KR20210036053A - Abnormal condition detection system using battery voltage data - Google Patents

Abstract

An embodiment of the present invention relates to an abnormal condition pre-detection system, and a technical object to be solved is to provide an abnormal condition pre-detection system, which detects a precursor phenomenon related to an abnormality of a battery using various temperature data of the battery and warns a user or stops the system operation to improve the system safety. According to the present invention, disclosed is the abnormal condition pre-detection system using battery temperature data, comprising: a temperature sensing unit sensing the temperature of each of the battery cells and providing battery temperature data for each of the battery cells; a temperature calculation unit including a temperature deviation calculation unit for calculating a temperature deviation (Ta) between each battery cell from the battery temperature data, a temperature change calculation unit for calculating a temperature change (Tb) of each battery cell over time from the battery temperature data, and a temperature deviation change calculation unit for calculating a temperature deviation change (Tc) of each battery cell over time from the battery temperature data; and an action signal output unit outputting a system action signal by comparing the temperature deviation (Ta), the temperature change (Tb), or the temperature deviation change (Tc) with a reference value.

Description

Abnormal condition detection system using battery voltage data

An embodiment of the present invention relates to a system for detecting an abnormal condition in advance using battery temperature data.

In general, the energy storage system (ESS) stores energy produced in the renewable energy market such as solar and wind power in a storage device (eg, battery) and supplies electricity to the required time period, resulting in efficient use of power. It means a device that improves.

These energy storage devices largely include batteries, PCS (Power Conversion System, AC-DC conversion function and distribution function), EMS (Energy Monitoring System, which operates and manages the entire ESS system), and the like. Here, the battery is monitored and managed for voltage, temperature, etc. by a BMS (Battery Management System), and the BMS exchanges necessary information with the PCS and/or EMS.

On the other hand, batteries include secondary batteries such as lithium ion batteries and lithium polymer batteries in recent years.Since the main material of these secondary batteries is lithium, which is unstable in the air, securing safety such as preventing deterioration, ignition or explosion of the battery is more important than anything else. It is important.

However, in the conventional ESS, when the voltage or temperature of the battery is out of the standard range, BMS, PCS and/or EMS operate to stop the charging/discharging of the battery, and perform a system warning or stop the operation of the system. By doing so, not only the safety of the ESS is low, but there is a problem that even a fire occurs in the ESS. In other words, the safety of the ESS can be further improved if a warning is given to the system or the operation of the system is stopped by detecting a pre-warning phenomenon before the voltage or temperature goes out of the standard range due to an abnormality of the battery. No technology has been developed that detects the occurrence of a precursor in the event of a battery abnormality and prevents future problems.

The above-described information disclosed in the technology that serves as the background of the present invention is only for improving an understanding of the background of the present invention, and thus may include information that does not constitute the prior art.

The problem to be solved according to an embodiment of the present invention is a battery temperature capable of improving system safety by detecting a precursor phenomenon related to an abnormality of the battery using various temperature data of the battery and warning the user or stopping the system operation. It is to provide a system for detecting abnormal conditions in advance using data.

An abnormal condition pre-detection system using battery temperature data according to an embodiment of the present invention includes: a temperature sensing unit that senses voltages of each of a plurality of battery cells and provides battery temperature data for each of the plurality of battery cells; A temperature deviation calculator configured to calculate a temperature deviation (Ta) between each battery cell from the battery temperature data; A temperature change calculator configured to calculate a temperature change (Tb) of each battery cell over time from the battery temperature data; A temperature calculation unit including a temperature deviation change calculation unit that calculates a temperature deviation change Tc of each battery cell according to the passage of time from the battery temperature data; And a measure signal output unit configured to output a system measure signal by comparing the temperature deviation (Ta), the temperature change (Tb), or the temperature deviation change (Tc) with a reference value.

The system action signal of the action signal output unit is a system warning signal that analyzes detailed battery operation data to determine whether an abnormality has occurred, a system danger signal that takes action on the checked abnormal area, or a system that shuts down the system. It may be a shutdown signal.

A reference value set for outputting the system shutdown signal may be higher than a reference value set for outputting the system warning signal and the system danger signal.

The temperature calculation unit may operate in an SOC ± 10% period centering on a time to enter a constant voltage charging period when charging the battery cell.

The temperature calculator may operate in a range of 5% to 30% of the remaining SOC when the battery cell is discharged.

The plurality of battery cells may include battery cells connected in series or battery cells connected in parallel.

The temperature calculator may determine whether an abnormality has occurred by considering a temperature of a battery cell together with a ratio (Tb/Tc) of a change in temperature deviation with respect to the temperature change.

An embodiment of the present invention detects a precursor phenomenon related to an abnormality of a battery using various temperature data of a battery, and warns a user or stops an operation of the system, thereby improving system safety. Provides a detection system.

1 is a schematic diagram showing the configuration of a general ESS system.
2A and 2B are schematic diagrams illustrating a configuration example of a battery used in a system for detecting an abnormal condition in advance using battery temperature data according to an exemplary embodiment of the present invention.
3 is a block diagram showing the configuration of a system for detecting an abnormal state in advance using battery temperature data according to an embodiment of the present invention.
4 is a block diagram showing the configuration of a temperature calculation unit and a measure signal output unit in a system for detecting an abnormal state in advance using battery temperature data according to an exemplary embodiment of the present invention.
5 is a graph showing a change in a battery voltage and a position of determining an abnormal condition for explaining the operation of an abnormal condition pre-detection system using battery temperature data according to an exemplary embodiment of the present invention.
6A and 6B are diagrams and graphs illustrating a temperature change according to a cycle of a bank in one of a plurality of module trays constituting a rack.
7A and 7B are diagrams and graphs showing temperature changes according to cycles of a bank having a problem and a bank having a problem in the module tray.
8A and 8B are diagrams and graphs showing a temperature change Tb and a temperature deviation change Tc of a battery cell according to cycles in a bank having a problem in a module tray and a bank in a normal state.

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

The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete, and to fully convey the spirit of the present invention to those skilled in the art.

In addition, in the following drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description, and the same reference numerals refer to the same elements in the drawings. As used herein, the term “and/or” includes any and all combinations of one or more of the corresponding listed items. In addition, the meaning of "connected" in the present specification means not only the case where the member A and the member B are directly connected, but also the case where the member A and the member B are indirectly connected by interposing a member C between the member A and the member B. do.

The terms used in this specification are used to describe specific embodiments, and are not intended to limit the present invention. As used herein, the singular form may include the plural form unless the context clearly indicates another case. In addition, when used herein, "comprise, include" and/or "comprising, including" refers to the mentioned shapes, numbers, steps, actions, members, elements, and/or groups thereof. It specifies existence and does not exclude the presence or addition of one or more other shapes, numbers, actions, members, elements, and/or groups.

In this specification, terms such as first and second are used to describe various members, parts, regions, layers and/or parts, but these members, parts, regions, layers and/or parts are limited by these terms. It is self-evident that it should not be. These terms are only used to distinguish one member, part, region, layer or portion from another region, layer or portion. Accordingly, a first member, component, region, layer or part to be described below may refer to a second member, component, region, layer or part without departing from the teachings of the present invention.

1 is a schematic diagram showing the configuration of a general ESS system.

As shown in FIG. 1, the ESS system receives and stores energy from a renewable energy source, and may include a battery having a BMS, a PCS, and an EMS for this purpose. BMS is a device that controls the state of the battery. Cell balancing that monitors the voltage, temperature, and charge/discharge status of the battery and adjusts the degree of charge/discharge between unit battery cells in the module to be the same, prevents overcharging and over-discharge for the safety of the battery. It performs protection functions such as electric discharge prevention, and also blocks the main switch in case of overcurrent or short circuit through a protection circuit, and also serves to communicate with PCS and EMS. In some examples, the battery may include a lithium ion battery, a lithium iron phosphate battery, a lithium polymer battery, or a lithium metal battery. PCS can receive electrical energy from a renewable energy source or system to charge the battery or convert the characteristics of electricity (AC/DC, voltage, frequency, etc.) to discharge the energy stored in the battery into the system. The EMS (or PMS) monitors/controls the state of the battery and PCS, and may include an operating system for integrated monitoring and control of the ESS in a control center or the like.

2A and 2B are schematic diagrams illustrating a configuration example of a battery used in a system for detecting an abnormal condition in advance using battery temperature data according to an exemplary embodiment of the present invention.

As shown in FIG. 2A, the battery 10 referred to in the abnormal state pre-sensing system according to an embodiment of the present invention may include a configuration in which a plurality of battery cells are connected in parallel. In some examples, battery cells S11, S12, S13, S14 are connected in parallel to form a first bank (S1), and battery cells S21, S22, S23, S24 are connected in parallel to form a second bank (S2). Battery cells S31, S32, S33, S34 are connected in parallel to form a third bank (S3), and battery cells S41, S42, S43, S44 are connected in parallel to form a fourth bank (S4). have. Here, the first to fourth banks S1 to S4 may be connected in series. In addition, as shown in FIG. 2B, the battery 10 referred to in the abnormal state pre-detection system according to an embodiment of the present invention may include a configuration in which a plurality of battery cells are connected in series. In some examples, the first battery cell S1, the second battery cell S2, the third battery cell S3, and the fourth battery cell S4 may be connected in series.

3 is a block diagram showing the configuration of an abnormal state pre-detection system 100 using battery temperature data according to an embodiment of the present invention, and FIG. 4 is a block diagram illustrating an abnormal state dictionary using battery temperature data according to an embodiment of the present invention. A block diagram showing the configuration of the temperature calculation unit 120 and the action signal output unit 130 of the detection system 100.

As shown in FIG. 3, the abnormal state pre-detection system 100 according to an embodiment of the present invention may include a temperature sensing unit 110, a temperature calculation unit 120, and a measure signal output unit 130. .

In some examples, the abnormal state pre-detection system 100 according to an embodiment of the present invention may further include an SOC estimating unit 140, a time estimating unit 150, and/or a reference value storage unit 160.

The temperature sensing unit 110 may sense voltages of each of the plurality of battery cells and provide battery temperature data for each of the plurality of battery cells to the temperature calculator 120. For example, referring again to FIG. 2A, the temperature sensing unit 110 may sense the temperatures of the first banks S1 to the second banks S4, respectively, and provide the temperature to the temperature calculator 120. As another example, referring again to FIG. 2B, the temperature sensing unit 110 may sense the temperatures of the first to fourth battery cells S1 to S4, respectively, and provide them to the temperature calculator 120. have.

The temperature calculation unit 120 may include a temperature deviation calculation unit 121, a temperature change calculation unit 122, and a temperature deviation change calculation unit 123, as illustrated in FIGS. 3 and 4.

The temperature deviation calculation unit 121 may calculate a temperature deviation Ta between each battery cell from the battery temperature data provided from the temperature sensing unit 110 and provide it to the action signal output unit 130. The temperature change calculation unit 122 calculates the temperature change (Tb) of each battery cell according to the lapse of time of each battery cell from the battery temperature data provided from the temperature sensing unit 110 and/or the temperature deviation calculation unit 121 And it can be provided to the action signal output unit 130. The temperature deviation change calculation unit 123 includes each battery according to the passage of time of each battery cell from the battery temperature data provided from the temperature sensing unit 110, the temperature deviation calculation unit 121, and/or the temperature change calculation unit 122. The temperature deviation change Tc of the cell may be calculated and provided to the action signal output unit 130.

The action signal output unit 130 outputs a system action signal when the temperature deviation (Ta), the temperature change (Tb) and/or the temperature deviation change (Tc) provided from the temperature calculation unit 120 deviates from a preset reference value. can do.

In some examples, the system action signal output from the action signal output unit 130 may include a system warning signal, a system danger signal, and/or a system shutdown signal.

In some examples, the system warning signal may include a signal to analyze detailed battery operation data to determine whether an actual abnormality has occurred, which may be provided to the EMS. Accordingly, the EMS may visually or audibly notify the administrator of this state through the system screen.

In some examples, the system danger signal may include a signal to take action on an abnormal site that has been checked, which may be provided to the EMS. Accordingly, the EMS may visually or audibly notify the administrator of this state through the system screen.

In some examples, the system shutdown signal may include a signal that causes the ESS system to shut down and cease use for any cause. Such a system shutdown signal may be provided to the BMS, PCS and/or EMS, thereby allowing the BMS, PCS and/or EMS to turn off the main switch to completely stop charging and discharging the battery cells. Of course, system shutdown information may be provided visually or aurally to the administrator through the EMS system screen.

The SOC estimating unit 140 may estimate the remaining capacity of the battery cell based on the voltage information of the battery cell, and provide this to the temperature calculator 120. In some examples, the SOC estimating unit 140 may provide the SOC estimated through another algorithm (eg, Kalman filter, screen, OCV) to the temperature calculator 120 without using the voltage information of the battery cell. have.

The time estimating unit 150 may estimate the usage time of the ESS system and provide this to the temperature calculation unit 120. In some examples, the time estimating unit 150 may estimate the use date and/or the number of charge/discharge cycles of the ESS system and provide the estimates to the temperature calculation unit 120.

The reference value storage unit 160 stores in advance a reference value for a temperature deviation (Ta), a reference value for a temperature change (Tb), and/or various reference values for a temperature deviation change (Tc). Can be provided to.

In this way, the embodiment of the present invention detects a precursor phenomenon related to an abnormality of the battery using various temperature data of the battery, and warns the administrator or user, or stops the system operation, thereby improving system safety. An abnormal state pre-detection system 100 using data may be provided.

5 is a graph showing a change in battery temperature and an abnormal situation determination position for explaining the operation of the abnormal state pre-detection system 100 using battery temperature data according to an exemplary embodiment of the present invention. In FIG. 5, the X-axis may indicate elapsed time, and the Y-axis may indicate voltage and temperature, respectively. In addition, the elapsed time of the X-axis may be divided into constant current (CC) charging, constant voltage (CV) charging, pause, and discharge.

As shown in FIG. 5, the battery voltage gradually increases over time in the CC charging period, and can maintain a constant value despite the passage of time in the CV charging period and the idle period. Can decrease.

In addition, as shown in FIG. 5, the battery temperature gradually increases with time in the CC charging period, gradually decreases with time in the CV charging period and the idle period, and may gradually increase with the passage of time in the discharge period. .

Here, the abnormal state pre-sensing system 100 according to an embodiment of the present invention does not continuously calculate the temperature using the detected battery temperature, but, for example, performs voltage calculation in approximately two regions over time. I can.

In some examples, the temperature calculation unit 120 may operate at a point where the difference in temperature is greatest or the temperature is highest. In some examples, the temperature calculation unit 120 may operate in the SOC ± 10% period centering on the entry time of the constant voltage charging period when charging the battery cell. In other examples, the temperature calculation unit 120 may operate in a range of 5% to 30% of the remaining SOC when the battery cell is discharged, or may operate at the time of the type of charge. Here, the temperature calculation unit 120 may obtain the remaining amount of SOC from the SOC estimating unit 140, but the present invention is not limited thereto.

Meanwhile, as described above, in the present invention, a reference value for a temperature deviation (Ta), a reference value for a temperature change (Tb), and/or various reference values for a temperature deviation change (Tc) can be set in advance. Warning signals, system danger signals and/or system shutdown signals can be output.

In some examples, a reference value for the temperature deviation Ta and an output signal therefor may be set as follows. These examples are only examples for the understanding of the present invention, and the present invention is not limited to the numerical ranges to be described below.

In the set charging section shown in FIG. 5, when the temperature deviation Ta by the temperature deviation calculating unit 121 is from about 5°C to about 20°C set as a reference value, and in the set discharge section shown in FIG. 5, the temperature When the temperature deviation Ta by the deviation calculation unit 121 is approximately 5° C. to approximately 20° C. set as a reference value, the action signal output unit 130 may output a system warning signal and/or a system danger signal.

In addition, in the set charging section shown in FIG. 5, when the temperature deviation Ta by the temperature deviation calculating unit 121 is approximately 10° C. to 20° C. set as a reference value, and the temperature in the set discharge section shown in FIG. 5 When the deviation Ta is 10°C to 20°C set as the reference value, the action signal output unit 130 may output a system shutdown signal.

Here, referring again to FIGS. 2A and 2B, the temperature deviation Ta may mean a difference between the maximum voltage and the minimum voltage of the battery cells S1, S2, S3, and S4.

In some examples, a reference value for a temperature change Tb and a temperature deviation change Tc, and an output signal therefor may be set as follows. These examples are only examples for the understanding of the present invention, and the present invention is not limited to the numerical ranges to be described below.

In the set charging section shown in FIG. 5, the temperature calculation unit 120 determines the temperature deviation change Tc of the individual cells of each bank after a certain period of time (or a certain cycle) is a reference value of the temperature change Tb at the time point. If it is set to about 30% to 100%, the action signal output unit 130 may output a system warning signal, a system danger signal, and/or a system shutdown signal.

In addition, in the set discharge period shown in FIG. 5, the temperature calculation unit 120, after a certain period of time (or a certain cycle), the temperature deviation change (Tc) of the individual cells of each bank is the corresponding temperature change (Tb) In the case of approximately 30% to 100% set as the reference value of, the action signal output unit 130 may output a system warning signal, a system danger signal, and/or a system shutdown signal.

Here, the temperature calculation unit 120 may obtain a predetermined time from the time estimating unit 150, and the number of days of use may be set between approximately 7 to 180 days, or the number of cycles may be set to approximately 20 to 200 cycles. The invention is not limited.

In addition, here, the individual battery of each bank may include S1 consisting of S11 to S14 connected in parallel in FIG. 2A, S2 consisting of S21 to S24, S3 consisting of S31 to S34, S4 consisting of S41 to S44, and temperature variation change (Tc) may include a temperature change after a certain period (or a certain cycle) of each of the cells S1 to S4.

Hereinafter, an operation of detecting a precursor phenomenon related to an abnormality in a battery by using temperature data using actual test data in a system for detecting an abnormal condition using battery temperature data according to an exemplary embodiment of the present invention will be described.

6A and 6B are diagrams and graphs illustrating a temperature change according to a cycle of a bank in one of a plurality of module trays constituting a rack.

First, referring to FIGS. 6A and 6B, 12 banks are included in one module tray selected from among a plurality of module trays constituting the rack. In addition, this diagram and graph show data for 15 to 84 cycles by way of example.

In addition, as shown in the diagrams and graphs, it can be seen that the deviation between banks starts to increase from the 35th cycle, and it can be seen that the temperature deviation between the banks increases to more than 10℃ in the 75th cycle or more.

This mentioned temperature deviation is due to the temperature rise in banks 7 and 9 shown. Specifically, it can be seen that the temperature of the 7th bank starts to rise from the 45th cycle, and after the 75th cycle, the temperature rises significantly compared to the other banks. In addition, in the case of bank 9, it can be seen that the temperature is higher than that of other banks from 15 cycles, and the state continues.

7A and 7B are diagrams and graphs showing temperature changes according to cycles of a bank having a problem and a bank having a problem in the module tray.

Referring to FIGS. 7A and 7B, it can be seen that in the case of the 7th bank, the temperature rises rapidly from the 55th cycle, and the 9th bank has a higher temperature than the initial period than the normal 10th bank and the state is maintained until the 85th cycle. .

On the other hand, it can be seen that the normal bank 10, shown together as a comparative example, maintains the minimum value of the deviation.

If reviewed based on these results, it can be seen that the banks in which the abnormality occurs show temperature deviation from the other normal banks from the beginning or as the cycle progresses.

8A and 8B are diagrams and graphs showing a temperature change Tb and a temperature deviation change Tc of a battery cell according to cycles in a bank having a problem in a module tray and a bank in a normal state. Here, FIGS. 8A and 8B are measured by setting a comparison check period of a temperature change (Tb) and a temperature deviation change (Tc) to 50 cycles.

Referring to FIG. 8A, for example, when the temperature deviation Ta between battery cells is described as 7° C. or less, the temperature deviation Ta may be determined to have a problem from 55 cycles. In addition, referring to FIG. 8B, when the ratio (Tb/Tc) of the temperature change (Tb) to the change in temperature deviation (Tc) is set to 100%, it is said that the 7th bank has already encountered a problem in 65 cycles. It can be seen, and it can be seen that the rate gradually increases as the cycle progresses, reaching 500% in the 85 cycle. Therefore, in the case of bank 7, it is necessary to gradually increase the warning level.

In addition, in the case of bank 9, it can be seen that the ratio from 83% in 75 cycles to 233% in 80 cycles is a serious level. In addition, since bank 9 is already at a high temperature when referring to FIGS. 7A and 7B, it can be seen that bank 9 must have a high level of warning.

On the other hand, in the case of bank 10, it can be seen that it has reached 100% in 80 cycles, but it can be seen that it is in a low temperature state when considering FIGS. 7A and 7B, and therefore, the risk level is determined by considering the ratio and temperature together. You can see it should be done.

What has been described above is only one embodiment for implementing an abnormal condition pre-detection system using battery temperature data according to the present invention, and the present invention is not limited to the above-described embodiment, but is claimed in the following claims. As described above, without departing from the gist of the present invention, anyone of ordinary skill in the field to which the present invention pertains will have the technical spirit of the present invention to the extent that various changes can be implemented.

100; Abnormal condition pre-detection system
110; Temperature sensing unit 120; Temperature calculator
121; Temperature deviation calculation unit 122; Temperature change calculation unit
123; A temperature deviation change calculation unit 130; Action signal output
140; SOC estimation unit 150; Time estimator
160; Reference value storage unit

Claims (7)

A temperature sensing unit sensing voltages of each of the plurality of battery cells and providing battery temperature data for each of the plurality of battery cells;
A temperature deviation calculator configured to calculate a temperature deviation (Ta) between each battery cell from the battery temperature data; A temperature change calculator configured to calculate a temperature change (Tb) of each battery cell over time from the battery temperature data; A temperature calculation unit including a temperature deviation change calculation unit that calculates a temperature deviation change Tc of each battery cell according to the passage of time from the battery temperature data; And
Abnormal state pre-detection system using battery temperature data, including a measure signal output unit that compares the temperature deviation (Ta), the temperature change (Tb), or the temperature deviation change (Tc) with a reference value and outputs a system action signal . The method of claim 1,
The system action signal of the action signal output unit is a system warning signal that analyzes detailed battery operation data to determine whether an abnormality has occurred, a system danger signal that takes action on the checked abnormal area, or a system that shuts down the system. Abnormal condition pre-detection system using battery temperature data, which is a shutdown signal. The method of claim 2,
An abnormal state pre-detection system using battery temperature data, wherein a reference value set to output the system shutdown signal is higher than a reference value set to output the system warning signal and the system danger signal. The method of claim 1,
The temperature calculation unit operates in an SOC ± 10% period centering on a period of entering a constant voltage charging period when charging the battery cell, and an abnormal state pre-detection system using battery temperature data. The method of claim 1,
The temperature calculation unit is a system for detecting an abnormal state in advance using battery temperature data, operating in a range of 5% to 30% SOC of a residual amount when the battery cell is discharged. The method of claim 1,
The plurality of battery cells includes battery cells connected in series or battery cells connected in parallel. An abnormal state pre-detection system using battery temperature data. The method of claim 1,
The temperature calculator is a system for detecting an abnormal state in advance using battery temperature data to determine whether an abnormality has occurred by considering a temperature of a battery cell together with a ratio (Tb/Tc) of a temperature deviation change to the temperature change.

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