KR20240082286A - Temperature monitoring apparatus for battery - Google Patents

Abstract

A battery temperature monitoring device according to an embodiment of the present invention includes a reference voltage generation circuit configured to generate a reference voltage using a feedback signal; a voltage comparator configured to generate a comparison signal using a monitoring voltage indicating the temperature of the battery and the reference voltage; and a feedback circuit configured to generate the feedback signal using the comparison signal. The voltage comparator is configured to float the comparison signal when the monitoring voltage is greater than or equal to the reference voltage. The feedback circuit is configured to generate a high-level voltage as the feedback signal when the comparison signal is floating. The reference voltage generating circuit is configured to generate, as the reference voltage, a first diagnostic voltage representing a first diagnostic temperature when the feedback signal is the high-level voltage.

Description

Battery temperature monitoring device {TEMPERATURE MONITORING APPARATUS FOR BATTERY}

The present invention relates to technology for monitoring the temperature of a battery to protect the battery from overheating.

Recently, as the demand for portable electronic products such as laptops, video cameras, and portable phones has rapidly increased, and as the development of electric vehicles, energy storage batteries, robots, and satellites has begun, the need for high-performance batteries capable of repeated charging and discharging has increased. Research is actively underway.

Currently commercialized batteries include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium batteries. Among these, lithium batteries have almost no memory effect compared to nickel-based batteries, so they can be freely charged and discharged, and have a very high self-discharge rate. It is attracting attention due to its low and high energy density.

Battery management systems are widely used to safely and efficiently charge and discharge batteries. In particular, the control unit mounted on the battery management system continuously monitors the temperature of the battery based on signals from the temperature sensing circuit so that the battery temperature can be managed within a predetermined range, and stops the battery when it overheats. Performs functions such as cooling or stopping charging and discharging. The control unit may include an MCU (Micro Control Unit), etc., which may sometimes malfunction (e.g., software error) or break down due to external shocks, etc. In this situation, temperature monitoring of the battery cannot be properly performed by the control unit, and a function to prevent the battery from overheating must also be executed.

The present invention was developed to solve the above problems, and its purpose is to provide a device that additionally monitors the temperature of the battery using hardware, independently of the battery temperature monitoring operation using software.

In addition, the present invention, when an abnormal temperature condition occurs in which the temperature of the battery rises and reaches the first diagnosis temperature (e.g., 80°C), a second diagnosis temperature (e.g., 80°C) lower than the first diagnosis temperature (e.g., 80°C) The purpose is to provide a device that automatically sets (e.g., 65°C) as the temperature of the boundary point between the abnormal temperature state and the normal temperature state.

Other objects and advantages of the present invention can be understood from the following description and will be more clearly understood by practicing the present invention. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means and combinations thereof indicated in the claims.

A battery temperature monitoring device according to an aspect of the present invention includes a reference voltage generation circuit configured to generate a reference voltage using a feedback signal; a voltage comparator configured to generate a comparison signal using a monitoring voltage indicating the temperature of the battery and the reference voltage; and a feedback circuit configured to generate the feedback signal using the comparison signal. The voltage comparator is configured to float the comparison signal when the monitoring voltage is greater than or equal to the reference voltage. The feedback circuit is configured to generate a high-level voltage as the feedback signal when the comparison signal is floating. The reference voltage generating circuit is configured to generate, as the reference voltage, a first diagnostic voltage representing a first diagnostic temperature when the feedback signal is the high-level voltage.

The fact that the monitoring voltage is lower than the first diagnostic voltage may indicate an abnormal temperature state in which the temperature of the battery is higher than the first diagnostic temperature.

The voltage comparator may be configured to generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage. The feedback circuit may be configured to generate the low-level voltage as the feedback signal when the comparison signal is the low-level voltage. The reference voltage generating circuit may be configured to generate a second diagnostic voltage representing a second diagnostic temperature as the reference voltage when the feedback signal is the low-level voltage.

The second diagnosis temperature may be lower than the first diagnosis temperature, and the second diagnosis voltage may be greater than the first diagnosis voltage.

The fact that the monitoring voltage is greater than the second diagnosis voltage may indicate a normal temperature state in which the temperature of the battery is lower than the second diagnosis temperature.

The reference voltage generating circuit includes: a first resistor connected between a reference node and a constant voltage terminal to which a first constant voltage is supplied; a second resistor connected between the reference node and ground; and a series circuit of a third resistor and a first switch connected in parallel to the second resistor. The first switch may be turned on when the feedback signal is the high-level voltage. The first diagnostic voltage may be a voltage across both ends of the second resistor when the first switch is turned on.

The feedback circuit includes a second switch including an emitter, a collector, and a base; a third switch including a source, drain and gate; And it may include a fourth resistor. The emitter may be connected to a third constant voltage terminal to which a second constant voltage is supplied. The collector may be connected to the gate. The base may be connected to the output pin of the voltage comparator. The source may be connected to the ground. The fourth resistor may be connected between the drain and a fourth constant voltage terminal to which a third constant voltage is supplied. When the comparison signal is a low-level voltage, the second switch and the third switch may be turned on. When the third switch is turned on, the low-level voltage may be applied to the first switch as the feedback signal.

The feedback circuit may further include a delay circuit connected between the collector and the gate. The delay circuit may be configured to delay the voltage between the collector and the ground by a predetermined time constant and apply it to the gate when the second switch is turned on.

The feedback circuit may further include a Zener diode connected between the drain and the source.

A battery temperature monitoring device according to another aspect of the present invention includes a reference voltage generation circuit configured to generate a reference voltage using a comparison signal; and a voltage comparator configured to generate the comparison signal using the reference voltage and a monitoring voltage representing the temperature of the battery. The voltage comparator is configured to generate a high-level voltage as the comparison signal when the monitoring voltage is greater than or equal to the reference voltage. The reference voltage generating circuit is configured to generate, as the reference voltage, a first diagnostic voltage representing a first diagnostic temperature when the comparison signal is the high-level voltage.

The voltage comparator may be configured to generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage. The reference voltage generation circuit may be configured to generate, as the reference voltage, a second diagnosis voltage indicating a second diagnosis temperature lower than the first diagnosis temperature when the comparison signal is the low-level voltage.

According to at least one of the embodiments of the present invention, the temperature of the battery can be additionally monitored using hardware, independently of the battery temperature monitoring operation using software.

Additionally, according to at least one of the embodiments of the present invention, when the temperature of the battery reaches the first diagnostic temperature (e.g., 80° C.), the temperature of the battery is set to a second diagnostic temperature (e.g., 80° C.) lower than the first diagnostic temperature. A signal indicating that the battery is in an abnormal temperature state can be automatically output until the temperature drops to 65°C.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described later, so the present invention includes the matters described in such drawings. It should not be interpreted as limited to only .
1 is a diagram schematically showing an energy storage system according to an embodiment of the present invention.
Figure 2 is a diagram schematically showing a battery management system including a battery temperature monitoring device according to the first embodiment.
FIG. 3 is a diagram illustrating the detailed configuration of the temperature monitoring device shown in FIG. 2.
Figure 4 is a diagram illustrating the configuration of a temperature monitoring device according to the second embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately define the concept of terms in order to explain his or her invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle of definability.

Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent the entire technical idea of the present invention, so at the time of filing this application, various alternatives are available to replace them. It should be understood that equivalents and variations may exist.

Terms containing ordinal numbers, such as first, second, etc., are used for the purpose of distinguishing one of the various components from the rest, and are not used to limit the components by such terms.

Throughout the specification, when a part is said to “include” a certain element, this means that it does not exclude other elements, but may further include other elements, unless specifically stated to the contrary. Additionally, terms such as <control unit> described in the specification refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

Additionally, throughout the specification, when a part is said to be "connected" to another part, this refers not only to the case where it is "directly connected" but also to the case where it is "indirectly connected" with another element in between. Includes.

FIG. 1 is a diagram schematically showing an energy storage system according to an embodiment of the present invention, and FIG. 2 is a diagram schematically showing a battery management system including a battery temperature monitoring device according to a first embodiment.

Referring to FIG. 1, the energy storage system 1 includes a power conversion system (PCS) 10 and a plurality of battery racks 20.

The power conversion system 10 is electrically connected between the electric system 2 and the plurality of battery racks 20. The power conversion system 10 can convert alternating current power from the electric system 2 into direct current power for charging the plurality of battery racks 20. The power conversion system 10 can convert direct current power from the plurality of battery racks 20 into alternating current power. The power conversion system 10 may generate constant voltages such as V _C1 , V _C2 , and V _C3 from the AC power or the DC power. Each constant voltage is supplied to each battery rack 20 and used to monitor the temperature of the battery 40. Alternatively, instead of the power conversion system 10, a voltage conversion device (e.g., Low Drop Output (LDO) regulator) within the battery management system (BMS) 40 uses the voltage of the battery 30. V _C1 , V _C2 and/or V _C3 may be generated.

A plurality of battery racks 20 are connected in parallel between the power conversion system 10 and ground. Each battery rack 20 includes a battery 30 and a battery management system 40.

The battery 30 includes a plurality of battery cells 31 electrically connected in series and/or parallel. Each battery cell 31 may be a lithium ion battery cell. Of course, the type of battery cell 31 is not particularly limited as long as repeated charging and discharging is possible.

Referring to FIG. 2 , the battery management system 40 includes a sensing unit 50, a control unit 100, and a battery temperature monitoring device 200.

The sensing unit 50 includes at least one of a voltage sensing circuit 52, a current sensing circuit 54, and a temperature sensing circuit 56.

The voltage sensing circuit 52 is electrically connected to the positive and negative terminals of the battery 30. The voltage sensing circuit 52 is configured to measure the battery voltage, which is the voltage across both ends of the battery 30, and output a signal D _V representing the measured battery voltage to the control unit 100.

Current sensing circuit 54 is electrically connected to a power line between battery 30 and power conversion system 10. For example, a shunt resistor or a Hall effect element can be used as the current sensing circuit 54. The current sensing circuit 54 is configured to measure the battery current flowing through the battery 30 and output a signal D _I representing the measured battery current to the control unit 100.

The temperature sensing circuit 56 is disposed in an area within a predetermined distance from the battery 30. The temperature sensing circuit 56 is configured to measure the battery temperature of the battery 30 and output a signal D _T indicating the measured battery temperature to the control unit 100.

In terms of hardware, the control unit 100 includes application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and microprocessors. It can be implemented using at least one of (microprocessors) and electrical units for performing other functions.

The control unit 100 may have a built-in memory. Programs and various data necessary for battery management may be stored in the memory. Memory, for example, flash memory type, hard disk type, SSD type (Solid State Disk type), SDD type (Silicon Disk Drive type), multimedia card micro type. , at least one of random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and programmable read-only memory (PROM) It may include types of storage media.

The control unit 100 is operably coupled to the sensing unit 50 . The control unit 100 acquires signals (D _V , D _I , D _T ) from each of the voltage sensing circuit 52, current sensing circuit 54, and temperature sensing circuit 56 as battery information, and Information can be recorded in memory.

The control unit 100 may determine the state of charge (SOC) of the battery 30 based on the battery voltage, battery current, and/or battery temperature. To determine SOC, known methods such as current integration method, Kalman filter, etc. may be used.

The control unit 100 may diagnose abnormalities in the battery 30 based on battery information. For example, the control unit 100 can diagnose overvoltage, undervoltage, overcharge, overdischarge, overheating, etc. of the battery 30.

In particular, the control unit 100 executes temperature diagnosis software stored in the memory to diagnose whether the battery 30 is overheated. Specifically, when running the temperature diagnosis software, the control unit 100 converts the analog signal D _T into a digital value using an analog-to-digital converter built into the control unit 100, and uses the digital value as the basis. It is diagnosed whether the temperature of the battery 30 is in an abnormal temperature state higher than the first diagnosis temperature (eg, 80°C) or in a normal temperature state lower than the second diagnosis temperature (eg, 65°C). The first diagnosis temperature and the second diagnosis temperature may be determined in advance in consideration of the electrochemical characteristics of the battery 30, the use environment of the energy storage system 1, etc.

The term 'monitoring voltage' as used herein refers to a signal (D _T ).

The battery temperature monitoring device 200 includes a reference voltage generation circuit 210, a voltage comparator 220, and a feedback circuit 230. The temperature monitoring device 200, separate from the control unit 100 as a 'primary protection means', serves as a 'secondary protection means' that redundantly monitors the temperature of the battery 30.

The reference voltage generation circuit 210 is configured to generate the reference voltage _DR using the feedback signal _DF from the feedback circuit 230 .

The voltage comparator 220 uses the monitoring voltage (D _T ) from the temperature sensing circuit 56 and the reference voltage (D _R ) from the reference voltage generation circuit 210 to generate a comparison signal (D _C ). It is composed. Specifically, the voltage comparator 220 includes an input pin (IN+), an input pin (IN-), and an output pin (OUT). The monitoring voltage (D _T ) is input to the input pin (IN+). The reference voltage ( _DR ) is input to the input pin (IN-). The comparison signal ( _DC ) is output from the output pin (OUT).

The feedback circuit 230 is configured to generate a feedback signal (D _F ) using the comparison signal (D _C ) from the voltage comparator 220 .

FIG. 3 is a diagram illustrating the detailed configuration of the temperature monitoring device 200 shown in FIG. 2.

Referring to FIG. 3, the temperature sensing circuit 56 includes a resistor 61 and a thermistor 60. The resistor 61 is connected between the constant voltage terminal CV1 and the reference node N1. The thermistor 60 is connected between the reference node N1 and ground. The reference node (N1) is connected to the input pin (IN+) of the voltage comparator 220. The reference node N1 refers to an electrical position where one end of the resistor 61 and one end of the thermistor 60 are connected. That is, the resistor 61 and the thermistor 60 are connected in series between the constant voltage terminal CV1 and ground. According to the resistance ratio of the resistor 61 and the thermistor 60, the constant voltage V _C1 (eg, 3.3 V) supplied through the constant voltage terminal CV1 is distributed.

The thermistor 60 has a negative temperature coefficient with respect to the temperature of the battery 30. The monitoring voltage (D _T ) is the voltage across both ends of the thermistor 60. Accordingly, as the temperature of the battery 30 increases, the resistance of the thermistor 60 and the monitoring voltage (D _T ) decrease respectively. Conversely, as the temperature of the battery 30 decreases, the resistance of the thermistor 60 and the monitoring voltage (D _T ) increase respectively.

The reference voltage generation circuit 210 includes a resistor 62, a resistor 63, a resistor 64, and a switch Q1. The resistor 62 is connected between the constant voltage terminal CV2 and the reference node N2. The resistor 63 is connected between the reference node N2 and ground. The reference node (N2) is connected to the input pin (IN-) of the voltage comparator 220. The reference node N2 refers to an electrical position where one end of the resistor 62 and one end of the resistor 63 are connected. That is, the resistor 62 and the resistor 63 are connected in series between the constant voltage terminal CV2 and ground. A constant voltage (V _C1 ) is supplied from the constant voltage terminal (CV2). The series circuit of the resistor 64 and the switch Q1 is connected in parallel to the resistor 63. Switch Q1 is provided to open and close the current path between the resistor 64 and ground.

In Figure 3, it is illustrated that the switch Q1 is an N-channel MOSFET. The source and drain of the switch Q1 may be connected to the resistor 64 and ground, respectively. The gate of the switch Q1 may be connected to the reference node N3. The feedback signal D _F may be input to the gate of the switch Q1. The switch Q1 may be turned on when the feedback signal _DF is a high-level voltage and turned off when the feedback signal _DF is a low-level voltage.

Resistance of the resistor 61 = R ₁ [Ω], resistance of the resistor 62 = R ₂ [Ω], resistance of the resistor 63 = R ₃ [Ω], resistance of the resistor 64 = R ₄ [Ω] ], Let us assume that the resistance of the thermistor 60 at the first diagnostic temperature = R _TH1 [Ω], and the resistance of the thermistor 60 at the second diagnostic temperature = R _TH2 [Ω]. Then, the following first and second relationships are satisfied.

<First relationship> R ₁ : R ₂ = R _TH1 : (R ₃ × R ₄ )/(R ₃ + R ₄ )

<Second relationship> R ₁ : R ₂ = R _TH2 : R ₃

Referring to the first relationship, when the switch Q1 is turned on, the constant voltage supplied through the constant voltage terminal CV2 according to the resistance ratio of the resistor 62 and the parallel circuit of the resistor 63 and the resistor 64. (V _C1 ) is distributed. Accordingly, a first diagnostic voltage representing the first diagnostic temperature is generated as the reference voltage _DR . The first diagnostic voltage is the voltage across the resistor 63 when the switch Q1 is turned on. The first diagnostic voltage = V _C1 × {(R ₃ × R ₄ )/(R ₃ + R ₄ )}/{R ₂ + (R ₃ × R ₄ )/(R ₃ + R ₄ )} [V] .

Referring to the second relationship, when the switch Q1 is turned off, the constant voltage V _C1 supplied through the constant voltage terminal CV2 is distributed according to the resistance ratio of the resistor 63 and the resistor 62. Accordingly, a second diagnostic voltage representing the second diagnostic temperature is generated as the reference voltage _DR . The second diagnostic voltage is the voltage across the resistor 63 when the switch Q1 is turned off. For example, the second diagnostic voltage = V _C1 × R ₃ /(R ₂ + R ₃ )} [V].

R ₃ is greater than (R ₃ × R ₄ )/(R ₃ + R ₄ ). Therefore, the second diagnostic voltage is greater than the first diagnostic voltage.

The fact that the monitoring voltage (D _T ) is below the first diagnosis voltage indicates an abnormal temperature state in which the temperature of the battery 30 is above the first diagnosis temperature. The fact that the monitoring voltage (D _T ) is greater than the second diagnosis voltage indicates a normal temperature state in which the temperature of the battery 30 is lower than the second diagnosis temperature.

The voltage comparator 220 may be activated by a constant voltage (V _C2 ) (eg, 12V) supplied through the constant voltage terminal (CV3). The voltage comparator 220 provides _a comparison signal ₍ D _C ) can be plotted. Floating the comparison signal means electrically insulating the output pin (OUT) from the feedback circuit 230. As the voltage comparator 220, for example, the LM2903 model can be used.

When the monitoring voltage (D _T ) input to the input pin (IN+) is smaller than the reference voltage (D _R ) input to the input pin (IN-), the voltage comparator 220 generates a low-level voltage as a comparison signal (D _C ) can be created as. The low-level voltage may be a ground voltage.

The feedback circuit 230 includes a switch Q2, a switch Q3, and a resistor 65. The feedback circuit 230 may further include at least one of a delay circuit 232 and a Zener diode (ZD1). The delay circuit 232 is configured to delay the time at which the feedback circuit 230 generates the feedback signal D _F in response to the comparison signal D _C . The delay circuit 232 has a predetermined time constant and suppresses fluctuations in the feedback signal D _F by filtering the high-frequency component of the comparison signal D _C .

In Figure 3, the switch Q2 is a PNP-type transistor, and the switch Q3 is an N-channel MOSFET. Switch Q2 includes an emitter, collector and base. Switch Q3 includes a source, drain, and gate. The emitter of the switch Q2 may be connected to a constant voltage terminal CV4 that supplies a constant voltage V _C2 . The voltage comparator 320 may operate using a constant voltage (V _C2 ). The collector of switch Q2 may be connected to the gate of switch Q3. The base of the switch Q2 may be connected to the output pin (OUT) of the voltage comparator 220. The source of switch Q3 may be connected to ground. The drain of the switch Q3 may be connected to the resistor 65 through the reference node N3. The resistor 65 is a pull-up resistor and may be connected between the reference node N3 and the constant voltage terminal CV4 that supplies the constant voltage V _C3 (eg, 5V). Feedback signal D _F may be a voltage across both ends of switch Q3.

When the comparison signal D _C is floating, the emitter-base voltage of switch Q2 becomes low-level, and switch Q2 is turned off. When switch Q2 is turned off, the gate-source voltage of switch Q3 becomes low-level, causing switch Q3 to turn off. When switch Q3 is turned off, the drain of switch Q3 is electrically isolated from ground, and a constant voltage V _C3 is applied between the drain of switch Q3 and ground. Accordingly, when the switch Q3 is turned off, the high-level voltage by the constant voltage V _C3 is supplied to the switch Q1 as a feedback signal D _F through the reference node N3, and the switch Q1 ) is turned on.

When the comparison signal ( _DC ) is a low-level voltage, the emitter-base voltage of the switch (Q2) becomes high-level due to the voltage between the constant voltage terminal (CV2) and the output pin (OUT), and the switch (Q2) becomes high-level. ) is turned on. To prevent overvoltage from being applied between the emitter and base of the switch Q2, a voltage divider for the resistor RP1 and the resistor RP2 may be added to the feedback circuit 230. Resistor RP1 may be connected between the emitter and base of switch Q2. The resistor RP2 may be connected between the base of the switch Q2 and the output pin OUT1.

When the switch Q2 is turned on, a high-level voltage due to the constant voltage V _C2 is supplied between the gate and source of the switch Q3, so that the switch Q3 is turned on. When switch Q3 is turned on, the drain of switch Q3 is electrically connected to ground, causing the voltage between the drain of switch Q3 and ground to be low-level. Accordingly, when the switch Q3 is turned on, a low-level voltage is supplied to the switch Q1 as the feedback signal D _F , so that the switch Q1 is turned off.

When the feedback circuit 230 includes a delay circuit 232, the collector of the switch Q2 may be connected to the gate of the switch Q3 through the delay circuit 232.

The delay circuit 232 includes a resistor 66 and a capacitor C1. Resistor 66 is connected between the collector of switch Q2 and the gate of switch Q3. Capacitor C1 is connected between the gate of switch Q3 and ground.

The delay circuit 232 may further include a resistor 67 . The resistor 67 may be connected in parallel to the capacitor C1. The series circuit of the resistor 66 and the resistor 67 functions as a voltage divider. Therefore, the voltage of capacitor C1 is limited by the resistance ratio of the resistor 66 and the resistor 67. Additionally, when the switch Q2 is turned off, the electrical energy charged in the capacitor C1 is consumed by the resistor 67, so that the switch Q3 can be quickly turned off.

When the switch Q2 is turned on, the constant voltage V _C2 supplied from the constant voltage terminal CV4 through the switch Q2 is delayed (flattened) by the delay circuit 232, and is connected to the gate and source of the switch Q3. approved in the liver. Accordingly, if the comparison signal D _C is maintained at a low level for less than a certain time, the voltage of the capacitor C1 becomes less than the threshold voltage of the switch Q3, and the switch Q3 is not turned on.

The cathode and anode of Zener diode ZD1 are connected to the drain and ground of switch Q3, respectively. The voltage between the reference node N3 and ground is limited by the breakdown voltage of the Zener diode ZD1. Accordingly, the switch Q1 and switch Q3 can be protected from overvoltage supplied to the reference node N3.

The feedback signal D _F is information indicating whether the battery 30 is overheated, and may be input to the control unit 100 and/or the power conversion system 10. The control unit 100 and/or the power conversion system 10 may execute safety measures such as stopping charging and discharging of the battery 30 when the feedback signal D _F is at a low level. The control unit 100 and/or the power conversion system 10 may release the safety measure when the feedback signal D _F is at a high level.

FIG. 4 is a diagram illustrating the configuration of the battery temperature monitoring device 300 according to the second embodiment.

Referring to FIG. 4 , the temperature monitoring device 300 according to the second embodiment includes a reference voltage generating circuit 310 and a voltage comparator 320. The temperature monitoring device 300 may further include at least one of a delay circuit 330 and a Zener diode (ZD2).

The reference voltage generation circuit 310 is configured to generate a reference voltage ( _DR ) using the comparison signal (D _C ) from the voltage comparator 320. Since the reference voltage generation circuit 310 is the same as the reference voltage generation circuit 210, repetitive description will be omitted.

The voltage comparator 320 uses the monitoring voltage (D _T ) from the temperature sensing circuit 56 and the reference voltage (D _R ) from the reference voltage generation circuit 310 to generate a comparison signal (D _C ). It is composed.

The voltage comparator 320 includes an input pin (IN+), an input pin (IN-), and an output pin (OUT). The monitoring voltage (D _T ) is input to the input pin (IN+). The reference voltage ( _DR ) is input to the input pin (IN-). The comparison signal ( _DC ) is output from the output pin (OUT).

The voltage comparator 320 may operate using a constant voltage (V _C2 ). The voltage comparator 320 provides _a comparison signal ₍ It differs from the voltage comparator 220 in that, instead of floating D _C ), it generates a high-level voltage as a comparison signal (D _C ).

When the monitoring voltage (D _T ) input to the input pin (IN+) is smaller than the reference voltage (D _R ) input to the input pin (IN-), the voltage comparator 320 generates a low-level voltage as a comparison signal (D _C ) can be created as.

The delay circuit 330 is configured to delay the time at which the comparison signal D _C from the voltage comparator 320 is transmitted to the reference voltage generation circuit 310. The delay circuit 330 has a predetermined time constant and filters the high-frequency component of the comparison signal D _C .

The delay circuit 330 includes a resistor 68 and a capacitor C2. The resistor 68 is connected between the output pin (OUT) of the voltage comparator 320 and the reference node (N4). The gate of switch Q1 is connected to the reference node N4. Capacitor C2 is connected between the gate of switch Q1 and ground.

The delay circuit 330 may further include a resistor 69 . The resistor 69 may be connected in parallel to the capacitor C2. The series circuit of the resistor 68 and the resistor 69 functions as a voltage divider. Therefore, the voltage of capacitor C2 is limited by the resistance ratio of the resistor 68 and the resistor 69.

When a high-level voltage (e.g., 12V) is supplied as a comparison signal ( _DC ) from the output pin (OUT), the comparison signal ( _DC ) is delayed (flattened) by the delay circuit 330, and the delayed comparison signal (D _C ) is applied between the gate and source of switch Q1 through reference node N4. Therefore, if the comparison signal D _C is maintained at a high level for less than a certain time, the voltage of the capacitor C2 becomes less than the threshold voltage of the switch Q1, and the switch Q1 is not turned on.

The voltage between the reference node N4 and ground is information indicating whether the battery 30 is overheated, and may be input to the control unit 100 and/or the power conversion system 10.

When the temperature monitoring device 300 does not include the delay circuit 330, the reference node (N4) refers to an electrical position where the output pin (OUT) and the gate of the switch (Q1) are connected.

When the temperature monitoring device 300 includes the delay circuit 330, the reference node N4 refers to an electrical position where the capacitor C2 and the gate of the switch Q1 are connected.

The cathode and anode of the Zener diode (ZD2) are connected to the reference node (N4) and ground, respectively. The voltage between the reference node (N4) and ground is limited by the breakdown voltage of the Zener diode (ZD2). Accordingly, the switch Q1, etc. can be protected from overvoltage supplied to the reference node N4.

The control unit 100 and/or the power conversion system 10 may execute safety measures such as stopping charging and discharging of the battery 30 when the voltage between the reference node N4 and ground is at a low level. The control unit 100 and/or the power conversion system 10 may release the safety measure when the voltage between the reference node N4 and ground is at a high level.

The embodiments of the present invention described above are not only implemented through devices and methods, but may also be implemented through a program that realizes the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. The implementation can be easily implemented by an expert in the technical field to which the present invention belongs based on the description of the embodiments described above.

Although the present invention has been described above with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the description below will be understood by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalence of the patent claims.

In addition, the present invention described above is capable of various substitutions, modifications and changes without departing from the technical spirit of the present invention to those of ordinary skill in the technical field to which the present invention pertains. It is not limited by the drawings, and all or part of each embodiment can be selectively combined so that various modifications can be made.

200, 300: Battery temperature monitoring device
210, 310: Reference voltage generation circuit
220, 320: Voltage comparator
230: feedback circuit

Claims (11)

a reference voltage generation circuit configured to generate a reference voltage using a feedback signal;
a voltage comparator configured to generate a comparison signal using a monitoring voltage indicating the temperature of the battery and the reference voltage; and
a feedback circuit configured to generate the feedback signal using the comparison signal,
The voltage comparator is configured to float the comparison signal when the monitoring voltage is greater than or equal to the reference voltage,
the feedback circuit is configured to generate a high-level voltage as the feedback signal when the comparison signal is floating,
The reference voltage generating circuit is configured to generate, as the reference voltage, a first diagnostic voltage representing a first diagnostic temperature when the feedback signal is the high-level voltage.
According to paragraph 1,
The battery temperature monitoring device wherein the fact that the monitoring voltage is lower than or equal to the first diagnostic voltage indicates an abnormal temperature state in which the temperature of the battery is higher than or equal to the first diagnostic temperature.
According to paragraph 1,
The voltage comparator is configured to generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage,
The feedback circuit is configured to generate the low-level voltage as the feedback signal when the comparison signal is the low-level voltage,
The reference voltage generating circuit is configured to generate, as the reference voltage, a second diagnostic voltage representing a second diagnostic temperature when the feedback signal is the low-level voltage.
According to paragraph 3,
The second diagnostic temperature is lower than the first diagnostic temperature,
The second diagnostic voltage is greater than the first diagnostic voltage.
According to paragraph 3,
The battery temperature monitoring device wherein the fact that the monitoring voltage is greater than the second diagnostic voltage indicates a normal temperature state in which the temperature of the battery is lower than the second diagnostic temperature.
According to paragraph 1,
The reference voltage generation circuit is,
a first resistor connected between a reference node and a constant voltage terminal to which a first constant voltage is supplied;
a second resistor connected between the reference node and ground; and
A series circuit of a third resistor and a first switch connected in parallel to the second resistor,
The first switch is turned on when the feedback signal is the high-level voltage,
The first diagnostic voltage is a voltage across both ends of the second resistor when the first switch is turned on.
According to clause 6,
The feedback circuit is,
a second switch including an emitter, a collector, and a base;
a third switch including a source, drain and gate; and
Including a fourth resistor,
The emitter is connected to a third constant voltage terminal to which a second constant voltage is supplied, the collector is connected to the gate, the base is connected to the output pin of the voltage comparator, the source is connected to the ground, and the first 4 The resistor is connected between the drain and a fourth constant voltage terminal to which a third constant voltage is supplied,
When the comparison signal is a low-level voltage, the second switch and the third switch are turned on,
When the third switch is turned on, the low-level voltage is applied to the first switch as the feedback signal.
In clause 7,
The feedback circuit is,
Further comprising a delay circuit connected between the collector and the gate,
The delay circuit is,
A battery temperature monitoring device configured to delay the voltage between the collector and the ground by a predetermined time constant and apply it to the gate when the second switch is turned on.
In clause 7,
The feedback circuit is,
A battery temperature monitoring device further comprising a Zener diode connected between the drain and the source.
a reference voltage generation circuit configured to generate a reference voltage using the comparison signal; and
A voltage comparator configured to generate the comparison signal using a monitoring voltage indicating the temperature of the battery and the reference voltage,
The voltage comparator is configured to generate a high-level voltage as the comparison signal when the monitoring voltage is higher than the reference voltage,
The reference voltage generating circuit is configured to generate, as the reference voltage, a first diagnostic voltage representing a first diagnostic temperature when the comparison signal is the high-level voltage.
According to clause 10,
The voltage comparator is configured to generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage,
The reference voltage generating circuit is configured to generate, as the reference voltage, a second diagnostic voltage representing a second diagnostic temperature lower than the first diagnostic temperature when the comparison signal is the low-level voltage. .

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