CN215706120U

CN215706120U - BMS and awakening device thereof

Info

Publication number: CN215706120U
Application number: CN202121954441.7U
Authority: CN
Inventors: 宋玲伟; 周庆生; 徐辉; 齐伟华; 鲍文光
Original assignee: Shandong Edbang Intelligent Technology Co ltd
Current assignee: Shandong Edbang Intelligent Technology Co ltd
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2022-02-01
Anticipated expiration: 2031-08-19

Abstract

The utility model discloses a BMS and a wake-up device thereof, and provides a BMS wake-up device aiming at the problem that the BMS can not be woken up by current in a loop when the current BMS is in a dormant state, which comprises the following components: the voltage divider resistor is arranged on the pre-discharge loop, the input end of the comparator is connected with the voltage divider resistor, the relation between the measured voltage value obtained by dividing the voltage divider resistor and the standard voltage value is compared, and when the measured voltage value is greater than the standard voltage value, the comparator sends a signal to the MCU to wake up the MCU. According to the BMS awakening device provided by the utility model, the voltage dividing resistor and the current limiting resistor form the voltage dividing circuit, the measured voltage divided by the voltage dividing resistor is compared with the standard voltage value through the comparator, and when the measured voltage value exceeds the standard voltage value, the comparator sends a signal to the MCU to awaken the MCU, so that the problem that the BMS cannot be awakened through small current in a loop at present is solved. In addition, the utility model also discloses a BMS with the same effect.

Description

BMS and awakening device thereof

Technical Field

The utility model relates to the field of power systems, in particular to a BMS and a wake-up device thereof.

Background

With the development of the existing new energy technology, new energy vehicles such as electric vehicles and the like are more and more favored by people. As an electrically driven vehicle, the performance of its battery largely determines the mass of the vehicle. At present, a Battery Management System (BMS) is generally used for monitoring the state of a battery in real time, so that the excessive charging and discharging of the battery are prevented, and the service life is prevented from being influenced. However, the BMS itself consumes power, and if the BMS is always in the on state, the BMS consumes the power stored in the battery, so that the BMS generally stays in the sleep state when the vehicle is in the non-driving state for a long time, and at this time, the BMS controls the switching device to disconnect the charging loop and the discharging loop through the Micro Control Unit (MCU), and only turns on the pre-discharging loop to supply power to the central control, so that the user can remotely know the vehicle state and remotely control the vehicle. When the vehicle is used for a long time or is in a wet state, the load becomes large, the load current increases, and unnecessary power consumption increases. At this time, a central control is usually adopted to send a corresponding level signal to wake up the MCU, the MCU detects whether the current in the circuit is normal, and if not, the MCU controls the switching device to close the pre-discharge loop.

Currently, when the BMS is in a sleep state, it is usually woken up by the central control. When the vehicle runs for a long time or is affected with damp, the load resistance value is increased, the load current is increased, namely, current additionally appears in the whole loop, and the current is small relative to the current in the loop when the vehicle normally works, but electric energy is also lost. And the small current cannot wake up the BMS, and the BMS cannot stop the power supply of the battery in time, so that the battery is completely emptied.

Therefore, there is a strong need in the art for a BMS wake-up device to wake up a BMS when a small current exceeding a preset value occurs in a circuit.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to provide a BMS and a wake-up apparatus thereof so that the BMS can be woken up when a small current exceeding a preset value occurs in a circuit.

In order to solve the above technical problems, the present invention provides a BMS wake-up device, including: the voltage divider resistor is arranged on the pre-discharge loop, the input end of the comparator is connected with the voltage divider resistor, the relation between the measured voltage value obtained by dividing the voltage divider resistor and the standard voltage value is compared, and when the measured voltage value is greater than the standard voltage value, the comparator sends a signal to the MCU to wake up the MCU.

Preferably, the MCU is effective in low level, the comparator is a voltage comparator, the forward end of the voltage comparator is connected with a standard signal source to obtain a standard voltage value, the reverse end of the voltage comparator is connected with a voltage dividing resistor to obtain a measured voltage value, and the output end of the voltage comparator is connected with the MCU.

Preferably, the standard signal source comprises: the first resistor, the second resistor and the MCU power supply end;

the first end of the first resistor and the second end of the first resistor are respectively connected with the MCU power supply end and the first end of the second resistor; the second end of the second resistor is grounded; the second end of the first resistor and the first end of the second resistor are connected with the positive phase end.

Preferably, the method further comprises the following steps: and the filter circuit is arranged between the MCU and the output end.

Preferably, the filter circuit is a filter capacitor, a first end of the filter capacitor is connected to the output end of the comparator, and a second end of the filter capacitor is grounded.

In order to solve the technical problem, the utility model also provides a BMS which comprises the pre-discharge switch device and the MCU, and further comprises the BMS awakening device as described above, wherein the MCU is respectively connected with the pre-discharge switch device and the BMS awakening device; when a trigger signal for entering a sleep mode is received, the MCU controls the pre-discharge switch device to be opened so as to enable the pre-discharge loop to be conducted to supply power to the central control unit; when the MCU receives a signal sent by the comparator, the MCU is awakened, and when the current of the pre-discharge loop is abnormal current, the pre-discharge switching device is controlled to be switched off so as to switch off the pre-discharge loop.

Preferably, the pre-discharge switching device is a MOS transistor.

Preferably, the pre-discharge switching device is a triode.

According to the BMS awakening device provided by the utility model, when the vehicle is in a power-off state, in order to save electric energy, the BMS enters a sleep mode, and only the pre-discharge switch device is turned on to conduct the pre-discharge loop so as to supply power for central control. The voltage dividing resistor is arranged on the pre-discharge loop, and the voltage dividing resistor and the current limiting resistor of the power supply form the voltage dividing circuit, so that the voltage dividing resistor can divide the measured voltage on the pre-discharge loop, the measured voltage value is compared with the standard voltage value by the comparator, and when the measured voltage value exceeds the standard voltage value, the comparator sends a signal to the MCU to wake up the MCU. Therefore, when the current exceeding the preset value appears in the pre-discharge loop, the BMS can be awakened, and the problem that the BMS cannot be awakened through the current exceeding the preset value appearing in the pre-discharge loop at present is solved.

In order to solve the technical problem, the utility model further provides a BMS comprising the BMS waking device as described above, and the effects are the same as above.

Drawings

In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained by those skilled in the art without inventive effort.

Fig. 1 is a structural diagram of a BMS wake-up apparatus according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the present invention.

The core of the utility model is to provide a BMS and a wake-up device thereof.

In order that those skilled in the art will better understand the disclosure, the utility model will be described in further detail with reference to the accompanying drawings and specific embodiments.

Nowadays, new energy automobiles mostly adopt electric energy as a main driving energy, and therefore, the quality of the vehicles is directly influenced by the performance of batteries. Since the battery needs to be frequently charged and discharged during the use of the electric vehicle, in order to prolong the service life of the battery, manufacturers often use the BMS to monitor and manage the battery. However, the BMS itself consumes power, and if the BMS is in an operating state for a long time, the battery usually lasts for about 40 days at most, so that when the electric vehicle is powered off, the BMS is in a sleep state, and at this time, the MCU12 inside the BMS controls the switching device to turn off the charging and discharging circuit, and only turns on the pre-discharging circuit to turn on the central control, so that the user can remotely monitor and control the vehicle, and can wake up the BMS through the central control. When the vehicle runs for a long time or gets wet, the load increases, the load current increases accordingly, unnecessary electric energy is consumed, and the service life of the battery is reduced, at this time, the BMS is required to be in an operating state to turn off the circuit, but the additionally generated small currents are not enough to wake up the BMS, so the embodiment provides a solution, as shown in fig. 1, including:

divider resistance R3, comparator 11, divider resistance R3 sets up on the predischarge circuit, and comparator 11 input is connected with divider resistance R3, compares the relation of the measured voltage value that divider resistance R3 divides with standard voltage value, and when measured voltage value is greater than standard voltage value, comparator 11 sends the signal in order to awaken MCU12 to MCU 12.

When the BMS is in the sleep state, only the pre-discharge loop is turned on in the electric vehicle, and unnecessary extra current is also in the pre-discharge loop, so that the voltage dividing resistor R3 disposed on the pre-discharge loop can divide a part of the voltage value, and the current value of the pre-discharge loop can be phase-changed and measured according to the resistance value of the voltage dividing resistor R3, so that the measured voltage value divided by the voltage dividing resistor R3 is compared with the standard voltage value by the comparator 11, when the measured voltage value is greater than the standard voltage value, i.e., a large current is generated in the loop, at this time, the comparator 11 sends a signal to wake up the MCU12, and after the MCU12 is awakened, the electric energy usage of each device in the vehicle is obtained by the Analog Front End (AFE) in the vehicle, so as to determine whether the current is a normal current. If the current is abnormal, the pre-discharge switching device 13 is controlled to be turned off, so that the pre-discharge loop is turned off.

It should be noted that the comparator 11 may be a voltage comparator, or may be another device capable of implementing the same logic function, such as a single chip. The standard voltage value is convenient for the comparator 11 to compare with the measured voltage value, and only when the measured voltage value exceeds the standard voltage value, it is considered that a large current is generated in the loop.

Therefore, when the loop generates a large current, the measured voltage value obtained by dividing the voltage dividing resistor R3 is greater than the standard voltage value, and the comparator 11 sends a signal to wake up the MCU12, so that the MCU12 is waken up by the current in the loop, and therefore the MCU12 can turn off the pre-discharge loop in time to prevent the power from being continuously lost.

Currently, most of the MCUs 12 used in electric vehicles are triggered by low level, and when the MCU12 enters the sleep mode, the MCU12 is woken up by a low level signal. Therefore, the present embodiment provides a preferable solution, including:

MCU12 is effective for the low level, and comparator 11 is the voltage comparator, and the forward end of voltage comparator connects the standard signal source in order to obtain standard voltage value, and the reverse end of voltage comparator connects divider resistance R3, obtains the measured voltage value, and MCU12 is connected to the output of voltage comparator.

Like the connection manner described in this embodiment, when the measured voltage value is greater than the standard voltage value, the voltage obtained at the inverting terminal of the voltage comparator is greater than the voltage obtained at the positive terminal, at this time, the output terminal of the comparator 11 outputs a low level, and the MCU12 receives the low level signal sent by the comparator 11 to be woken up.

It should be noted that the connection relationship of the present embodiment is applicable to the case where the MCU12 of the BMS is triggered at the low level, and actually, the MCU12 is triggered at the high level, and at this time, the connection relationship between the voltage comparator and the voltage dividing resistor R3, and the connection relationship between the standard signal source and the MCU12 are as follows:

MCU12 is that the high level is effective, and comparator 11 is voltage comparator, and voltage comparator's reverse end is connected standard signal source in order to obtain standard voltage value, and voltage comparator's forward end is connected divider resistance R3, obtains being surveyed voltage value, and voltage comparator's output is connected MCU 12.

The connection relationship between the voltage comparator and the voltage dividing resistor R3, the standard signal source and the MCU12 is not limited in this embodiment to be only the connection relationship that the MCU12 is active at low level, only because the MCU12 used in the BMS is mostly triggered at low level, and for the preferred scheme provided herein, the specific implementation can be determined according to actual needs.

The present embodiment uses a voltage comparator as the comparator 11, and has the advantages that: voltage comparator simple structure easily realizes, and voltage comparator's sensitivity is high, is applicable to the load current that this application is directed against, has improved BMS awakening device's sensitivity.

In practical use, in order to save cost, it is usually inclined to use the original device to implement new functions, so this embodiment provides a preferred solution on the basis of the above embodiments:

the standard signal source comprises: the power supply end of the MCU12 is connected with a first resistor R1, a second resistor R2;

a first end of the first resistor R1 and a second end of the first resistor R1 are respectively connected with a power supply end of the MCU12 and a first end of the second resistor R2; a second end of the second resistor R2 is grounded; the second terminal of the first resistor R1 and the first terminal of the second resistor R2 are connected to the non-inverting terminal.

The power supply end of the MCU12 is connected with a power supply through a diode, the power supply is 3.3V, after passing through the diode, the voltage input to the power supply end of the MCU12 is 2.8V, the resistance value of the first resistor R1 is 12K, and the resistance value of the second resistor R2 is 10M.

The voltage value of the standard signal source is:

2.8V×12K/(10M+12K)≈0.0332V

therefore, in this embodiment, on the basis of the above embodiment, it is equivalent to that a standard voltage of 0.0332V is input to the forward terminal of the comparator 11, and when the measured voltage value input to the reverse terminal is greater than 0.0332V, the comparator 11 outputs a low level to the MCU12, which also indicates that there is a current greater than 32.2mA in the pre-discharge circuit.

It should be noted that, this embodiment is only a specific implementation case, the power supply voltage is not necessarily 3.2V, the power supply terminal of the MCU12 is not necessarily connected to the power supply through a diode, and the voltage is not necessarily 2.8V, meanwhile, the standard voltage value is not necessarily set to 0.0332V, the resistance value of the first resistor R1 is not necessarily 12K, and the resistance value of the second resistor R2 is not necessarily 10M.

The advantages of this embodiment are: the simple implementation mode of the standard signal source is provided, on the basis of the original circuit, an extra power supply is not needed, only two resistors are added, the original power supply is utilized to provide the standard signal source, the cost is reduced, and the circuit is simple and easy to implement.

Since the battery supply voltage will fluctuate, the level signal output by the comparator 11 powered by the battery supply voltage will fluctuate too, and in order to avoid false triggering caused by fluctuation, the present embodiment provides a preferable solution, on the basis of the above-mentioned embodiments, further comprising: and the filter circuit is arranged between the MCU12 and the output end.

The filter circuit is arranged between the MCU12 and the output of the comparator 11 to filter out fluctuations in the level signal output at the output. It should be noted that the specific connection manner of the filter circuit is not limited in this embodiment, and it is not necessary that only the filter circuit is disposed between the MCU12 and the output terminal of the comparator 11. The filter circuit may be a passive filter circuit composed of one or more of a capacitor, an inductor, and a resistor, or may be an active filter circuit composed of active elements such as a bipolar tube, a unipolar tube, and an integrated operational amplifier, which is not limited in this embodiment, and a corresponding circuit implementation may be selected according to actual situations.

The advantages of this embodiment over the above embodiments are: a filter circuit is added between the MCU12 and the output end of the comparator 11, so that disturbance in a level signal sent by the comparator 11 can be filtered, the stability of the signal is improved, and the possibility of false triggering of the MCU12 is reduced.

In the above embodiment, no limitation is made on the specific implementation of the filter circuit, but in consideration of cost, the present embodiment provides a preferable solution, including:

the filter circuit mainly comprises a filter capacitor C1, wherein the first end of the filter capacitor C1 is connected with the output end of the comparator 11, and the second end of the filter capacitor C1 is grounded.

It should be noted that the filter capacitor C1 is not limited in this embodiment, but an electrolytic capacitor is generally preferred to ensure the filtering effect.

The advantages of this embodiment are: the circuit is simple and easy to realize, the volume is small, the weight is light, and the cost is saved.

On the basis of the above embodiments, the present application further provides a BMS, including the pre-discharge switching device 13 and the MCU12, and further including the BMS wake-up apparatus disclosed in the above embodiments;

the MCU12 is respectively connected with the pre-discharge switching device 13 and the BMS wake-up device; when receiving a trigger signal for entering the sleep mode, the MCU12 controls the pre-discharge switching device 13 to be turned on, so that the pre-discharge loop is turned on to supply power to the central controller; when the MCU12 receives the signal sent by the comparator 11, it wakes up and controls the pre-discharge switching device 13 to open the pre-discharge loop when the current in the pre-discharge loop is abnormal.

When the vehicle is powered off, the BMS enters a sleep state, at which time the MCU12 controls the switching device to turn off the charging and discharging loops, and only turns on the pre-discharging loop to supply power to the central control, and when the BMS is awakened by a signal transmitted from the comparator 11, detects the in-loop current, determines whether the in-loop current is normal from data transmitted from the AFE, and turns off the pre-discharging loop if not normal.

It should be noted that, the present embodiment does not limit the switching device, and may be a field effect transistor (MOS transistor) or a triode.

The BMS provided by the embodiment can wake up whether the current in the BMS detection loop is normal or not when the current which is larger than the preset value is generated in the vehicle loop, and can turn off the pre-discharge loop if the current is abnormal, so that the function of waking up the BMS by the current in the circuit is realized, and unnecessary loss of electric energy is reduced.

The above embodiments do not limit the switching device, but in practical use, a MOS transistor or a triode is generally preferred as the switching device for controlling the circuit to be turned off.

Therefore, the present embodiment provides a preferred solution: the pre-discharge switching device 13 is a MOS transistor.

And another preferred scheme is as follows: the pre-discharge switching device 13 is a triode.

The advantage of the preferred pre-discharge switching device 13 being a MOS transistor is that: the MOS tube has strong load capacity, low power consumption and simple driving circuit, and can simplify the circuit and reduce the power consumption.

The advantage of the preferred pre-discharge switching device 13 being a triode is that: triode switching speed is high, and low cost can improve BMS's efficiency.

The above description provides a BMS and a wake-up apparatus thereof according to the present invention. The embodiments are described in a progressive manner in the specification, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Claims

1. A BMS wake-up device, comprising: the voltage divider resistor is arranged on a pre-discharge loop, the input end of the comparator is connected with the voltage divider resistor, the relation between a measured voltage value obtained by dividing the voltage divider resistor and a standard voltage value is compared, and when the measured voltage value is larger than the standard voltage value, the comparator sends a signal to the MCU to wake up the MCU.

2. The BMS wake-up device according to claim 1, wherein the MCU is active low, the comparator is a voltage comparator, a positive phase terminal of the voltage comparator is connected to a standard signal source to obtain the standard voltage value, a negative phase terminal of the voltage comparator is connected to the voltage dividing resistor to obtain the measured voltage value, and an output terminal of the voltage comparator is connected to the MCU.

3. The BMS wake-up unit according to claim 2, characterized in that the standard signal source comprises: the first resistor, the second resistor and the MCU power supply end;

4. The BMS wake-up device according to claim 2, characterized in that it further comprises: and the filter circuit is arranged between the MCU and the output end.

5. The BMS wake-up device according to claim 4, wherein the filter circuit is a filter capacitor, a first end of the filter capacitor is connected to the comparator output terminal, and a second end of the filter capacitor is grounded.

6. A BMS including a pre-discharge switching device and an MCU, further comprising a BMS wake-up unit according to any one of claims 1 to 5, the MCU being connected to the pre-discharge switching device and the BMS wake-up unit, respectively; when a trigger signal for entering a sleep mode is received, the MCU controls the pre-discharge switching device to be opened so as to enable the pre-discharge loop to be conducted to supply power to the central control unit; when the MCU receives a signal sent by the comparator, the MCU is awakened, and when the current of the pre-discharge loop is abnormal current, the MCU controls the pre-discharge switching device to be switched off so as to switch off the pre-discharge loop.

7. The BMS of claim 6, wherein the pre-discharge switching device is a MOS transistor.

8. The BMS of claim 6, wherein the pre-discharge switching device is a triode.