DE102011006761A1 - Switching matrix of switching system, has switching devices that are arranged to switch supply terminals with respect to output ports in response to control signals to form series/parallel/bridging circuit with power sources - Google Patents

Abstract

The switching matrix (4) has supply terminals (2a-2n,3a-3n) that are connected to power sources (1a-1n) to provide power supply voltage. Two output ports (4a,4b) are adapted to provide an output voltage by combination of the supply voltages. The switching devices (5-12) are arranged to switch the supply terminals with respect to the output ports in response to control signals to form a series circuit, a parallel circuit and a bridging circuit with the power sources. Independent claims are included for the following: (1) switching system; and (2) method for actuating switching matrix.

Description

The invention relates to a switching matrix, a system with a plurality of switching matrices and a method for driving a switching matrix, in particular for the dynamic coupling of electrical energy stores.

State of the art

It is becoming apparent that in the future, both in stationary applications, such as wind turbines, as well as in vehicles such as hybrid or electric vehicles, increasingly electronic systems will be used, which combine new energy storage technologies with electric drive technology. In order to meet the given requirements for a given application in terms of performance and energy, usually several battery cells are connected in series. Since the current provided by such a drive system must flow through all battery cells and a battery cell can only conduct a limited current, battery cells are often additionally connected in parallel in order to increase the maximum current.

The series connection of several battery cells in addition to a high total voltage involves the problem that the entire energy storage fails if a single battery cell fails, because then no battery power can flow. Such a failure of the energy storage can lead to a failure of the entire system. In a vehicle, failure of the traction battery can result in the vehicle "stalling". For other applications, such as. B. the rotor blade adjustment of wind turbines, it may be in unfavorable conditions such. B. strong wind, even come to safety-threatening situations. Therefore, a high reliability of the energy storage is always desirable, with "reliability" is the ability of a system to work for a given time error-free.

It is therefore possible to operate batteries with several battery module strings, which can be connected directly to phase lines of an electrical machine. The battery module strands in this case have a plurality of battery modules connected in series, each battery module having at least one battery cell and an associated controllable coupling unit, which makes it possible to interrupt the respective battery module string depending on control signals, or to bridge the respectively assigned at least one battery cell, or to switch the respectively assigned at least one battery cell into the respective battery module string. By suitable control of the coupling units, z. B. by means of pulse width modulation, suitable phase signals for controlling the electric machine can be provided, so that can be dispensed with a separate pulse inverter.

The publication US 5,642,275 discloses, for example, a drive system for a three-phase electric machine with cascaded DC voltage sources with which sinusoidal supply voltages for the electric machine can be generated via individual full-bridge inverters.

The publication US 6,577,087 B2 discloses a multi-stage drive system with a pulse inverter and a strand of selectively bridgeable battery cells for supplying an electrical machine with stepped supply voltages.

A previous approach was to use a serial arrangement of battery cells, whereby selectively individual battery cells can be separated from the serial arrangement. In a charge transfer from one battery cell to another, that is, in a charge balance, the so-called "charge balancing", therefore, more switches and / or passive components such as capacitors, coils or resistors are necessary. For example, it is possible to dispense with the use of the excess charge and to partially discharge the fully charged cell via a resistor, so that the entire serial arrangement can be further charged. This causes thermal losses that can significantly affect the efficiency of the overall system.

Disclosure of the invention

According to one embodiment, the present invention provides a switching matrix for coupling at least two energy sources, having a plurality of supply terminals, which are adapted to be connected to a plurality of energy sources, each providing a supply voltage, exactly two output terminals arranged therefor are to provide an output voltage of the switching matrix as a combination of the plurality of supply voltages, and a plurality of switching devices, each of which connect one of the plurality of supply terminals each switchably connected to one of the two output terminals, and which are designed, in response to control signals between the two output terminals making a series connection of the plurality of power sources, a parallel connection of the plurality of power sources and bridging a group of power sources.

According to a further embodiment, the present invention provides a system with a first switching matrix according to the invention, which is designed to provide a first output voltage at exactly two first output terminals, a second switching matrix according to the invention, which is designed to provide a second output voltage at exactly two second output terminals, and a third switching matrix with exactly two third output terminals, which are configured to provide a third output voltage of the third switching matrix as a combination of the first and second output voltages, and a plurality of further switching devices respectively connecting one of the first and second output terminals each switchably to one of the two third output terminals and configured therefor are, in response to control signals between the two third output terminals, a series connection of the first and second switching matrix, a parallel connection of the first and second switching matrix and a Übbe bridging one of the two first and second switching matrices.

According to a further embodiment of the present invention, there is provided a method of driving a switching matrix according to the invention, comprising the steps of: determining a power requirement of an electrical load connected to the output terminals of the switching matrix;
Driving the plurality of switching means to establish a series connection of the plurality of power sources between the two output terminals if the determined power demand is above a predetermined threshold; and
Driving the plurality of switching means to establish a parallel connection of the plurality of power sources between the two output terminals if the determined power demand is below the predetermined threshold.

Advantages of the invention

One idea of the invention is to use a cascaded system of energy sources or energy stores which can be flexibly coupled via a switching matrix. By coupling a switching matrix, it is possible to connect two energy sources in series or in parallel as well as to selectively bridge them. In this case, the switching devices of the switching matrix can be controlled dynamically in order to be able to set any desired coupling of energy sources.

The system is modular, so that a plurality of energy sources paired in pairs, each with an associated switching matrix in turn can be coupled via parent switching matrices the same topology. This makes it possible to control any combination of parallel or series connected energy sources dynamically via the switching matrices.

This topology also allows a uniform load on all energy sources or all energy storage, so that to achieve a respective supply voltage value, the individual energy sources can be charged different current by appropriate control of the switching matrix or switching matrices. In this way a uniform average load of all energy sources can be achieved on average over time.

With the switching matrix according to the invention, a charge transfer or "charge balancing" is to be realized in a simple manner, since the energy storage can be connected in parallel as needed, so that energy storage of higher charge energy storage of lower charge does not affect.

The switching matrix can be realized cost-effectively with semiconductor components which can be used in particular as a function of their position in the switching cascade with a different design, for example with regard to current carrying capacity or dielectric strength. Furthermore, the switching matrix can advantageously be integrated into an integrated circuit.

Further features and advantages of embodiments of the invention will become apparent from the following description with reference to the accompanying drawings.

Brief description of the drawings

Show it:

1 a schematic representation of an embodiment of a system according to the invention with switching matrix;

1a a time-voltage diagram for illustrating a possible operation of the system 1 according to another embodiment of the invention;

2 a schematic representation of another embodiment of a system according to the invention with switching matrix;

3 a schematic representation of another embodiment of a system according to the invention with switching matrix;

4 a schematic representation of another embodiment of a system according to the invention with switching matrix;

5 a schematic representation of a method for operating a system according to the invention with switching matrix according to another embodiment; and

6 a tabular representation of switching states of a switching matrix according to another embodiment of the invention.

Energy sources in the context of the present invention include all devices that can emit and / or store electrical energy temporarily or permanently. For this purpose, the energy sources can have two supply connections, for example a connection with a high potential and a connection with a low potential, at which an electrical voltage can be tapped off and provided via the electrical supply current. Energy sources may include, for example, energy storage devices such as (traction) batteries, battery cells, super caps, power caps or similar devices.

Switching devices according to the present invention include all devices that can be controlled with control signals, and depending on the control signals can establish an electrically conductive connection between two nodes of a circuit, or can interrupt them. Switching devices may comprise semiconductor components such as MOSFET switches, IGBT switches, BJT switches, MISFET switches, JFET switches, thyristors or similar switching devices.

1 shows a system 100 with a switching matrix 4 according to one embodiment. The system 100 includes a variety of energy sources 1a . 1b , ... In, which each have two supply connections 2a . 3a . 2 B . 3b , ... 2n . 3n with input terminals of the switching matrix 4 are connected. The energy sources 1a . 1b , ... 1n may be, for example, energy storage devices, such as battery cells. It can be provided that in an energy source 1a . 1b , ... 1n several battery cells are arranged in series or in parallel. It can also be provided that each of the energy sources 1a . 1b , ... 1n having the same internal structure, and thus can provide the same supply voltage via the respective supply terminals. The supply connections 2a . 3a . 2 B . 3b , ... 2n . 3n For example, may be arranged in pairs, so that a first of the supply connections 2a . 2 B , ... 2n one supply potential and a second of the supply connections 3a . 3b , ... 3n can provide a reference potential. The number of energy sources 1a . 1b , ... 1n is basically unlimited. It may be in an advantageous embodiment of the system 100 be that number of energy sources 1a . 1b , ... 1n is two.

The switching matrix 4 has an internal interconnection, which is designed such that the energy sources 1a . 1b , ... 1n be connected so that an output signal or an output voltage to two output terminals 4a . 4b the switching matrix 4 can be provided. It may be provided that the switching matrix 4 the energy sources 1a . 1b , ... 1n dynamically interconnected, so that the output voltage at the output terminals 4a . 4b is variable in time and is, for example, a sinusoidal AC voltage.

1a shows an example of one of the switching matrix 4 in 1 Output voltage output in a time-voltage diagram. In this case, the output voltage U varies with time t as a function of the connection of the energy sources 1a . 1b , ... 1n in the switching matrix 4 , For example, at a time t _1, the switching matrix 4 so interconnected that the output voltage U has the value U ₁ . For example, the value U ₁ is three times a supply voltage of a single one of the energy sources 1a . 1b , ... in. At a time t ₂ , the switching matrix 4 are then controlled such that the output voltage U assumes the value U ₂ , which, for example, exactly the value of a supply voltage of a single one of the energy sources 1a . 1b , ... 1n can correspond. That way, via the switching matrix 4 an output voltage is generated which has approximately a sinusoidal shape. The deviation of the output voltage from a sinusoidal shape can thereby depend on the temporal resolution of the interconnection in the switching matrix 4 and the number of energy sources used 1a . 1b ... 1n depend.

2 shows a schematic representation of an exemplary embodiment of a system 20 with a switching matrix 4 , The system 20 is different from the system 100 in 1 to the effect that the number of energy sources 1a . 1b is limited to two. The switching matrix 4 has a variety of switching devices 5 . 6 . 7 . 8th . 9 . 10 . 11 . 12 which are suitably arranged around the two energy sources 1a . 1b can be connected in series, switched in parallel, switched on one side or completely bridged. The switching devices 5 . 6 . 7 . 8th . 9 . 10 . 11 . 12 can be controlled individually and in a coordinated manner to the output terminals 4a . 4b to provide an output voltage resulting from a corresponding combination of the supply voltages of the energy sources 1a . 1b results.

6 shows an example tabular representation of switching states of a switching matrix. The output connections are shown in each case 4a . 4b as well as the supply connections of the energy sources 1a . 1b , The symbols of the table indicate which of the terminals are connected to each other via a switching device.

In this case, the half of the table marked with the reference symbol F in the left-hand side are the table 60 those switching states listed with the switching devices 5 . 6 . 7 . 8th . 9 . 10 . 11 and 12 the switching matrix 4 in 2 let realize. The switching state 61 is a series connection of the two energy sources 1a . 1b , The switching state 62 is a parallel connection of the two energy sources 1a . 1b , The switching state 63 is a bridging of the energy source 1b so that only the energy source 1a contributes to the output voltage. The switching state 64 is a bridging of the energy source 1a so that only the energy source 1b contributes to the output voltage. The switching state 65 is a bridging of both energy sources 1a . 1b so none of the energy sources 1a . 1b contributes to the output voltage.

In the half of the table marked with J 60 are inverse switching states of the in the F marked half of the table 60 represented, for their realization further switching devices 13 . 14 . 15 and 16 must be provided in a switching matrix. The switching devices 13 . 14 . 15 and 16 can thereby according to the desired switching states 66 . 67 . 68 or 69 in the switching matrix 4 in addition to the switching devices 5 . 6 . 7 . 8th . 9 . 10 . 11 and 12 be arranged. The switching state 66 is one in relation to the switching state 61 inverse series connection of the two energy sources 1a . 1b , The switching state 67 is one in relation to the switching state 62 inverse parallel connection of the two energy sources 1a . 1b , The switching state 68 is one in relation to the switching state 63 inverse connection of only the energy source 1a , The switching state 69 is one in relation to the switching state 64 inverse connection of only the energy source 1b ,

3 shows a schematic representation of a system 30 Cascaded switching matrices according to one embodiment. The system 30 includes a system 20 respectively. 100 according to one of 1 respectively. 2 with a switching matrix 4 as well as two energy sources 1a . 1b , Furthermore, the system includes 30 another switching matrix 34 with two more energy sources 31a . 31b , where the switching matrix 34 and the two other sources of energy 31a . 31b in a similar way as in 1 respectively. 2 are shown interconnected. The system 30 further comprises a third switching matrix 35 , which have two output connections 35a . 35b features. The third switching matrix 35 is with four input terminals each with the two output terminals 4a . 4b respectively. 34a . 34b the switching matrices 4 respectively. 34 connected. In this way, the switching matrices 4 and 34 each utilities, which are similar to the energy sources 1a . 1b respectively. 31a . 31b Act. The system 30 is thus a cascade of switching matrices which can be switched in series to obtain an output voltage at two output terminals. In principle, the cascading of the switching matrices can be continued as desired, so that in principle any number of energy sources can be cascaded in pairs in each case via a number of switching matrices with all other energy sources. Such cascaded switching matrices can also be used, for example, in multiphase direct inverters.

The switching devices of all in the 1 . 2 and or 3 Switching matrices shown can be controlled dynamically during a charging or discharging of designed as an energy storage energy sources. It may, for example, be possible for the switching matrices to be connected via the output connections to an electrical load, for example an electrical machine, an electrical load or an electrical supply network, the electrical load having a variable power requirement. For this purpose, it can be determined dynamically how high the power requirement of the electrical load is. It is conceivable, for example, to switch the energy stores in series when high power is required, ie when a power requirement is above a predetermined threshold value, in order to achieve a higher output voltage, while in normal operation, for example in the case of a power requirement below the predetermined threshold, a parallel circuit can be set to achieve, for example, a uniform charge of all energy storage when charging the energy storage, with a fully charged energy storage does not affect a not fully charged.

The in the 1 . 2 and or 3 For example, interconnection of power sources using switch matrices can be used in battery systems for hybrid and / or electric vehicles and in battery packs for laptops, power tools, mobile phones, cameras, or similar electrical devices.

The design of the components used for the switching devices, for example semiconductor components, can take place differently depending on their position in a switching matrix cascade with regard to current carrying capacity and / or dielectric strength.

As in 4 shown, especially for lower power, for example, when used in electrical equipment, integration the switching matrix in an integrated circuit 41 respectively. The system 40 in 4 is different from the one in 2 shown system 20 in that the switching matrix in an integrated circuit 41 embedded, in addition to the switching matrix also a state machine 42 , a voltage measuring device 43 , a current measuring device 44 and / or a communication interface 45 can have. For example, the integrated circuit 41 be designed to use two sources of energy 1a . 1b or energy storage 1a . 1b autonomously monitor and, for example, automatically charge balance, a so-called "charge balancing" between the two energy storage 1a . 1b to initiate and regulate. Via the communication interface 45 can the integrated circuit 41 For example, receive and set by a (not shown) central control device desired setting for the switching matrix.

5 shows a method according to an embodiment for driving a switching matrix, for example, in the 1 to 4 explained switching matrices. In a first step 51 there is a determination of a power requirement of an electrical load connected to the output terminals of a switching matrix. In a second step 52 a plurality of switching devices are used to establish a series connection of a plurality of energy sources between the two output terminals if the determined power requirement is above a predetermined threshold value, for example if an electrical machine controlled by the switching matrix has a high power requirement. In a third step 53 alternatively, driving the plurality of switching means for establishing a parallel connection of the plurality of power sources between the two output terminals if the determined power requirement is below the predetermined threshold value. This may be the case, for example, when the electrical load, for example an electrical machine, is operated in a normal mode.

It can also be provided that in a fourth step 54 driving the plurality of switching means for establishing a parallel connection of the plurality of power sources between the two output terminals, if the switching matrix is operated in a charging operation for the power sources, for example, when the power sources include batteries. In a fifth step 55 It may then be provided that during operation of the switching matrix is continuously checked to what extent the operating mode and / or the power requirement of the connected electrical load changes. Based on this check can then be provided by one of the steps 52 to 54 set activation modes to another activation mode.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5642275 [0005]
• US 6577087 B2 [0006]

Claims (6)

Switching matrix ( 4 ), comprising: a plurality of supply terminals ( 2a . 3a ; 2 B . 3b ; 2n . 3n ), which are designed with a variety of energy sources ( 1a . 1b . 1n ) each providing a supply voltage to be connected; exactly two output connections ( 4a . 4b ), which are adapted to an output voltage of the switching matrix ( 4 ) as a combination of the plurality of supply voltages; and a plurality of switching devices ( 5 - 12 ), each one of the plurality of supply terminals ( 2a . 3a ; 2 B . 3b ; 2n . 3n ) each switchable with one of the two output terminals ( 4a . 4b ), and which are designed to operate in response to control signals between the two output terminals ( 4a . 4b ) a series connection of the plurality of energy sources ( 1a . 1b . 1n ), a parallel connection of the plurality of energy sources ( 1a . 1b . 1n ) and bridging a group of energy sources ( 1a . 1b . 1n ). System ( 30 ), comprising: a first switching matrix ( 4 ) according to claim 1, which is adapted to generate a first output voltage at exactly two first output terminals ( 4a . 4b ) to provide; a second switching matrix ( 34 ) according to claim 1, which is adapted to provide a second output voltage at exactly two second output terminals ( 34a . 34b ) to provide; and a third switching matrix ( 35 ) with exactly two third output connections ( 35a . 35b ), which are adapted to a third output voltage of the third switching matrix ( 35 ) as a combination of the first and second output voltages; and a plurality of third switching devices ( 5 - 12 ), each having one of the first and second output terminals ( 4a . 4b ; 34a . 34b ) each switchable with one of the two third output terminals ( 35a . 35b ), and which are designed to operate in response to control signals between the two third output terminals ( 35a . 35b ) a series circuit of the first and second switching matrix ( 4 ; 34 ), a parallel connection of the first and second switching matrix ( 4 ; 34 ) and bridging one of the two first and second switching matrices ( 4 ; 34 ). System ( 30 ) according to claim 2, wherein the first, second and / or third switching matrix ( 4 ; 34 ; 35 ) in an integrated circuit ( 41 ) are integrated. The system of claim 2, further comprising: a fourth switching matrix according to claim 1, which is adapted to provide a fourth output voltage at exactly two fourth output terminals; a fifth switching matrix according to claim 1, which is adapted to provide a fifth output voltage at exactly two fifth output terminals; a sixth switching matrix with exactly two sixth output terminals configured to provide a sixth output voltage of the sixth switching matrix as a combination of the fourth and fifth output voltages; and a plurality of sixth switching means respectively connecting one of the fourth and fifth output terminals each switchably to one of the two sixth output terminals, and configured to connect in series between the two sixth output terminals a series connection of the third and fourth switch matrix, a parallel circuit of Figs third and fourth switching matrix and bridging one of the two third and fourth switching matrices produce; and a seventh switching matrix with exactly two seventh output terminals configured to provide a seventh output voltage of the seventh switching matrix as a combination of the third and sixth output voltages; and a plurality of seventh switching devices respectively connecting one of the third and sixth output terminals each switchably to one of the two seventh output terminals, and configured to connect in series between the two seventh output terminals a series connection of the third and sixth switching matrix in parallel with the control circuit third and sixth switching matrix and bridging one of the two third and sixth switching matrices produce. Method for controlling a switching matrix ( 4 ) according to claim 1, comprising the steps of: determining a power requirement of a to the output terminals ( 4a . 4b ) of the switching matrix ( 4 ) connected electrical load; Driving the plurality of switching devices ( 5 - 12 ) for making a series connection of the plurality of energy sources ( 1a . 1b . 1n ) between the two output terminals ( 4a . 4b ) if the determined power requirement is above a predetermined threshold; and driving the plurality of switching devices ( 5 - 12 ) for establishing a parallel connection of the plurality of energy sources ( 1a . 1b . 1n ) between the two output terminals ( 4a . 4b ) if the determined power requirement is below the predetermined threshold. The method of claim 5, further comprising the step of: driving the plurality of switching devices ( 5 - 12 ) for establishing a parallel connection of the plurality of energy sources ( 1a . 1b . 1n ) between the two output terminals if the switching matrix ( 4 ) in a charging operation for the energy sources ( 1a . 1b . 1n ) is operated.

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