Patent Description:
Secondary batteries having electrical characteristics such as high energy density are variously used in portable devices as well as electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power. Secondary batteries are attracting attention as a new energy source for eco-friendless and energy efficiency improvement in that these secondary batteries do not generate by-products caused by the use of energy as well as the primary advantage of dramatically reducing the use of fossil fuels.

Types of secondary batteries that are currently widely used include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydride batteries, and nickel zinc batteries. The operating voltage of this unit secondary battery cell, i.e., a unit battery cell, is about <NUM> V to about <NUM> V. Thus, when a higher output voltage is required, a battery module is configured by connecting a plurality of battery cells in series. A battery module is also configured by connecting a plurality of battery cells in parallel according to the charge/discharge capacity required for the battery module. In addition, when a high output voltage of several hundred V or more is required, a battery system may be configured by connecting a plurality of battery modules in series. The number and connection configuration of battery cells that constitute the battery system may be variously set according to the required output voltage and charge/discharge capacity.

<FIG> is a block diagram of a battery system according to the related art.

Referring to <FIG>, a battery system <NUM> includes a first battery module <NUM> and a second battery module <NUM> connected in series with each other. The first battery module <NUM> includes first battery cells BMa and a first battery management module BMMa, and the second battery module <NUM> includes second battery cells BMb and a second battery management module BMMb.

The battery system <NUM> includes a battery disconnection unit (BDU) <NUM>. The battery disconnection unit (BDU) <NUM> may control a current flow on a high voltage path of the battery system <NUM>, i.e., a path between the first battery module <NUM> and a first battery terminal B+.

The battery disconnection unit (BDU) <NUM> may include a first main switch SW1, a precharge switch SWp, a precharge resistor Rp, and a first fuse FS1 arranged on the high voltage path. The battery disconnection unit (BDU) <NUM> may include a second main switch SW2 and a current sensor CS arranged on a low voltage path, i.e., a path between the second battery module <NUM> and a second battery terminal B-.

The battery system <NUM> includes a battery management unit <NUM> that transmits/receives data to/from the first and second battery management modules BMMa and BMMb so as to manage the first and second battery modules <NUM> and <NUM>. The battery management unit <NUM> controls the first and second main switches SW1 and SW2 and the precharge switch SWp and receives a signal corresponding to the magnitude of current detected by the current sensor CS.

The battery system <NUM> includes a manual safety disconnector (MSD) <NUM>. The manual safety disconnector (MSD) <NUM> may be arranged between the first battery module <NUM> and the second battery module <NUM> and may connect or separate the first battery module <NUM> and the second battery module <NUM> to or from each other.

The manual safety disconnector (MSD) <NUM> may be connected to contact terminals that may be manually connected or separated by a user to or from each other. For example, the user manually inserts the manual safety disconnector (MSD) <NUM> between the contact terminals, thereby connecting the first battery module <NUM> and the second battery module <NUM> to each other. The user manually separates the manual safety disconnector (MSD) <NUM> from the contact terminals, so that the first battery module <NUM> and the second battery module <NUM> may be separated from each other. The manual safety disconnector (MSD) <NUM> may include a second fuse FS2.

A failure may occur in the battery system <NUM>. In this case, the battery system <NUM> needs to be disassembled to check the cause of the failure or repair. When disassembling the battery system <NUM>, the user may manually separate the manual safety disconnector (MSD) <NUM> for safety and then start disassembling the battery system <NUM>.

The manual safety disconnector (MSD) <NUM> manually disconnects a conductive path between the battery modules <NUM> and <NUM> connected in series with each other, thereby guaranteeing the user's safety during disassembling and repairing of the battery system <NUM> and replacement of the battery modules <NUM> and <NUM> and preventing an accident such as a short circuit between the first and second battery modules <NUM> and <NUM> that may occur in the battery system <NUM>.

However, since the manual safety disconnector (MSD) <NUM> needs to be connected between the first and second battery modules <NUM> and <NUM>, the overall cost may be increased, the overall volume may be increased, and the complexity of the battery system <NUM> may be increased. <CIT>, <CIT>, <CIT> and <CIT> all provide disclosures related to batteries.

According to an aspect, there is provided a battery system according to Claim <NUM>. Details of embodiments are provided in the dependent claims. One or more embodiments include a battery system from which a manual safety disconnector (MSD) according to the related art has been removed.

According to one or more embodiments, a battery system includes a first battery module including a plurality of first battery cells, a second battery module including a plurality of second battery cells, and a battery disconnection unit (BDU) connected between the first battery module and the second battery module. The battery disconnection unit (BDU) may include a first main switch connected in series between the plurality of first battery cells and the plurality of second battery cells, and a precharge switch and a precharge resistor connected in parallel with the first main switch and connected in series with each other.

The battery system may further include a first battery terminal connected to the first battery module and a second battery terminal connected to the second battery module. The battery disconnection unit (BDU) may further include a second main switch connected in series between the plurality of second battery cells and the second battery terminal.

The battery system may further include a battery management unit configured to control the first main switch, the second main switch, and the precharge switch.

The first battery module may include a first module management unit configured to monitor the plurality of first battery cells, and the second battery module may include a second module management unit configured to monitor the plurality of second battery cells. The battery management unit may transmit/receive data to/from the first module management unit and the second module management unit.

The plurality of first battery cells included in the first battery module and the plurality of second battery cells included in the second battery module may have the same connection configuration.

A rated module voltage of the first battery module and a rated module voltage of the second battery module may have substantially the same magnitude.

Example embodiments will be described in more detail with reference to the accompanying drawings, so that features will be apparent to those skilled in the art.

At least some of the above features that accord with the invention and other features according to the invention are set out in the claims.

Now, example embodiments will be described in more detail with reference to the accompanying drawings. However, the example embodiments can be embodied in many forms and should not be considered as being limited to the embodiments described herein. However, the example embodiments can be embodied in many forms and should not be considered as being limited to the embodiments described herein.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present disclosure. As used herein, the singular forms "a," "an," and the "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components. It will be understood that although the terms "first," "second," etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from other components.

Hereinafter, embodiments will be described with reference to the accompanying drawings in which example embodiments are shown.

<FIG> is a block diagram of a battery system according to an embodiment.

Referring to <FIG>, a battery system <NUM> may include a first battery module <NUM> including a plurality of first battery cells BMa, a second battery module <NUM> including a plurality of second battery cells BMb, and a battery disconnection unit (BDU) <NUM> connected between the first battery module <NUM> and the second battery module <NUM>.

Throughout the specification, when reference is made to a component being connected between two terminals, it means that the component is electrically connected to and between both terminals, either directly or indirectly via another component. Connection between a terminal and a component or between two components has the same meaning mutatis mutandis.

The battery disconnection unit (BDU) <NUM> may include a first main switch SW1 connected in series between the first battery cells BMa of the first battery module <NUM> and the second battery cells BMb of the second battery module <NUM>, and a precharge switch SWp and a precharge resistor Rp connected in parallel with the first main switch SW1 and connected in series with each other.

The battery system <NUM> may include a first battery terminal B+ connected to the first battery module <NUM> and a second battery terminal B- connected to the second battery module <NUM>. According to an embodiment, the first battery terminal B+ may have a higher electric potential than the second battery terminal B-. However, this is just an example and may be the opposite. According to an example, the second battery terminal B- may be connected to a ground. However, this just an example, and the first battery terminal B+ may be connected to the ground. In the following description, it is assumed that the first battery terminal B+ has a higher electric potential than the second battery terminal B-. A path between the first battery module <NUM> and the first battery terminal B+ is referred to as a high voltage path, and a path between the second battery module <NUM> and the second battery terminal B- is referred to as a low voltage path.

When the battery system <NUM> operates normally, a voltage between the first battery terminal B+ and the second battery terminal B- may be several hundred V or more. For example, the voltage between the first battery terminal B+ and the second battery terminal B- may have the magnitude of about <NUM> V to about <NUM> V. Hereinafter, the voltage between the first battery terminal B+ and the second battery terminal B- is referred to as a system voltage.

The first and second battery terminals B+ and B- may be connected to a load such as an electric motor, which is driven by using power stored in the battery system <NUM>, or may be connected to power devices such as generators, rectifiers, or converters for supplying power to the battery system <NUM>.

The first and second battery cells BMa and BMb in which power is stored, may be connected in series with each other to configure the first and second battery modules <NUM> and <NUM>. The first and second battery cells BMa and BMb may be rechargeable secondary batteries. For example, the first and second battery cells BMa and BMb may include at least one selected from the group consisting of a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel metal hydride (Ni-MH) battery, a nickel-zinc (Ni-Zn) battery, and a lead acid battery. The number of the first and second battery cells BMa and BMb of the battery system <NUM> and the connection configuration thereof may be determined according to a required output voltage and a charge/discharge capacity.

In <FIG>, each of the first battery module <NUM> and the second battery module <NUM> is shown as being one. However, this is just an example, and each of the first battery module <NUM> and the second battery module <NUM> may include a plurality of battery modules.

The first battery module <NUM>, the first main switch SW1 of the battery disconnection unit (BDU) <NUM>, and the second battery module <NUM> may be connected in series with one another so that the electric potential of the first main switch SW1 of the battery disconnection unit (BDU) <NUM> with respect to the second battery terminal B- is approximately half of the electric potential of the first battery terminal B+, and a first module voltage of the first battery module <NUM> and a second module voltage of the second battery module <NUM> may have substantially the same magnitude.

According to an example, a rated module voltage of the first battery module <NUM> and a rated module voltage of the second battery module <NUM> may have substantially the same magnitude. The first and second battery modules <NUM> and <NUM> may have the rated module voltage with the same magnitude. According to another example, the first battery cells BMa of the first battery module <NUM> and the second battery cells BMb of the second battery module <NUM> may have the same specifications, the same number, and the same connection configuration. In this case, since an electric component, for example, a relay or a power semiconductor switch having a dielectric withstand of about half compared to the related art may be used in the first main switch SW1, manufacturing cost may be reduced.

The first main switch SW1 of the battery disconnection unit (BDU) <NUM> may connect or disconnect a path between the first battery module <NUM> and the second battery module <NUM>. The first main switch SW1 may be shorted so as to charge or discharge the first battery cells BMa and the second battery cells BMb. When the first battery cells BMa and the second battery cells BMb are over-charged or discharged or in a high temperature state, the first main switch SW1 may be opened to protect the first battery cells BMa and the second battery cells BMb.

The precharge switch SWp and the precharge resistor Rp may prevent the battery system <NUM>, the load or the power device from being damaged by an inrush current that flows when the load or power device is suddenly connected to the first and second battery terminals B+ and B-. The precharge switch SWp is first shorted before the first main switch SW1 is shorted, so that the magnitude of the inrush current may be limited by the precharge resistor Rp. When current flowing through the precharge resistor Rp is less than or equal to a preset magnitude, the first main switch SW1 may be shorted, and the precharge switch Swp may be opened.

In an embodiment, the battery disconnection unit (BDU) <NUM> may further include a second main switch SW2 arranged on a low voltage path between the second battery cells BMb and the second battery terminal B-. When the first main switch SW1 is not controlled by a failure or the like, the second main switch SW2 may be opened to protect the battery system <NUM>. Although the second main switch SW2 is arranged on the low voltage path, the second main switch SW2 may be arranged on the high voltage path. In an embodiment, the first main switch SW1, the second main switch SW2, and the precharge switch SWp may be configured as a relay switch or a power transistor.

In an embodiment, the battery disconnection unit (BDU) <NUM> may further include a current sensor CS arranged on the low voltage path between the second battery cells BMb and the second battery terminal B-. The current sensor CS may detect the magnitude of a charge/discharge current that flows through the second battery terminal B-, the second battery module <NUM>, the first battery module <NUM>, and the first battery terminal B+. The current sensor CS may output a signal corresponding to the magnitude of the charge/discharge current. The current sensor CS may include a shunt resistor, for example. In this case, the current sensor CS may output a voltage signal corresponding to the magnitude of the charge/discharge current. Although the current sensor CS is arranged on the low voltage path, the current sensor CS may be arranged on the high voltage path.

In an embodiment,he battery disconnection unit (BDU) <NUM> may include a substrate, sub, having first through fourth terminals t1 to t4. In an embodiment, the first terminal t1 may be connected to a negative terminal of the first battery cells BMa, and the second terminal t2 may be connected to a positive terminal of the second battery cells BMb. The third terminal t3 may be connected to the positive terminal of the second battery cells BMb, and the fourth terminal t4 may be connected to the second battery terminal B-. In an alternative embodiment, the polarities of the terminals of the battery cells may be the other way round. In embodiments where there is no second main switch, the second battery module may be connected between the second terminal t2 of the BDU and the second battery terminal.

In an embodiment, the first main switch SW1, the second main switch SW2, the precharge switch SWp, the precharge resistor Rp, and the current sensor CS may be mounted on the substrate sub. The first main switch SW1 may be connected between the first and second terminals t1 and t2. The precharge switch SWp and the precharge resistor Rp may be connected between the first and second terminals t1 and t2. The second main switch SW2 and the current sensor CS may be connected between the third and fourth terminals t3 and t4.

In an embodiment, the battery system <NUM> may further include a fuse FS so as to prevent an overcurrent from flowing. The fuse FS may be arranged on an overvoltage current. However, the fuse FS may be arranged on the low voltage path.

In an embodiment, the battery system <NUM> may further include a battery management unit <NUM> that controls the first main switch SW1, the second main switch SW2 and the precharge switch SWp and receives a signal corresponding to the magnitude of the charge/discharge current from the current sensor CS. For example, when the battery management unit <NUM> receives a signal from the current sensor CS, detects the magnitude of the charge/discharge current and the magnitude of the charge/discharge current exceeds a preset over-current setting value, at least one of the first main switch SW1 and the second main switch SW2 may be opened.

When the load or power device is connected to the first and second battery terminals B+ and B-, the battery management unit <NUM> may open the first main switch SW1, and the second main switch SW2 and the precharge switch SWp may be shorted. The battery management unit <NUM> may detect the magnitude of current that flows through the precharge resistor Rp by using the current sensor CS, and when the magnitude of the current is less than a preset setting value, the battery management unit <NUM> may short the first main switch SW1 and may open the precharge switch SWp.

In an embodiment, the first battery module <NUM> may include a first module management unit BMMa that monitors the first battery cells BMa. The second battery module <NUM> may include a second module management unit BMMb that monitors the second battery cells BMb.

Each of the first and second module management units BMMa and BMMb may detect a cell voltage and temperature of each of the first and second battery cells BMa and BMb and may equally adjust cell voltages of the first and second battery cells BMa and BMb according to a preset cell balancing algorithm. For this cell balancing operation, each of the first and second module management units BMMa and BMMb may include a cell balancing circuit.

The first and second module management units BMMa and BMMb may transmit monitoring data to the battery management unit <NUM> and may receive a control command or the like from the battery management unit <NUM>. The first and second module management units BMMa and BMMb and the battery management unit <NUM> may perform data communication with each other by using a controller area network (CAN) bus, for example.

In an embodiment, the battery management unit <NUM> may stably disconnect a high voltage and a high current input and output between the battery system <NUM> and power devices such as an inverter and a DC/DC converter by using the battery disconnection unit (BDU) <NUM>. When an overcurrent occurs due to unintended external collision or internal circuit malfunction, the battery management unit <NUM> may quickly detect the overcurrent by using the current sensor CS and may quickly open the first and second main switches SW1 and SW2, thereby protecting the life of the battery system <NUM>.

The battery management unit <NUM> may monitor the cell voltages of the first and second battery cells BMa and BMb, the module voltages of the first and second battery modules <NUM> and <NUM>, the system voltages between the first and second battery terminals B+ and B-, and temperatures of the first and second battery modules <NUM> and <NUM>. The battery management unit <NUM> may control and manage the overall operation of the battery system <NUM> according to a preset management control algorithm.

When the load and the power devices are separated from the first and second battery terminals B+ and B-, the battery management unit <NUM> may open the first main switch SW1 and the precharge switch SWp, thereby electrically separating the first battery module <NUM> and the second battery module <NUM> from each other. According to another example, the battery management unit <NUM> may open the second main switch SW2.

The user needs to disassemble the battery system <NUM> for reasons such as maintenance such as that a failure occurs in the battery system <NUM> or that at least one of the battery modules <NUM> and <NUM> is deteriorated and needs to be replaced. The user may separate the load and the power devices connected to the battery system <NUM> from the first and second battery terminals B+ and B-. The battery management unit <NUM> may detect separation of the load and the power devices to open the first main switch SW1 and the precharge switch SWp and to electrically separate the first battery module <NUM> and the second battery module <NUM> from each other, thereby performing the function of the manual safety disconnector (MSD) <NUM> described with reference to <FIG>. The user may perform tasks such as checking the battery system <NUM> or replacing the battery modules <NUM> and <NUM>.

In the related art, the user needs to manually separate the manual safety disconnector (MSD) <NUM>. However, according to the present disclosure, the first battery module <NUM> and the second battery module <NUM> may be automatically separated from each other by the battery disconnection unit (BDU) <NUM>, so that operation convenience may be enhanced.

In addition, the position of the battery disconnection unit (BDU) <NUM> may be changed between the first and second battery modules <NUM> and <NUM>, so that the function of the manual safety disconnector (MSD) <NUM> according to the related art may be performed by the battery disconnection unit (BDU) <NUM>. Thus, the battery system <NUM> may be not equipped with the manual safety disconnector (MSD) <NUM>. Thus, manufacturing cost may be reduced by the cost of a manual safety disconnector (MSD), and volume may be reduced.

In a battery system according to the present embodiment, the function of the manual safety disconnector (MSD) of a battery system according to the related art is replaced with a switch controlled by a battery management unit so that cost, complexity, and volume may be reduced. In addition, since there is no need to manually separate the battery modules, convenience and safety of operation are increased together.

The specific implementations shown and described herein are examples for description and are not intended to limit the scope of the embodiments in any way. For the sake of brevity, conventional electronics, control systems, software development and other functional aspects of the systems (and components of the individual operating components of the systems) may not be described in detail. Furthermore, the connection lines, or connectors shown in the various figures presented are intended to represent examples of functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device. Moreover, no item or component is essential to the practice of the present disclosure unless the element is specifically described as "essential" or "critical".

In the specification of embodiments (in particular, claims), the use of the terms "a" and "an" and "the" and similar referents in the context of describing the present disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural. Furthermore, recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Finally, the steps of all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The present disclosure is not necessarily limited according to the description order of the steps. Numerous modifications and adaptations will be readily apparent to those skilled in this art without departing from the scope of the claims.

Although example embodiments have been presented herein and certain terms have been used, these terms are not intended to be limiting and should be interpreted as being general and illustrative. In some examples, although it will be apparent to those skilled in the art at the time of filing this application, the features, and/or components described in connection with a specific embodiment may be used alone, unless specifically stated otherwise, or may be used together with the features, and/or components described in connection with other embodiments.

Claim 1:
A battery system (<NUM>) comprising:
a first battery terminal (B+);
a second battery terminal (B-);
a first battery module (<NUM>) comprising a plurality of first battery cells (BMa) and a first module management unit (BMMa) configured to monitor the plurality of first battery cells and connected to the first battery terminal;
a second battery module (<NUM>) comprising a plurality of second battery cells (BMb) and a second module management unit (BMMb) configured to monitor the plurality of second battery cells, and connected to the second battery terminal;
a battery management unit (<NUM>) configured to transmit data to and receive data from the first module management unit and the second module management unit; and
a battery disconnection unit, BDU, connected between the first and second battery modules and between the second battery module and the second battery terminal,
wherein the BDU comprises:
a substrate including a first terminal (t1) connected to a negative terminal of the first battery module, a second terminal (t2) connected to a positive terminal of the second battery module, a third terminal (t3) connected to a negative terminal of the second battery module, and a fourth terminal (t4) connected to the second battery terminal;
a first main switch (SW1) mounted on the substrate and connected between the first terminal and the second terminal;
a precharge switch (SWp) and a precharge resistor (Rp) mounted on the substrate and connected in series between the first terminal and the second terminal; and
a second main switch (SW2) mounted on the substrate and connected between the third terminal and the fourth terminal, and
wherein the battery management unit is configured to control the first main switch, the second main switch, and the precharge switch.