Fire early detecting system for elctric vehicles

Abstract

An electric vehicle battery fire early detection system according to one embodiment of the present invention comprises: an ambient temperature measurement step for measuring the ambient temperature of a parking lot; an ambient temperature comparison step for comparing the ambient temperature measured in the ambient temperature measurement step with a reference ambient temperature; a reference temperature set setting step for setting a first reference temperature set when the ambient temperature in the ambient temperature comparison step is lower than or equal to the reference ambient temperature, and setting a second reference temperature set when the ambient temperature is higher than the reference ambient temperature; a battery temperature measurement step for measuring the battery temperature of an electric vehicle; a reference temperature set comparison step for comparing the battery temperature measured in the battery temperature measurement step with the reference temperature set; and a signal transmission step for transmitting a status signal according to the comparison result of the reference temperature set comparison step. The electric vehicle battery fire early detection system according to the present invention monitors the temperature of the battery installed at the bottom of the electric vehicle and has the effect of responding early to a fire in the electric vehicle caused by an increase in the battery temperature.

Description

Technology Field

[0001] The present invention relates to an electric vehicle battery fire early detection system, and more specifically, to a system for early detection of a fire in an electric vehicle battery parked in a parking lot. Background Technology

[0003] Electric vehicles, which are equipped with 300 to 500 battery cells to ensure a long driving range, commonly use lithium-based rechargeable batteries due to their high energy density, long cycle life, fast charging, and lightweight properties.

[0004] Lithium-ion batteries used in electric vehicles have a higher energy density (Wh / kg) and a higher power density (W / kg) than conventional batteries, and are about three times lighter than conventional lead-acid batteries, which has the advantage of reducing the overall weight of the vehicle by about 60 to 80 percent.

[0005] However, when a lithium secondary battery installed in a vehicle is overcharged, subjected to external impact, or experiences an internal short circuit due to defects in the battery cells, it triggers a chemical reaction called thermal runaway, generating high temperatures of 800 to 1,000°C, which can cause fires lasting for several hours and result in damages tens of times greater than those caused by internal combustion engines.

[0006] To reduce such damage, there is an increasing need for technology capable of detecting electric vehicle fires in advance. Prior art literature

[0008] Republic of Korea Published Patent 10-2023-0025549 (Published Feb. 22, 2023) The problem to be solved

[0009] The electric vehicle battery fire early detection system according to the present invention aims to solve the following problems in order to solve the aforementioned problems.

[0010] We aim to provide a system that can reduce damage caused by electric vehicle fires by continuously monitoring electric vehicle batteries to detect signs of fire early and respond to them.

[0011] In addition, we intend to install it on the floor of the parking lot where the vehicle is parked, under the vehicle, to more effectively detect fires in electric vehicles at an early stage.

[0012] In addition, we aim to provide an electric vehicle battery fire early detection system capable of detecting fires even in rain or when the floor is wet. means of solving the problem

[0014] An electric vehicle battery fire early detection system according to one embodiment of the present invention comprises: an ambient temperature measurement step for measuring the ambient temperature of a parking lot; an ambient temperature comparison step for comparing the ambient temperature measured in the ambient temperature measurement step with a reference ambient temperature; a reference temperature set setting step for setting a first reference temperature set when the ambient temperature in the ambient temperature comparison step is lower than or equal to the reference ambient temperature, and setting a second reference temperature set when the ambient temperature is higher than the reference ambient temperature; a battery temperature measurement step for measuring the battery temperature of an electric vehicle; a reference temperature set comparison step for comparing the battery temperature measured in the battery temperature measurement step with the reference temperature set; and a signal transmission step for transmitting a status signal according to the comparison result of the reference temperature set comparison step.

[0015] In the ambient temperature comparison step of an electric vehicle battery fire early detection system according to one embodiment of the present invention, the reference ambient temperature is 0℃, and in the reference temperature set setting step, the reference temperature first set is composed of a first temperature, a second temperature, and a third temperature, and the first temperature, the second temperature, and the third temperature are set to 40℃, 50℃, and 60℃, and the reference temperature second set is composed of a first temperature, a second temperature, and a third temperature, and the first temperature, the second temperature, and the third temperature are preferably 55℃, 60℃, and 70℃.

[0016] In one embodiment of the present invention, the status signal of the signal transmission step of the electric vehicle battery fire early detection system is composed of an interest signal, a warning signal, and a danger signal. In the reference temperature set comparison step, if the battery temperature is above a first temperature and below a second temperature, the interest signal is transmitted in the signal transmission step; if the battery temperature is above a second temperature and below a third temperature, the warning signal is transmitted in the signal transmission step; and if the battery temperature is above a third temperature, the danger signal is transmitted in the signal transmission step.

[0017] In the battery temperature measurement step of an electric vehicle battery fire early detection system according to one embodiment of the present invention, a previous temperature comparison step is added to compare the current battery temperature with the previous battery temperature, and it is preferable to send an interest signal in the signal sending step when the difference between the current battery temperature and the previous battery temperature is 10°C or more and less than 20°C, send an interest signal in the signal sending step when the difference between the current battery temperature and the previous battery temperature is 20°C or more and less than 30°C, and send a danger signal in the signal sending step when the difference between the current battery temperature and the previous battery temperature is 30°C or more.

[0018] In the signal transmission step of the electric vehicle battery fire early detection system according to one embodiment of the present invention, the priority is lowered in the order of danger signal, warning signal, and interest signal, and it is preferable to transmit a signal with a higher or equal priority by comparing the priority of the status signal based on the comparison result of the reference temperature set comparison step with the priority of the status signal based on the comparison result of the previous temperature comparison step.

[0019] In the previous temperature comparison step of the electric vehicle battery fire early detection system according to one embodiment of the present invention, if the difference between the current battery temperature and the previous battery temperature is less than 0℃, it is preferable to transmit a normal signal in the signal transmission step.

[0020] In the battery temperature measurement step of an electric vehicle battery fire early detection system according to one embodiment of the present invention, the battery temperature is measured by a battery temperature sensor comprising: a housing composed of a side plate having a wide lower side and a narrow upper side, and an upper plate closing the upper surface of the side plate; a through hole formed in the side plate of the housing; a step formed on the inner surface of the through hole in the direction inward of the housing to reduce the diameter of the through hole; an infrared sensor array disposed in the through hole of the step; a filter member disposed in the direction outward of the step; and a PCB including a magnetic sensor disposed inside the housing to check whether the vehicle is parked; and a battery for supplying power to the circuit. When a vehicle is parked on top of the battery temperature sensor, the magnetic sensor generates a parking signal for the vehicle, and the infrared sensor array senses and transmits the battery temperature of the vehicle.

[0021] In the infrared sensor array of the electric vehicle battery fire early detection system according to one embodiment of the present invention, one sensor senses the temperature of the inner surface of the through hole, and another sensor senses the temperature of the vehicle's battery, and it is preferable that the temperature of the inner surface of the through hole is the ambient temperature.

[0022] The sensor of the infrared sensor array of the electric vehicle battery fire early detection system according to one embodiment of the present invention senses a wavelength of 8 to 12 μm, the filter member is made of silicon or germanium, and it is preferable that a water discharge groove is formed in the side plate, the upper part of which communicates with a through hole to discharge water within the through hole. Effects of the invention

[0024] The electric vehicle battery fire early detection system according to the present invention monitors the temperature of the battery installed at the bottom of the electric vehicle and has the effect of responding early to a fire in the electric vehicle caused by an increase in the battery temperature.

[0025] In addition, installing a sensor to measure battery temperature on the parking lot floor allows for effective monitoring of the battery temperature when the vehicle is parked or stopped.

[0026] In addition, by configuring the sensor to prevent water from entering the battery temperature measuring sensor, it is possible to provide a detection system that can operate effectively even in rainy weather or during water cleaning. Brief explanation of the drawing

[0028] FIG. 1 is a block diagram of an electric vehicle battery fire early detection system according to one embodiment of the present invention. Figure 2 is a control flowchart of the electric vehicle battery fire early detection system illustrated in Figure 1. FIG. 3 is a block diagram of an electric vehicle battery fire early detection system according to another embodiment of the present invention. FIGS. 4 and FIGS. 5 are control flowcharts according to another embodiment of the electric vehicle battery fire early detection system illustrated in FIG. 1. FIG. 6 is a perspective view and a cross-sectional view of a battery temperature sensor used in an electric vehicle battery fire early detection system according to one embodiment of the present invention. FIG. 7 is an example of the installation of a battery temperature sensor of an electric vehicle battery fire early detection system according to another embodiment of the present invention. Specific details for implementing the invention

[0029] Preferred embodiments according to the present invention will be described in detail with reference to the attached drawings, provided that identical or similar components are given the same reference number regardless of the drawing symbols, and redundant descriptions thereof will be omitted.

[0030] Furthermore, in describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such descriptions could obscure the essence of the invention. Additionally, it should be noted that the attached drawings are intended only to facilitate an understanding of the concept of the present invention and should not be interpreted as limiting the concept of the invention.

[0032] An electric vehicle battery fire early detection system according to one embodiment of the present invention can detect a fire in the battery early by measuring the battery temperature of the electric vehicle as described above, and detects a fire in the electric vehicle battery early through an ambient temperature measurement step (S1), an ambient temperature comparison step (S2), a reference temperature set setting step (S3), a battery temperature measurement step (S4), a reference temperature set comparison step (S5), and a signal transmission step (S6) as shown in FIGS. 1 and 2.

[0033] The ambient temperature measurement step (S1) measures the ambient temperature (Ta) of the parking lot where the electric vehicle is parked, and is measured to assess the risk of the electric vehicle's battery temperature (Tb) by reflecting the temperature according to the season. The ambient temperature may be measured using a temperature sensor separately installed in the parking lot, or it may be measured using the battery temperature sensor (100) described later.

[0034] The ambient temperature comparison step (S2) compares the ambient temperature (Ta) measured in the ambient temperature measurement step (S1) with the reference ambient temperature to set the reference ambient temperature, and the reference ambient temperature sets the reference temperature set for determining the fire risk of the electric vehicle battery temperature (Tb) in the reference temperature set setting step (S3).

[0035] The reference temperature set set in the reference temperature set setting step (S3) may be set into two sets, such as the first reference temperature set (Tf1, Tf2, Tf3) and the second reference temperature set (Tf1, Tf2, Tf3), as in this embodiment, but may also be set into three or more sets depending on the embodiment.

[0036] The battery temperature measurement step (S4) measures the battery temperature (Tb) of the electric vehicle, and the measurement method can be performed in various ways, and may be carried out through a battery temperature sensor (100) such as the embodiment to be described later.

[0037] When the electric vehicle battery temperature (Tb) is measured in the battery temperature measurement step (S4), it is compared with a reference temperature set (Tf1, Tf2, Tf3), and based on the comparison result, it is determined whether a fire may occur in the battery and a status signal is transmitted in the signal transmission step (S6).

[0038] Referring to FIG. 2, the reference ambient temperature set in the ambient temperature comparison step (S2) can be set to various temperatures, but in this embodiment, the reference ambient temperature is set to 0°C, and in the reference temperature set setting step (S3), the first reference temperature set is composed of a first temperature (Tf1), a second temperature (Tf2), and a third temperature (Tf3), and the first temperature (Tf1), the second temperature (Tf2), and the third temperature (Tf3) are set to 40°C, 50°C, and 60°C, and the second reference temperature set is composed of a first temperature (Tf1), a second temperature (Tf2), and a third temperature (Tf3), and the first temperature (Tf1), the second temperature (Tf2), and the third temperature (Tf3) can be composed to 55°C, 60°C, and 70°C.

[0039] Additionally, the status signal of the signal transmission step (S6) may be configured to consist of an interest signal, a warning signal, and a danger signal, and to transmit an interest signal in the signal transmission step (S6) when the battery temperature (Tb) is greater than or equal to the first temperature (Tf1) and less than the second temperature (Tf2) in the reference temperature set comparison step (S5); transmit a warning signal in the signal transmission step (S6) when the battery temperature (Tb) is greater than or equal to the second temperature (Tf2) and less than the third temperature (Tf2); and transmit a danger signal in the signal transmission step (S6) when the battery temperature (Tb) is greater than or equal to the third temperature (Tf2).

[0041] For example, if the ambient temperature (Ta) measured in the ambient temperature measurement step (S1) is -5℃, the ambient temperature (Ta) is determined to be 0℃ or lower in the ambient temperature comparison step (S2), so a first set of reference temperatures (Tf1, Tf2, Tf3) of 40℃, 50℃, and 60℃ is set in the reference temperature set setting step (S3). In this state, the battery temperature (Tb) of the electric vehicle is measured in the battery temperature measurement step (S4), and in the reference temperature set comparison step (S5), if the battery temperature (Tb) is 40℃ or higher and less than 50℃, an interest signal is sent; if it is 50℃ or higher and less than 60℃, a warning signal is sent; and if it is 60℃ or higher, a danger signal is sent, thereby enabling early detection of an electric vehicle battery fire.

[0042] Generally, electric vehicle batteries consist of a positive electrode, a negative electrode, and a separator. A film called SEI (Solid Electrolyte Interphase) is formed on the surface of the negative electrode. This SEI breaks down at 60 to 80°C. If the temperature continues to rise after the SEI breaks down, the separator is damaged at 130 to 150°C, causing the positive and negative electrodes to mix and resulting in a fire caused by thermal runaway. Therefore, to detect electric vehicle fires early, the battery temperature must be maintained at 80°C or lower. More conservatively, it is desirable to generate a danger signal based on 60°C, as in this embodiment. If this temperature is too low, a danger signal may be emitted even when there is no actual danger, causing inconvenience in use; thus, caution is required when setting this temperature.

[0044] Referring to FIGS. 3 and 4, it is preferable to add a previous temperature comparison step (S5-1) to the battery temperature measurement step (S4) to compare the current battery temperature (Tb) with the previous battery temperature (Tb-1).

[0045] By using the current battery temperature (Tb) and the previous battery temperature (Tb-1), it is possible to dynamically check whether the battery temperature is rising or falling. Through this, a normal signal can be sent simply when the battery temperature is falling, and if the difference between the current battery temperature (Tb) and the previous battery temperature (Tb-1) is 10°C or more and less than 20°C, an interest signal can be sent in the signal sending step (S6), and if the difference between the current battery temperature (Tb) and the previous battery temperature (Tb-1) is 20°C or more and less than 30°C, an interest signal can be sent in the signal sending step (S6), and if the difference between the current battery temperature (Tb) and the previous battery temperature (Tb-1) is 30°C or more, the danger signal can be sent in the signal sending step (S6).

[0046] At this time, the measurement interval between the current battery temperature (Tb) and the previous battery temperature (Tb-1) can be set to various intervals, such as 1 minute or 3 minutes, but the ambient temperature (Ta) measured during the ambient temperature measurement stage may also be reflected. For example, if the ambient temperature (Ta) is higher than 0℃, the battery temperature (Tb) may decrease later after driving due to the ambient temperature (Ta); in this case, the measurement interval can be set to 3 minutes, and if it is 0℃ or lower, it can be set to 1 minute. In addition, the ambient temperature (Ta) can be further subdivided into 0℃ or lower, 0℃ to 30℃, and above 30℃, so that the energy required to measure the battery temperature (Tb) is reduced by setting the interval to 1 minute when it is 0℃ or lower, 3 minutes when it is between 0℃ and 30℃, and 5 minutes when it is above 30℃.

[0048] Referring to FIG. 5, in the signal transmission step (S6), priorities can be set in the order of danger signal, warning signal, and interest signal according to the signal stage. Additionally, the priority of the status signal based on the comparison result of the reference temperature set comparison step (S5) and the priority of the status signal based on the comparison result of the previous temperature comparison step (S5-1) can be compared to transmit a signal with a higher or equal priority. In this case, confusion caused by the overlapping transmission of the warning signal and the danger signal can be avoided.

[0050] Referring to FIG. 6, which is a perspective view and cross-sectional view of a battery temperature sensor used in an electric vehicle battery fire early detection system according to an embodiment of the present invention, the battery temperature sensor (100) comprises a housing (110) composed of a side plate (112) having a wide lower side and a narrow upper side, and an upper plate (114) that closes the upper surface of the side plate (112); a through hole (112a) formed in the side plate (112) of the housing (110); a step (112b) formed in the inner side of the through hole (112a) in the direction of the inner side of the housing (110) to reduce the diameter of the through hole (112a); an infrared sensor array (120) disposed in the through hole (112a) of the step (112b); a filter member (130) disposed in the direction of the outer side of the step; a battery (140) disposed inside the housing (110) for supplying power to a circuit; and a magnetic sensor disposed inside the housing (110) for checking whether the vehicle is parked. It can be composed of a sensor (150).

[0051] The housing (110) can be formed in various shapes, but it is desirable to form it robustly so that the battery temperature sensor (100) can be run over when the electric vehicle is parked. It is desirable to form it in the shape of a conical column with a wide bottom and a narrow top, as shown in FIG. 6, so that the infrared sensor array (120) installed in the through hole (112a) of the side plate (112) can measure the battery temperature of the electric vehicle.

[0052] The battery temperature sensor (100) generates a parking signal for the vehicle when the vehicle is parked on top of the sensor, and the infrared sensor array (120) senses and transmits the battery temperature (Tb) of the vehicle when the parking signal for the vehicle is generated.

[0053] These signals are transmitted to control devices for parking lot management, and the transmission method may be wireless, wired, or wired / wireless depending on the parking lot situation.

[0054] As explained above, the ambient temperature (Ta) can be sensed through a separate temperature sensor, but the sensor close to the through hole (120) of the infrared sensor array (120) can sense the temperature of the inner surface of the through hole (112a), and other sensors can sense the vehicle's battery temperature (Tb). In this case, the temperature of the inner surface of the through hole (112a) sensed close to the through hole (120) can be used as the ambient temperature (Ta).

[0056] In this embodiment, the sensor of the infrared sensor array (120) used can be configured to sense wavelengths of 8 to 12 μm, and the filter member (130) is preferably made of silicon or germanium to sense wavelengths of 8 to 12 μm. At this time, as shown in FIG. 6 (b), it is preferable to install an O-ring (132) on the side of the filter member (130) to prevent water from flowing into the sensor array (120) through the through hole (112), and it is preferable to form an adhesive surface (134) made of silicon between the step (112b) and the filter member (130) to more effectively block the inflow of water.

[0057] In addition, it is more preferable to form a water discharge groove (112c) in the side plate (112) so that the upper part is connected to the through hole (112a) to effectively discharge water, thereby discharging water within the through hole (112b).

[0059] The battery temperature sensor (100) described above may be arranged in groups to sense the temperature of the entire battery from the center of the parked vehicle as shown in FIG. 7 (a), or two may be placed at the front and center of the vehicle as shown in FIG. 7 (b) to sense the temperature of the battery placed from the front of the vehicle to the center and the battery placed from the center to the rear. Additionally, as shown in FIG. 7 (c), the temperature of the battery placed from the front of the vehicle to the center may be sensed, and the temperature of the battery placed from the rear of the vehicle to the center may be sensed.

[0061] Although the present invention has been described in detail using preferred embodiments, the scope of the invention is not limited to specific embodiments and should be interpreted by the appended claims. Furthermore, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the invention. Explanation of the symbols

[0063] S1: Ambient temperature measurement step S2: Ambient temperature comparison step S3: Reference temperature set setting step S4: Battery temperature measurement step S5: Reference temperature set comparison step S5-1: Previous temperature comparison step S6: Signal transmission stage Ta: Ambient temperature Tb: Battery temperature Tf1, Tf2, Tf3: Reference temperature set, Reference temperature set 1, Reference temperature set 2 100: Battery temperature sensor 110: Housing 112: Side plate 112a: Through hole 112b : Step 112c : Water drainage groove 114: Upper plate 120: Infrared array 130: Filter missing 132: O-ring 134 : Adhesive surface 140 : Battery 150 : Magnetic sensor

Claims

Claim 1 An electric vehicle battery fire early detection system characterized by comprising: an ambient temperature measurement step for measuring the ambient temperature of a parking lot; an ambient temperature comparison step for comparing the ambient temperature measured in the ambient temperature measurement step with a reference ambient temperature; a reference temperature set setting step for setting a first reference temperature set when the ambient temperature in the ambient temperature comparison step is lower than or equal to the reference ambient temperature, and setting a second reference temperature set when the ambient temperature is higher than the reference ambient temperature; a battery temperature measurement step for measuring the battery temperature of an electric vehicle; a reference temperature set comparison step for comparing the battery temperature measured in the battery temperature measurement step with the reference temperature set; and a signal transmission step for transmitting a status signal according to the comparison result of the reference temperature set comparison step. Claim 2 An electric vehicle battery fire early detection system according to claim 1, wherein in the above-mentioned ambient temperature comparison step, the reference ambient temperature is 0℃, and in the above-mentioned reference temperature set setting step, the first reference temperature set is composed of a first temperature, a second temperature, and a third temperature, and the first temperature, the second temperature, and the third temperature are set to 40℃, 50℃, and 60℃, and the second reference temperature set is composed of a first temperature, a second temperature, and a third temperature, and the first temperature, the second temperature, and the third temperature are 55℃, 60℃, and 70℃. Claim 3 An electric vehicle battery fire early detection system according to claim 2, wherein the status signal of the signal transmitting step is composed of an interest signal, a warning signal, and a danger signal, and wherein, in the reference temperature set comparison step, if the battery temperature is above a first temperature and below a second temperature, the interest signal is transmitted in the signal transmitting step; if the battery temperature is above a second temperature and below a third temperature, the warning signal is transmitted in the signal transmitting step; and if the battery temperature is above a third temperature, the danger signal is transmitted in the signal transmitting step. Claim 4 An electric vehicle battery fire early detection system according to claim 3, wherein the battery temperature measurement step includes a previous temperature comparison step for comparing the current battery temperature with the previous battery temperature, wherein if the difference between the current battery temperature and the previous battery temperature is 10°C or more and less than 20°C, the signal transmission step transmits the interest signal, if the difference between the current battery temperature and the previous battery temperature is 20°C or more and less than 30°C, the signal transmission step transmits the warning signal, and if the difference between the current battery temperature and the previous battery temperature is 30°C or more, the signal transmission step transmits the danger signal. Claim 5 An electric vehicle battery fire early detection system according to claim 4, wherein in the signal transmission step, the priority is lowered in the order of the danger signal, warning signal, and interest signal, and the priority of the state signal according to the comparison result of the reference temperature set comparison step is compared with the priority of the state signal according to the comparison result of the previous temperature comparison step to transmit a signal with a higher or equal priority. Claim 6 An electric vehicle battery fire early detection system according to claim 5, characterized in that if the difference between the current battery temperature and the previous battery temperature (Tb-1) in the previous temperature comparison step is less than 0℃, a normal signal is transmitted in the signal transmission step. Claim 7 An electric vehicle battery fire early detection system, characterized in that, in the battery temperature measurement step according to claim 1, the battery temperature is measured by a battery temperature sensor comprising: a housing comprising a side plate having a wide lower side and a narrow upper side, and an upper plate closing the upper surface of the side plate; a through hole formed in the side plate of the housing; a step formed on the inner surface of the through hole in the direction inward of the housing to reduce the diameter of the through hole; an infrared sensor array disposed in the through hole of the step; a filter member disposed in the direction outward of the step; and a magnetic sensor disposed inside the housing to check whether a vehicle is parked, wherein when a vehicle is parked on the battery temperature sensor, the magnetic sensor generates a parking signal for the vehicle, and the infrared sensor array senses and transmits the battery temperature of the vehicle. Claim 8 An electric vehicle battery fire early detection system according to claim 7, wherein one sensor among the infrared sensor array senses the temperature of the inner surface of the through hole, another sensor senses the battery temperature of the vehicle, and the temperature of the inner surface of the through hole is the ambient temperature. Claim 9 An electric vehicle battery fire early detection system according to claim 8, wherein the sensor of the infrared sensor array senses a wavelength of 8 to 12 μm, the filter member is made of silicon or germanium, and the side plate has a water discharge groove formed therein that communicates with the upper part of the through hole to discharge water within the through hole.

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