KR102553037B1 - Abnormal condition detection system using battery voltage data - Google Patents

Abstract

Embodiments of the present invention relate to an abnormal state advance detection system, and a technical problem to be solved is to detect a precursor phenomenon related to an abnormality of the battery using various voltage data of the battery, and to warn the user or stop the operation of the system. An object of the present invention is to provide an abnormal state advance detection system using battery voltage data capable of improving system safety. To this end, the present invention provides a voltage sensing unit for sensing the voltage of each of a plurality of battery cells and providing battery voltage data for each of the plurality of battery cells; a voltage deviation calculator configured to calculate a voltage deviation (Va) between battery cells from the battery voltage data; a voltage change calculation unit that calculates a voltage change (Vb) of each battery cell over time from the battery voltage data; a voltage calculator including a voltage deviation change calculator that calculates a change (Vc) of a voltage deviation of each battery cell over time from the battery voltage data; and an action signal output unit configured to output a system action signal by comparing the voltage deviation (Va), the voltage change (Vb), or the change (Vc) of the voltage deviation with a reference value. start the system

Description

Abnormal condition detection system using battery voltage data}

An embodiment of the present invention relates to a system for pre-detecting an abnormal state using battery voltage data.

In general, an energy storage system (ESS) stores energy produced from renewable energy markets, such as solar and wind power, in a storage device (e.g., a battery) and supplies electricity at a time when it is needed to increase power use efficiency. means a device that improves

These energy storage devices largely include batteries, PCS (Power Conversion System, performing AC-DC conversion and distribution functions), and EMS (Energy Management System, operating and managing the entire ESS system), and the like. Here, voltage, temperature, etc. of the battery are monitored and managed by a battery management system (BMS), and the BMS exchanges necessary information with the PCS and/or EMS.

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

However, in the conventional ESS, when the voltage or temperature of the battery is out of the standard range, the BMS, PCS, and/or EMS operate to stop charging/discharging of the battery, issue a system warning, or stop the operation of the system. By doing so, not only the safety of the ESS was low, but there was also a problem that a fire occurred in the ESS. In other words, the safety of the ESS can be further improved if the system is warned or the system is stopped by detecting a precursor phenomenon before the voltage or temperature is out of the standard range due to an abnormality in the battery. No technology has been developed to prevent future problems by detecting precursors in case of battery abnormalities in advance.

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

The problem to be solved according to an embodiment of the present invention is to detect a precursor phenomenon related to an abnormality of the battery using various voltage data of the battery, and to warn the user or stop the system operation, thereby improving the battery voltage. It is to provide an abnormal state advance detection system using data.

An abnormal state advance detection system using battery voltage data according to an embodiment of the present invention includes a voltage sensing unit configured to sense voltages of each of a plurality of battery cells and provide battery voltage data for each of the plurality of battery cells; a voltage deviation calculation unit that calculates a voltage deviation (Va), which is a difference between a maximum voltage and a minimum voltage between each series-connected battery cell, from the battery voltage data sensed by the voltage sensing unit; a voltage change calculator calculating a voltage change (Vb) of each battery cell according to the lapse of time and the number of charging and discharging of each battery cell from the battery voltage data provided from the voltage sensing unit and the voltage deviation calculating unit; From the battery voltage data provided from the voltage sensing unit, the voltage deviation calculation unit, and the voltage change calculation unit, the change (Vc) of the voltage deviation of each battery cell according to the lapse of time and the number of charging and discharging of each battery cell, and a voltage calculation unit including a voltage deviation change calculation unit that calculates a ratio of the change (Vc) of the voltage deviation to the reference value of the voltage change (Vb); and the voltage deviation (Va), the voltage change (Vb), the change in voltage deviation (Vc), and the ratio of the change (Vc) of the voltage deviation to the reference value of the voltage change (Vb) are respective reference values that are predetermined. and an action signal output unit for outputting a system action signal when out of range, and the system action signal of the action signal output unit analyzes detailed battery operation data to determine whether an actual abnormality has occurred. It includes a system danger signal for taking action and a system shutdown signal for shutting down the system, and a reference value set for outputting the system shutdown signal compared to a reference value set for outputting the system warning signal and the system danger signal The voltage calculator operates in an SOC ± 10% section or a preset voltage section centered on the time when the battery cell enters the constant voltage charging section when charging the battery cell, and the voltage calculator calculates the remaining amount SOC 5 when the battery cell is discharged. It operates in a range of % to 30% or a range of a preset voltage, and the plurality of battery cells include battery cells connected in series or connected in parallel.

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An embodiment of the present invention detects a precursor phenomenon related to an abnormality of the battery using various voltage data of the battery, warns the user or stops system operation, and thus improves system safety. detection system is provided.

1 is a schematic diagram showing the configuration of a general ESS system.
2A and 2B are schematic diagrams illustrating configuration examples of a battery used in a system for pre-detecting an abnormal state using battery voltage data according to an embodiment of the present invention.
3 is a block diagram showing the configuration of a system for pre-detecting an abnormal state using battery voltage data according to an embodiment of the present invention.
4 is a block diagram showing configurations of a voltage calculation unit and an action signal output unit in a system for pre-detecting an abnormal state using battery voltage data according to an embodiment of the present invention.
5 is a graph illustrating a change in battery voltage and an abnormal situation determination position for explaining an operation of a system for detecting an abnormal state in advance using battery voltage data according to an embodiment of the present invention.
6A and 6B are graphs and tables illustrating examples of voltage changes of a battery for explaining the operation of a system for detecting an abnormal state in advance using battery voltage data according to an embodiment of the present invention.
7 is a table showing an example of battery voltage change for explaining the operation of a system for detecting an abnormal state in advance using battery voltage data according to an embodiment of the present invention.

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 explain the present invention to those skilled in the art, and the following examples may be modified in many different forms, and the scope of the present invention is as follows It is not limited to the examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the 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 explanation, and the same reference numerals refer to the same elements in the drawings. As used herein, the terms “or” and “and/or” include any one and all combinations of one or more of the applicable listed items. In addition, the meaning of "connected" in the present specification means not only when member A and member B are directly connected, but also when member A and member B are indirectly connected by interposing member C between member A and member B. do.

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 otherwise. Also, when used herein, “comprise, include” and/or “comprising, including” refers to a referenced form, number, step, operation, member, element, and/or group thereof. presence, but does not preclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

In this specification, terms such as first and second are used to describe various members, components, regions, layers and/or portions, but these members, components, regions, layers and/or portions are limited by these terms. It is self-evident that These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described in detail below may refer to a second member, component, region, layer or section 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 with a BMS, a PCS, and an EMS for this purpose. BMS is a device that controls the state of the battery. It monitors the voltage, temperature, and charge/discharge state of the battery, and performs cell balancing to make sure that the degree of charge and discharge is the same between unit battery cells in a module. It performs protective functions such as electric shock, blocks the main switch in case of overcurrent or short circuit through the protective circuit, and also plays a role in communicating 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. The PCS can convert electrical characteristics (AC/DC, voltage, frequency, etc.) to charge the battery by receiving electrical energy from a renewable energy source or grid or to release the energy stored in the battery to the grid. The EMS (or PMS) may include an operating system for monitoring/controlling the state of the battery and PCS, and for integrated monitoring and control of the ESS in a control center.

2A and 2B are schematic diagrams illustrating configuration examples of a battery used in a system for pre-detecting an abnormal state using battery voltage data according to an embodiment of the present invention.

As shown in FIG. 2A , the battery 10 referred to in the abnormal state advance detection 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, and S14 are connected in parallel to form a first bank S1, and battery cells S21, S22, S23, and S24 are connected in parallel to form a second bank S2. In addition, battery cells S31, S32, S33, and S34 are connected in parallel to form a third bank (S3), and battery cells S41, S42, S43, and S44 are connected in parallel to form a fourth bank (S4). there is. Here, the first bank S1 to the fourth bank S4 may be connected in series. In addition, as shown in FIG. 2B , the battery 10 referred to in the abnormal state advance 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 advance detection system 100 using battery voltage data according to an embodiment of the present invention, and FIG. 4 is an abnormal state dictionary using battery voltage data according to an embodiment of the present invention. It is a block diagram showing the configuration of the voltage calculation unit 120 and the action signal output unit 130 in the detection system 100.

As shown in FIG. 3 , the abnormal state advance detection system 100 according to an embodiment of the present invention may include a voltage sensing unit 110, a voltage calculating unit 120, and an action signal output unit 130. .

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

The voltage sensing unit 110 may sense voltages of each of the plurality of battery cells and provide battery voltage data for each of the plurality of battery cells to the voltage calculator 120 . As an example, referring back to FIG. 2A , the voltage sensing unit 110 senses the voltages of the first bank S1 to the second bank S4, respectively, and converts them into battery voltage data, thereby calculating the voltage calculation unit 120. can be provided to As another example, referring back to FIG. 2B , the voltage sensing unit 110 senses the voltages of the first battery cell S1 to the fourth battery cell S4, respectively, and converts them into battery voltage data so that the voltage calculation unit ( 120) can be provided.

As shown in FIGS. 3 and 4 , the voltage calculator 120 may include a voltage deviation calculator 121 , a voltage change calculator 122 , and a voltage deviation change calculator 123 .

The voltage deviation calculation unit 121 may calculate the voltage deviation Va between battery cells from the battery voltage data received from the voltage sensing unit 110 and provide it to the action signal output unit 130 . The voltage change calculation unit 122 calculates the voltage change (Vb) of each battery cell over time from the battery voltage data provided from the voltage sensing unit 110 and/or the voltage deviation calculation unit 121. And it can be provided to the action signal output unit 130. The voltage deviation change calculation unit 123 calculates each battery according to the lapse of time of each battery cell from the battery voltage data provided from the voltage sensing unit 110, the voltage deviation calculation unit 121, and/or the voltage change calculation unit 122. The voltage deviation change (Vc) 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 voltage deviation (Va), the voltage change (Vb) and/or the voltage deviation change (Vc) provided from the voltage calculator 120 are out of 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 for determining whether an abnormality has actually occurred by analyzing detailed battery operation data, which may be provided to the EMS. Accordingly, the EMS may visually or audibly notify the manager of this state through the system screen.

In some examples, the system danger signal may include a signal to take action on the checked anomaly, which may be provided to the EMS. Accordingly, the EMS may visually or audibly notify the manager of this state through the system screen.

In some examples, the system shutdown signal may include a signal to shut down the ESS system for any reason to cease use. This system shutdown signal may be provided to the BMS, PCS and/or EMS, and accordingly, the BMS, PCS and/or EMS may turn off the main switch to completely stop charging and discharging of the battery cells. Of course, system shutdown information may be visually or audibly provided to an administrator through the EMS system screen.

The SOC estimator 140 may estimate the remaining capacity of the battery cell based on the voltage information provided from the voltage sensing unit 110 and provide the estimated remaining capacity to the voltage calculator 120 . In some examples, the SOC estimator 140 calculates the SOC estimated through another algorithm (eg, a Kalman filter, screen, OCV, or other types of calculation information) without using the voltage sensing unit 110 as a voltage calculator. (120).

The time estimator 150 may estimate the usage time of the ESS system and provide it to the voltage calculator 120 . In some examples, the time estimator 150 may estimate a usage date and/or the number of charge/discharge cycles of the ESS system and provide the estimated value to the voltage calculator 120 .

The reference value storage unit 160 stores in advance a reference value for the voltage deviation Va, a reference value for the voltage change Vb, and/or a reference value for the voltage deviation change Vc. can provide

In this way, the embodiment of the present invention uses various voltage data of the battery to detect a precursor phenomenon related to an abnormality of the battery, and warns the manager or user or stops the system operation, thereby improving system safety. An abnormal state advance detection system 100 using data may be provided.

5 is a graph showing a change in battery voltage and an abnormal situation determination position for explaining the operation of the abnormal state advance detection system 100 using battery voltage data according to an embodiment of the present invention. In FIG. 5 , the X axis may mean elapsed time, and the Y axis may mean voltage. 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 section, maintains a constant value despite the passage of time in the CV charging section and the idle section, and gradually increases over time in the discharging section. can decrease

In some examples, the abnormal state advance detection system 100 according to an embodiment of the present invention does not continuously calculate the voltage using the detected battery voltage, but, for example, calculates the voltage in approximately 2 areas over time. can be done

In some examples, the voltage calculator 120 may operate in an SOC ± 10% section centered on the entry time of the constant voltage charging section when charging the battery cell. In other examples, the voltage calculator 120 may operate in a range of 5% to 30% of the remaining SOC when discharging the battery cell. Here, the voltage calculator 120 may obtain the remaining SOC amount from the SOC estimator 140, but the present invention is not limited thereto.

The reason why the voltage is calculated in a specific time interval is that the voltage difference is the largest when a battery cell failure occurs in the specific interval. That is, it is possible to most certainly grasp the abnormal precursor phenomenon of the battery cell in the specific section. Meanwhile, as described above, the present invention may preset a reference value for voltage deviation (Va), a reference value for voltage change (Vb) and/or a reference value for voltage deviation change (Vc). signal, system critical signal and/or system shutdown signal can be output.

In some examples, the reference value for the voltage deviation Va and the output signal for it may be set as follows. These examples are only examples for understanding the present invention, and the present invention is not limited to the numerical ranges to be described below.

In the set charging period shown in FIG. 5, when the voltage deviation (Va) by the voltage difference calculation unit 121 is approximately 10 mV to approximately 200 mV set as a reference value, and in the set discharging period shown in FIG. 5, voltage deviation calculation When the voltage deviation Va by the unit 121 is approximately 50 mV to approximately 300 mV 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, when the voltage deviation (Va) by the voltage deviation calculator 121 is approximately 200 mV set as a reference value in the set charging section shown in FIG. 5, and in the set discharging section shown in FIG. 5, the voltage deviation (Va) When is approximately 300 mV set as a reference value, the action signal output unit 130 may output a system shutdown signal.

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

In some examples, the reference values for the voltage change (Vb) and the voltage deviation change (Vc) and the output signal for them may be set as follows. These examples are only examples for understanding the present invention, and the present invention is not limited to the numerical ranges to be described below.

In the set charging period shown in FIG. 5 , the voltage calculator 120 calculates that, after a certain period of time (or a certain cycle), the change in voltage deviation (Vc) of each battery in each bank is the reference value of the voltage change (Vb) at that point in time. In the case of approximately 30% to 100% set as , 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 interval shown in FIG. 5, the voltage calculator 120 determines that, after a certain period of time (or a certain period of cycle), the change in voltage deviation (Vc) of each battery in each bank is the change in voltage (Vb) at that point in time. If it is 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 voltage calculator 120 may obtain a certain amount of time from the time estimator 150, and the number of days of use may be set between approximately 7 and 180 days, or the number of cycles may be set between approximately 20 and 200 cycles. The invention is not limited.

In addition, the individual batteries of each bank may include S1 made of S11 to S14 connected in parallel in FIG. 2a, S2 made of S21 to S24, S3 made of S31 to S34, and S4 made of S41 to S44, and voltage deviation change (Vc) may include a voltage change after a certain period of time (or a certain cycle) of each of the batteries S1 to S4.

6A and 6B are graphs and tables illustrating examples of voltage changes of a battery for explaining the operation of the abnormal state advance detection system 100 using battery voltage data according to an embodiment of the present invention. In FIG. 6A, the X axis is the elapsed time, the Y axis is the cell voltage, and A, B, C, and D are the battery cells.

As shown in FIGS. 6A and 6B, the number of cycles is 0 to 100 cycles, where the voltage deviation (Va), for example, the voltage change (Vb) of battery cell D, for example, the voltage deviation change (Vc) of battery cell D ) was measured. As shown in FIG. 6B , from the 50th cycle, the voltage change (Vb) of battery cell D was detected and calculated, and the voltage deviation change (Vc) of battery cell D was also detected and calculated.

In this example, a reference value for outputting a system warning signal, a system danger signal, and/or a system shutdown signal by the action signal output unit 130 during charging may be set as follows.

First, the reference values for the voltage deviation (Va) may be set to 20 mV for a system warning signal, 50 mV for a system danger signal, and 200 mV for a system shutdown signal. In addition, the reference value for the voltage change (Vb) may be set to 40% of the system warning signal, 50% of the system danger signal, and 70% of the system shutdown signal in 2 months and/or 50 cycles.

Accordingly, for the voltage deviation Va, the action signal output unit 130 outputs a system warning signal at 50 cycles and does not output a system danger signal until 100 cycles. In addition, with regard to the voltage change (Vb), the action signal output unit 130 outputs a system danger signal at 50 cycles and outputs a system shutdown signal at 100 cycles.

Meanwhile, in the case of discharge, the voltage is lowered, and the system warning signal, system danger signal, and/or system shutdown signal may be configured under the above conditions.

Next, signal output by the action signal output unit 130 due to the voltage deviation change (Vc) may be performed as follows.

In the set charging section shown in FIG. 5 , the action signal output unit 130 outputs a system warning signal and/or a system danger signal when the value after a certain time elapses (or a certain cycle elapses) is greater than about 5% to about 50% of the reference value. may be output, and a system shutdown signal may be output when the value is greater than the reference value of approximately 30% to approximately 200%.

In the set discharge interval shown in FIG. 5 , the action signal output unit 130 outputs a system warning signal and/or a system danger signal when the value after a certain time elapses (or a certain cycle elapses) is greater than about 5% to about 50% of the reference value. may be output, and a system shutdown signal may be output when the value is greater than the reference value of approximately 30% to approximately 200%. Here, as described above, the predetermined time may be set between about 7 to about 180 days (the number of cycles is about 20 to 200 cycles).

FIG. 7 is a table showing an example of voltage change of a battery for explaining the operation of the abnormal state advance detection system 100 using battery voltage data according to an embodiment of the present invention.

Here, the battery voltage deviation change (Vc) may be set to 20% of the system warning signal, 50% of the system danger signal, and 100% of the system shutdown signal in 50 cycles as a reference value. In this case, the action signal output unit 130 already outputs a system warning signal at the initially set 50 cycles, outputs a system danger signal at 80 cycles, and outputs a system shutdown signal at 90 cycles.

What has been described above is only one embodiment for implementing an abnormal state advance detection system using battery voltage data according to the present invention, and the present invention is not limited to the above-described embodiment, and claims in the following claims As such, anyone skilled in the art in the field to which the present invention pertains without departing from the gist of the present invention will say that the technical spirit of the present invention exists to the extent that various changes can be made.

100; Anomaly Pre-Detection System
110; voltage sensing unit 120; voltage calculator
121; voltage deviation calculator 122; voltage change calculator
123; voltage deviation change calculator 130; action signal output
140; SOC estimation unit 150; time estimator
160; Reference value storage unit

Claims (6)

a voltage sensing unit sensing voltages of each of the plurality of battery cells and providing battery voltage data for each of the plurality of battery cells;
a voltage deviation calculation unit that calculates a voltage deviation (Va), which is a difference between a maximum voltage and a minimum voltage between each series-connected battery cell, from the battery voltage data sensed by the voltage sensing unit; a voltage change calculator calculating a voltage change (Vb) of each battery cell according to the lapse of time and the number of charging and discharging of each battery cell from the battery voltage data provided from the voltage sensing unit and the voltage deviation calculating unit; From the battery voltage data provided from the voltage sensing unit, the voltage deviation calculation unit, and the voltage change calculation unit, the change (Vc) of the voltage deviation of each battery cell according to the lapse of time and the number of charging and discharging of each battery cell, and a voltage calculation unit including a voltage deviation change calculation unit that calculates a ratio of the change (Vc) of the voltage deviation to the reference value of the voltage change (Vb); and
The voltage deviation (Va), the voltage change (Vb), the change in voltage deviation (Vc), and the ratio of the change (Vc) of the voltage deviation to the reference value of the voltage change (Vb) are predetermined reference values, respectively. Including an action signal output unit for outputting a system action signal when out of order,
The system action signal of the action signal output unit is a system warning signal to analyze detailed battery operation data to determine whether an actual abnormality has occurred, a system danger signal to take action on the checked abnormal part, and a system to shut down the system contain a shutdown signal;
A reference value set for outputting the system shutdown signal is higher than a reference value set for outputting the system warning signal and the system danger signal;
The voltage calculator operates in an SOC ± 10% section or a preset voltage section centered on the time of entering the constant voltage charging section when charging the battery cell,
The voltage calculator operates in a range of 5% to 30% of the remaining SOC or a preset voltage when the battery cell is discharged,
The plurality of battery cells include battery cells connected in series or battery cells connected in parallel, abnormal state advance detection system using battery voltage data.

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