KR102346847B1 - Energy storage system and control method of energy storage system - Google Patents

Abstract

An energy storage device according to one technical aspect of the present invention comprises: an energy storage unit which includes a plurality of battery racks, wherein each of the battery racks includes a plurality of battery cells connected in series; a shunt unit which includes a plurality of shunts provided at an input end of the energy storage unit and an input end of the plurality of battery racks; and a control unit which calculates a circulating current generated between the plurality of battery racks by using the current sensed by the shunt unit. According to one embodiment of the present invention, provided is an effect of fundamentally preventing the energy storage device from being damaged, by calculating a calorific value of the energy storage device and determining whether the energy storage device is overcharged.

Description

ENERGY STORAGE SYSTEM AND CONTROL METHOD OF ENERGY STORAGE SYSTEM

The present invention relates to an energy storage device and a method for controlling the energy storage device, and more specifically, an energy storage device and energy that can fundamentally prevent damage to the energy storage device by calculating the calorific value of the energy storage device and determining whether or not overcharging is present. It relates to the control method of the storage device.

An energy storage device is a device that stores and stores a large amount of energy, and provides the stored energy when power is needed, such as a power outage.

As the energy storage device can cover a larger capacity according to the development of battery technology, it is being applied to various fields, such as a semiconductor production line, a hospital operating room, etc., in which a stable supply of electrical energy is essential.

The energy storage device includes a plurality of racks connected in parallel, and each of the racks includes a plurality of battery cells connected in series.

The energy storage device includes a control device for controlling charging and discharging of the energy storage device, wherein the control device monitors voltage and current in units of racks to determine whether overcharging occurs.

On the other hand, circulating current is generated by the voltage difference between the racks. In the case of a conventional control device, it is difficult to check the circulating current even if a specific rack is overcharged, and the resulting battery fire or explosion is exposed to the risk of occurrence. There is this.

In addition, the conventional control device determines the overcharge state by using the percentage of states of charge according to the open circuit voltage. However, in a rack, a plurality of battery cells are connected in series, and even if some of the plurality of series-connected battery cells are overcharged - for example, overcharged by 200% or more - if the open-circuit voltage of the entire series-connected rack is within the SOC effective range can't detect this Accordingly, even if overcharge of a specific battery cell occurs, it is not detected, and there is a problem in that the overcharged battery cell is vulnerable to fire due to a rise in temperature.

Korean Patent Publication No. 10-2009-0038607

One technical aspect of the present invention is to solve the problems of the prior art, and an energy storage device capable of fundamentally preventing damage to the energy storage device by calculating the calorific value of the energy storage device and determining whether or not overcharging is performed. It relates to a control method of an energy storage device.

In addition, one technical aspect of the present invention is by detecting the internal resistance of each rack of the battery storage device and calculating the amount of heat generated by the rack unit based on this and sensing the temperature rise of the battery cells included in the rack, the battery cell An object of the present invention is to provide an energy storage device and a control method of the energy storage device capable of fundamentally preventing fire due to temperature rise.

In addition, one technical aspect of the present invention detects the total charging current and the charging current input to each rack and calculates the circulating current induced between each rack based on this, and each rack in consideration of both the charging current and the circulating current An object of the present invention is to provide an energy storage device and a control method of the energy storage device that can block overcharge due to circulating current and prevent damage or explosion due to overcharge by determining whether overcharge occurs in the .

The above objects and various advantages of the present invention will become more apparent from preferred embodiments of the present invention by those skilled in the art.

One technical aspect of the present invention proposes an energy storage device. The energy storage device includes a plurality of battery racks, wherein the battery rack includes a plurality of battery cells connected in series. It may include a shunt unit including a shunt and a control unit for calculating a circulating current generated between the plurality of battery racks by using the current sensed in the shunt unit.

In one embodiment, the shunt unit may include an input shunt connected to the input terminal of the energy storage unit and a plurality of rack shunts respectively connected to the input terminals of the plurality of battery racks.

In one embodiment, the controller detects a plurality of rack currents flowing in or out for each of the plurality of battery racks by using the plurality of rack shunts, and based on the input current input through the input shunt, the plurality of The circulating current can be calculated by calculating the change in the inflow and outflow of the rack current.

In one embodiment, the rack current may include an inflow rack current flowing into the battery rack, and an outflow rack current flowing from the battery rack. Here, the control unit, when the outflow rack current is sensed in at least one battery rack, compares the input current with the summed value of a plurality of inflow rack currents detected in the plurality of battery racks, the flow of circulating current And it may include a circulating current calculation module for calculating the amount of circulating current and a control module for preventing a current greater than a standard from flowing into any battery rack based on the circulating current and the rack current.

In one embodiment, the control unit calculates a rack internal resistance for each of the plurality of battery racks using the circulating current and the rack current, and uses the calculated internal resistance of the rack to each of the plurality of battery racks Calculates the calorific value for the battery, and when the calculated calorific value exceeds the critical temperature, the current inflow to the corresponding battery rack can be blocked.

In one embodiment, the controller calculates the internal resistance for each of the plurality of battery racks using the voltage across the input terminal, the circulating current and the rack current, and the circulating current, the rack current and the inside of the battery rack It may further include a calorific value calculation module for calculating the calorific value for each of the plurality of battery racks using a resistor.

In one embodiment, the control module, when the amount of heat of any battery rack exceeds a threshold criterion, may stop charging for the corresponding battery rack.

Another technical aspect of the present invention proposes a method for controlling an energy storage device. The control method of the energy storage device is a control method of an energy storage device using an energy storage unit including a plurality of battery racks, wherein the battery rack includes a plurality of battery cells connected in series, and is input to an input terminal of the energy storage unit. Providing a shunt, each with a plurality of rack shunts at the input end of the plurality of battery racks, detecting a plurality of rack currents flowing in or out for each of the plurality of battery racks using the plurality of rack shunts, and the input It may include calculating a circulating current by calculating changes in the inflow and outflow of the plurality of rack currents based on the input current input through the shunt.

In one embodiment, the rack current may include an inflow rack current flowing into the battery rack, and an outflow rack current flowing from the battery rack.

In one embodiment, the step of calculating the circulating current, when the outflow rack current is sensed in at least one battery rack, the summed value of a plurality of inflow rack currents detected in the plurality of battery racks and the input current By comparison, it may include calculating the flow of the circulating current and the amount of circulating current.

In one embodiment, the control method of the energy storage device, based on the circulating current and the rack current may further include the step of preventing more than a standard current from flowing into any battery rack.

In one embodiment, the control method of the energy storage device calculates a rack internal resistance for each of the plurality of battery racks using the circulating current and the rack current, and uses the calculated rack internal resistance to the plurality of It may further include the step of calculating the calorific value for each of the battery rack.

In one embodiment, the calculating of the amount of heat generated includes calculating the internal resistance for each of the plurality of battery racks using the voltage across both ends of the input terminal, the circulating current and the rack current, and the circulating current, the rack current And by using the internal resistance of the battery rack may include the step of calculating the calorific value for each of the plurality of battery racks.

In one embodiment, the control method of the energy storage device, when the amount of heat of a certain battery rack exceeds a threshold criterion, the step of stopping charging for the corresponding battery rack may further include.

The means for solving the above-described problems do not enumerate all the features of the present invention. Various means for solving the problems of the present invention may be understood in more detail with reference to specific embodiments in the following detailed description.

According to one embodiment of the present invention, there is an effect that can fundamentally prevent damage to the energy storage device by calculating the calorific value of the energy storage device and determining whether the energy storage device is overcharged.

In addition, one technical aspect of the present invention is by detecting the internal resistance of each rack of the battery storage device and calculating the amount of heat generated by the rack unit based on this and sensing the temperature rise of the battery cells included in the rack, the battery cell There is an effect that can fundamentally prevent fire caused by temperature rise.

In addition, one technical aspect of the present invention detects the total charging current and the charging current input to each rack and calculates the circulating current induced between each rack based on this, and each rack in consideration of both the charging current and the circulating current By judging whether overcharging occurs, there is an effect of blocking overcharging due to circulating current and preventing damage or explosion due to overcharging.

1 is a view for explaining an energy storage device according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining an example in which a control unit calculates a circulating current according to an embodiment of the present invention.
3 is a diagram illustrating an embodiment of a control unit applicable to an energy storage device according to an embodiment of the present invention.
4 is a view for explaining an example in which the control unit detects the amount of heat, according to an embodiment of the present invention.
5 is an equivalent circuit diagram of FIG. 4 .
6 is a view for explaining an example of an energy storage device according to an embodiment of the present invention.
7 is a view for explaining the rack protection function performed by the control module in the example shown in FIG.
8 is a view for explaining a structure of an energy storage device according to an embodiment of the present invention.
9 is a view for explaining a protection stop function performed by the control module in the example shown in FIG.
10 is a flowchart illustrating a method of controlling an energy storage device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

That is, the above-described objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, a person of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

In addition, various components and sub-components thereof are described below in order to describe the system according to the present invention. These components and sub-components thereof may be implemented in various forms, such as hardware, software, or a combination thereof. For example, each element may be implemented as an electronic configuration for performing a corresponding function, or may be software itself operable in an electronic system or implemented as a functional element of such software. Alternatively, it may be implemented with an electronic configuration and corresponding driving software.

The various techniques described herein may be implemented with hardware or software, or a combination of both, where appropriate. As used herein, terms such as "Unit", "Server" and "System" likewise refer to computer-related entities, i.e. hardware, a combination of hardware and software, software or It can be treated as equivalent to software at the time of execution. In addition, each function executed in the system of the present invention may be configured in units of modules, and may be recorded in one physical memory, or may be recorded while being dispersed between two or more memories and recording media.

Although various flowcharts are disclosed to describe the embodiments of the present invention, this is for convenience of description of each step, and each step is not necessarily performed according to the order of the flowchart. That is, each step in the flowchart may be performed simultaneously with each other, performed in an order according to the flowchart, or may be performed in an order opposite to the order in the flowchart.

Hereinafter, various embodiments of an energy storage device and a method for controlling the energy storage device according to the present invention will be described.

1 is a view for explaining an energy storage device according to an embodiment of the present invention.

Referring to FIG. 1 , the energy storage device may include an energy storage unit 100 , a shunt unit 200 , a Power Conditioning Syste (PCS) 400 and a control unit 300 (shown in FIG. 2 ). can

Energy storage unit 100 may include a plurality of battery racks (110 to 130). A plurality of battery racks (110 to 130) may be connected to each other in parallel.

Each battery rack 110 to 130 may include a plurality of battery cells connected in series. In the example shown in FIG. 1, each battery rack shows an example in which battery cells connected in series are connected in parallel in two rows, which is illustrative and not limited thereto.

The power conversion unit (PCS, Power Conditioning Syste) 400 is connected to the input terminal of the energy storage unit 100 , and may supply power to the battery rack under the control of the control unit 300 .

The shunt unit 200 may include a plurality of shunts provided at the input end of the input end battery rack of the energy storage unit 100 . In the illustrated example of FIG. 1 , the shunt unit 200 includes an input shunt 201 connected to the input terminal 100 of the energy storage unit, and a plurality of battery racks 110 to 130 respectively individually connected to the input terminals. Rack shunts 210 to 230 may be included.

Each shunt included in the shunt unit 200 may sense the direction and magnitude of a current passing through the shunt. For example, the shunt may include a shunt resistor, and the controller 300 may check the direction and magnitude of a current flowing through the shunt resistor using the shunt resistor.

Here, the shunt must sense a smaller current, unlike a general current sensor (eg, a Hall sensor, etc.). To this end, the shunt must satisfy the current measurement range as in Equation 1 below.

[Equation 1]

Minimum value of shunt's current measurement range ≤

Here, C.Max-rate is the maximum charging current of the battery cells, n is the number of battery cells connected in series, and m is the number of rows of battery cells connected in parallel.

For example, the maximum charging current of the battery cells is 50A, in the case of a battery rack having two rows of 240 series-connected battery cells, a current of about 0.1A must be read.

The control unit 300 may calculate the circulating current generated between the plurality of battery racks 110 to 130 by using the current sensed by the shunt unit 200 .

For example, the controller 300 may calculate the circulating current by calculating changes in the inflow and outflow of a plurality of rack currents based on the input current input through the input shunt.

For example, the controller 300 detects a plurality of rack currents flowing in or out of each battery rack by using a plurality of rack shunts, and based on the input current input through the input shunt, the amount of inflow of the plurality of rack currents and The circulating current can be calculated by calculating the change in the outflow.

The circulating current is a flow of current generated between power storage means connected in parallel, and is a current naturally induced by a voltage difference when the power storage means connected in parallel have different voltages.

When a plurality of battery racks are connected in parallel as in the present invention, a circulating current flowing from one battery rack to another battery rack may be induced by a voltage difference between the battery racks.

This circulating current causes an error in the state of charge (SOC) information for each rack, and in particular, when the circulating current flows in the reverse direction of the charging current, in the case of the prior art, only the offset current of the charging current and the circulating current It does not detect when a particular rack is overcharged.

Therefore, in one embodiment of the present invention, the input terminal 100 of the energy storage unit detects the current supplied from the power conversion unit (PCS, Power Conditioning Syste) 400, and the current flowing through each rack using the rack shunt It can be sensed to calculate the circulating current.

By calculating and reflecting the circulating current in this way, it is possible to more accurately calculate the calorific value by reflecting the effect due to the circulating current when calculating the calorific value of the battery rack.

That is, the control unit 300 calculates the internal resistance of the rack for each of the plurality of battery racks by using the circulating current and the rack current, and calculates the amount of heat generated for each of the plurality of battery racks using the calculated internal resistance of the rack. When the amount of heat generated exceeds the threshold temperature, it can be controlled to cut off the current flow to the corresponding battery rack.

FIG. 2 is a diagram for explaining an example in which the control unit calculates a circulating current, and FIG. 3 is a diagram illustrating an embodiment of the control unit applicable to an energy storage device according to an embodiment of the present invention.

Hereinafter, the control unit 300 will be described in more detail with reference to FIGS. 2 and 3 .

In FIG. 2 , the control unit 300 may sense _{an input current A pcs} input to the energy storage unit 100 through the input shunt 201 .

In addition, the control unit 300 may sense the rack current flowing into or out of each battery rack (110 to 130) through the rack shunt (210 to 230).

The rack current may include an incoming rack current flowing into the battery rack, and an outgoing rack current flowing from the battery rack.

In the example shown in FIG. 2 , the inflow rack current A _{r1 flowing into the first battery rack 110 through the first rack shunt 210 and the outflow rack current A rc1} flowing out from the first battery rack can be detected. .

If there is an outflow rack current in either battery pack, this is because there is a circulating current. Therefore, the controller 300 may calculate the circulating current using the inflow rack current, the outflow rack current and the input current.

To this end, the control unit 300 may include a circulating current calculation module 310 .

The circulating current calculation module 310 compares the input current with the summed value of a plurality of inflow rack currents detected in a plurality of battery racks when an outflow rack current is detected in at least one battery rack, and the flow of circulating current and The amount of circulating current can be calculated.

In the example shown in Figure 2, _assume that the input current A pcs is 12A, the incoming rack current A _r1 is 4A, the incoming rack current A _r2 is 4A, the incoming rack current A _r3 is 6A, and the outgoing rack current A _rc1 is 2A. The circulating current calculation module 310 can know that the circulating current exists in the presence _{of the outflow rack current A rc1 2A.}

Alternatively, the circulating current calculation module 310 has an input current A _pcs of 12A, but the sum of the incoming rack currents input to each battery rack is 14A (4A+4A+6A), so the sum of the input current and the incoming rack current is the same Therefore, it can be seen that there is a circulating current.

The circulating current calculation module 310 may calculate _{the inflow value of the circulating current based on the difference between the input current A pcs} and the sum of the inflow rack currents flowing into each battery rack. In addition, it is possible to verify that the inflow value of the circulating current is the same as the outgoing rack current.

As a result, in the illustrated example, the circulating current calculation module 310 can see that the input current is 12A, and the current provided to each battery rack among the input current is 4A, 4A, and 4A, respectively. Also, it may be calculated that a circulating current of 2A is generated from the first battery pack 110 to the third battery pack 130 .

The control unit 300 may include a control module 330 .

The circulating current calculation module 310 may provide information about the input current, the rack current, and the circulating current to the control module 330 .

The control module 330 may prevent the introduction of more than a standard current to any battery rack based on the circulating current and the rack current.

In one embodiment, the control unit 300 calculates the internal resistance of the battery rack, using this can be calculated individually for each battery rack calorific value of the battery rack. Therefore, it is possible to prevent any battery rack from being overcharged.

To this end, the control unit 300 may include a calorific value calculation module 320 .

The calorific value calculation module 320 may calculate the internal resistance for each of a plurality of battery racks by using the voltage across both ends of the input terminal, the circulating current and the rack current. The calorific value calculation module 320 may calculate the calorific value for each of a plurality of battery racks by using the circulating current, the rack current, and the internal resistance of the battery rack.

4 is a diagram for explaining an example in which the calorific value calculation module 320 of the control unit detects the calorific value in an embodiment of the present invention, which will be further described with reference to FIG. 4 .

4 shows an example in which two battery cells are connected in series to constitute a battery rack, and two battery racks are connected in parallel for convenience of explanation.

That is, the first battery rack 110 is configured such that the first battery cell 11 and the second battery cell 12 are connected in series, and the second battery rack 120 is the third battery cell 21 and the fourth The battery cells 22 are connected in series.

Both ends of the power conversion unit (PCS, Power Conditioning Syste) 400 are connected to both ends of the first battery rack 110 and the second battery rack 120 in a parallel structure.

_{Here, the input voltage V Th} may be detected by detecting the voltage across both ends of the power conversion unit (PCS, Power Conditioning Syste) 400 .

On the other hand, the input voltage V _Th may be different from the voltage across both ends of the first battery rack 110 and / or the voltage across the second battery rack (120). In addition, the voltage across the first battery rack 110 and the voltage across the second battery rack 120 may also be different. When the voltage across both ends of the first battery rack 110 and the voltage across both ends of the second battery rack 120 are different, as described above, the circulating current flows between the first battery rack 110 and the second battery rack 120 . do.

The voltage across both ends of the first battery rack 110 V _oc1 and the voltage across the second battery rack 120 V _oc2 satisfies Equation 2 below.

[Equation 2]

In addition, the first and the combined resistance R of the battery _1, a rack 110, a second synthesis of a battery rack 120, the resistance R ₂ satisfies the expression (3) below.

[Equation 3]

The calorific value calculation module 320 may apply Equation 4 below to the _{input voltage V Th .}

[Equation 4]

In addition, as described above, since it is possible to check the current flowing in the battery rack through the rack shunt, the calorific value calculation module 320 is the rack current I ₁ of the first battery rack 110 and the second battery rack 120 of the rack. The current I ₂ can be found.

On the other hand, the circuit of FIG. 4 may be interpreted as a bridge circuit, as shown in FIG. 5 , and thus, the voltage difference ΔV between the first battery 110 and the second battery rack 120 is the following Equation 5 and can be calculated together.

[Equation 5]

After all, the calorific value calculation module 320 can know information about the current flowing in each battery rack by using the circulating current and the rack current, and also know the voltage difference between the battery cells, so that the input voltage V _Th is By reflecting this, the combined resistances R1 and R2 of each battery cell may be calculated.

In addition, the calorific value calculation module 320 may calculate the calorific value of each battery rack by using Equation 6 below.

[Equation 6]

calorific value = I ² Rt

The calorific value calculation module 320 may provide information on the calorific value of the calculated battery rack to the control module 330 .

The control module 330 may stop charging for the corresponding battery rack when the amount of heat of any battery rack exceeds the threshold standard.

Hereinafter, various embodiments of the control module 330 will be described with reference to FIGS. 6 to 9 .

FIG. 6 is a view for explaining an example of an energy storage device according to an embodiment of the present invention, and FIG. 7 is a view for explaining a rack protection function performed by the control module in the example shown in FIG. 6 .

The circuit shown in FIG. 7 is a logic circuit illustrating the protection function of the control module, and provides an operation current and time correction calculation function by applying a thermal time constant to the passing current of each battery cell unit.

Here, AH is the manufacturer's guarantee of the battery rack unit Ampere hour (Ampere hour), Ah is the actual value of the battery rack unit Ampere hour (Ampere hour), 87F is the differential relay (let through differential current relay) , 92 is a balancing over load relay.

DF is a deviation factor and is calculated as in Equation 7 below.

[Equation 7]

In addition, r is the cell internal resistance, m is the number of parallel connections, n is the number of series connections of battery cells, k is the number of battery racks, d is the differential voltage between battery cells in the same rack, and lp is the battery The circulating current between cells, Is means the circulating current between the battery racks.

dVoc corresponds to some value in V.max (the battery cell upper limit charging voltage specified by the manufacturer), and in this example, dVoc corresponds to 8% of V.max. C.mam-rate is the maximum charging current specified by the manufacturer.

Here, dVoc corresponding to 8% of V.max is an exemplary value and may be adjusted according to the battery V-Ah curve.

Is and ratio can be calculated as in Equation 8 below.

[Equation 8]

As a result, the control module 330 using the circuit shown in FIG. 7 may provide a protection function for each battery rack.

Here, the protection function means that any one battery cell performs a trip before reaching 200% reflecting a deviation factor (DF) in the ampere-hour AH guaranteed by the manufacturer.

8 is a view for explaining a structure of an energy storage device according to an embodiment of the present invention, and FIG. 9 is a view for explaining a protection stop function performed by the control module in the example shown in FIG. 8 .

The circuit shown in FIG. 9 shows a limit function for stopping the rack unit output control and PCS as a control function of the control module 330 .

In the example of FIG. 9 , dVoc corresponds to a partial value at V.max (the battery cell upper limit charging voltage specified by the manufacturer), and in this example, dVoc corresponds to 6.8% of V.max.

Here, dVoc corresponding to 6.8% of V.max is an exemplary value and may be adjusted according to the battery V-Ah curve.

As described above, AH is the battery rack unit (or cell unit) guaranteed by the manufacturer Ampere hour (Ampere hour), Ah is the actual value of the battery rack unit Ampere hour (Ampere hour), 87F is the differential relay ( let through differential current relay), and 92 is a balancing over load relay.

As a result, using the circuit shown in FIG. 9, the control module 330 may provide a rack trip function as a control function for each battery rack, and may also provide a limit function through stopping the PCS operation.

Here, the control function means that any one battery cell turns the battery rack OFF before reaching 170% reflecting the deviation factor (DF) in the ampere-hour AH guaranteed by the manufacturer, and for a certain period of time (heat It is set in consideration of the time constant) and it means to switch to ON after elapse of time.

In the above, various embodiments of the energy storage device have been described with reference to FIGS. 1 to 9 .

Hereinafter, a method for controlling an energy storage device according to an embodiment of the present invention will be described.

Since the method for controlling the energy storage device to be described below is performed in the energy storage device described above with reference to FIGS. 1 to 9 , it can be more easily understood with reference to the description described above based on FIGS. 1 to 9 .

10 is a flowchart illustrating a method of controlling an energy storage device according to an embodiment of the present invention.

Referring to FIG. 10 , the energy storage device includes an input shunt at the input end of the energy storage unit 100 and a plurality of rack shunts at the input end of the plurality of battery racks, respectively (S1010).

The energy storage device, ie, the control unit 300, may sense a plurality of rack currents flowing in or out of each battery rack by using a plurality of rack shunts (S1020).

The controller 300 may calculate the circulating current by calculating the change in the inflow and outflow of a plurality of rack currents based on the input current input through the input shunt (S1030).

Here, the rack current may include an inflow rack current flowing into the battery rack, and an outflow rack current flowing from the battery rack.

The control unit 300 may prevent a current more than a standard from flowing into any battery rack based on the circulating current and the rack current (S1040).

The control unit 300 calculates the rack internal resistance for each of the plurality of battery racks by using the circulating current and the rack current, and using the calculated internal resistance of the rack can calculate the calorific value for each of the plurality of battery racks. (S1050).

The control unit 300, when the calorific value of a certain battery rack exceeds the threshold standard, may stop charging for the corresponding battery rack (S1060).

In one embodiment for step S1030, the control unit 300, when the outflow rack current is detected in at least one battery rack, by comparing the input current with the summed value of a plurality of inflow rack currents detected in a plurality of battery racks , calculating the flow of circulating current and the amount of circulating current may be performed.

In one embodiment for step S1050, the control unit 300, the step of calculating the internal resistance for each of a plurality of battery racks by using the voltage across the input terminal, circulating current and the rack current, circulating current, rack current and Using the internal resistance of the battery rack may perform the step of calculating the calorific value for each of a plurality of battery racks.

The present invention described above is not limited by the above-described embodiments and the accompanying drawings, but is limited by the claims described below, and the configuration of the present invention may vary within the scope without departing from the technical spirit of the present invention. Those of ordinary skill in the art to which the present invention pertains can easily recognize that it can be easily changed and modified.

100: energy storage unit
110, 120, 130: battery rack
11, 12, 21, 22 : battery cell
200: shunt unit
201 : input shunt
210, 220, 230: rack shunt
300: control unit
310: circulating current calculation module
320: calorific value calculation module
330: control module
400: PCS

Claims (14)

an energy storage unit comprising a plurality of battery racks, wherein the battery rack includes a plurality of battery cells connected in series;
a shunt unit including an input shunt connected to an input end of the energy storage unit and a plurality of rack shunts respectively connected to an input end of the plurality of battery racks; and
Detect a plurality of rack currents flowing in or out of each of the plurality of battery racks using the plurality of rack shunts, and change the inflow and outflow of the plurality of rack currents based on the input current input through the input shunt a control unit for calculating a circulating current generated between the plurality of battery racks by calculation;
Energy storage device comprising a.
The method of claim 1, wherein the rack current is
Including an incoming rack current flowing into the battery rack, and an outgoing rack current flowing from the battery rack,
The control unit is
When the outflow rack current is sensed in at least one battery rack, by comparing the input current with the summed value of a plurality of inflow rack currents detected in the plurality of battery racks, cycle to calculate the flow of circulating current and the amount of circulating current current calculation module; and
a control module for preventing a current exceeding a standard from flowing into any battery rack based on the circulating current and the rack current;
Energy storage device comprising a.
According to claim 2, wherein the control unit,
Calculating the internal resistance of the rack for each of the plurality of battery racks using the circulating current and the rack current, and calculating the amount of heat generated for each of the plurality of battery racks using the calculated internal resistance of the rack, the calculated calorific value If this threshold temperature is exceeded, it will cut off the current draw to that battery rack.
Energy storage device characterized in that.
According to claim 2, wherein the control unit,
Calculating the internal resistance for each of the plurality of battery racks using the voltage across the input terminal, the circulating current and the rack current, and using the circulating current, the rack current and the internal resistance of the battery rack, the plurality of battery racks a calorific value calculation module for calculating calorific value for each;
Energy storage device, characterized in that it further comprises.
According to claim 4, wherein the control module,
To stop charging for a battery rack when the heat output of that battery rack exceeds a threshold threshold;
Energy storage device characterized in that.
A method of controlling an energy storage device using an energy storage unit including a plurality of battery racks, wherein the battery rack includes a plurality of battery cells connected in series,
providing an input shunt at the input end of the energy storage unit, and a plurality of rack shunts at the input end of the plurality of battery racks, respectively;
detecting a plurality of rack currents including inflow rack currents flowing in or outflow rack currents for each of the plurality of battery racks by using the plurality of rack shunts; and
When the outflow rack current is detected in at least one battery rack, by comparing the summed value of a plurality of inflow rack currents detected in the plurality of battery racks with the input current input through the input shunt, the flow of circulating current and calculating an amount of circulating current;
Control method of an energy storage device comprising a.
According to claim 6, The control method of the energy storage device,
Preventing more than a standard current from flowing into any battery rack based on the circulating current and the rack current;
Control method of the energy storage device, characterized in that it further comprises.
According to claim 6, The control method of the energy storage device,
Calculating the internal resistance of the rack for each of the plurality of battery racks using the circulating current and the rack current, and calculating the calorific value for each of the plurality of battery racks using the calculated internal resistance of the rack;
Control method of the energy storage device, characterized in that it further comprises.
The method of claim 8, wherein calculating the calorific value comprises:
Calculating the internal resistance for each of the plurality of battery racks using the voltage across the input terminal, the circulating current and the rack current; and
Calculating the calorific value for each of the plurality of battery racks using the circulating current, the rack current and the internal resistance of the battery rack;
Control method of an energy storage device comprising a.
10. The method of claim 9, wherein the control method of the energy storage device,
When the amount of heat of any battery rack exceeds a threshold criterion, stopping charging for the corresponding battery rack;
Control method of the energy storage device, characterized in that it further comprises.
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