KR102237845B1 - Method of protecting batteries by multiple pathes in an energy storage system - Google Patents

Abstract

The present invention relates to a multi-battery protection method of an energy storage system capable of preventing a fire or the like by protecting multiple batteries even when a communication failure of a battery management system occurs in an energy storage system. The multi-battery protection method of this embodiment includes a plurality of battery racks having a rack battery management device (R-BMS), a DC distribution rack having a master battery management device (M-BMS), and a power conversion device (PCS). In the battery protection method of the energy storage system, even when a communication failure occurs between the master battery management device (Master BMS) and the power conversion device (PCS) by connecting the battery rack and the power conversion device (PCS) through a third communication Each battery rack (Battery Rack) is transmitted to the power conversion device (PCS) through the third communication through the third communication, it is possible to continue charging and discharging control by the power conversion device (PCS).

Description

Method of protecting batteries by multiple pathes in an energy storage system

The present invention relates to a battery protection technology for an energy storage system, and more particularly, a method for protecting multiple batteries of an energy storage system capable of preventing a fire by protecting multiple batteries even when a communication failure of the battery management system occurs in the energy storage system. It is about.

In general, an ESS (Energy Storage System) is a system that can stably supply power according to a demand pattern by storing generated power.It stores excess power produced by a power plant and transmits it when power is temporarily insufficient. Refers to the storage device. Such an energy storage system does not directly deliver the power produced by a power plant to homes or factories, but stores energy in an energy storage means such as a large secondary battery, generates power at the time and place where power is most needed, and then transmits energy. It is a system that increases efficiency. The energy storage system is a key technology that is indispensable for the construction of a new and renewable energy system and smart grid that have recently emerged. Smart grid refers to an intelligent power grid that optimizes energy efficiency by grafting information technology to the existing one-way power grid, which was formed in the stages of power generation, transmission, and sales, and exchanges real-time information between power providers and consumers in both directions.

Typically, an energy storage system includes a battery system including a plurality of battery racks and a battery management system (BMS), a power conversion system (PCS), and an energy management system (EMS). do. The plurality of battery racks are for charging and storing energy and discharging and outputting energy when necessary, and the battery management system is for managing a plurality of battery racks, and the power conversion system connects to the grid, which is a power grid, and converts direct current into AC. It is for converting or converting alternating current to direct current and controlling charging and discharging of the battery, and the energy management system is for controlling the battery management system and the power conversion system in consideration of loads and battery conditions.

Each of the plurality of battery racks included in the battery system includes a plurality of battery trays, and each battery tray includes a plurality of battery cells. In general, when each of the plurality of battery cells included in the battery tray is charged significantly higher than the rated charging range, it may be dangerous, and when discharged below the rated charging range, the life of the battery may be shortened. The state of charge of the battery cells is unbalanced due to various factors, and mainly during manufacturing or during repetitive charging and discharging of the battery, the state of charge of the battery cells is unbalanced. When overcharging is performed due to the imbalance of the battery cells, a large accident such as a fire may occur.

In the battery system disclosed in Korean Patent Application Publication No. 10-2018-0079769, the rack BMS with the highest priority among the first to third rack BMS operates as the master BMS, and at this time, the master BMS is from the remaining rack BMS. The received information is integrated and provided to the power conversion system (PCS), but when an error occurs in the rack BMS with the highest priority, the next rack BMS with the highest priority operates as the master BMS to operate the battery system normally. It is to let you do.

An object of the present invention is to provide a multi-battery protection method of an energy storage system capable of preventing a fire by protecting multiple batteries even when a communication failure of a battery management system occurs in an energy storage system.

The multi-battery protection method of this embodiment includes a plurality of battery racks having a rack battery management device (R-BMS), a DC distribution rack having a master battery management device (M-BMS), and a power conversion device (PCS). In the battery protection method of the energy storage system, even when a communication failure occurs between the master battery management device (Master BMS) and the power conversion device (PCS) by connecting the battery rack and the power conversion device (PCS) through a third communication It is characterized in that it is possible to continue charging and discharging control by the power conversion device (PCS) by transmitting the abnormality of each battery rack (Battery Rack) to the power conversion device (PCS) through the third communication. The third communication may be either a controller area network (CAN) or a Modbus-TCP.

The method of protecting multiple batteries according to another embodiment includes the steps of sensing a cell voltage and temperature by a tray battery management device (Tray BMS) of each tray; A rack battery management device (RACK BMS) collecting and calculating the tray information, and detecting the rack voltage and current; Diagnosing, by the rack battery management device (RACK BMS), a state of a battery rack; If the battery rack is within the range of reference state information as a result of the diagnosis, and charging and discharging is possible, displaying a normal state and operating normally; And if the diagnosis result is a state in which charging and discharging is difficult outside the reference state range, generating an alarm, blocking the charging/discharging relay in case of a fault, and transmitting alarm information to the master battery management device.

The method of protecting multiple batteries according to another embodiment includes the steps of obtaining, by a master battery management device, information on each battery rack; A step of collecting and diagnosing all battery rack information by a master battery management device; As a result of the diagnosis, if the entire battery rack is within the reference state information range and charging/discharging is possible, the master battery management device displays a normal state in green on the operation state display screen and maintains the normal operation; And a step of displaying, by the master battery management device, on the operation display screen, and requesting the power conversion device to stop charging and discharging, if the battery rack is out of the range of the reference state information and charging/discharging is impossible.

The method of protecting multiple batteries according to another embodiment includes the steps of connecting each battery rack and a power converter through third communication; Each of the rack battery management devices diagnosing information obtained from the corresponding trays and, if the corresponding battery rack is in a charge/discharge state, transmitting a charge/discharge possible code to the power conversion device through the third communication; And if each rack battery management apparatus diagnoses the information obtained from the corresponding tray and the corresponding battery rack is in a state in which charging and discharging is impossible, transmitting a charge/discharge impossible code to the power conversion apparatus through the third communication.

According to an embodiment of the present invention, while the battery is primarily protected by the tray battery management device and the rack battery management device, the battery can be secondarily protected by the rack battery management device and the master battery management device. As a result, the batteries can be protected by the environmental management unit, and when a communication failure occurs in the battery management system, the power conversion device controls the charging and discharging of the battery through the third communication, thereby protecting the battery multiple times.

1 is an overall configuration diagram of an energy storage system to which an embodiment of the present invention is applied,
Figure 2 is an example of the tray shown in Figure 1,
Figure 3 is an example of the stack shown in Figure 2,
4 is a schematic configuration diagram of a DC distribution rack according to an embodiment of the present invention;
Figure 5 is a block diagram of the configuration of the environmental management unit shown in Figure 4;
6 is a flow chart showing a procedure for managing a battery by a rack battery management apparatus according to an embodiment of the present invention;
7 is a flow chart showing a procedure for managing a battery by a master battery management apparatus according to an embodiment of the present invention;
8 is a flow chart showing a battery management procedure through a third communication according to an embodiment of the present invention;
9 is an example of a screen displaying operating states of battery racks according to an embodiment of the present invention;
10 is an example of a communication frame format according to an embodiment of the present invention.

The present invention and the technical problems achieved by the implementation of the present invention will become more apparent by the preferred embodiments of the present invention described below. The following examples are merely illustrative for explaining the present invention, and are not intended to limit the scope of the present invention.

1 is an overall configuration diagram of an energy storage system to which an embodiment of the present invention is applied, FIG. 2 is an example of a battery tray shown in FIG. 1, and FIG. 3 is an example of a battery stack shown in FIG. 2.

The energy storage system to which the embodiment of the present invention is applied, as shown in FIG. 1, includes a plurality of battery racks 10-1 to 10-10, one DC distribution rack 20, and one power conversion device ( It includes a PCS; 30, and a third communication unit 40 connecting between the power conversion device (PCS) 30 and the rack battery management device (R-BMS) 210. In an embodiment of the present invention, 10 battery racks 10-1 to 10-10 are connected in parallel to one DC distribution rack 20 to form one battery bank, and each battery rack 10-1 ~10-10) is a lithium secondary battery system for ESS, 15 trays (120-1 to 120-15) are connected in series, and the battery is managed by communicating with the trays at the top or bottom of the rack in CAN method. A rack battery management device (R-BMS; 210) for doing so is provided.

In the embodiment of the present invention, each tray 120 is made of eight stacks 140, each stack 140 is made of eight battery cells 130 connected in series, and each of the battery cells 130 ) Has a capacity of 3.2V 30Ah. Therefore, one stack 140 has a capacity of 25.6V 30Ah, but when two are connected in series, it has a capacity of 51.2V 30Ah. In the tray 120 of the present embodiment, four stacks 140 connected in series with each other are connected in parallel to form a 16S4P structure, thus providing a capacity of 51.2Vx120Ah = 6.144KWh. In addition, one battery rack 10-1 to 10-10 may provide a capacity of 768V x 120Ah =92.16 Kw by connecting 15 trays 120 in series.

The entire battery management system includes a rack battery management device (R-BMS; 210) installed in each battery rack (10-1 to 10-10), and a master battery management device (M-BMS; 220) installed in the DC distribution rack (20). It can be configured as a hierarchical structure or a master/slave structure, and a battery management device (BMS) is implemented in each tray. In an embodiment of the present invention, the battery management device (BMS) of the tray and the rack management device (R-BMS) 210 are connected by a CAN method, and the rack battery management device of each battery rack (10-1 to 10-10) 210 may be connected to the master battery management device 220 and the Modbus-TCP method, the master battery management device 220 may be connected to the power conversion device (PCS) 30 and the Modbus-TCP method. Such a battery management system (BMS) measures values such as voltage, current, and temperature of a battery cell so that the battery can be safely and efficiently used, and controls the charging/discharging current through communication with a power conversion device (PCS; 30). In case of abnormal operation, it provides protection function. For example, when the battery is charged, battery balancing is also performed in the BMS. As a balancing method, a passive cell balancing method using a discharge method by resistance and an active cell balancing method using a DC converter are widely known. In the passive cell balancing method, information on the voltage deviation between cells is obtained through real-time voltage measurement, and whether or not the balancing operation is performed is determined based on this value.

The DC distribution rack 20 classifies data transmitted from R-BMS (Rack BMS; 210) and displays them on a screen, and includes an M-BMS 220 that transmits the converted data to the PCS 30, and sensors. It includes an environmental management unit 230 that monitors the current voltage and environmental conditions, and a DC distribution panel 240 that distributes DC power between the PCS 30 and each BAT-RACK (10-1 to 10-10). , Provides an additional function of protecting the battery by connecting or disconnecting DC power according to the control of the environmental management unit 230.

The power converter (PCS) 30 converts DC power stored in the battery into AC to supply power to the power system, or converts AC power from the power system to DC and stores power in the battery.

The third communication unit 40 is a multiple communication line for directly connecting the power conversion device 30 and the rack battery management device 210, and may be wired or wireless, but preferably, CAN, Modbus-TCP, etc. can be used. have.

Fig. 2 shows the tray of this embodiment. As shown in FIG. 2, the tray 120 may be formed in a rectangular parallelepiped structure having a stack 140 accommodating space therein. A separate cover may be installed on the open top of the tray 120. Two terminal portions 180 electrically connected to the stack 140 are spaced apart and installed on the front of the tray 120. The two terminal portions 180 may be, for example, a positive terminal portion connected to the positive electrode of the stack 140 and a negative terminal portion connected to the negative electrode of the stack 140. Hereinafter, the term terminal 180 may refer to both a positive terminal portion and a negative terminal portion.

A management circuit unit 122 connected to the stack 140 to manage the battery cells 130 may be installed at the front center of the tray 120. In addition, handles 124 that can be used when inserting or withdrawing the tray 120 into or withdrawal from the tray 120 may be further installed at both front ends of the front of the tray 120.

Each tray 120 loaded in the box is electrically connected through a connection bar installed between the terminal units 180. For example, a connection bar may be connected and installed between the positive terminal portion of one tray 120 and the negative terminal portion of the adjacent tray 120. Accordingly, each tray 120 may be connected in series within the enclosure. A plurality of stacks 140 are loaded inside the tray 120, and each stack 140 is electrically connected.

In the apparatus of the present embodiment, as shown in FIG. 2, eight stacks 140 may be disposed in a symmetrical form in one tray 120 to be stacked. The number or arrangement structure of the stacks 140 loaded in the tray 120 can be variously modified. Inside the tray 120, each stack 140 may be connected in series. Of the stacks 140 connected in series, the anode and the cathode of the stack 140 located at the ends are respectively connected to the two terminal portions 180 of the tray 120. Accordingly, it is possible to store or withdraw power to each stack 140 loaded on the tray 120 through the terminal unit 180. Each of the stacks 140 loaded in the tray 120 may have the same structure.

As shown in FIG. 3, the stack 140 of the present embodiment supports and supports the battery cells 130 and is stacked with each other in the vertical direction to form a space for accommodating the battery cells 130 therebetween, An electrical connection part for electrically connecting the positive terminal 132 and the negative terminal 134 of each battery cell 130 accommodated in the pallet 150 may be included. The stack 140 may be formed by stacking a plurality of pallets 150 on which the battery cells 130 are supported. Accordingly, the plurality of battery cells 130 are stably supported between the pallets 150, so that the stack 140 can be formed by being stacked up and down. Each of the plurality of pallets 150 constituting the stack 140 may be formed in the same shape.

Referring to FIG. 3, the pallet 150 of the present embodiment is integrally formed at both ends of the plate 152 and the plate 152 on which the battery cells 130 are placed and supported, and protrudes in the vertical direction to neighboring pallets ( 150) and at least one protrusion 156 that is formed on both sides of the support 154 and the support 154 to maintain a gap between the plate 152 and the plate 152 and is coupled to the neighboring pallet 150, It may include a groove (157).

The plate 152 is a plate structure having a thin thickness, and may be formed to have a size corresponding to the battery cell 130 in the form of a pouch of an approximately square plate. A hole having a size smaller than that of the battery cell 130 may be formed in the center of the plate 152. Accordingly, while the weight of the pallet 150 can be minimized, the battery cell 130 can be stably supported and supported.

The support 154 is integrally formed at both ends of the plate 152. The support part 154 is formed thick so as to protrude in the vertical direction with respect to the plate 152 to form a portion formed relatively high on the surface of the plate 152.

Accordingly, when the pallets 150 are stacked in the vertical direction, the support portions 154 of the pallets 150 adjacent to each other come into contact with each other, and there is a space between the plates 152 and the plates 152 of the neighboring pallets 150. Is formed. Accordingly, when the pallets 150 are stacked, the battery cells 130 can be stably placed in a space provided between the plates 152 and the plates 152 of the adjacent pallets 150. The protruding height of the support part 154 with respect to the plate 152 may be variously modified according to the thickness of the battery cell 130.

In addition, unlike the front and rear surfaces of the stack 140 (faces facing the x-axis direction in FIG. 3), which are in close contact with each other by the support 154, the side surfaces of the stack 140 (surfaces facing the z-axis direction in FIG. 3) Between the plate 152 and the plate 152 is open. Accordingly, when the battery cells 130 are supported by the pallet 150, heat generated from the battery cells 130 may be more easily radiated through the side of the stack 140 that is open.

A protrusion 156 and a groove 157 may be formed on the upper and lower surfaces of the support 154, respectively. The protrusion 156 is formed to protrude outward from the upper surface of the support part 154, and the groove part 157 is formed to be recessed inward from the lower surface of the support part 154. In this embodiment, the protrusion 156 and the groove portion 157 may be formed to face both surfaces of the support portion 154 at the same position with each other. The protrusion 156 may be formed to have a size that can be forcefully fitted to the groove 157. The protrusion 156 and the groove 157 may be formed, for example, on the front edge of the support 154. The positions or the number of formations of the protrusions 156 and the grooves 157 can be variously modified.

The electrical connection part of this embodiment is electrically connected at the junction 160 of the pallet 150 by drawing the positive terminal 132 and the negative terminal 134 of the battery cell 130 toward the front of the pallet 150, and each junction A separate connection plate 164 may be installed between 160 to be electrically connected.

The bonding portion 160 may be formed on the front surface of the support portion 154 of the pallet. The positive terminal 132 or the negative terminal 134 of the adjacent battery cells 130 are electrically connected to each other with the pallet between the junction 160. A bolt fastening hole 161 may be formed in the junction 160 so that a bolt 165 for fixing a terminal may be fastened.

The positive terminal 132 and the negative terminal 134 of the battery cell 130 disposed above and below the pallet 150 having the junction 160 formed therebetween are formed to be bent toward the junction 160, respectively. Accordingly, the positive terminal 132 and the negative terminal 134 between the battery cells 130 adjacent to each other at the junction 160 may be overlapped according to their polarity to be electrically connected. For example, on the pallet 150, two junctions 160 are formed to be spaced apart according to the positions of the positive terminal 132 and the negative terminal 134 of the battery cell 130. The two battery cells 130 arranged vertically with the pallet 150 interposed therebetween are arranged such that terminals of the same polarity face each other. Accordingly, the positive terminal 132 and the positive terminal 132 of the two adjacent battery cells 130 are bent and connected to one junction 160 at the same position, and the negative terminal 134 and the negative terminal 134 are also different. The side joint 160 is bent and joined. Accordingly, terminals of the same polarity are joined to the junction unit 160. In this way, it is possible to configure the stack 140 with a desired power capacity by easily connecting in parallel between neighboring battery cells 130 with the pallet 150 interposed therebetween.

In this embodiment, the positive terminal 132 and the negative terminal 134 of the neighboring battery cells 130 are aligned with the fastening hole 161 of the junction 160 on the surface overlapping each other, and the hole 162 This can be formed through. Thus, the bolt 165 passes through the hole 162 of the anode terminal 132 and the cathode terminal 134 and is fastened to the fastening hole 161 in the junction 160 to the anode terminal 132 and the cathode terminal 134 Is fixed by bonding.

A connection plate 164 is installed between the junction 160 and the junction 160 and between the stack 140 and the junction 160 of the stack 140 to electrically connect the adjacent junction 160. The connection plate 164 has a hole formed at a position corresponding to the fastening hole 161 of the junction 160 so that the bolt 165 can pass therethrough. Accordingly, the connection plate 164 is fixed to the junction 160 of the pallet 150 via bolts 165. The bolt 165 pressurizes the connection plate 164 to the joint 160. As the connection plate 164 is pressed by the bolt 165, the positive terminal 132, the negative terminal 134, and the positive plate 164 of the adjacent battery cells 130 are closely pressed and electrically connected to each other.

In this way, the positive terminal 132 and the negative terminal 134 of the stacked battery cells 130 are bent into two junctions 160 of the pallet 150 positioned therebetween, and bonded to each other between the terminals, and the stack 140 By connecting the connection plates 164 between them, it is possible to more easily electrically connect each battery cell 130 of the stack 140.

In addition, as shown in FIG. 3, pins 166 may be protruded on the front surface of the support part 154 of the pallet 150 so that the connection plate 164 can be installed at the correct position on both sides of the bonding part 160. A pinhole is formed in the connection plate 164 at a position corresponding to the pin 166. Accordingly, when the pin hole formed in the connection plate 164 is fitted in accordance with the pins 166 formed on the pallet 150, the connection plate 164 is accurately aligned with the installation position of the pallet 150. In this state, it is possible to easily fix and install the connection plate 164 to the junction 160 of the pallet 150 with bolts. The connection plate 164 is a plate structure, and may be formed in various sizes according to a position installed in the stack 140 or an electrical connection structure between the stacks 140.

4 is a schematic configuration diagram of a DC distribution rack according to an embodiment of the present invention, and FIG. 5 is a configuration block diagram of the environment management unit shown in FIG. 4.

The DC distribution rack 20 according to the embodiment of the present invention is a DC power line connected to each battery unit rack 10-1 to 10-10 from a power conversion device (PCS) 30, as shown in FIG. 4. A fuse 241 connected in series to, a disconnect switch 242 for connecting or disconnecting a DC power line under the control of an environmental management unit (EMU) 230, and a voltage sensor for detecting the voltage of the DC power line ( 243), a current sensor 244 for sensing the current of the DC power line, a surge protection device (SPD; 240a), a flood sensor 245, a door opening sensor 246, a fire sensor 247, a temperature sensor 248 ), LED 249, an environmental management unit 230 that controls to cut off the power of the battery side and the load side through a cut-off switch 242 to protect the battery when overcharging or overdischarging is detected by receiving a detection signal from the sensors. , Consisting of a network switch 231 for connecting the environmental management unit 230 to the master battery management device 220.

Referring to FIG. 4, a surge protect device (SPD) is a device for attenuating a surge voltage when a surge exceeds the system maximum operating voltage to a power line, and a voltage sensor 243 and a current sensor 244 ) Is a sensor to detect the voltage and current of the DC power line. The immersion sensor 245 is a sensor for detecting inundation at the installation location, the door opening sensor 246 is a sensor for detecting the opening of the door of the DC distribution rack 20, and the LED 249 is a sensor for detecting the opening of the door. This is an indicator to indicate this. The fire sensor 247 detects a fire, and the temperature sensor 248 detects the temperature of the installation environment and provides it to the environmental management unit 230.

The environment management unit (EMU; 230), as shown in Figure 5, the communication unit 232 for communicating with the master battery management device 220, a storage unit 234 for storing various data, a power supply unit 235 , The state acquisition unit 236 for receiving detection values from each sensor, the switch driving unit 237 for driving the cut-off switch 242, the state acquisition unit 236 diagnoses the state with the data obtained from the emergency When it is determined, it consists of a control unit 233 that controls the switch driving unit 237 to trip the cut-off switch 242 and transmits the sensing data and operation status to the master battery management device (M-BMS) 220 through the communication unit 232 do.

This environmental management unit 230 is obtained after acquiring the status of the DC distribution panel 240, that is, voltage, temperature, current, flooding, fire, SPD, door open, and emergency stop switch status from the status acquisition unit 236. In addition to transmitting information to the M-BMS 220, the state of the DC distribution panel 240 is diagnosed, and if the result of the diagnosis is within the range of the reference state information and charging/discharging is possible, maintain a normal state, and When this is detected, the disconnection switch 242 is tripped through the switch driving unit 237 to cut off the connection between the battery rack units 10-1 to 10-10 and the PCS 30, and stop charging and discharging.

6 is a flow chart showing a battery management procedure by the rack battery management apparatus according to an embodiment of the present invention.

Referring to FIG. 6, a tray battery management device (Tray BMS) of each tray 120 senses a cell voltage and temperature (S101). As described above, the tray 120 is made of eight stacks, and each stack is made of eight battery cells. In this embodiment, each cell has a voltage of 3.2V, an overcharge cut-off voltage of 3.65±0.05V, and an overdischarge cut-off voltage of 2.0V. In addition, each tray 120 has a voltage of 51.2V, an overcharge cut-off voltage of 56.8±0.05V, and an overdischarge cut-off voltage of 44.8V.

The rack battery management device (RACK BMS) 210 collects and calculates the tray information, and detects the rack voltage and current (S102). In this embodiment, each of the battery racks 10-1 to 10-10 has a voltage of 768V, a charge cut-off voltage of 852.0±0.05V, and an overdischarge cut-off voltage. Voltage) is 672.0V.

Then, the rack battery management device (RACK BMS) diagnoses the state of the battery rack (S103). Diagnosis of the battery rack state is to determine whether the measured voltage is out of the range of the overcharge cutoff voltage or the overdischarge cutoff voltage or the allowable operating temperature range.

As a result of the diagnosis, if the battery rack is within the reference state information range, and charging and discharging is possible, a normal state is displayed and normal operation (S104, S105).

As a result of the diagnosis, if charging/discharging is difficult outside the standard state range, an alarm is generated, the charging/discharging relay is cut off when a fault occurs, and the alarm information is transmitted to the master battery management device (M-BMS) (S106 to S108).

7 is a flowchart illustrating a procedure for managing a battery by a master battery management apparatus according to an embodiment of the present invention.

Referring to FIG. 7, a master battery management apparatus (M-BMS) 220 acquires each battery rack information (S201). The master battery management device 220 and the rack battery management device 210 are connected in a Modbus-TCP manner to transmit data in a frame format as shown in FIG. 10. Referring to FIG. 10, a Check Charge Ready Frame, a Check Discharge Frame, a Request frame between a Master and a Slave, and a Response frame structure from a Slave to a Master are illustrated.

The master battery management device (M-BMS) 220 collects all battery rack information (S202).

As a result of the diagnosis of the master battery management device (M-BMS; 220), if the entire battery rack is within the reference state information range, and charging and discharging is possible, the normal state is displayed in green on the operation state display screen as shown in FIG. 9 and normal operation is performed. Maintain (S203, S204). Referring to FIG. 9, on the operation display screen, numerical values such as connection status, voltage, temperature, etc. of each rack, and alarm states such as high temperature, low temperature, overvoltage, and overcurrent are displayed in green, yellow, and red colors.

As a result of the diagnosis of the master battery management device (M-BMS; 220), if the battery rack is out of the reference state information range and charging/discharging is impossible, a request for charging/discharging stop is requested to the power conversion device (PCS), and the operation is displayed as shown in FIG. Red or emergency status is displayed on the screen (S205). The power conversion device (PCS) 30 stops charging and discharging at the request of the master battery management device 220 (S206).

As described above, since the master battery management device 220 cannot directly cut off the DC power line, it requests a power conversion device (PCS) or another control device to block charging and discharging.

8 is a flowchart illustrating a battery management procedure through a third communication according to an embodiment of the present invention.

Referring to FIG. 8, each of the battery racks 10-1 to 10-10 and the PCS 30 are connected to the third communication 40 (S301).

Each rack battery management device 210 diagnoses the information obtained from the corresponding tray 120, and if each of the battery racks 10-1 to 10-10 is in a charge/discharge state, the PCS ( 30), the charge/discharge code is transmitted (S302, S303).

Each rack battery management device 210 diagnoses the information obtained from the corresponding tray 120, and if each battery rack is in a state in which charging and discharging is impossible, the charging/discharging code is transmitted to the PCS 30 through the third communication 40. Transmit (S304).

As described above, according to an embodiment of the present invention, the battery rack (Battery Rack; 10-1 to 10-10) and the power conversion device (PCS; 30) are connected through the third communication 40 to the master battery management device (Master BMS). ;220) and power converter (PCS;30) communication (1st, 2nd communication) error occurs in each battery rack (Battery Rack; 10-1~10-10) It can be transmitted to the power conversion device (PCS) 30 to continue charging and discharging control by the power conversion device (PCS) 30.

In the above, the present invention has been described with reference to an embodiment shown in the drawings, but those of ordinary skill in the art will understand that various modifications and other equivalent embodiments are possible therefrom.

10-1~10-10: Battery rack 20: DC distribution rack
30: power conversion device (PCS) 40: 3rd communication department
120: tray 210: rack battery management device (R-BMS)
220: master battery management device (M-BMS) 230: environmental management unit 230
240: DC distribution board

Claims (5)

A plurality of battery racks (10-1 to 10-10) with a rack battery management device (R-BMS), a DC distribution rack (20) with a master battery management device (M-BMS), and a power converter (PCS) In the battery protection method of the energy storage system comprising; 30),
By connecting the battery rack and the power conversion device (PCS) through a third communication 40
Even when a communication failure occurs between the master battery management device (Master BMS) 220 and the power conversion device (PCS; 30), the power conversion device is used to determine whether or not there is an abnormality in each battery rack through the third communication (40). By transmitting to (PCS), it is possible to continue charging and discharging control by the power conversion device (PCS),
The third communication
Either CAN or Modbus-TCP,
Detecting a cell voltage and temperature by a tray battery management device (Tray BMS) of each tray 120;
Calculating, by a rack battery management device (RACK BMS) 210, collecting and calculating tray information from the tray battery management device, and detecting a corresponding rack voltage and current;
Diagnosing, by the rack battery management device (RACK BMS) 210, a state of a corresponding battery rack;
If the battery rack is within the range of the reference state information as a result of the diagnosis, and charging and discharging is possible, displaying a normal state and operating normally; And
As a result of the diagnosis, if the battery rack is in a state in which charging and discharging is difficult outside the reference state range, generating an alarm, blocking the charging/discharging relay in case of a fault, and transmitting alarm information to the master battery management device 220;
Obtaining, by the master battery management device 220, each battery rack information from each rack battery management device;
The master battery management device 220 collecting and diagnosing all battery rack information;
As a result of the diagnosis, if the entire battery rack is within the reference state information range and charging/discharging is possible, the master battery management device 220 displays a normal state in green on the operation state display screen and maintains normal operation; And
As a result of the diagnosis, if any one of the battery racks is out of the reference state information range and charging/discharging is impossible, the master battery management device displays this on an operation display screen, and requests the power conversion device to stop charging and discharging;
Connecting each of the battery racks and the power conversion device through third communication;
Each rack battery management device diagnosing information obtained from the corresponding trays and, if the corresponding battery rack is in a charge/discharge state, transmitting a charge/discharge possible code to the power conversion device through the third communication; And
An energy storage system comprising the step of transmitting a charge/discharge code to the power conversion device through the third communication when each rack battery management device diagnoses the information obtained from the corresponding tray and the corresponding battery rack is in a state that cannot be charged or discharged. Battery multiple protection method delete delete delete delete

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