Battery current sampling circuit, battery management device and battery management system

Abstract

The utility model discloses a battery current sampling circuit, a battery management device and a battery management system, relates to the technical field of new energy, and discloses the battery current sampling circuit, the battery management device and the battery management system, and the battery current sampling circuit comprises a battery current detection module which is connected with the current output end of a main battery and is used for detecting the battery current; the current sampling end of the battery current processing module is connected to the two ends of the battery current detection module, the battery current flowing through the battery current detection module is sampled and subjected to operational amplification, and a battery charge state signal is output. The battery current sampling circuit is used for sampling and operational amplifying the battery current, outputting a battery charge state signal to the control processor and calculating and outputting the battery charge quantity of the battery, so that the problem that the device cost is increased due to the fact that an analog front-end sampling chip needs to be arranged to achieve the functions is solved; the production cost of the BMS is reduced, and the profit margin is increased.

Description

Technical Field

[0001] The present application relates to the field of new energy technologies, and particularly to a battery current sampling circuit, a battery management device, and a battery management system. Background Art

[0002] With the rapid development of the new energy industry, more and more batteries are applied to energy storage systems. Due to the high requirements of energy storage systems for batteries, the BMS (Battery Management System) of batteries has attracted attention. Most of the conventional BMSs collect the SOC (System On Chip) through an analog front-end chip. After the analog front-end chip collects the battery current of the battery, the collected battery current signal is input into the MCU (Microcontroller Unit), and the battery current signal is calculated based on the MCU to output the power.

[0003] However, since the price of the analog front-end sampling chip is generally high, the production cost of the BMS increases, resulting in a problem of narrowing profit margins.

[0004] Application Content

[0005] The main purpose of the present application is to provide a battery current sampling circuit, a battery management device, and a battery management system, aiming to solve the technical problem that the price of the analog front-end sampling chip is generally high, resulting in an increase in the production cost of the BMS and a narrowing of the profit margin.

[0006] To achieve the above object, the present application proposes a battery current sampling circuit, and the battery current sampling circuit includes:

[0007] A battery current detection module, which is connected to the current output end of the main battery and is used to detect the battery current;

[0008] A battery current processing module, the current sampling end of which is connected to both ends of the battery current detection module, samples and operational-amplifies the battery current flowing through the battery current detection module, and outputs a state-of-charge signal of the battery.

[0009] In one embodiment, the battery current detection module includes a charge and discharge detection resistor;

[0010] The first end of the charge and discharge detection resistor is connected to the current output end, and the second end of the charge and discharge detection resistor is connected to the ground end.

[0011] In one embodiment, the current sampling end includes a positive input end and a negative input end, and the battery current processing module includes a battery charge and discharge current detection and amplification chip;

[0012] The positive input terminal of the battery charge and discharge current detection and amplification chip is connected to the first end of the charge and discharge detection resistor, and the negative input terminal of the battery charge and discharge current detection and amplification chip is connected to the second end of the charge and discharge detection resistor.

[0013] In addition, to achieve the above object, the present application also proposes a battery management device, which includes the battery current sampling circuit as described above, and the battery management device further includes a main battery and a DC conversion circuit;

[0014] The current output terminal of the main battery is connected to the input terminal of the DC conversion circuit, and the DC conversion circuit converts the input battery current into a supply current;

[0015] The output terminal of the DC conversion circuit is connected to the battery current processing module in the battery current sampling circuit, and is used to input the supply current into the battery current processing module to supply power to the battery current processing module.

[0016] In an embodiment, the battery current processing module includes a battery charge and discharge current detection and amplification chip;

[0017] The reference voltage pin and the power supply pin of the battery charge and discharge current detection and amplification chip are respectively connected to the output terminal of the DC conversion circuit.

[0018] In an embodiment, the battery management device is connected to a control processor, and the battery management device further includes an isolation communication interface;

[0019] The isolation communication interface is connected to the signal output terminal of the battery charge and discharge current detection and amplification chip, and is used to forward the state of charge signal of the battery output by the signal output terminal to the control processor.

[0020] In an embodiment, the battery management device further includes a control acquisition module, and the control acquisition module includes the battery current sampling circuit and a control acquisition unit;

[0021] The control acquisition unit is respectively connected to the main battery and the DC conversion circuit, and is used to collect the operation data of the main battery and generate a control signal and a collection signal according to the collection result.

[0022] In an embodiment, the battery management device further includes a control switch;

[0023] The input terminal of the control switch is connected to the main battery;

[0024] The input control terminal of the control switch is connected to the control acquisition module, and is used to access the control signal output by the control acquisition module and convert the switch state according to the control signal.

[0025] In one embodiment, the battery management device further includes a main battery voltage output module;

[0026] The main battery voltage output module is connected to the output control terminal of the control switch, and is used to control the output state of the battery voltage of the main battery according to the switch state of the control switch.

[0027] In addition, to achieve the above object, the present application also proposes a battery management system, which includes the battery management device as described above. The battery management device includes a battery current sampling circuit, and the battery current sampling circuit includes:

[0028] A battery current detection module, which is connected to the current output terminal of the main battery and is used to detect the battery current;

[0029] A battery current processing module, the current sampling terminal of the battery current processing module is connected to both ends of the battery current detection module, samples and amplifies the battery current flowing through the battery current detection module, and outputs a state of charge signal of the battery.

[0030] One or more technical solutions proposed by the present application have at least the following technical effects:

[0031] The present application proposes a battery current sampling circuit for replacing an analog front-end sampling chip. The battery current sampling circuit includes: a battery current detection module, which is connected to the current output terminal of the main battery and is used to detect the battery current; a battery current processing module, the current sampling terminal of the battery current processing module is connected to both ends of the battery current detection module, samples and amplifies the battery current flowing through the battery current detection module, and outputs a state of charge signal of the battery. It realizes the functions of sampling, amplifying the battery current through the battery current sampling circuit and outputting the state of charge signal of the battery to the control processor for calculating and outputting the state of charge of the battery, avoiding the problem of increased device cost caused by setting an analog front-end sampling chip to achieve the above functions, reducing the production cost of the BMS and increasing the profit margin. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0033] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a module schematic diagram of the battery current sampling circuit of the present application;

[0035] Figure 2 It is a detailed circuit schematic diagram of the battery current sampling circuit of the present application;

[0036] Figure 3 It is a module schematic diagram of the battery management device of the present application.

[0037] Label:

[0038] Explanation of the reference numerals in the drawings:

[0039] 10. Battery current detection module; CON, power supply; R1, charge and discharge detection resistor;

[0040] 20. Battery current processing module; U1, battery charge and discharge current detection and amplification chip.

[0041] The realization of the purpose, functional features and advantages of the present application will be further described with reference to the embodiments and the drawings. Specific embodiments

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0043] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present application, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0044] In addition, if descriptions such as "first" and "second" are involved in the embodiments of this application, such descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0045] This application proposes a battery current sampling circuit.

[0046] Please refer to Figure 1 , in an embodiment of this application, the battery current sampling circuit includes:

[0047] A battery current detection module 10, the battery current detection module 10 is connected to the current output terminal of the main battery (i.e., Figure 1 VBAT in) for detecting the battery current. By connecting the battery current detection module 10 in series with the main battery, the battery current is detected to achieve the effect of subsequently sampling the battery in the main battery through the battery current detection module 10.

[0048] A battery current processing module 20, the current sampling terminal of the battery current processing module 20 is connected to both ends of the battery current detection module 10, samples and amplifies the battery current flowing through the battery current detection module 10, and outputs a state of charge signal of the battery. By connecting the battery current processing module 20 to sample and amplify the battery current flowing through the battery current detection module 10, the acquisition and arithmetic amplification of the battery current are realized, and a state of charge signal of the battery is output.

[0049] By using the battery current sampling circuit composed of the battery current detection module 10 and the battery current processing module 20 to replace the analog front-end sampling chip required for the conventional output of the state of charge signal of the battery, the situation of increased device cost due to the use of the analog front-end sampling chip is avoided, thereby reducing the production cost of the BMS and increasing the profit margin.

[0050] At the same time, the volume of the battery current sampling circuit proposed in this embodiment is smaller than the volume of the analog front-end sampling chip, which can reduce the size of the BMS board of the BMS to a certain extent and is beneficial to reducing the energy loss of the BMS.

[0051] Specifically, referring to Figure 2 as shown, the battery current detection module 10 includes a charge and discharge detection resistor R1;

[0052] The first end of the charge and discharge detection resistor R1 is connected to the current output terminal, and the second end of the charge and discharge detection resistor R1 is connected to the ground terminal.

[0053] In order to improve the accuracy of the battery current sampled by the battery current processing module 20, in this embodiment, a charge and discharge detection resistor R1 is placed in the circuit of the battery current detection module 10. The first end of the charge and discharge detection resistor R1 is connected to the current output terminal of the main battery, and the second end is connected to the ground terminal. The battery current of the main battery (i.e., Figure 2 VBAT in Figure 2 flows through the charge and discharge detection resistor R1, generating a voltage difference across the two ends of the charge and discharge detection resistor R1. Dividing this voltage difference by the resistance value of the charge and discharge detection resistor R1 can obtain the state of charge signal of the main battery (i.e.,

[0054] SOC_AD in Figure 2 In addition, the first coil connected to the current output terminal in the power supply CON in

[0055] is the current access terminal, and the second coil connected to the first end of the charge and discharge detection resistor R1 is the current output terminal of the main battery. Figure 2 Further, the current sampling terminal includes a positive input terminal (i.e., Figure 2 IN+ in

[0056] and a negative input terminal (i.e.,

[0057] IN- in

[0058] The positive input terminal and the negative input terminal of the battery charge and discharge current detection and amplification chip U1 are respectively connected to the first end and the second end of the charge and discharge detection resistor R1. The positive input terminal is connected to the input battery current of the main battery flowing into the charge and discharge detection resistor R1, and the negative input terminal is connected to the output battery current flowing out of the charge and discharge detection resistor R1 of the main battery. After obtaining the voltage difference between the input battery current and the output battery current internally, dividing the voltage difference by the resistance value of the charge and discharge detection resistor R1 can obtain the state of charge signal of the main battery. The state of charge signal of the battery is output from the signal output terminal (i.e., Figure 2 OUT in

[0059] In addition, a resistor R and a capacitor C are connected to the signal output terminal for filtering.

[0060] The technical solution of this application proposes a battery current sampling circuit for replacing an analog front-end sampling chip. The battery current sampling circuit includes: a battery current detection module 10, which is connected to the current output terminal of the main battery and is used to detect the battery current; a battery current processing module 20, the current sampling terminal of the battery current processing module 20 is connected to both ends of the battery current detection module 10, samples and amplifies the battery current flowing through the battery current detection module 10, and outputs the state of charge signal of the battery. It realizes the functions of sampling, amplifying the battery current through the battery current sampling circuit and outputting the state of charge signal of the battery to the control processor for calculating and outputting the state of charge of the battery, avoiding the problem of increased device cost caused by setting an analog front-end sampling chip to achieve the above functions, reducing the production cost of the BMS and increasing the profit margin.

[0061] This application also proposes a battery management device. The battery management device includes the battery current sampling circuit as described above. The specific structure of the battery current sampling circuit refers to the above embodiments. Since this battery management device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one. Among them, please refer to Figure 3 and the battery management device further includes a main battery and a DC conversion circuit;

[0062] The current output terminal of the main battery is connected to the input terminal of the DC conversion circuit, and the DC conversion circuit converts the input battery current into a supply current; the output terminal of the DC conversion circuit is connected to the battery current processing module 20 in the battery current sampling circuit for inputting the supply current into the battery current processing module 20 to supply power to the battery current processing module 20.

[0063] Further, the battery current processing module 20 includes a battery charge and discharge current detection and amplification chip U1;

[0064] The reference voltage pin (i.e., Figure 2 REF in Figure 2 ) and the power supply pin (i.e.,

[0065] VCC in Figure 2 ) of the battery charge and discharge current detection and amplification chip U1 are respectively connected to the output end of the DC conversion circuit. Figure 2 As can be seen from Figure 2 , a reference power supply voltage needs to be connected to the reference voltage pin and the power supply pin of the battery charge and discharge current detection and amplification chip U1 in

[0066] respectively to ensure the stability of the operation of the battery charge and discharge current detection and amplification chip U1, and this reference power supply voltage (i.e.,

[0067] VCC in Figure 2 ) is provided by the DC conversion circuit. The input end of the DC conversion circuit is connected to the current output end of the main battery. In this embodiment, the DC conversion circuit converts the battery current input from the current output end into a reference power supply voltage of 2.5V. This reference power supply voltage flows into the reference voltage pin to provide a voltage reference point for the battery charge and discharge current detection and amplification chip U1, and at the same time, this reference power supply voltage flows into the power supply pin to supply power to the battery charge and discharge current detection and amplification chip U1.

[0068] In addition, the resistor R connected between the reference voltage pin and the output end of the DC conversion circuit is used to protect the safety of the reference voltage pin; at the same time, the capacitor C and the diode D are connected in parallel and connected to the ground terminal on the connection line between the reference voltage pin and the output end of the DC conversion circuit, which is used to further stabilize the reference power supply voltage input to the reference voltage pin.

[0069] The battery charge and discharge current detection and amplification chip U1 in this embodiment also includes a ground terminal (i.e., Figure 2 GND in

[0068] ), and this ground terminal is grounded. At the same time, a capacitor C is connected between the power supply pin and the ground terminal, which plays a role in energy storage and filtering. Further, the battery management device is connected to the control processor, and the battery management device also includes an isolation communication interface; the isolation communication interface is connected to the signal output end of the battery charge and discharge current detection and amplification chip U1, and is used to forward the battery state of charge signal output by the signal output end to the control processor.

[0069] The battery management device should include an isolated communication interface, which is the communication interface between the battery management device and the control processor. Through the isolated communication interface, the state-of-charge signal of the battery sampled by the battery charge and discharge current detection and amplification chip U1 is forwarded to the control processor, and the control processor calculates the state-of-charge signal of the battery to obtain the SOC power of the current main battery.

[0070] The isolated communication interface in this embodiment adopts an isolated 485 communication port.

[0071] Furthermore, the battery management device further includes a control acquisition module, and the control acquisition module includes the battery current sampling circuit and the control acquisition unit; the control acquisition unit is respectively connected to the main battery and the DC conversion circuit, and is used for acquiring the operation data of the main battery and generating a control signal and an acquisition signal according to the acquisition result.

[0072] In addition, the battery management device also includes a control acquisition module. The control acquisition module includes, in addition to the above-mentioned battery current sampling circuit, a control acquisition unit. The control acquisition unit is respectively connected to the main battery and the DC conversion circuit, and is used for acquiring the operation data of the main battery and generating a control signal and an acquisition signal according to the acquisition result.

[0073] Specifically, the control acquisition unit includes a temperature acquisition sub-unit and a charge and discharge control sub-unit. Among them, after the temperature acquisition sub-unit enters the on state based on the reference power supply voltage accessed from the DC conversion circuit, it acquires the battery current of the main battery, calculates according to the acquired battery current, outputs a temperature acquisition signal, and can output the temperature acquisition signal to the control processor through the isolated communication interface, and the control processor calculates to obtain the battery temperature of the current main battery.

[0074] After the charge and discharge control sub-unit enters the on state based on the reference power supply voltage accessed from the DC conversion circuit, it acquires the battery current of the main battery, calculates according to the acquired battery current, and outputs a control signal for output control of the battery voltage of the main battery.

[0075] Furthermore, the battery management device further includes a control switch;

[0076] The input end of the control switch is connected to the main battery; the input control end of the control switch is connected to the control acquisition module, and is used for accessing the control signal output by the control acquisition module and switching the switch state according to the control signal.

[0077] As mentioned above, the control signal output by the charge and discharge control sub-unit is transmitted to the control switch to convert the switch state of the control switch, thereby controlling the output path of the battery voltage of the main battery.

[0078] Further, the battery management device further includes a main battery voltage output module;

[0079] The main battery voltage output module is connected to the output control end of the control switch and is used to control the output state of the battery voltage of the main battery according to the switch state of the control switch.

[0080] If the control switch enters the conducting state based on the control signal, the battery voltage of the connected main battery is output to the main battery voltage output module through the conducting control switch, and the battery voltage is output through the main battery voltage output module; if the control switch enters the off state based on the control signal, the battery voltage output to the main battery voltage output module is cut off through the off control switch.

[0081] The present application also proposes a battery management system. The battery management system includes the battery management device as described above. The battery management device includes a battery current sampling circuit, and the battery current sampling circuit includes:

[0082] A battery current detection module 10, which is connected to the current output end of the main battery and is used to detect the battery current;

[0083] A battery current processing module 20, the current sampling end of which is connected to both ends of the battery current detection module 10, samples and amplifies the battery current flowing through the battery current detection module 10, and outputs a state of charge signal of the battery.

[0084] The above are only exemplary embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. A battery current sampling circuit, characterized in that: The battery current sampling circuit comprises: A battery current detection module, which is connected to the current output terminal of the main battery and is used to detect the battery current; A battery current processing module, wherein the current sampling terminals of the battery current processing module are connected to the two ends of the battery current detection module, samples and amplifies the battery current flowing through the battery current detection module, and outputs a battery charge state signal.

2. The battery current sampling circuit according to claim 1, characterized in that: The battery current detection module includes a charge and discharge detection resistor; The first end of the charge and discharge detection resistor is connected to the current output end, and the second end of the charge and discharge detection resistor is connected to the ground end.

3. The battery current sampling circuit as claimed in claim 2, characterized in that: The current sampling terminal includes a positive input terminal and a negative input terminal, and the battery current processing module includes a battery charge and discharge current detection amplifier chip; The positive input terminal of the battery charge and discharge current detection amplifier chip is connected to the first end of the charge and discharge detection resistor, and the negative input terminal of the battery charge and discharge current detection amplifier chip is connected to the second end of the charge and discharge detection resistor.

4. A battery management device, comprising the battery current sampling circuit according to any one of claims 1 to 3, and further comprising a main battery and a DC conversion circuit; The current output terminal of the main battery is connected to the input terminal of the DC conversion circuit, and the DC conversion circuit converts the connected battery current into the power supply current; The output end of the DC conversion circuit is connected to the battery current processing module in the battery current sampling circuit, and is used to input the power supply current into the battery current processing module to supply power to the battery current processing module.

5. The battery management device according to claim 4, characterized in that: The battery current processing module includes a battery charge and discharge current detection amplifier chip; The reference voltage pin and the power supply pin of the battery charge and discharge current detection amplifier chip are respectively connected to the output end of the DC conversion circuit.

6. The battery management device according to claim 5, characterized in that: The battery management device is connected to the control processor, and the battery management device also includes an isolated communication interface; The isolated communication interface is connected to the signal output end of the battery charge and discharge current detection amplifier chip, and is used to forward the battery charge state signal output by the signal output end to the control processor.

7. The battery management device according to claim 6, characterized in that: The battery management device further includes a control acquisition module, and the control acquisition module includes the battery current sampling circuit and a control acquisition unit; The control acquisition unit is connected to the main battery and the DC conversion circuit respectively, and is used to collect the operating data of the main battery and generate a control signal and an acquisition signal according to the acquisition results.

8. The battery management device according to claim 7, characterized in that: The battery management device also includes a control switch; The input end of the control switch is connected to the main battery; The input control end of the control switch is connected to the control acquisition module, and is used to receive the control signal output by the control acquisition module and convert the switch state according to the control signal.

9. The battery management device according to claim 8, characterized in that: The battery management device also includes a main battery voltage output module; The main battery voltage output module is connected to the output control end of the control switch and is used to control the output state of the battery voltage of the main battery according to the switch state of the control switch.

10. A battery management system, characterized in that: The battery management system comprises the battery management device as claimed in any one of claims 4 to 9.

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