DE102017112387A1 - Battery, use of those and motor vehicle - Google Patents

Abstract

The invention provides a battery (1) having the following features: the battery (1) comprises a first number (N) of logic modules (3) and a switching regulator (5); each of the modules (3) comprises a second number (n) of serially connected logical cells (2) and a switching system (4) with a first switching state in which the cells (2) are bridged, and a second switching state in which the Cells (2) are connected; each of the cells (2) comprises parallel galvanic elements; and the switching regulator (5) is connected to the switching systems (4) and arranged to control the switching states at a predetermined timing.
The invention further provides a method of using such a battery as well as a corresponding motor vehicle.

Description

The present invention relates to a battery. The present invention further relates to the use of such a battery and a corresponding motor vehicle.

State of the art

Conventional high-voltage batteries usually satisfy a so-called xSyP configuration. This notation indicates a series combination of x logical cells, each consisting of y galvanic elements connected in parallel. An xSyP battery in this sense thus includes x · y galvanic elements.

The total voltage of a generic xSyP battery is x · V _cell , where V _{cell is} the nominal voltage of a galvanic _cell . The total energy is corresponding to x · y · V _cell · C _cell , where C _cell indicates the capacity of the element. If a galvanic element of a certain type was selected and thus V _cell and C _{cell were} determined, a desired specification of the battery according to the prior art is achieved by suitable adaptation of the design parameters x and y.

GB 2493694 and US 2015188347 each discloses a switching system for adjusting the voltage level of a battery in which a plurality of battery modules, controlled by a logic controller, in series or in parallel can be switched.

US 2010231166 relates to the use of a time division multiplexing scheme for the switching system in a battery such that each battery module is discharged by a time division multiplex (TDM) method.

The switching system for a battery according to US 2016248125 Finally, it has a control logic to achieve a fast switching sequence for the battery cells, so that the state of charge of the cells is balanced.

Disclosure of the invention

The invention provides a battery, in particular a high-voltage battery, a method for their use and a corresponding motor vehicle according to the independent claims.

In particular, to adjust the voltage level of the battery while maintaining the capacity, according to the invention, logical cells are grouped into a number of logic modules. Each logical module comprises a number of logical cells in series and each logical cell a number of cells in parallel. Each logic module can thus be independently connected in series with the battery string or bridged with a switching system.

As a control scheme for the logical module switching system, a TDM approach is proposed. The status of the switching system in each logical module is periodically updated by a controller. A sufficiently fast switching sequence means that the average discharge rate of the logical modules is distributed equally and thus the state of charge of each logical module is compensated.

One advantage of this solution is that the rated voltage of the battery can be adjusted to a desired target value without designing or selecting a galvanic element of differing capacitance. An embodiment of the invention is thus inexpensive and ensures maximum flexibility in the case of required changes. The battery according to the invention behaves like a conventional xSyP battery with the difference that the design parameters x and y can be given not only integral but also other rational values.

Further advantageous embodiments of the invention are specified in the dependent claims.

list of figures

• 1 zeigt das Schaltbild einer erfindungsgemäßen Hochvoltbatterie.
• 2 zeigen allgemein den zeitlichen Verlauf der Stromstärke in den Batteriezellen eines einzigen logischen Modules.
• 3 bis 7 zeigen exemplarisch den zeitlichen Verlauf der Stromstärke in den Batteriezellen fünf in Reihe geschalteter Module.
• 8 zeigt den resultierenden Verlauf des gesamten Entladestroms.

An embodiment of the invention is illustrated in the drawings and will be described in more detail below.

• 1 shows the diagram of a high-voltage battery according to the invention.
• 2 generally show the time course of the current in the battery cells of a single logic module.
• 3 to 7 show an example of the time course of the current in the battery cells of five modules connected in series.
• 8th shows the resulting course of the total discharge current.

Embodiments of the invention

1 illustrates the structure of a high-voltage battery according to the invention. The battery ( 1 ) comprises N logical modules ( 3 ), each of which in turn is serially connected logical cells ( 2 ) as well as a switching system ( 4 ) of electromechanical switches ( P ₁₁ - S _N1 . S ₁₂ - S _N2 ). It is understood that, in an alternative embodiment, semiconductor switches instead of electromechanical switches may be used without departing from the scope of the invention.

For illustration, the imagewise left switching systems ( 4 ) in a first switching state, in which the cells ( 2 ) of the respective logical module ( 3 ) are bridged. An imagewise right switching system ( 4 ) assumes a second switching state in which the cells ( 2 ) of the associated module ( 3 ) are connected. Although not shown in the drawing, each of the cells ( 2 ) in turn y parallel galvanic elements.

With the switching systems ( 4 ) is a central switching regulator ( 5 ) of the battery ( 1 ), which controls the switching states in a periodic clock. According to 3 is the clock here with a period ( T ), wherein the switching states cyclically after a multiple of the period ( T ) repeat which of the number N logical modules ( 3 ) corresponds. The switching regulator ( 5 ) is further arranged such that at any operating time of the battery ( 1 ) always M of the N Switching systems ( 4 ) are in the second switching state.

zur Gesamtzeit verbunden, sodass sein durchschnittlicher Entladestrom in eben diesem Verhältnis zum größtmöglichen Entladestrom steht. Der resultierende Effektivstrom steht entsprechend in einem Verhältnis von $\sqrt{\frac{M}{N}}$

zum maximalen Effektivstrom.This circuit scheme causes the cells to be switched during a cycle of switching states ( 2 ) of each module ( 3 ) for the duration M · T are connected. During the remaining period of ( N - M · · T will the respective module ( 3 ) bridged by its switching system ( 4 ) is placed in the first switching state. Consequently, the relevant module ( 3 ) in a ratio of $\frac{M}{N}$

connected to the total time, so that its average discharge current is in just this ratio to the largest possible discharge. The resulting RMS current is correspondingly in a ratio of $\sqrt{\frac{M}{N}}$

to the maximum RMS current.

wobei x = n · N die Gesamtzahl der Zellen (2) bezeichnet. Eine gewünschte Spannung kann somit - bei gegebenem x - mittels des Konstruktionsparameters N sowie des Konfigurationsparameters M des Schaltreglers (5) angepasst werden.A synopsis of the other figures illuminates this mode of action by means of a topology N = 5 modules ( 3 ), of which, like the 3 to 7 it can always be seen M = 3 modules ( 3 ) at the same time. Overall, this results in the constant, in 8th clarified the RMS current of the battery ( 1 ). Their nominal voltage satisfies the equation $V=M\cdot \frac{x}{N}\cdot V_{\text{cell}}.$

where x = n · N the total number of cells ( 2 ) designated. A desired tension can thus - given x - by means of the design parameter N and the configuration parameter M of the switching regulator ( 5 ) be adjusted.

an die Stelle von x und der Term $y\cdot \frac{M}{N}$

an die Stelle von y tritt. Somit eröffnet sich die Möglichkeit einer „virtuellen Konfiguration“ der Batterie (1), welche die Einschränkung der konventionellen Konstruktionsparameter x und y auf ganzzahlige Werte praktisch aufzuheben vermag.The characteristics of the battery ( 1 ) can thus be modeled as in the case of a conventional xSyP topology, but the term $x\cdot \frac{N}{M}$

in the place of x and the term $y\cdot \frac{M}{N}$

in the place of y occurs. This opens up the possibility of a "virtual configuration" of the battery ( 1 ), which limits the conventional design parameters x and y to be able to practically nullify integer values.

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

• GB 2493694 [0004]
• US 2015188347 [0004]
• US 2010231166 [0005]
• US 2016248125 [0006]

Claims (9)

Battery (1), characterized by the following features: - the battery (1) comprises a first number (N) of logic modules (3) and a switching regulator (5), - each of the modules (3) comprises a second number (n) serially connected logic cells (2) and a switching system (4) with a first switching state in which the cells (2) are bridged, and a second switching state in which the cells (2) are connected, - each of the cells (2 ) comprises galvanic elements connected in parallel, and - the switching regulator (5) is connected to the switching systems (4) and is arranged to control the switching states at a predetermined rate. Battery (1) after Claim 1 characterized by the following feature: - the switching system (4) comprises electromechanical switches (S ₁₁ -S _N1 , S ₁₂ -S _N2 ). Battery (1) after Claim 1 characterized by the following feature: - the switching system (4) comprises semiconductor switches. High-voltage battery after one of Claims 1 to 3 , Use of a battery (1) according to one of Claims 1 to 4 , characterized by the following feature: the clock is preset periodically with a specific period (T). Use after Claim 5 , characterized by the following feature: - the switching regulator (5) is set up such that the switching states repeat cyclically after a multiple of the period (T), which corresponds to the first number (N). Use after Claim 6 characterized by the following feature: - the switching regulator (5) is set up in such a way that a third number (M) of the switching systems (4) is in the second switching state at any operating time of the battery (1). Use after Claim 7 characterized by the following feature: the switching regulator (5) is set up in such a way that, during one cycle of the switching states, each of the switching systems (4) is in the second switching state for a multiple of the period (T), which is the third number (M) equivalent. Motor vehicle with a traction battery after Claim 4 ,

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