CN220066940U

CN220066940U - Detection circuit for improving battery SOC electric quantity precision and energy storage power supply system thereof

Info

Publication number: CN220066940U
Application number: CN202321466633.2U
Authority: CN
Inventors: 黄忠东; 张长章; 崔彬彬; 林可楼
Original assignee: Fujian Tiancheng Times New Energy Technology Co ltd
Current assignee: Fujian Tiancheng Times New Energy Technology Co ltd
Priority date: 2023-06-09
Filing date: 2023-06-09
Publication date: 2023-11-21
Anticipated expiration: 2033-06-09

Abstract

The utility model provides a detection circuit for improving the accuracy of the SOC electric quantity of a battery and an energy storage power supply system thereof, wherein the circuit comprises a main control chip, a power supply voltage chip, a battery unit connecting end and a reference voltage chip; the positive pole of battery cell link is used for connecting the positive pole of battery cell, the positive pole of battery cell link with the power input of power supply voltage chip holds, the power output of power supply voltage chip holds with the power of main control chip with the power input of reference voltage chip holds and be connected. The precision of the reference voltage of the main control chip is improved, so that the precision of the obtained battery unit voltage is also greatly improved, and the electric quantity of the battery unit with high precision can be obtained.

Description

Detection circuit for improving battery SOC electric quantity precision and energy storage power supply system thereof

Technical Field

The utility model relates to the technical field of energy storage power supply circuits, in particular to a detection circuit for improving the precision of the SOC electric quantity of a battery and an energy storage power supply system thereof.

Background

The SOC remaining capacity (SOC) is the ratio of the available electric power in the battery to the nominal capacity, and is an important monitoring data of the battery management system, and the battery management system controls the battery working state according to the SOC value. The remaining charge of the battery is also referred to as the state of charge of the battery. The energy storage power supply is a device for storing electric energy, can store the electric energy in a storage battery, and can be portable to a required place for power supply and output. In order to realize charge and discharge control of the energy storage power supply, the SOC residual capacity needs to be judged.

The patent of the circuit related to the energy storage power supply, which is applied by the applicant before, comprises a control chip and a control unit for controlling the charge and discharge. The patent number of the applicant is 202222402938.9, and the name of the patent is an utility model patent of an energy storage power supply with a pre-charging battery safety management circuit, wherein the circuit comprises a main control chip U3, and the pre-charging management of the energy storage power supply circuit is realized through the main control chip. For another example, the patent number of the applicant is 202222368509.4, and the name of the patent is an utility model patent of an energy storage power supply with a pre-discharge battery safety management circuit, and the circuit comprises a main control chip U3, and the pre-discharge management of the energy storage power supply circuit is realized through the main control chip.

In the existing energy storage power supply, the main control chip generally needs to acquire the electric quantity of the storage battery so as to ensure the safety of the storage battery, such as no overcharge or overdischarge. The electric quantity of the storage battery is obtained by judging the voltage of the storage battery, and if the voltage is high, the electric quantity of the storage battery is high, the voltage is low, and the electric quantity of the storage battery is low. The prior main control chip internally comprises an analog-to-digital converter, and can directly acquire the voltage. However, the reference voltage of the analog-to-digital converter of the main control chip adopts the power supply voltage, and the power supply voltage is influenced by the fluctuation of the load size and the precision of the power supply voltage, so that the power supply voltage is not accurate enough. And then, the inaccuracy power supply voltage is used for carrying out high-requirement electric quantity precision measurement, so that the deviation is large. In some cases, the voltage of the storage battery of the energy storage power supply reaches the full-power voltage, but the electric quantity obtained by the main control chip cannot be in the full-power state. Namely, the precision of the SOC electric quantity is lower, and the problem that the SOC electric quantity and the storage battery electric quantity are not accurately corresponding exists.

Disclosure of Invention

Therefore, it is necessary to provide a detection circuit for improving the accuracy of the SOC electric quantity of the battery and an energy storage power supply system thereof, which solve the problems of lower accuracy of the existing SOC electric quantity and inaccurate correspondence between the existing SOC electric quantity and the electric quantity of the storage battery.

In order to achieve the above purpose, the utility model provides a detection circuit for improving the accuracy of the SOC electric quantity of a battery, which comprises a main control chip, a power supply voltage chip, a battery unit connecting end and a reference voltage chip; the positive pole of battery unit link is used for connecting the positive pole of battery unit, the positive pole of battery unit link with the power input of power supply voltage chip is connected, the power output of power supply voltage chip with the power end of main control chip with the power input of reference voltage chip is connected, the power output of reference voltage chip with the reference voltage pin of main control chip is connected, the positive pole of battery unit link pass through behind the divider resistor with the voltage acquisition pin of main control chip is connected, the ground connection of main control chip, the ground connection of power supply voltage chip, the negative pole of battery unit link, the ground connection of reference voltage chip and the negative pole ground connection of battery unit.

In some embodiments, the battery unit further comprises a discharging switch tube and a starting button, the positive electrode of the battery unit connecting end is used for being connected with the positive electrode of the battery unit through the discharging switch tube, the input end of the discharging switch tube is connected with the positive electrode of the battery unit, the output end of the discharging switch tube is connected with the positive electrode of the battery unit connecting end, the control end of the discharging switch tube is connected with one end of the starting button and one end of a pull-up resistor, the other end of the pull-up resistor is connected to the positive electrode of the battery unit, and the other end of the starting button is grounded.

In some embodiments, the power-on control device further comprises a holding switch tube, one end of the power-on button is connected with the input end of the holding switch tube, the control end of the holding switch tube is connected with a power-on control pin of the main control chip, and the output end of the holding switch tube is grounded.

In some embodiments, the power-on switch further comprises a detection switch tube and a grounding resistor, the other end of the power-on key is grounded through the grounding resistor, the other end of the power-on key is connected with the control end of the detection switch tube, the input end of the detection switch tube is connected with a power-on detection pin of the main control chip, and the output end of the detection switch tube is grounded.

In some embodiments, the voltage-withstanding circuit further comprises a first zener diode, wherein the negative electrode of the first zener diode is grounded, the positive electrode of the first zener diode is connected with the voltage acquisition pin of the main control chip, and the withstand voltage of the first zener diode is the same as the voltage of the power output end of the reference voltage chip.

In some embodiments, the circuit further comprises a second zener diode, wherein the cathode of the second zener diode is grounded, the anode of the second zener diode is connected with the power output end of the power supply voltage chip, and the withstand voltage of the second zener diode is the same as the voltage of the power output end of the power supply voltage chip.

In some embodiments, a power-up diode is further included, the power-up diode being configured to be coupled to the charging input, a negative electrode of the power-up diode being coupled to a power input of the power supply voltage chip.

In some embodiments, the battery cell further comprises a fuse through which the positive electrode of the battery cell connection end is connected to the positive electrode of the battery cell.

The utility model also provides an energy storage power supply, which comprises a detection circuit and a battery unit, wherein the detection circuit is any one of the detection circuits in the embodiment of the utility model, and two ends of the battery unit are connected with the battery unit connecting end of the detection circuit.

Compared with the prior art, the technical scheme can convert the voltage of the battery unit connection end into the power supply voltage required by the main control chip through the power supply voltage chip, and simultaneously provide the power supply voltage for the reference voltage chip, so that the reference voltage chip can provide accurate reference voltage. The reference voltage is provided for a reference voltage pin of the main control chip, and the main control chip can calculate the accurate value of the battery unit voltage through the reference voltage of the reference voltage pin after obtaining the voltage of the battery unit connecting end through the voltage dividing resistor. Since the accuracy of the reference voltage is improved, the accuracy of the obtained battery cell voltage is also greatly improved, and the SOC electric quantity of the battery cell with high accuracy can be obtained. Therefore, the problems that the accuracy of the existing SOC electric quantity is low, and the existing SOC electric quantity and the storage battery electric quantity are inaccurate are solved.

Drawings

A circuit diagram of a main control chip part in the embodiment of fig. 1;

a circuit diagram of a supply voltage chip portion according to the embodiment of fig. 2;

FIG. 3 is a circuit diagram of a reference voltage chip portion according to an embodiment;

fig. 4 is a circuit diagram of a battery voltage and voltage dividing resistor section according to an embodiment;

the power-on switch tube and the power-on button part are circuit diagrams in the embodiment shown in fig. 5.

Detailed Description

In order to describe the technical content, constructional features, achieved objects and effects of the technical solution in detail, the following description is made in connection with the specific embodiments in conjunction with the accompanying drawings.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of the phrase "in various places in the specification are not necessarily all referring to the same embodiment, nor are they particularly limited to independence or relevance from other embodiments. In principle, in the present utility model, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment may be combined in any manner to form a corresponding implementable technical solution.

Unless defined otherwise, technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present utility model pertains; the use of related terms herein is for the purpose of describing particular embodiments only and is not intended to limit the utility model.

In the description of the present utility model, the term "and/or" is a representation for describing logical relationships between objects, which means that three relationships may exist, e.g., a and/or B, representing: there are three cases, a, B, and both a and B. In addition, the character "/" herein generally indicates that the context associated object is a logical relationship of a type "or".

In the present utility model, terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual number, order, or sequence of such entities or operations.

Without further limitation, the use of the terms "comprising," "including," "having," or other like terms in this specification is intended to cover a non-exclusive inclusion, such that a process, method, or article of manufacture that comprises a list of elements does not include additional elements but may include other elements not expressly listed or inherent to such process, method, or article of manufacture.

As in the understanding of "review guidelines," the expressions "greater than", "less than", "exceeding" and the like are understood to exclude this number in the present utility model; the expressions "above", "below", "within" and the like are understood to include this number. Furthermore, in the description of embodiments of the present utility model, the meaning of "a plurality of" is two or more (including two), and similarly, the expression "a plurality of" is also to be understood as such, for example, "a plurality of" and the like, unless specifically defined otherwise.

In the description of embodiments of the present utility model, spatially relative terms such as "center," "longitudinal," "transverse," "length," "width," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc., are used herein as a basis for the description of the embodiments or as a basis for the description of the embodiments, and are not intended to indicate or imply that the devices or components referred to must have a particular position, a particular orientation, or be configured or operated in a particular orientation and therefore should not be construed as limiting the embodiments of the present utility model.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," "affixed," "disposed," and the like as used in the description of embodiments of the utility model should be construed broadly. For example, the "connection" may be a fixed connection, a detachable connection, or an integral arrangement; the device can be mechanically connected, electrically connected and communicated; it can be directly connected or indirectly connected through an intermediate medium; which may be a communication between two elements or an interaction between two elements. The specific meaning of the above terms in the embodiments of the present utility model can be understood by those skilled in the art to which the present utility model pertains according to circumstances.

Referring to fig. 1 to 5, the present embodiment provides a detection circuit for improving the accuracy of the SOC of a battery, which includes a main control chip U4, a power supply voltage chip U3, a battery unit connection terminal pack+ and a reference voltage chip U10; the positive pole PACK+ of battery cell link is used for connecting the positive pole PACK_PACK+ of battery cell (or refer to as battery, energy storage battery), the positive pole PACK+ of battery cell link with power supply input (VIN end) of power supply voltage chip U3 is connected, power supply output (OUT end) of power supply voltage chip U3 is connected with power supply end (VDD end) of main control chip U4 and the power supply input of reference voltage chip U10, power supply output ADC_REF of reference voltage chip U10 is connected with the reference voltage pin of main control chip U4, the positive pole PACK+ of battery cell link is connected with voltage acquisition pin BAT_VOL_ADC of main control chip U4 behind divider resistance (resistance R73 and R124), ground terminal VSS of main control chip U4, ground terminal of power supply voltage chip U3, negative pole GND of battery cell link, ground terminal of reference voltage chip U10 and the negative pole GND of battery cell ground.

In the energy storage power supply, chips such as a main control chip and the like can be arranged on the circuit board. The main control chip U4 may be a single chip microcomputer, preferably, the main control chip U4 is a GD32F series or STM32 series chip, which may implement more complex control functions, such as voltage acquisition, voltage judgment, electric quantity judgment, and control of whether to discharge or not. The power supply voltage chip U3 is used for converting voltage, converting the voltage of the battery unit into the voltage of the main control chip U4, for example, converting 12V into 3.3V, and can be a DC-DC voltage conversion chip or an LDO voltage conversion chip. The battery unit connecting end is used for being connected with a battery unit of an energy storage power supply. The reference voltage chip U10 is used to realize a reference voltage with higher accuracy, and may be realized by a CJ431 chip. For the CJ431 chip, a voltage-reducing resistor R100 is connected in series between the power input end of the CJ431 chip and the power output end of the power voltage chip U3, as shown in fig. 3, so as to achieve voltage-reducing and voltage-stabilizing effects, and preferably, a voltage-stabilizing resistor C31 is connected to the output end, so that filtering of the voltage of the output end can be achieved. When the utility model works, the voltage of the battery unit connection end can be converted into the power supply voltage required by the main control chip U4 through the power supply voltage chip U3, and meanwhile, the power supply voltage is provided for the reference voltage chip U10, so that the reference voltage chip U10 can provide accurate reference voltage. The reference voltage is provided for a reference voltage pin of the main control chip U4, and after the main control chip U4 obtains the voltage of the battery unit connecting end through the voltage dividing resistor, the accurate value of the battery unit voltage can be calculated through the reference voltage of the reference voltage pin. Since the accuracy of the reference voltage is improved, the accuracy of the obtained battery cell voltage is also greatly improved, and the SOC electric quantity of the battery cell with high accuracy can be obtained. Therefore, the problems that the accuracy of the existing SOC electric quantity is low, and the existing SOC electric quantity and the storage battery electric quantity are inaccurate are solved.

The energy storage power supply can comprise a discharging branch and a charging branch. The discharging branch is used for realizing discharging control and controlling whether the battery unit discharges outwards. The charging branch is used for realizing charging control and controlling whether a charging end of an external charging power supply is connected to the battery unit. In order to realize the discharging control, in some embodiments, as shown in fig. 5, the battery unit further comprises a discharging switch tube Q24 and a start button SW1, the positive electrode of the battery unit connection end is used for being connected with the positive electrode of the battery unit through the discharging switch tube Q24, the input end of the discharging switch tube Q24 is connected with the positive electrode pack_pack+ of the battery unit, the output end of the discharging switch tube Q24 is connected with the positive electrode pack+ of the battery unit connection end, the control end of the discharging switch tube Q24 is connected with one end of the start button SW1 and one end of a pull-up resistor R120, the other end of the pull-up resistor R120 is connected with the positive electrode pack_pack+ of the battery unit, and the other end of the start button SW1 is grounded. When the start-up discharging needs to be controlled, a user presses a start-up key SW1, the start-up key SW1 is conducted to the ground, so that the input end of the discharging switch tube Q24 is conducted to the output end, the current of the battery unit flows to the power supply voltage chip U3 through the discharging switch tube Q24, and the whole circuit starts to work.

In some embodiments, the electronic device further includes a holding switch Q25, one end of the power-on button SW1 is connected to an input end of the holding switch Q25, a control end dsg_en of the holding switch Q25 is connected to a power-on control pin of the main control chip U4, and an output end of the holding switch Q25 is grounded. After the power is started, the main control chip U4 receives power supply start. The main control chip U4 outputs high level through DSG_EN, keeps the switch tube Q25 to be conducted to the ground, and enables the discharge switch tube Q24 to be continuously conducted to the ground, so that the battery unit is locked to continuously discharge.

In some embodiments, the power-on switch further includes a detection switch Q26 and a ground resistor R126, where the other end of the power-on button SW1 is grounded through the ground resistor R126, the other end of the power-on button SW1 is connected to the control end of the detection switch Q26, the input end of the detection switch Q26 is connected to a power-on detection pin of the main control chip U4, and the output end of the detection switch Q26 is grounded. Through detecting the switch tube Q26, the main control chip U4 can detect whether the start button SW1 is pressed down again, after the start button SW1 is pressed down, the shutdown is indicated, and after the start button SW 4 passes through DSG_EN, the output low level keeps the switch tube Q25 to be turned off so that the control end of the discharge switch tube Q24 is pulled up to be high level, the discharge switch tube Q24 is turned off, and therefore the battery unit is not discharged outwards, and the shutdown is realized.

In some embodiments, the circuit further includes a first zener diode TVS21, a negative electrode of the first zener diode TVS21 is grounded, an anode of the first zener diode TVS21 is connected to the voltage collecting pin of the main control chip U4, and a withstand voltage of the first zener diode TVS21 is the same as a voltage of the power output end of the reference voltage chip U10. Through the first zener diode TVS21, the output voltage of the reference voltage chip is not higher than the withstand voltage (e.g., 2.5V) of the first zener diode TVS21, so as to avoid the pin of the main control chip U4 from being damaged due to receiving the excessive voltage.

In some embodiments, the circuit further includes a second zener diode TVS2, a negative electrode of the second zener diode TVS2 is grounded, an anode of the second zener diode TVS2 is connected to the power output end of the power supply voltage chip U3, and a withstand voltage of the second zener diode TVS2 is the same as a voltage of the power output end of the power supply voltage chip U3. Through the second zener diode TVS2, the output voltage of the power supply voltage chip U3 is not higher than the withstand voltage (e.g. 3.3V) of the second zener diode TVS2, so as to avoid damage caused by the power supply pin of the main control chip U4 receiving the excessive voltage.

IN some embodiments, a Power-up diode D3 is further included, the Power-up diode being configured to be connected to the charging input terminal power_in, and a negative electrode of the Power-up diode being connected to the Power input terminal of the Power supply voltage chip U3. Therefore, when the internal battery unit is not powered, the external charger is connected to the charging input end Power_IN, and the current of the external charger can immediately flow to the Power supply voltage chip U3 and supply Power to the main control chip U4, so that the main control chip U4 can immediately work. The charging input terminal Power_IN is connected with a charging branch, and the charging branch comprises a charging switch tube, and the charging switch tube is controlled by a main control chip U4. The charging branch and the charging control are described in the patents (such as the patents described in the background art) filed by the applicant, and are not improvement points of the present utility model, and are not described herein.

In some embodiments, the battery cell further comprises a fuse F4, and the positive electrode of the battery cell connection end is connected with the positive electrode PACK_PACK+ of the battery cell through the fuse F4. When the discharge current is overlarge, the output of the battery unit can be disconnected through the fuse, so that the safety of the battery is ensured.

The utility model also provides an energy storage power supply, which comprises a detection circuit and a battery unit, wherein the detection circuit is any one of the detection circuits in the embodiment of the utility model, and two ends of the battery unit connecting end are connected with the battery unit connecting end of the detection circuit. After the voltage of the battery unit connection end is obtained through the voltage dividing resistor, the main control chip in the energy storage power supply can calculate the accurate value of the battery unit voltage through the reference voltage of the reference voltage pin. The accuracy of the reference voltage is improved, so that the accuracy of the obtained battery cell voltage is also greatly improved, and the electric quantity of the battery cell with high accuracy can be obtained. Therefore, the problems that the accuracy of the existing SOC electric quantity is low, and the existing SOC electric quantity and the storage battery electric quantity are inaccurate are solved.

Preferably, the battery cell is a lithium battery, such as a lithium iron phosphate battery or a ternary lithium battery. The energy density of lithium batteries is relatively high, and higher amounts of electricity can be provided in smaller volumes.

It should be noted that, although the foregoing embodiments have been described herein, the scope of the present utility model is not limited thereby. Therefore, based on the innovative concepts of the present utility model, alterations and modifications to the embodiments described herein, or equivalent structures or equivalent flow transformations made by the present description and drawings, apply the above technical solutions directly or indirectly to other relevant technical fields, all of which are included in the scope of protection of the present patent.

Claims

1. The utility model provides an improve detection circuit of battery SOC electric quantity precision which characterized in that: the device comprises a main control chip, a power supply voltage chip, a battery unit connecting end and a reference voltage chip; the positive pole of battery unit link is used for connecting the positive pole of battery unit, the positive pole of battery unit link with the power input of power supply voltage chip is connected, the power output of power supply voltage chip with the power end of main control chip with the power input of reference voltage chip is connected, the power output of reference voltage chip with the reference voltage pin of main control chip is connected, the positive pole of battery unit link pass through behind the divider resistor with the voltage acquisition pin of main control chip is connected, the ground connection of main control chip, the ground connection of power supply voltage chip, the negative pole of battery unit link, the ground connection of reference voltage chip and the negative pole ground connection of battery unit.

2. The detection circuit for improving the accuracy of the SOC of a battery according to claim 1, wherein: the battery cell is characterized by further comprising a discharging switch tube and a starting button, wherein the positive electrode of the battery cell connecting end is used for being connected with the positive electrode of the battery cell through the discharging switch tube, the input end of the discharging switch tube is connected with the positive electrode of the battery cell, the output end of the discharging switch tube is connected with the positive electrode of the battery cell connecting end, the control end of the discharging switch tube is connected with one end of the starting button and one end of a pull-up resistor, the other end of the pull-up resistor is connected to the positive electrode of the battery cell, and the other end of the starting button is grounded.

3. The detection circuit for improving the accuracy of the SOC of a battery according to claim 2, wherein: the power-on control circuit further comprises a holding switch tube, one end of the power-on button is connected with the input end of the holding switch tube, the control end of the holding switch tube is connected with a power-on control pin of the main control chip, and the output end of the holding switch tube is grounded.

4. The detection circuit for improving the accuracy of the SOC of a battery according to claim 2, wherein: the power-on switch comprises a main control chip, and is characterized by further comprising a detection switch tube and a grounding resistor, wherein the other end of the power-on key is grounded through the grounding resistor, the other end of the power-on key is connected with the control end of the detection switch tube, the input end of the detection switch tube is connected with a power-on detection pin of the main control chip, and the output end of the detection switch tube is grounded.

5. The detection circuit for improving the accuracy of the SOC of a battery according to claim 1, wherein: the voltage-withstanding circuit further comprises a first voltage-stabilizing diode, wherein the negative electrode of the first voltage-stabilizing diode is grounded, the positive electrode of the first voltage-stabilizing diode is connected with the voltage acquisition pin of the main control chip, and the voltage-withstanding voltage of the first voltage-stabilizing diode is the same as the voltage of the power output end of the reference voltage chip.

6. The detection circuit for improving the accuracy of the SOC of a battery according to claim 1, wherein: the power supply circuit further comprises a second voltage stabilizing diode, wherein the negative electrode of the second voltage stabilizing diode is grounded, the positive electrode of the second voltage stabilizing diode is connected with the power supply output end of the power supply voltage chip, and the withstand voltage of the second voltage stabilizing diode is the same as the voltage of the power supply output end of the power supply voltage chip.

7. The detection circuit for improving the accuracy of the SOC of a battery according to claim 1, wherein: the power supply voltage chip is characterized by further comprising a power-on diode, wherein the power-on diode is used for being connected with a charging input end, and the cathode of the power-on diode is connected to the power input end of the power supply voltage chip.

8. The detection circuit for improving the accuracy of the SOC of a battery according to claim 1, wherein: the battery cell also comprises a fuse, and the positive electrode of the battery cell connecting end is connected with the positive electrode of the battery cell through the fuse.

9. An energy storage power supply system, characterized in that: the detection circuit is as claimed in any one of claims 1 to 8, and two ends of the battery unit are connected with the battery unit connection end of the detection circuit.