KR20210089449A - Battery management system, baptter rack, and energy storage system - Google Patents

Abstract

The present invention relates to a battery management system (BMS) to monitor the temperature of a battery in a dual mode, and a battery rack and an energy storage system using the same. According to an embodiment of the present invention, the BMS comprises a temperature sensing circuit generating a monitoring voltage indicating the temperature of a battery and a temperature monitoring device. The temperature monitoring device includes: a reference voltage generation circuit generating a reference voltage; a voltage comparator generating a comparison signal; and a feedback circuit generating a feedback signal. When the monitoring voltage is equal to or greater than the reference voltage, the voltage comparator floats the comparison signal. When the monitoring voltage is less than the reference voltage, the voltage comparator generates a low-level voltage as the comparison signal. When the comparison signal is floated, the feedback circuit generates a high-level voltage as a feedback signal. When the comparison signal is the low-level voltage, the feedback circuit generates the low-level voltage as the feedback signal. When the feedback signal is the high-level voltage, the reference voltage generation circuit generates a first diagnostic voltage representing a first diagnostic temperature as a reference voltage.

Description

BATTERY MANAGEMENT SYSTEM, BAPTTER RACK, AND ENERGY STORAGE SYSTEM

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

Recently, as the demand for portable electronic products such as laptops, video cameras, and portable telephones is rapidly increasing and the development of electric vehicles, energy storage batteries, robots, satellites, etc. is in full swing, high-performance batteries that can be repeatedly charged and discharged have been developed. Research is being actively conducted.

Currently commercialized batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium batteries. Among them, lithium batteries have almost no memory effect compared to nickel-based batteries, so they are free to charge and discharge and have a very high self-discharge rate. It is attracting attention due to its low energy density and high energy density.

A battery management system for safely and efficiently charging and discharging a battery is widely used. In particular, the control unit mounted in the battery management system continuously monitors the temperature of the battery based on a signal from the temperature sensing circuit so that the temperature of the battery can be managed within a predetermined range, and controls the battery when the battery is overheated. Execute functions such as cooling or stopping charging and discharging. The control unit may include a micro control unit (MCU), etc., and may occasionally malfunction (eg, software error) or malfunction due to an external shock or the like. In such a situation, temperature monitoring of the battery cannot be properly performed by the control unit, and a function for preventing the battery from overheating must also be executed.

The present invention has been devised to solve the above problems, and includes a device for additionally monitoring the temperature of the battery using hardware independently of a control unit for monitoring the temperature of the battery using software. , for the purpose of providing a battery rack and an energy storage system.

In addition, the present invention provides a second diagnostic temperature (eg, 80°C) lower than the first diagnostic temperature (eg, 80°C) when an abnormal temperature state in which the battery temperature rises and reaches the first diagnostic temperature (eg, 80°C) occurs. An object of the present invention is to provide a battery management system, a battery rack, and an energy storage system including a device for automatically setting the temperature of the boundary point between the abnormal temperature state and the normal temperature state.

Other objects and advantages of the present invention may be understood by the following description, and will become more clearly understood by the examples of 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 management system according to a first embodiment of the present invention includes: a temperature sensing circuit configured to generate a monitoring voltage indicating a temperature of a battery; and a temperature monitoring device. The temperature monitoring device includes: a reference voltage generating circuit configured to generate a reference voltage by using a feedback signal; a voltage comparator configured to generate a comparison signal using the monitoring voltage 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 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 a high-level voltage as the feedback signal when the comparison signal is floated. 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 first diagnostic voltage representing a first diagnostic temperature when the feedback signal is the high-level 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 feedback signal is the low-level voltage.

The second diagnosis voltage may be greater than the first diagnosis voltage.

When the monitoring voltage is less than or equal to the first diagnostic voltage, the temperature of the battery indicates an abnormal temperature state equal to or greater than the first diagnostic temperature. When the monitoring voltage is greater than the second diagnosis voltage, it indicates a normal temperature state in which the temperature of the battery is lower than the second diagnosis temperature.

The temperature sensing circuit may include: a first resistor connected between a first constant voltage terminal to which a first constant voltage is supplied and a first reference node; and a thermistor having a negative temperature coefficient with respect to the temperature of the battery and connected between the first reference node and a ground. The monitoring voltage is the voltage across the thermistor.

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

The first switch may be turned off when the feedback signal is the low-level voltage. The second diagnostic voltage is a voltage across both ends of the third resistor when the first switch is turned off.

The voltage comparator may include: a first input pin connected to the first reference node; a second input pin connected to the second reference node; and an output pin for outputting the comparison signal.

The feedback circuit may include: a second switch including an emitter, a collector, and a base; a third switch comprising a source, a drain and a gate; and a fifth 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. The source may be connected to the ground. The fifth resistor may be connected between a fourth constant voltage terminal to which a third constant voltage is supplied and the drain. When the comparison signal is the low-level voltage, the second switch and the third switch may be sequentially 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 management system according to a second embodiment of the present invention includes: a temperature sensing circuit configured to generate a monitoring voltage indicating a temperature of a battery; and a temperature monitoring device. The temperature monitoring device includes: a reference voltage generating circuit configured to generate a reference voltage by using the comparison signal; and a voltage comparator configured to generate the comparison signal using the monitoring voltage and the reference voltage. The voltage comparator is configured to generate a high-level voltage as the comparison signal when the monitoring voltage is equal to or greater than the reference voltage. 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 first diagnostic voltage representing a first diagnostic temperature when the comparison signal is the high-level voltage. and 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.

A battery pack according to another aspect of the present invention includes the battery management system.

An energy storage system according to another aspect of the present invention includes the battery rack.

According to at least one of the embodiments of the present invention, the battery management system may double-monitor the temperature of the battery.

Also, according to at least one of the embodiments of the present invention, when the temperature of the battery rises to reach the first diagnosis temperature (eg, 80° C.), the battery temperature is lower than the first diagnosis temperature at the second diagnosis temperature ( Yes, it can automatically output a signal indicating that the battery is in an abnormal temperature state until it drops to 65°C).

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 spirit of the present invention together with the detailed description of the present invention to be described later, so the present invention is described in such drawings should not be construed as being limited only to
1 is a diagram schematically illustrating an energy storage system according to an embodiment of the present invention.
2 is a diagram schematically illustrating a battery management system including a temperature monitoring device according to the first embodiment.
FIG. 3 is a diagram exemplarily showing a detailed configuration of the temperature monitoring device shown in FIG. 2 .
4 is a diagram exemplarily showing 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 accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the configuration shown in the embodiments and drawings described in the present specification is only the most preferred embodiment of the present invention and does not represent all of the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

Terms including an ordinal number such as 1st, 2nd, etc. are used for the purpose of distinguishing any one of various components from the others, and are not used to limit the components by such terms.

Throughout the specification, when a part "includes" a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated. In addition, a term such as <control unit> described in the specification means a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

In addition, throughout the specification, when a part is "connected" with another part, it is not only "directly connected" but also "indirectly connected" with another element interposed therebetween. include

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 temperature monitoring device according to the 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 electrical system 2 and the plurality of battery racks 20 . The power conversion system 10 may convert AC power from the electrical system 2 into DC power for charging of the plurality of battery racks 20 . The power conversion system 10 may convert DC power from a plurality of battery racks 20 into AC power. The power conversion system 10 may generate a constant voltage 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 is used to monitor the temperature of the battery 40 . Alternatively, instead of the power conversion system 10 , a voltage conversion device (eg, a low drop output (LDO) regulator) in 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 the 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 in parallel. Each battery cell 31 may be a lithium ion battery cell. Of course, as long as repeated charging and discharging are possible, the type of the battery cell 31 is not particularly limited.

Referring to FIG. 2 , the battery management system 40 includes a sensing unit 50 , a control unit 100 , and a 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 a positive terminal and a negative terminal of the battery 30 . The voltage sensing circuit 52 is configured to measure a battery voltage, which is a voltage across both ends of the battery 30 , and _{output a signal D V} representing the measured battery voltage to the controller 100 .

The current sensing circuit 54 is electrically connected to a power line between the battery 30 and the power conversion system 10 . For example, a shunt resistor or a Hall effect element may be used as the current sensing circuit 54 . The current sensing circuit 54 is configured to measure a battery current flowing through the battery 30 and _{output a signal D I} representing the measured battery current to the controller 100 .

The temperature sensing circuit 56 is disposed in a region 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 controller 100 .

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

The controller 100 may have a built-in memory. A program and various data necessary for managing the battery may be stored in the memory. The memory is, for example, a flash memory type, a hard disk type, a solid state disk type, an SDD type (Silicon Disk Drive type), and a 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) may include a type of storage medium of

The control unit 100 is operatively coupled to the sensing unit 50 . _{The control unit 100 acquires the signals D V} , D _I , D _T from each of the voltage sensing circuit 52 , the current sensing circuit 54 , and the temperature sensing circuit 56 as battery information, and the obtained battery Information can be written to memory.

The controller 100 may determine a state of charge (SOC) of the battery 30 based on the battery voltage, the battery current, and/or the battery temperature. For the determination of the SOC, a known method such as a current integration method or a Kalman filter may be utilized.

The controller 100 may diagnose an abnormality of the battery 30 based on the battery information. For example, the controller 100 may diagnose overvoltage, undervoltage, overcharging, overdischarging, overheating, and the like of the battery 30 .

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

As used herein, the term 'monitoring voltage' refers to a _{signal D T .}

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

The reference voltage generation circuit 210 is configured to generate the reference voltage D _{R using the feedback signal D F from the feedback circuit 230 .}

The voltage comparator 220 using the reference voltage (D _R) from the monitored voltage (D _T) and a reference voltage generating circuit 210 from a temperature sensing circuit 56, to generate a comparison signal (D _C) 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 D _R is input to the input pin IN-. The comparison signal (D _C) is output from the output pin (OUT).

Feedback circuit 230, using the comparison signal _(C D) from the voltage comparator 220, is configured to generate a feedback signal _(F D).

3 is a diagram exemplarily showing a 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 the 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 the ground. _{The constant voltage V C1} (eg, 3.3V) supplied through the constant voltage terminal CV1 is distributed according to the resistance ratio between the resistor 61 and the thermistor 60 .

The thermistor 60 has a negative characteristic temperature coefficient with respect to the temperature of the battery 30 . The monitoring voltage D _T is the voltage across 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 generating 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 the 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 the ground. _{A constant voltage V C1} is supplied from the constant voltage terminal CV2 . A series circuit of the resistor 64 and the switch Q1 is connected in parallel to the resistor 63 . The switch Q1 is provided to open and close the current path between the resistor 64 and the ground.

3 illustrates 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 the 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 . Switch (Q1), the feedback signal _(F D) is a high-turned on when the voltage level, the feedback signal _(F D) the low-may be turned off when the voltage level.

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

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

<Second Relation> 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 between the parallel circuit of the resistor 63 and the resistor 64 and the resistor 62 . (V _C1 ) is distributed. Accordingly, the first diagnostic voltage representing the first diagnostic temperature is generated as the _{reference voltage D R .} The first diagnostic voltage is a voltage across both ends of the resistor 63 when the switch Q1 is turned on. 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 between the resistor 63 and the resistor 62 . Accordingly, the second diagnostic voltage representing the second diagnostic temperature is generated as the _{reference voltage D R .} The second diagnostic voltage is a voltage across both ends of 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 ).} Accordingly, the second diagnostic voltage is greater than the first diagnostic voltage.

The monitoring voltage D _T being equal to or less than the first diagnosis voltage indicates an abnormal temperature state in which the temperature of the battery 30 is equal to or greater than the first diagnosis temperature. When the monitoring voltage D _T is greater than the second diagnostic voltage, it indicates a normal temperature state in which the temperature of the battery 30 is lower than the second diagnostic temperature.

_{The voltage comparator 220 may be activated by a constant voltage V C2} (eg, 12V) supplied through the constant voltage terminal CV3 . If there is more than the voltage comparator 220, an input pin (IN +) monitoring the voltage (D _T), the reference voltage (D _R) that is input to the input pin (IN-) input to, compare signal from the output pin (OUT) ( 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.

Voltage comparator 220 includes an input pin (IN +) is smaller than the reference voltage (D _R) that is input to the monitor voltage (D _T), the input pin (IN-) inputted to the low-comparison signal (D level voltage _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 .} A delay circuit 232, has a predetermined time constant of, by filtering the high frequency components of the comparison signal _(C D), to suppress the fluctuation of the feedback signal _(F D).

3 illustrates that the switch Q2 is a PNP-type transistor and the switch Q3 is an N-channel MOSFET. The switch Q2 includes an emitter, a collector and a base. The switch Q3 includes a source, a drain, and a gate. An 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 the _{constant voltage V C2 .} The collector of the switch Q2 may be connected to the gate of the switch Q3. The base of the switch Q2 may be connected to the output pin OUT of the voltage comparator 220 . The source of the switch Q3 may be connected to the ground. A drain of the switch Q3 may be connected to the resistor 65 through a reference node N3. The resistor 65 is a pull-up resistor and may be connected between the constant voltage terminal CV4 that supplies a constant _{voltage V C3 (eg, 5V) and the reference node N3 .} The feedback signal D _F may be a voltage across the switch Q3 .

If the comparison signal (D _C) which is floating, and the emitter of the switch (Q2) - the base-low voltage - is the level, the switch (Q2) is turned off. When the switch Q2 is turned off, the gate-source voltage of the switch Q3 becomes low-level, so that the switch Q3 is turned off. When the switch Q3 is turned off, the drain of the switch Q3 is electrically isolated from the ground, and a constant voltage V _C3 is applied between the drain of the switch Q3 and the 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, so that the switch Q1 ) is turned on.

When the comparison signal D _C is a low-level voltage, the emitter-base voltage of the switch Q2 becomes high-level by the voltage between the constant voltage terminal CV2 and the output pin OUT, and the switch Q2 ) is turned on. A voltage divider between the resistor RP1 and the resistor RP2 may be added to the feedback circuit 230 so that an overvoltage is not applied between the emitter and the base of the switch Q2 . The resistor RP1 may be connected between the emitter and the base of the 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 by the constant voltage V C2} is supplied between the gate-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, so that the voltage between the drain of switch Q3 and ground is brought to a 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 the 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 resistor 66 and resistor 67 functions as a voltage divider. Accordingly, the voltage of the capacitor C1 is limited by the resistance ratio between the resistor 66 and the resistor 67 . In addition, 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, so that the gate and the source of the switch Q3 approved in the liver. Thus, the comparison signal (D _C) is low - If the time kept at a level less than a predetermined time, the voltage of the capacitor (C1) is the threshold voltage is less than the switch (Q3), the switch (Q3) is not turned on.

The cathode and the anode of the Zener diode ZD1 are connected to the drain and the ground of the switch Q3, respectively. The voltage between the reference node N3 and the ground is limited by the breakdown voltage of the Zener diode ZD1. Accordingly, the switch Q1 and the switch Q3 may be protected from the 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 controller 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 a high-level.}

4 is a diagram exemplarily showing the configuration of the temperature monitoring device 300 according to the second embodiment.

Referring to FIG. 4 , the temperature monitoring apparatus 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 .

A reference voltage generating circuit 310, using the comparison signal _(C D) from the voltage comparator 320, is configured to generate a reference voltage (D _R). The reference voltage generation circuit 310 is the same as the reference voltage generation circuit 210 , and a repetitive description thereof 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 .} 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 D _R is input to the input pin IN-. The comparison signal (D _C) is output from the output pin (OUT).

The voltage comparator 320 may operate using the _{constant voltage V C2 .} If there is more than the voltage comparator 320, an input pin (IN +) monitoring the voltage (D _T), the reference voltage (D _R) that is input to the input pin (IN-) input to, compare signal from the output pin (OUT) ( instead, the high-to-floating D _C), - in that it generates a comparison signal (D _C voltage level), it is different from the voltage comparator 220.

The voltage comparator 320, an input pin (IN +) is smaller than the reference voltage (D _R) that is input to the monitor voltage (D _T), the input pin (IN-) inputted to the low-comparison signal (D level voltage _C ) can be created as

A delay circuit 330, the comparison signal _(C D) from the voltage comparator 320 is configured to delay the amount of time that passes as the reference voltage generation circuit 310. The delay circuit 330 has a predetermined time constant of, the filter high frequency components 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 the 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 resistor 68 and resistor 69 functions as a voltage divider. Accordingly, the voltage of the capacitor C2 is limited by the resistance ratio between the resistor 68 and the resistor 69 .

High-case supplied from a low level voltage (e.g., 12V) output pin (OUT) as a comparison signal (D _C), the comparison signal (D _C) is delayed (flattened) by the delay circuit 330, the delayed comparison signal (D _C ) is applied between the gate and source of switch Q1 via reference node N4. Thus, the comparison signal (D _C) is high - if the time kept at a level less than a predetermined time, the voltage of the capacitor (C2) is the threshold voltage is less than the switch (Q1), the switch (Q1) is not turned on.

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

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.

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

The controller 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 the ground is low-level. The controller 100 and/or the power conversion system 10 may release the safety measure when the voltage between the reference node N4 and the ground is a high-level.

The embodiment of the present invention described above is not implemented only through the apparatus and method, and may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded. The implementation can be easily implemented by those skilled in the art to which the present invention pertains from the description of the above-described embodiments.

In the above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto and will be described below with the technical idea of the present invention by those of ordinary skill in the art to which the present invention belongs. Of course, various modifications and variations are possible within the scope of equivalents of the claims.

In addition, since the present invention described above can be various substitutions, modifications and changes within the scope that does not depart from the technical spirit of the present invention for those of ordinary skill in the art to which the present invention pertains, the above-described embodiments and attachments It is not limited by the illustrated drawings, and all or part of each embodiment may be selectively combined and configured so that various modifications may be made.

1: Energy storage system 2: Electrical system
10: power conversion system 20: battery rack
30: battery 31: battery cell
40: battery management system 50: sensing unit
52: voltage sensing circuit 54: current sensing circuit
56: temperature sensing circuit 100: control unit
200, 300: temperature monitoring device
210, 310: reference voltage generating circuit
220, 320: voltage comparator
230: feedback circuit

Claims (13)

a temperature sensing circuit configured to generate a monitoring voltage indicative of a temperature of the battery; and
a temperature monitoring device;
The temperature monitoring device,
a reference voltage generation circuit configured to generate a reference voltage by using the feedback signal;
a voltage comparator configured to generate a comparison signal using the monitoring voltage and the reference voltage; and
a feedback circuit configured to generate the feedback signal using the comparison signal;
The voltage comparator is
and float the comparison signal when the monitoring voltage is greater than or equal to the reference voltage;
and generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage;
The feedback circuit is
and generate a high-level voltage as the feedback signal when the comparison signal is floated;
and generate the low-level voltage as the feedback signal when the comparison signal is the low-level voltage;
The reference voltage generation circuit,
and when the feedback signal is the high-level voltage, generate a first diagnostic voltage indicative of a first diagnostic temperature as the reference voltage;
and when the feedback signal is the low-level voltage, generate, as the reference voltage, a second diagnostic voltage representing a second diagnostic temperature lower than the first diagnostic temperature.
According to claim 1,
The second diagnostic voltage is greater than the first diagnostic voltage.
According to claim 1,
When the monitoring voltage is less than or equal to the first diagnostic voltage, the battery temperature indicates an abnormal temperature state equal to or greater than the first diagnostic temperature,
When the monitoring voltage is greater than the second diagnosis voltage, the battery management system indicates a normal temperature state in which the temperature of the battery is lower than the second diagnosis temperature.
3. The method of claim 2,
The temperature sensing circuit is
a first resistor connected between a first constant voltage terminal to which a first constant voltage is supplied and a first reference node; and
a thermistor having a sub-characteristic temperature coefficient for the temperature of the battery and connected between the first reference node and the ground,
The monitoring voltage is a voltage across both ends of the thermistor.
5. The method of claim 4,
The reference voltage generation circuit,
a second resistor connected between a second constant voltage terminal to which the first constant voltage is supplied and a second reference node;
a third resistor connected between the second reference node and the ground; and
a series circuit of a fourth resistor and a first switch connected in parallel to the third 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 third resistor when the first switch is turned on.
6. The method of claim 5,
The first switch is turned off when the feedback signal is the low-level voltage,
The second diagnostic voltage is a voltage across both ends of the third resistor when the first switch is turned off.
7. The method of claim 6,
The voltage comparator is
a first input pin connected to the first reference node;
a second input pin connected to the second reference node; and
and an output pin for outputting the comparison signal.
8. The method of claim 7,
The feedback circuit is
a second switch comprising an emitter, a collector and a base;
a third switch comprising a source, a drain and a gate; and
including a fifth 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,
The source is connected to the ground,
the fifth resistor is connected between a fourth constant voltage terminal to which a third constant voltage is supplied and the drain;
When the comparison signal is the low-level voltage, the second switch and the third switch are sequentially turned on,
When the third switch is turned on, the low-level voltage is applied to the first switch as the feedback signal.
9. The method of claim 8,
The feedback circuit is
Further comprising a delay circuit connected between the collector and the gate,
The delay circuit is
and when the second switch is turned on, delay the voltage between the collector and the ground by a predetermined time constant and apply to the gate.
9. The method of claim 8,
The feedback circuit is
The battery management system further comprising a Zener diode coupled between the drain and the source.
a temperature sensing circuit configured to generate a monitoring voltage indicative of a temperature of the battery; and
a temperature monitoring device;
The temperature monitoring device,
a reference voltage generating circuit configured to generate a reference voltage by using the comparison signal; and
a voltage comparator configured to generate the comparison signal using the monitoring voltage and the reference voltage;
The voltage comparator is
and generate a high-level voltage as the comparison signal when the monitoring voltage is greater than or equal to the reference voltage;
and generate a low-level voltage as the comparison signal when the monitoring voltage is less than the reference voltage;
The reference voltage generation circuit,
and generate a first diagnostic voltage representing a first diagnostic temperature as the reference voltage when the comparison signal is the high-level voltage;
and 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.
A battery rack comprising the battery management system according to any one of claims 1 to 11.
An energy storage system comprising the battery rack according to claim 12 .

Images