-bridge converter.

Converter and / or designed as a resonant converter.

3 shows a circuit diagram of a DC adjuster with a memory transformer 62. A DC voltage source 64, which in the case of the invention corresponds to an energy storage module 12, 14, 16, 56, 58, 60, is connected via a switch

66 periodically connected to a primary coil 68 of the memory transformer 62 and decoupled again. When the DC voltage source 64 is connected to the primary coil 68 (first coil), a current flows through the primary coil 68, which leads to the establishment of a magnetic field in the storage transformer 62. When the switch 66 is opened again, the magnetic field gives the information stored in it

Energy via a secondary coil 70 (second coil) of the memory transformer 62 from. The output current generated in this way charges via a diode 72 to a buffer capacitor 74, which caches and smoothes the jerky by the timing of the switch 66 output current. At the first and the second outputs 42, 44 of the DC adjuster arises a

Output voltage, which is dependent on the timing of the switch 66 in addition to the capacitance C of the buffer capacitor 74. The DC-DC converter has a between the first output 42 and the second output 44 connected in the reverse direction freewheeling diode 76 and a freewheeling diode 76 connected in parallel switch 78. The switch 78 is a switch operable by a control signal, such as a transistor 78 switch. The DC chopper thus has a first control input for a first control signal (not shown) and is configured to be the first one upon receiving the first control signal Output 42 of the DC adjuster 28, 30, 32; 50, 52, 54 to the second output 44 of the DC adjuster 28, 30, 32; 50, 52, 54 electrically connect.

Known DC regulators have a controller that adjusts the timing of the switch 66 to the operating situation. It is also customary to provide a feedback in which the output voltage applied to the outputs 42, 44 is determined and used to adapt the timing of the switch 66, so that the output voltage is as stable as possible. In the context of the invention, these properties of DC actuators allow the setting of a desired total voltage of the energy storage system 10, depending on the operating situation, or the switching off of one or all of the DC choppers 28, 30, 32, 50, 52, 54.

An important advantage of the embodiment of the DC adjuster shown in Fig. 3 is the galvanic decoupling of the input voltage of the DC voltage source 64 (or the energy storage module 12, 14, 16, 56, 58, 60) from the output voltage at the outputs 42, 44, which are the Enable series connection of the outputs of the DC controllers. Other known DC regulators which offer this advantage are also suitable for implementing the invention.

Claims

claims

1 . An energy transfer system (20) for an energy storage system (10), in particular a battery system, comprising a plurality of DC converter modules (22; 24; 26) each having a DC chopper (22,24,26) and / or an output side series connection of a plurality of DC choppers (22,24) , 26; 50, 52, 54) each having a first and a second module output (46, 48), each of the DC controllers (22, 24, 26; 50, 52, 54) having a first input and a second input ( 34, 36) for connecting an energy storage module (12, 14, 16) of the energy storage system (10) and the Gleichstellstellermodule (22; 24; 26) are connected in parallel on the output side.

2. Energy transfer system according to claim 1, characterized in that at least one of the DC choppers (22, 24, 26, 50, 52, 54) has a first coil (68) and a second coil (70) which together to form a power transformer and / or storage transformer (62) are coupled.

3. Energy transfer system according to one of the preceding claims, characterized in that the DC-DC converter are designed as a fly-back converter, forward converter, push-pull converter, half-bridge converter, full-bridge converter and / or as a resonant converter ,

4. Energy transmission system according to one of the preceding claims, characterized in that the first input (34) or the second input (36) of at least one DC adjuster (28, 30, 32, 50, 52, 54) of the DC actuator module (22, 24, 26 ) is connected to mass (M).

5. Energy transmission system according to one of the preceding claims, characterized in that at least one of the DC controllers (28, 30, 32, 50, 52, 54) has a freewheeling diode (78), wherein in each case one anode of the freewheeling diode (78) with a second Output (44) of the same Electric actuator (28, 30, 32, 50, 52, 54) and a cathode of the freewheeling diode (78) with a first output (42) of the DC adjuster is electrically connected.

6. energy transfer system according to one of claims 1 to 4, characterized in that at least one of the DC chopper has a first control input for a first control signal and is formed, upon receipt of the first control signal out the first output (42) of the DC adjuster (28, 30, 32, 50, 52, 54) to be electrically connected to the second output (44) of the DC adjuster (28, 30, 32, 50, 52, 54).

7. Energy transfer system according to one of claims 5 or 6, characterized in that at least one of the DC controllers (28, 30, 32, 50, 52, 54) has a second control input for a second control signal and is adapted to receive the second Control signal to increase a voltage between the first and the second output (42, 44) of the DC adjuster.

8. Energy storage system with an energy transfer system according to one of the preceding claims, characterized by a plurality of energy storage modules (12, 14, 16, 56, 58, 60) each having at least one memory cell (18) and a first and a second pole (38, 40 ), wherein the poles (38, 40) are releasably electrically connected to respective first and second inputs (34, 36) of one of the DC choppers (28, 30, 32, 50, 52, 54) of the energy transfer system (20).

9. Motor vehicle with an energy storage system (10) according to claim 8.

10. Motor vehicle according to claim 9, characterized in that the energy storage system (10) is designed as an energy storage system for supplying an electric drive system of the motor vehicle.