KR102364237B1 - Apparatus and method for pre-charging - Google Patents

Abstract

The present invention relates to an apparatus and method for precharging in which an energy saving effect can be expected in a process of precharging a precharge capacitor. A precharge device according to the present invention is a device for charging a precharge capacitor configured to be electrically connectable to both ends of a battery module including a plurality of secondary batteries, and is electrically connected to both ends of the plurality of secondary batteries, respectively. a storage circuit configured to receive power from a plurality of secondary batteries and store the supplied power; a precharge circuit electrically connected to one end of the storage circuit to receive a precharge current from the storage circuit and to transmit the supplied precharge current to the precharge capacitor; a battery monitoring unit connected to the battery module and the battery module and electrically connected to a charging/discharging path through which a charging/discharging current flows to monitor the voltage and the charging/discharging current of each of the plurality of secondary batteries; and a battery control unit configured to control opening/closing of the storage circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit.

Description

Apparatus and method for pre-charging

The present invention relates to a precharge apparatus and method, and more particularly, to a precharge apparatus and method in which an energy saving effect can be expected in the process of precharging a precharge capacitor.

In recent years, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has rapidly increased, and energy storage batteries, robots, and satellites have been developed in earnest, high-performance secondary batteries that can be repeatedly charged and discharged have been developed. Research is being actively conducted.

Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries do not have much memory effect compared to nickel-based secondary batteries, so charging and discharging are free, Due to its advantages such as a very low self-discharge rate and high energy density, it is receiving a lot of attention.

Batteries are used in various fields, and fields in which batteries are recently used a lot, such as electric powered vehicles or smart grid systems, often require large capacity. In order to increase the capacity of the battery pack, there may be a method of increasing the capacity of the secondary battery, that is, the battery cell itself. has Therefore, in general, a battery pack in which a plurality of battery modules are connected in series and in parallel is widely used.

Secondary batteries constituting the battery module may not have the same electrochemical characteristics. In addition, when the number of charge/discharge cycles of the secondary battery increases, the degree of degradation varies for each secondary battery, so that the performance variation of the secondary batteries may increase. Accordingly, while the battery module is being charged to the full charge state, the state of charge of each secondary battery may rise at different rates.

When the battery module is charged to the fully charged state, the rate of increase in the state of charge of the degraded secondary battery may be faster than that of the secondary battery without capacity degradation. This is because the degraded secondary battery is in a state in which the full charge capacity is reduced compared to that of the non-degraded secondary battery. Accordingly, while the battery module is being charged, the state of charge of each secondary battery may be different from each other.

In the related art, buck balancing for forcibly discharging a secondary battery having a relatively high state of charge has been mainly used in order to resolve the difference in the state of charge between the secondary batteries. However, buck balancing has a problem in that energy is wasted in the balancing process.

Meanwhile, a battery management system (BMS) may include a protection circuit, that is, a pre-charge circuit, for preventing an inrush current, which is an overcurrent that may occur at the initial stage of driving of the battery. there is. Here, the inrush current is an overcurrent that may occur instantaneously at the initial stage of driving the battery, and the inrush current may be limited by precharging the precharge capacitor at the initial stage of driving the battery.

In general, in order to limit the inrush current, it is necessary to pre-charge the precharge capacitor with a voltage of 90% of the battery module voltage. There was a problem that the efficiency was lowered.

Accordingly, the present invention has been devised to solve the above problems, and an object of the present invention is to provide an improved precharge apparatus and method capable of improving energy efficiency in a process of precharging a precharge capacitor.

Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of the present invention. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

A precharge device according to an embodiment of the present invention for achieving the above object is a device for charging a precharge capacitor configured to be electrically connectable to both ends of a battery module including a plurality of secondary batteries, the plurality of a storage circuit electrically connected to both ends of a secondary battery of a precharge circuit electrically connected to one end of the storage circuit to receive a precharge current from the storage circuit and to transmit the supplied precharge current to the precharge capacitor; a battery monitoring unit connected to the battery module and the battery module and electrically connected to a charging/discharging path through which a charging/discharging current flows to monitor the voltage and the charging/discharging current of each of the plurality of secondary batteries; and a battery control unit configured to control opening/closing of the storage circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit.

In addition, in the precharge device according to the present invention, a main circuit configured to include a main relay electrically connected to one end of the battery module to open and close a main line through which the charge/discharge current flows, and a main circuit connected in parallel with the main circuit The apparatus may further include a main precharge circuit configured to include a precharge relay for opening and closing a precharge line through which a charge current flows, and a precharge resistor connected in series with the precharge relay.

Also, the precharge circuit may be configured to be electrically connected between one end of the main circuit and a contact point to which one end of the main precharge circuit is commonly connected and one end of the storage circuit.

In addition, the battery control unit may control opening and closing of the storage circuit, the main circuit, and the main precharge circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit. can

In addition, the precharge device according to the present invention may further include a discharge circuit configured to be electrically connected to both ends of the plurality of secondary batteries, respectively, to receive power from the plurality of secondary batteries and discharge the supplied power. there is.

In addition, the precharge circuit may include a transformer circuit for boosting the voltage applied to the storage circuit so as to transfer the power stored in the storage circuit to the precharge capacitor, and a precharge circuit connected to one end of the transformer circuit through which a precharge current flows. A charge line may be provided.

In addition, the storage circuit includes a plurality of unit circuits connected to both ends of the plurality of secondary batteries, wherein the unit circuits have one end connected to the precharge circuit and the other end connected to both ends of the secondary battery in parallel with each other. It can be configured to be connected.

In addition, the unit circuit includes a storage capacitor electrically connected to both ends of the secondary battery to store power supplied from the secondary battery, and a storage capacitor connected between the secondary battery and the storage capacitor to apply charging power to the storage capacitor A charging switch and a supply switch connected between one end of the precharge circuit and the storage capacitor to apply a precharge current to the precharge circuit may be provided.

In addition, when balancing of the battery module is required, the battery control unit sequentially opens and closes the charging switch and the supply switch provided in the storage circuit to supply a precharge current to the precharge capacitor through the precharge circuit. can supply

In addition, a battery pack according to an embodiment of the present invention for achieving the above object includes the precharge device according to the present invention.

In addition, the precharge device according to an embodiment of the present invention for achieving the above object is electrically connected to one end of a battery module including a plurality of secondary batteries to open and close a main line through which a charge/discharge current flows A device for charging a precharge capacitor configured to be connectable to one end of a relay, the storage circuit configured to be electrically connected to both ends of the plurality of secondary batteries, respectively, to receive power from the plurality of secondary batteries and store the supplied power ; a precharge circuit electrically connected to one end of the storage circuit to receive a precharge current from the storage circuit and to transmit the supplied precharge current to the precharge capacitor; a battery monitoring unit connected to the battery module and the battery module and electrically connected to a charging/discharging path through which a charging/discharging current flows to monitor the voltage and the charging/discharging current of each of the plurality of secondary batteries; a battery control unit configured to control opening/closing of the storage circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit; and a communication unit that receives the state information of the battery module monitored by the battery monitoring unit from the battery control unit and transmits the state information to the vehicle side.

In addition, a precharge method according to an embodiment of the present invention for achieving the above object is a method of charging a precharge capacitor configured to be electrically connectable to both ends of a battery module including a plurality of secondary batteries, monitoring a voltage of each of the plurality of secondary batteries and a charging/discharging current flowing through a charging/discharging path connected to the battery module; determining a secondary battery that needs balancing from among the plurality of secondary batteries based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the monitoring step; determining the secondary battery determined by the secondary battery determination step as a secondary battery to be discharged, receiving power from the secondary battery to be discharged, and storing the supplied power; and transferring the power stored by the power storage step to the precharge capacitor.

According to the present invention, power discharged in the cell balancing process can be stored. In addition, the precharge capacitor may be precharged using the stored power. Accordingly, there is an advantage in that energy efficiency can be improved in the process of precharging the precharge capacitor.

In addition, the present invention may have various other effects, and these other effects of the present invention can be understood by the following description, and can be seen more clearly by the examples of the present invention.

The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the detailed description of the present invention to be described later. should not be construed as being limited only to
1 is a diagram schematically illustrating a functional configuration of a precharge device according to an embodiment of the present invention.
2 is a diagram schematically illustrating a configuration in which a precharge device is connected to an external device according to an embodiment of the present invention.
3 is a diagram schematically illustrating a connection relationship between some components of a precharge device and a precharge capacitor according to an embodiment of the present invention.
4 is a flowchart schematically illustrating a precharging method according to an embodiment of the present invention.
5 is a flowchart schematically illustrating a precharging method according to another exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Accordingly, the configuration shown in the embodiments and drawings described in the present specification is only the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

In addition, when it is determined that a detailed description of a known configuration or function related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless specifically stated otherwise. In addition, a term such as 'control unit' described in the specification means a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

In addition, throughout the specification, when a part is "connected" with another part, it is not only "directly connected" but also "indirectly connected" with another element interposed therebetween. include

In the present specification, the secondary battery may include one unit cell or a plurality of unit cells connected in parallel. The unit cell means one independent cell that has a negative terminal and a positive terminal and is physically separable. For example, one pouch-type lithium polymer cell may be regarded as a unit cell.

1 is a diagram schematically showing a functional configuration of a precharge device according to an embodiment of the present invention. 2 is a diagram schematically illustrating a configuration in which a precharge device is connected to an external device according to an embodiment of the present invention.

In the precharge device according to the present invention, the precharge capacitor C may be charged. In particular, the precharge device according to the present invention may charge the precharge capacitor C configured to be electrically connectable to both ends of the battery module B including the plurality of secondary batteries 10 . For example, as shown in the configuration of FIG. 2 , the positive terminal of the battery module B including the plurality of secondary batteries 10 may be electrically connected to the positive terminal of the battery pack. Also, the negative terminal of the battery module B may be electrically connected to the negative terminal of the battery pack. Here, the precharge capacitor C may be configured such that both ends of the precharge capacitor C are connectable to the positive terminal of the battery pack and the negative terminal of the battery pack, respectively.

1 and 2 , the precharge device according to the present invention may include a storage circuit 100 , a precharge circuit 200 , a battery monitoring unit 300 , and a battery control unit 400 .

The storage circuit 100 may be connected to the battery module B. In particular, the storage circuit 100 may be electrically connected to both ends of the plurality of secondary batteries 10 , respectively. For example, as shown in the configuration of FIG. 2 , the storage circuit 100 may be directly electrically connected to both ends of each secondary battery 10 .

Also, the storage circuit 100 may be configured to store power. In particular, the storage circuit 100 may be configured to receive power from the plurality of secondary batteries 10 and store the supplied power. For example, as shown in the configuration of FIG. 2 , the storage circuit 100 includes a passive element capable of storing electric power, and receives electric power supplied from the secondary battery 10 connected to the passive element. It can be configured to store . To this end, the storage circuit 100 may include an electric circuit between the secondary battery 10 and the passive element, and a switch on the electric circuit. For example, the passive element may be implemented as a capacitor. Also, the switch may be implemented as a Metal Oxide Semiconductor Field Effect Transistor (MOSFET).

The precharge circuit 200 may be electrically connected to one end of the storage circuit 100 . For example, as shown in the configuration of FIGS. 1 and 2 , the precharge circuit 200 is located between the storage circuit 100 and the precharge capacitor C, and includes one end of the storage circuit 100 and may be electrically connected.

In addition, the precharge circuit 200 may be configured to transmit a precharge current to the precharge capacitor C . In particular, the precharge circuit 200 may be configured to receive a precharge current from the storage circuit 100 and transfer the supplied precharge current to the precharge capacitor C . Specifically, the precharge circuit 200 may be configured to receive a precharge current generated from power stored in the storage circuit 100 , and transfer the supplied precharge current to the precharge capacitor C . To this end, the precharge circuit 200 may include an electric circuit electrically connecting the storage circuit 100 and the precharge capacitor C to each other.

The battery monitoring unit 300 may be electrically connected to the battery module B and the charging/discharging path. Here, the charging/discharging path may be a path provided between the terminal of the battery module and the terminals (Pack+, Pack-) of the battery pack and configured to flow the charging current or the discharging current of the battery module. For example, as shown in the configuration of FIGS. 1 and 2 , the battery monitoring unit 300 may be electrically connected to the battery module (B). In addition, the battery monitoring unit 300 may be electrically connected to a charging/discharging path connected to the battery module (B).

In particular, the battery monitoring unit 300 may be configured to monitor the voltage and charge/discharge current of each of the plurality of secondary batteries 10 . Specifically, the battery monitoring unit 300 is connected to the battery module (B) and the battery module (B) and is electrically connected to a charge/discharge path through which a charge/discharge current flows, so that the voltage and charge of each of the plurality of secondary batteries (10) and It may be configured to monitor the discharge current. To this end, the battery monitoring unit 300 may include a voltage measuring means and a current measuring means. Preferably, the battery monitoring unit 300 may be configured to monitor the temperature of each of the plurality of secondary batteries 10 . To this end, the battery monitoring unit 300 may further include a temperature measuring means. Preferably, the battery monitoring unit 300 may be configured to monitor the state of charge of each of the plurality of secondary batteries 10 . To this end, the battery monitoring unit 300 may further include a state of charge estimating means.

The battery control unit 400 may control opening/closing of the storage circuit 100 based on the voltage and charging/discharging current of each of the plurality of secondary batteries 10 monitored by the battery monitoring unit 300 . For example, the battery controller 400 may control the opening and closing of the storage circuit 100 by controlling turn-on and turn-off operations of a plurality of switches provided in the storage circuit 100 .

To this end, preferably, the battery monitoring unit 300 according to the present invention, as shown in the configuration of FIG. 2 , a voltage measurement unit 310 , a current measurement unit 320 , a temperature measurement unit 330 and It may include an SOC estimator 340 . In addition, the battery monitoring unit 300 may be electrically coupled to the battery control unit 400 to transmit and receive electrical signals.

The voltage measuring unit 310 may be electrically coupled to the battery control unit 400 and the SOC estimating unit 340 to transmit and receive electrical signals. For example, as shown in the configuration of FIG. 2 , the voltage measuring unit 310 may be electrically connected to both ends of each secondary battery 10 . In addition, the voltage measuring unit 310 may exchange electrical signals with the battery control unit 400 and the SOC estimator 340 . In addition, the voltage measuring unit 310 measures the voltage across both ends of each secondary battery 10 at time intervals under the control of the battery control unit 400 and transmits a signal indicating the magnitude of the measured voltage to the battery control unit 400 and It may output to the SOC estimator 340 . In this case, the battery controller 400 and the SOC estimator 340 may determine the voltage of each secondary battery 10 from the signal output from the voltage measurer 310 . For example, the voltage measuring unit 310 may be implemented using a voltage measuring circuit generally used in the art.

The current measurement unit 320 may be electrically coupled to the battery control unit 400 and the SOC estimation unit 340 to transmit and receive electrical signals. For example, as shown in the configuration of FIG. 2 , the current measuring unit 320 may be located on a charge/discharge path connected to the battery module B. In addition, the current measuring unit 320 may exchange electrical signals with the battery control unit 400 and the SOC estimating unit 340 . In addition, the current measuring unit 320 repeatedly measures the size of the charging current or the discharging current of each secondary battery 10 at a time interval under the control of the battery control unit 400 and outputs a signal indicating the size of the measured current. It may output to the battery controller 400 and the SOC estimator 340 . In this case, the battery control unit 400 and the SOC estimator 340 may determine the magnitude of the current from the signal output from the current measurement unit 320 . For example, the current measuring unit 320 may be implemented using a Hall sensor or a sense resistor generally used in the art.

The temperature measuring unit 330 may be electrically coupled to the battery control unit 400 and the SOC estimating unit 340 to transmit and receive electrical signals. For example, as shown in the configuration of FIG. 2 , the temperature measuring unit 330 may be connected to the battery module B to measure the temperature of each secondary battery 10 . In addition, the temperature measuring unit 330 may exchange electrical signals with the battery control unit 400 and the SOC estimating unit 340 . In addition, the temperature measurement unit 330 repeatedly measures the temperature of each secondary battery 10 at a time interval and outputs a signal indicating the magnitude of the measured temperature to the battery control unit 400 and the SOC estimator 340 . can In this case, the battery control unit 400 and the SOC estimator 340 may determine the temperature of each secondary battery 10 from the signal output from the temperature measurement unit 330 . For example, the temperature measuring unit 330 may be implemented using a thermocouple generally used in the art.

The SOC estimator 340 may be electrically coupled to the battery controller 400 to transmit and receive electrical signals. In addition, the SOC estimator 340 may include voltage measurement values, current measurement values and Using the temperature measurement value, the state of charge (SOC) of each secondary battery 10 may be calculated and monitored. Also, the SOC estimator 340 may output a signal indicating the state of charge of each secondary battery 10 to the battery controller 400 . Through such a configuration, the battery monitoring unit 300 may monitor the state of charge of each secondary battery 10 while the plurality of secondary batteries 10 are being charged or discharged.

In one aspect of the present invention, the SOC estimator 340 may estimate the state of charge of each secondary battery 10 by integrating the charging current and the discharging current of each secondary battery 10 . Here, when the charging or discharging of each secondary battery 10 starts, the initial value of the state of charge is determined using the open circuit voltage (OCV) of each secondary battery 10 measured before charging or discharging starts. can To this end, the SOC estimator 340 includes an open circuit voltage-charge state lookup table that defines the state of charge for each open voltage, and the charge state corresponding to the open circuit voltage of each secondary battery 10 can be mapped from the lookup table. there is.

In another aspect of the present invention, the SOC estimator 340 may calculate the state of charge of each secondary battery 10 by using the extended Kalman filter. The extended Kalman filter refers to a mathematical algorithm for adaptively estimating the state of charge of the secondary battery 10 by using the voltage, current, and temperature of the battery cell. Here, the estimation of the state of charge using the extended Kalman filter is, as an example, Gregory L. Plett's paper "Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs Parts 1, 2 and 3" (Journal of Power Source 134, 2004, p. 252-261).

The state of charge of each secondary battery 10 may be determined by other known methods capable of estimating the state of charge by selectively utilizing voltage, current, and temperature of each secondary battery 10 in addition to the above-described current integration method or the extended Kalman filter. can

Preferably, the precharge device according to the present invention may further include a main circuit 500 and a main precharge circuit 600 as shown in the configuration of FIGS. 1 and 2 .

The main circuit 500 may be configured to include a main line L and a main relay 510 . The main line L may be a line configured to be electrically connected to one end of the battery module B so that a charging/discharging current flows. For example, as shown in the configuration of FIGS. 1 and 2 , the main circuit 500 may be positioned between one end of the battery module B and one end of the precharge capacitor C . Also, the main relay 510 may be a switch that opens and closes the main line L. For example, the main relay 510 may open and close the main line L through turn-on and turn-off operations. For example, the main relay 510 may be implemented as a mechanical relay or a semiconductor relay.

The main precharge circuit 600 may include a precharge relay 610 and a precharge resistor 620 . The precharge relay 610 and the precharge resistor 620 may be provided on the precharge line L1 . The main precharge circuit 600 may be connected in parallel with the main circuit 500 . In particular, as shown in the configuration of FIGS. 1 and 2 , the main line L and the precharge line L1 may be electrically connected in parallel. Also, the precharge relay 610 may open/close the precharge line L1 through which the precharge current flows. The precharge relay 610 may be a switch that opens and closes the precharge line L1 . For example, the precharge relay 610 may open and close the precharge line L1 through turn-on and turn-off operations. For example, the precharge relay 610 may be implemented as a mechanical relay or a semiconductor relay. Also, the precharge resistor 620 may be connected in series with the precharge relay 610 . In particular, the precharge resistor 620 may be connected in series with the precharge relay 610 on the precharge line L1 .

More preferably, in the precharge circuit 200 according to the present invention, as shown in the configuration of FIGS. 1 and 2 , one end of the main circuit 500 and one end of the main precharge circuit 600 are commonly connected. It may be configured to be electrically connected between the contact point and one end of the storage circuit 100 . In particular, a contact point at which one end of the main circuit 500 and one end of the main precharge circuit 600 are commonly connected may be connected to one end of the precharge capacitor C .

More preferably, the battery control unit 400 according to the present invention, the storage circuit 100, the main based on the voltage and charge/discharge current of each of the plurality of secondary batteries 10 monitored by the battery monitoring unit 300, Opening and closing of the circuit 500 and the main precharge circuit 600 may be controlled. Specifically, the battery control unit 400 includes a storage circuit 100, a main circuit 500, and Turn-on and turn-off operations of a switch provided in the main precharge circuit 600 may be controlled. For example, the battery controller 400 determines the secondary battery 10 to be discharged based on the voltage and charge/discharge current of each of the plurality of secondary batteries 10 , and a storage circuit connected to the secondary battery 10 to be discharged By turning on the switch provided in 100 , power may be supplied from the secondary battery 10 to be discharged to the storage circuit 100 . In addition, the battery control unit 400 turns off each switch provided in the main circuit 500 and the main precharge circuit 600 , and turns on a switch provided in the storage circuit 100 , so that the storage circuit 100 ) may be transferred from the storage circuit 100 to the precharge capacitor C through the precharge circuit 200 .

On the other hand, the battery control unit 400, in order to perform the operation as described above, a processor, an application-specific integrated circuit (ASIC), other chipsets, logic circuits, registers, communication modems and / or data processing devices known in the art. It may be implemented in a form including selectively.

Preferably, the battery control unit 400 may include a memory device. A memory device is not particularly limited in its type as long as it is a storage medium capable of recording and erasing information. For example, the memory device may be a RAM, ROM, register, hard disk, optical recording medium, or magnetic recording medium. The memory device may also be electrically connected to the battery controller 400 through, for example, a data bus so that it can be accessed by the battery controller 400 . The memory device may also store and/or update and/or erase and/or transmit a program including various control logic executed by the battery control unit 400 and/or data generated when the control logic is executed. A memory device can be logically divided into two or more.

Preferably, the precharge device according to the present invention may further include a discharging circuit 700 as shown in the configuration of FIGS. 1 and 2 .

The discharging circuit 700 may be connected to the battery module B. In particular, the discharge circuit 700 may be electrically connected to both ends of the plurality of secondary batteries 10 , respectively. For example, as shown in the configuration of FIG. 2 , the discharge circuit 700 may be directly electrically connected to both ends of each secondary battery 10 , respectively. Also, the discharging circuit 700 may be located between the battery module B and the battery monitoring unit 300 .

Also, the discharging circuit 700 may be configured to discharge electric power. In particular, the discharging circuit 700 may be configured to receive power from the plurality of secondary batteries 10 and discharge the supplied power. For example, as shown in the configuration of FIG. 2 , the discharging circuit 700 includes a passive element capable of discharging power, and receives power from the secondary battery 10 connected to the passive element. It may be configured to discharge power. To this end, the discharge circuit 700 may include an electric circuit between the secondary battery 10 and the passive element, and a switch on the electric circuit. For example, the passive element may be implemented as a resistor. Also, the switch may be implemented as a Metal Oxide Semiconductor Field Effect Transistor (MOSFET).

Preferably, the discharge circuit 700 according to the present invention may include a plurality of unit discharge circuits 710 as shown in the configuration of FIG. 2 . In particular, each unit discharge circuit 710 may be connected in parallel with each secondary battery 10 . In addition, the unit discharge circuit 710 may include a discharge switch 712 and a discharge resistor 711 . The discharge switch 712 and the discharge resistor 711 may be electrically connected in series.

Also, preferably, the precharge circuit 200 according to the present invention may include a transformer circuit 210 and a precharge line L2 as shown in the configuration of FIG. 2 .

The transformer circuit 210 may be configured to receive a voltage applied to the storage circuit 100 and boost the voltage applied to the storage circuit 100 . In particular, the transformer circuit 210 may boost the voltage applied to the storage circuit 100 so that the power stored in the storage circuit 100 can be transferred to the precharge capacitor C . For example, as shown in the configuration of FIG. 2 , the transformer circuit 210 has one end connected to the storage circuit 100 and the other end connected to the precharge capacitor C, and is stored in the storage circuit 100 . Power may be transferred to the precharge capacitor (C). Here, the transformation ratio of the transformer circuit 210 may be adjusted according to the voltage applied to the storage circuit 100 . For example, when the voltage applied to the storage circuit 100 is 2V, the transformer circuit 210 may supply a voltage of 8V boosted from 2V to a transformation ratio of 1:4 to the precharge capacitor C. .

The precharge line L2 may be connected to one end of the transformer circuit 210 so that a precharge current flows. For example, as shown in the configuration of FIG. 2 , the precharge line L2 is located between one end of the transformer circuit 210 and one end of the precharge capacitor C, and is supplied from the transformer circuit 210 . The received precharge current may be transferred to the precharge capacitor (C).

Also, preferably, the storage circuit 100 according to the present invention may include a plurality of unit circuits 110 as shown in the configuration of FIG. 2 . The plurality of unit circuits 110 may be connected to both ends of the plurality of secondary batteries 10 . In particular, each unit circuit 110 may be electrically connected to both ends of each secondary battery 10 . Specifically, the unit circuit 110 may have one end connected to the precharge circuit 200 and the other end connected to both ends of the secondary battery 10 . Also, the plurality of unit circuits 110 may be configured to be connected in parallel to each other. For example, as shown in the configuration of FIG. 2 , the plurality of unit circuits 110 are configured such that a line connected to the positive terminal of each secondary battery 10 is commonly connected, and the The line connected to the negative terminal may be configured to be connected in common. Here, a contact point to which a line connected to the positive terminal of each secondary battery 10 is commonly connected may be connected to one end of the precharge circuit 200 . Also, a contact point to which a line connected to the negative terminal of each secondary battery 10 is commonly connected may be connected to one end of the precharge circuit 200 .

As shown in the configuration of FIG. 2 , the unit circuit 110 may include a storage capacitor 111 , a charging switch 112 , and a supply switch 113 .

The storage capacitor 111 may be electrically connected to both ends of the secondary battery 10 to store power supplied from the secondary battery 10 . For example, the storage capacitor 111 may be connected in parallel with the secondary battery 10 to receive power from the secondary battery 10 .

The charging switch 112 may be connected between the secondary battery 10 and the storage capacitor 111 to apply charging power to the storage capacitor 111 . For example, the charging switch 112 may be connected between the positive terminal of the secondary battery 10 and one end of the storage capacitor 111 . Also, the charging switch 112 may apply charging power to the storage capacitor 111 through turn-on and turn-off operations. For example, when the charging switch 112 is turned on, charging power stored in the secondary battery 10 may be supplied from the secondary battery 10 to the storage capacitor 111 through the charging switch 112 .

The supply switch 113 may be connected between one end of the precharge circuit 200 and the storage capacitor 111 to apply a precharge current to the precharge circuit 200 . For example, the supply switch 113 may be located on a line connected to the positive terminal of each secondary battery 10 . Also, the supply switch 113 may supply a precharge current to the precharge circuit 200 through turn-on and turn-off operations. For example, when the supply switch 113 is turned on, the charging power stored in the storage capacitor 111 is converted into a precharge current, and the precharge circuit 200 is converted from the storage capacitor 111 through the supply switch 113 . can be supplied with

More preferably, as shown in the configuration of FIGS. 1 and 2 , the precharge device according to the present invention may further include a switching unit 420 and a balancing control unit 410 .

The switching unit 420 may be electrically coupled to the battery control unit 400 to transmit and receive electrical signals. Also, the switching unit 420 may control turn-on and turn-off operations of the main precharge circuit 600 and the precharge relay 610 and the main relay 510 provided in the main circuit 500 .

The balancing control unit 410 may be electrically coupled to the battery control unit 400 to transmit and receive electrical signals. In addition, the balancing control unit 410 controls the turn-on and turn-off operations of each charging switch 112 , the supply switch 113 , and the discharging switch 712 provided in the storage circuit 100 and the discharging circuit 700 . can do. Here, the balancing control unit 410 may selectively control the charging switch 112 , the supply switch 113 , and the discharging switch 712 .

Preferably, as shown in the configuration of FIG. 2 , the precharge device according to the present invention may be configured to be connectable to the external device 50 . When the precharge device is mounted on a vehicle, the external device 50 may be a component of the vehicle.

The external device 50 may include a precharge capacitor C, a load 51 , and an ECU 52 .

The precharge capacitor C may be configured such that both ends of the precharge capacitor C are connectable to a positive terminal of the battery pack and a negative terminal of the battery pack. The precharge capacitor C may be connected in parallel with the battery module B. For example, as shown in the configuration of FIG. 2 , the precharge capacitor C may be electrically connected to the battery module B in parallel to receive charging power from the battery module B to be charged. Preferably, the capacitor capacity of the precharge capacitor C may be determined such that a voltage of 90% of the charging voltage of the battery module B may be charged.

The precharge capacitor C may be connected in parallel with the load 51 and the ECU 52 . The load 51 may be an electric device mounted in a vehicle such as an audio device, an air conditioner, or lighting and driven by electricity. In addition, the ECU 52 may be an electronic control unit (ECU 52) that controls electric components of the vehicle and a motor of the vehicle.

Also, preferably, the precharge device according to the present invention may further include a communication unit 800 as shown in the configuration of FIG. 2 .

The communication unit 800 may be electrically coupled to the battery control unit 400 and the ECU 52 to transmit and receive electrical signals. The communication unit 800 may receive status information of the battery module B monitored by the battery monitoring unit 300 from the battery control unit 400 and transmit the status information of the battery module B to the vehicle side.

3 is a diagram schematically illustrating a connection relationship between some components of a precharge device and a precharge capacitor according to an embodiment of the present invention. Here, the parts with differences from the previous embodiment will be mainly described, and detailed descriptions of parts to which the description of the previous embodiment may be applied in the same or similar manner will be omitted.

Referring to FIG. 3 , the battery controller 400 according to the present invention may receive status information of the battery module B from the battery module B. As shown in FIG. For example, the battery control unit 400 may receive voltage, current, and temperature information of the battery module (B).

Subsequently, the battery controller 400 may determine whether balancing is required based on the state information of the battery module B. Here, the balancing refers to a process of equalizing the charges of the plurality of secondary batteries 10 included in the battery module B.

Next, if there is a secondary battery 10 requiring discharging among the plurality of secondary batteries 10, the battery control unit 400 determines the secondary battery 10 to be discharged that needs balancing, and the secondary battery 10 to be discharged ( The charging switch 112 provided in the storage circuit 100 connected to 10) may be turned on. In this case, the storage capacitor 111 connected in parallel with the secondary battery 10 to be discharged may be charged by receiving power from the secondary battery 10 to be discharged. In this case, the battery control unit 400 may transmit a command to turn on and turn off the selective charging switch 112 to the balancing control unit 410 . Also, the balancing control unit 410 may selectively turn on and off the charging switch 112 .

Subsequently, the battery controller 400 may turn on the supply switch 113 connected to the storage capacitor 111 charged by the secondary battery 10 to be discharged. In this case, a precharge current generated from the power stored in the storage capacitor 111 may flow from the storage capacitor 111 to the precharge circuit. In this case, the battery control unit 400 may transmit the selective supply switch 113 turn-on and turn-off commands to the balancing control unit 410 . In addition, the balancing control unit 410 may selectively turn on and off the supply switch 113 .

Through such a configuration, the battery control unit 400 according to the present invention sequentially opens and closes the charging switch 112 and the supply switch 113 to precharge the precharge capacitor C through the precharge circuit 200 . A charge current can be supplied.

Accordingly, according to the pre-charging device according to the present invention, pre-charging with improved power efficiency can be performed. Specifically, by using the power generated in the cell balancing process as the precharge power, it is possible to reduce power wastage occurring in the conventional cell balancing process.

The precharge device according to the present invention may be provided in the battery pack itself. That is, the battery pack according to the present invention may include the above-described precharge device according to the present invention. Here, the battery pack may include one or more secondary batteries, the pre-charge device, an electronic device (including a BMS, a relay, a fuse, etc.), a case, and the like. In this configuration, at least some of the respective components of the precharge device according to the present invention may be implemented by supplementing or adding functions of components included in the conventional battery pack. For example, the battery monitoring unit, the battery control unit, the switching unit, and/or the balancing control unit of the precharge device according to the present invention may be implemented by a Battery Management System (BMS) provided in the battery pack.

4 is a flowchart schematically illustrating a precharging method according to an embodiment of the present invention. In FIG. 4 , the subject performing each step may be referred to as each component of the precharge device according to the present invention described above.

As shown in FIG. 4 , in step S100 , the battery monitoring unit monitors a voltage and a charging/discharging current of each of the plurality of secondary batteries. In particular, the battery monitoring unit monitors a voltage of each of the plurality of secondary batteries and a charge/discharge current flowing through a charge/discharge path connected to the battery module.

Subsequently, in step S110 , the battery controller determines a secondary battery that needs balancing from among the plurality of secondary batteries based on the voltage and charging/discharging current of each of the plurality of secondary batteries monitored by the monitoring step.

Subsequently, in step S120 , the battery controller determines the secondary battery determined in the secondary battery determination step as the secondary battery to be discharged. In addition, the storage circuit receives power from the secondary battery to be discharged and stores the supplied power.

Subsequently, in step S130, the precharge circuit transfers the power stored by the power storage step to the precharge capacitor.

5 is a flowchart schematically illustrating a precharging method according to another exemplary embodiment of the present invention. In FIG. 5 , the subject performing each step may be referred to as each component of the precharge device according to the present invention described above.

As shown in FIG. 5 , in step S200 , the battery monitoring unit monitors the voltage and charge/discharge current of each of the plurality of secondary batteries. In particular, the battery monitoring unit monitors a voltage of each of the plurality of secondary batteries and a charge/discharge current flowing through a charge/discharge path connected to the battery module.

Subsequently, in step S210 , the battery controller determines a secondary battery that needs balancing from among the plurality of secondary batteries based on the voltage and charging/discharging current of each of the plurality of secondary batteries monitored by the monitoring step. For example, the battery controller may determine a secondary battery that needs to be discharged from among the plurality of secondary batteries, and determine the secondary battery that needs to be discharged as a secondary battery to be discharged.

Next, in step S220, the battery control unit determines whether power storage is required in the storage circuit. If the determination result in step S220 is NO, the process proceeds to step S230. On the other hand, if the determination result of step S220 is YES, the process proceeds to step S240. For example, when the storage capacitor provided in the storage circuit is fully charged, the battery controller may determine that power storage is not required in the storage circuit. Meanwhile, when the storage capacitor provided in the storage circuit is not fully charged, the battery control unit may determine that power storage is required in the storage circuit.

Subsequently, in step S230 , the battery controller may selectively turn on a discharge switch provided in a discharge circuit connected to the secondary battery to be discharged, thereby discharging the power supplied from the secondary battery to be discharged through the discharge resistor. Meanwhile, in step S240 , the battery controller may selectively turn on a charging switch provided in a charging circuit connected to the secondary battery to be discharged to store power supplied from the secondary battery to be discharged through the storage capacitor.

Next, in step S250, the battery control unit determines whether pre-charge for charging the pre-charge capacitor is necessary. If the determination result of step S250 is NO, the process is terminated. On the other hand, if the determination result in step S250 is YES, the process proceeds to step S260. For example, when the precharge device according to the present invention is provided in a vehicle, the battery controller may detect an on signal of an ignition switch that is a main switch of the vehicle to precharge the precharge capacitor. Here, the battery control unit may receive an on signal of the ignition switch from the ECU of the vehicle. In this case, the battery controller may determine whether pre-charge is necessary based on the state of charge of the pre-charge capacitor. For example, the state of charge of the precharge capacitor may be received from the ECU. In an embodiment of the present invention, when the state of charge of the precharge capacitor is less than 90%, the battery controller may determine that precharge for charging the precharge capacitor is required. Meanwhile, when the state of charge of the precharge capacitor is 90% or more, the battery controller may determine that precharge is not required.

Subsequently, in operation S260 , the battery controller may charge the precharge capacitor through the precharge circuit. For example, the battery controller may selectively control a supply switch provided in the supply circuit to supply the precharge current to the precharge capacitor.

In addition, when the control logic is implemented in software, the battery control unit may be implemented as a set of program modules. In this case, the program module may be stored in the memory device and executed by the processor.

In addition, as long as at least one or more of the various control logics of the battery control unit are combined, and the combined control logics are written in a computer-readable code system and have computer-readable access, there is no particular limitation on the type. As an example, the recording medium includes at least one selected from the group consisting of a ROM, a RAM, a register, a CD-ROM, a magnetic tape, a hard disk, a floppy disk, and an optical data recording device. In addition, the code system may be distributed, stored, and executed in computers connected to a network. In addition, functional programs, codes and segments for implementing the combined control logic can be easily inferred by programmers in the art to which the present invention pertains.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

On the other hand, although the term 'unit' is used in the present specification, such as 'monitoring unit' and 'control unit', it indicates a logical structural unit, and indicates a component that can be physically separated or must be physically separated. It is obvious to those skilled in the art that this is not the case.

10: secondary battery
50: external device
51: load
52: ECU
100: storage circuit
110: unit circuit
111: storage capacitor
112: charging switch
113: supply switch
200: precharge circuit
210: transformer circuit
300: battery monitoring unit
310: voltage measuring unit
320: current measuring unit
330: temperature measurement unit
340: SOC estimator
400: battery control unit
410: balancing control
420: switching unit
500: main circuit
510: main relay
600: main precharge circuit
610: pre-charge relay
620: precharge resistor
700: discharge circuit
710: unit discharge circuit
711: discharge resistance
712: discharge switch
800: communication department
B: battery module
C: precharge capacitor
L: main line
L1: precharge line
L2: precharge line

Claims (12)

A precharge device for charging a precharge capacitor configured to be electrically connectable to both ends of a battery module including a plurality of secondary batteries, the precharge device comprising:
a storage circuit electrically connected to both ends of the plurality of secondary batteries to receive power from the plurality of secondary batteries and store the supplied power;
a precharge circuit electrically connected to one end of the storage circuit to receive a precharge current from the storage circuit and to transmit the supplied precharge current to the precharge capacitor;
a battery monitoring unit connected to the battery module and the battery module and electrically connected to a charging/discharging path through which a charging/discharging current flows to monitor the voltage and the charging/discharging current of each of the plurality of secondary batteries; and
A battery control unit configured to control opening and closing of the storage circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit to control charging of the precharge capacitor by the precharge current Precharge device comprising a.
According to claim 1,
A main circuit configured to include a main relay electrically connected to one end of the battery module to open and close a main line through which the charge/discharge current flows, and a precharge line connected in parallel with the main circuit to open and close a precharge line through which a precharge current flows A main precharge circuit configured to include a charge relay and a precharge resistor connected in series with the precharge relay
Precharge device further comprising a.
3. The method of claim 2,
and the precharge circuit is configured to be electrically connected between a contact point to which one end of the main circuit and one end of the main precharge circuit are commonly connected and one end of the storage circuit.
4. The method of claim 3,
The battery control unit controls opening and closing of the storage circuit, the main circuit, and the main pre-charge circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit pre-charge device.
According to claim 1,
and a discharging circuit configured to be electrically connected to both ends of the plurality of secondary batteries, respectively, to receive power from the plurality of secondary batteries and to discharge the supplied power.
According to claim 1,
The precharge circuit includes a transformer circuit for boosting the voltage applied to the storage circuit so as to transfer the power stored in the storage circuit to the precharge capacitor, and a precharge line connected to one end of the transformer circuit and through which a precharge current flows. A precharge device comprising a.
According to claim 1,
The storage circuit includes a plurality of unit circuits connected to both ends of the plurality of secondary batteries, and the unit circuits have one end connected to the precharge circuit and the other end connected to both ends of the secondary battery and connected in parallel with each other. Precharge device, characterized in that configured.
8. The method of claim 7,
The unit circuit includes a storage capacitor electrically connected to both ends of the secondary battery to store power supplied from the secondary battery, and a charging switch connected between the secondary battery and the storage capacitor to apply charging power to the storage capacitor and a supply switch connected between one end of the precharge circuit and the storage capacitor to apply a precharge current to the precharge circuit.
9. The method of claim 8,
When balancing of the battery module is required, the battery control unit sequentially opens and closes the charging switch and the supply switch provided in the storage circuit to supply a precharge current to the precharge capacitor through the precharge circuit Precharge device, characterized in that.
10. A battery pack comprising the precharge device according to any one of claims 1 to 9.
A precharge device for charging a precharge capacitor configured to be electrically connected to one end of a battery module including a plurality of secondary batteries and connectable to one end of a main relay that opens and closes a main line through which a charge/discharge current flows,
a storage circuit electrically connected to both ends of the plurality of secondary batteries to receive power from the plurality of secondary batteries and store the supplied power;
a precharge circuit electrically connected to one end of the storage circuit to receive a precharge current from the storage circuit and to transmit the supplied precharge current to the precharge capacitor;
a battery monitoring unit connected to the battery module and the battery module and electrically connected to a charging/discharging path through which a charging/discharging current flows to monitor the voltage and the charging/discharging current of each of the plurality of secondary batteries;
A battery control unit configured to control opening and closing of the storage circuit based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the battery monitoring unit to control charging of the precharge capacitor by the precharge current ; and
and a communication unit for receiving the state information of the battery module monitored by the battery monitoring unit from the battery control unit and transmitting the state information to the vehicle side.
A precharge method for charging a precharge capacitor configured to be electrically connectable to both ends of a battery module including a plurality of secondary batteries, the precharge method comprising:
monitoring a voltage of each of the plurality of secondary batteries and a charging/discharging current flowing through a charging/discharging path connected to the battery module;
determining a secondary battery in need of balancing among the plurality of secondary batteries based on the voltage and the charging/discharging current of each of the plurality of secondary batteries monitored by the monitoring step;
determining the secondary battery determined by the secondary battery determination step as a secondary battery to be discharged, receiving power from the secondary battery to be discharged, and storing the received power in a storage circuit; and
and receiving the power stored in the storage circuit as a pre-charge current according to whether the storage circuit is opened or closed by the power storage step, and transferring the supplied pre-charge current to the pre-charge capacitor. How to occupy.

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