A BMS self-consumption detection circuit

Abstract

The utility model relates to detection circuit technical field especially, it relates to a kind of BMS self-consumption power detection circuit, including battery management system, battery module and the detection module between the battery management system and battery module of being connected;The battery module includes N battery units connected in series, and form (N+1) first terminal;The battery management system includes at least N second terminal;The detection module includes (N+1) detection components, respectively connected between the first terminal and second terminal, for detecting the current value between the first terminal and second terminal.The utility model discloses the purpose of the present application is to provide a kind of BMS self-consumption power detection circuit, using the technical solutions provided by the utility model can solve the technical problems of low self-consumption power detection precision and low detection efficiency of conventional detection mode.

Description

Technical Field

[0001] This utility model relates to the field of detection circuit technology, and in particular to a BMS self-consumption power detection circuit. Background Technology

[0002] Consumers are paying increasing attention to the driving range of power battery packs. Many factors affect driving range, among which the power consumption of the battery management system itself is an important factor. Self-power consumption can affect the state of charge of the battery pack, the consistency of individual cells, and power loss during transportation and shipping.

[0003] The Battery Management System (BMS) is a management circuit applied to a battery to intelligently manage and maintain each battery cell, monitor the battery's status, and prevent overcharging and over-discharging, thereby extending the battery's lifespan. Since the BMS is not a load, it requires additional power from the battery pack; therefore, the BMS's own power consumption affects the battery's range. The BMS's self-consumption refers to the current it consumes, that is, the additional current it draws from the battery.

[0004] For these reasons, many manufacturers are seeking more accurate current consumption detection solutions to address battery pack charging capacity and reduce unnecessary losses. Early solutions often involved connecting an ammeter in series with the detection circuit, but there is significant room for improvement in both detection efficiency and cost-effectiveness.

[0005] Existing technologies detect current consumption using ammeters, which cannot meet the requirements of high-precision and high-reliability detection, nor can they accurately assess the power consumption of the battery management system; they cannot be applied to the detection of current consumption in the battery management system of energy storage systems; they cannot achieve wireless communication to transmit data and cannot obtain current consumption data in real time; and they cannot communicate with the energy management system (EMS) or battery management unit (BMU). Utility Model Content

[0006] The purpose of this invention is to provide a BMS self-consumption power detection circuit. The technical solution provided by this invention can solve the technical problems of low self-consumption power detection accuracy and low detection efficiency in conventional detection methods.

[0007] To achieve the above-mentioned objectives, this utility model provides a BMS self-discharge detection circuit, including a battery management system, a battery module, and a detection module connected between the battery management system and the battery module; the battery module includes N battery cells connected in series and forming (N+1) first terminals; the battery management system includes at least N second terminals; the detection module includes (N+1) detection components, which are respectively connected in series between the first terminals and the second terminals for detecting the current value between the first terminals and the second terminals.

[0008] Preferably, the detection component includes a voltage detection unit, a conduction switch, and several current detection resistors connected in parallel; one end of each of the several current detection resistors is open-circuited and connected to a switching switch.

[0009] Preferably, the resistance values ​​of the several current sensing resistors are different.

[0010] Preferably, it also includes a data transmission module; the voltage detection units are electrically connected to the data transmission module.

[0011] Preferably, the data transmission module is one or more of a wireless communication module, an Ethernet communication module, and a CANFD communication module.

[0012] Preferably, the battery cell is a physical cell, a physical battery, or a simulated cell.

[0013] Compared with the prior art, the detection module of this utility model consists of multiple sets of detection components. Each set of detection components can independently detect the voltage value of the resistor by detecting the current, and then calculate the current flowing through the second terminal to obtain the current consumption of the battery management system. This solves the problems of low detection accuracy and high detection cost of the current consumption of the battery management system, and truly reflects the power consumption of the battery management system. Attached Figure Description

[0014] Figure 1 This is a circuit connection block diagram of an embodiment of the present utility model;

[0015] Figure 2 This is a circuit diagram of an embodiment of the present invention. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Existing technologies detect current consumption using ammeters, which cannot meet the requirements of high-precision and high-reliability detection, nor can they accurately assess the power consumption of the battery management system; they cannot be applied to the detection of current consumption in the battery management system of energy storage systems; they cannot achieve wireless communication to transmit data and cannot obtain current consumption data in real time; and they cannot communicate with the energy management system (EMS) or battery management unit (BMU).

[0018] Please see Figures 1 to 2To address the aforementioned technical problems, this embodiment provides a BMS self-consumption power detection circuit. The technical solution provided in this embodiment can solve the technical problems of low self-consumption power detection accuracy and low detection efficiency in conventional detection methods.

[0019] This embodiment of a BMS self-consumption detection circuit includes a battery management system 10, a battery module 20, and a detection module 30 connected between the battery management system 10 and the battery module 20.

[0020] Specifically, the battery module 20 has N battery cells 21 connected in series, forming (N+1) first terminals 22. It should be noted that this embodiment can be applied in battery systems or simulated battery systems; that is, the battery cells 21 can be physical cells, physical batteries, or simulated cells. It is unaffected by the detection object or detection device and can also be installed in an energy storage system to collect system power consumption in real time.

[0021] The battery management system 10 includes (N+1) second terminals 11, and the detection module 30 includes (N+1) detection components 31. Taking 8 battery cells 21 as an example, the battery module 20 has 9 first terminals 22, the battery management system 10 has 9 second terminals 11, and the detection module 30 has 9 detection components 31.

[0022] Nine detection components 31 are connected in series between the first terminal 22 of the battery module 20 and the second terminal 11 of the battery management system 10, forming nine current consumption detection loops of the battery management system.

[0023] Specifically, the detection component 31 includes a voltage detection unit 311, a conduction switch 312, and several current detection resistors 314 connected in parallel. One end of each current detection resistor 314 is open-circuited and connected to a switching switch 313.

[0024] The resistance value of the current sensing resistor 314 varies, and its number can be adjusted according to the current value range of the battery management system in different operating modes; two or more can be used. The voltage sensing unit 311 can be a voltmeter, specifically a voltmeter with two ranges: 100mV and 10V.

[0025] The switching switch 313 can switch to a suitable current sensing resistor 314 according to the current consumption value of the battery management system in different operating modes. Since the current flowing through the battery management system varies for different operating modes, different current sensing resistors 314 are required for detection. For example, a high-resistance current sensing resistor 314 is used under low current conditions, and a low-resistance current sensing resistor 314 is used under high current conditions. If an incompatible current sensing resistor 314 is used, it will not only fail to detect the voltage but will also affect the actual current value, resulting in a discrepancy between the detected and actual current values. This embodiment uses different current sensing resistors 314, making the voltage value detected by the voltage detection unit 311 more accurate. This solves the technical problems of low self-discharge detection accuracy and high detection cost of the battery management system 10, and provides a true reflection of the power consumption of the battery management system 10.

[0026] The power consumption of the current sensing resistor 314 itself will not affect the detection of the current consumption by the battery management system.

[0027] When the battery management system starts up, the conduction switch 312 of each detection component 31 is closed first, and the battery management system works normally at this time. When it is necessary to detect the current consumption of the battery management system, the battery management system is switched to different operating modes. The startup modes of the battery management system include standby mode, hibernation mode, power-off mode, operating mode, and equalization mode.

[0028] When the battery management system switches to standby mode, hibernation mode, or power-off mode, in these three modes, the switch 313 is closed to one of the current sensing resistors 314, and the on / off switch 312 is opened. At this time, the voltage detection unit 311 detects the voltage value on the current sensing resistor 314, and then calculates the current value flowing through the current sensing resistor 314 using the formula I = V / R. This current value is the current consumed by the battery management system. Because the current consumed by the battery management system is very small in standby mode, hibernation mode, or power-off mode—for example, in standby mode, the current consumed by the battery management system is generally between 0.1mA and 2mA; in hibernation mode, the current consumed by the battery management system is generally between 0.01mA and 0.5mA; and in power-off mode, the current consumed by the battery management system is even lower, between 0.01μA and 20μA—it is extremely low. Therefore, the required current sensing resistor 314 varies depending on the operating mode. For small current values, a large resistance current sensing resistor 314 is used. For example, for current values ​​in the μA range, a current sensing resistor 314 with a resistance of 100Ω to 2KΩ is used. In this case, the detected voltage value is an accurate voltage drop, and the calculated current consumption is also an accurate current. For large current values, a small resistance current sensing resistor 314 is used. For example, for current values ​​in the mA range, a current sensing resistor 314 with a resistance of 0.05Ω to 20Ω is used. In this case, the detected voltage value is an accurate voltage drop, and the calculated current consumption is also an accurate current.

[0029] When the battery management system switches to working mode, its internal components operate normally to monitor the status of the battery cells. At this time, the current value flowing through the second terminal is larger than the current value in the three modes mentioned above, reaching 5mA to 100mA. At this time, a suitable current sensing resistor 314 can be switched to adapt to the current value at this time.

[0030] When the battery management system is in balancing mode, it is divided into active balancing and passive balancing. The current value of passive balancing is generally 20mA to 300mA, while the current value of active balancing reaches 1A to 10A. The current sensing resistors 314 used are different for both.

[0031] In this embodiment, each detection component 31 can independently detect the voltage value of the current detection resistor 314, and then calculate the current flowing through the second terminal to obtain the current consumed by the battery management system. This solves the problems of low detection accuracy and high detection cost of the current consumed by the battery management system, and truly reflects the power consumption of the battery management system.

[0032] To enable the uploading and processing of detection data, this embodiment also includes a data transmission module 40; the voltage detection unit 311 is electrically connected to the data transmission module 40. The data transmission module 40 is one or more of a wireless communication module, an Ethernet communication module, and a CANFD communication module.

[0033] The detection and data transmission can be controlled via a wireless communication module. Specifically, the detection function can be activated via software systems, such as 4G / 5G, WiFi, or Bluetooth, and the detected current value can be uploaded to a cloud server or terminal APP. Detection data can be transmitted via Ethernet or CAN communication. The receiving end can be a computer host computer, an energy storage EMS, or a main control system. It can realize real-time monitoring of battery management system self-consumption and real-time data upload, which helps with battery life management and traceability, improves detection accuracy and efficiency, and enhances detection reliability and accuracy.

[0034] Furthermore, by using the detected voltage data, the consumed current can be calculated, and the amount of electricity flowing into / out of each battery cell can be integrated to determine the difference in electricity consumption between each battery cell. At the same time, by combining the voltage value of each battery cell, the consistency between battery cells can be determined, thereby improving the safety of the battery system and the consistency of individual cells, and improving the accuracy of SOC estimation.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A BMS self-consumption power detection circuit, characterized in that: The system includes a battery management system, a battery module, and a detection module connected between the battery management system and the battery module. The battery module includes N battery cells connected in series and forming (N+1) first terminals. The battery management system includes at least N second terminals. The detection module includes (N+1) detection components, which are connected in series between the first terminals and the second terminals to detect the current value between the first terminals and the second terminals.

2. The BMS self-consumption power detection circuit according to claim 1, characterized in that: The detection component includes a voltage detection unit, a conduction switch, and several current detection resistors connected in parallel; one end of each of the several current detection resistors is open-circuited and connected to a switching switch.

3. The BMS self-consumption power detection circuit according to claim 2, characterized in that: The resistance values ​​of the various current sensing resistors are different.

4. The BMS self-consumption power detection circuit according to claim 3, characterized in that: It also includes a data transmission module; the voltage detection units are electrically connected to the data transmission module.

5. The BMS self-consumption power detection circuit according to claim 4, characterized in that: The data transmission module is one or more of the following: a wireless communication module, an Ethernet communication module, and a CANFD communication module.

6. The BMS self-consumption power detection circuit according to any one of claims 1-5, characterized in that: The battery unit is a physical cell, a physical battery, or a simulated cell.

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