Battery management system

Abstract

The utility model discloses a battery management system, which comprises a flyback isolation switch power supply, a transformer, a detection chip and an energy storage capacitor, the input end of the flyback isolation switch power supply is connected with the storage battery, and the output end is connected with the input end of the transformer; the output end of the transformer is connected with the detection chip and is used for supplying power to the detection chip; the detection chip comprises an MOS tube, an analog-to-digital converter and a switch controller; the MOS tube is connected with the energy storage capacitor, and when the flyback isolation switch power supply is normally connected with the storage battery, the energy storage capacitor is charged; the analog-to-digital converter is used for being connected with the diverter and collecting battery current passing through the diverter; the switch controller is used for being connected with the fuse; when the flyback isolation switch power supply cannot be connected with the storage battery, the energy storage capacitor supplies power to the detection chip, and when the current of the battery passing through the shunt exceeds a set threshold value, the switch controller directly explodes the fuse connected with the switch controller. According to the utility model, functions of battery loop over-current detection and fuse driving after power failure are realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to battery management technical field, concretely relates to a battery management system. BACKGROUND

[0002] In the normal driving process of electric vehicles, after the power supply of 12V storage battery suddenly loses, the battery pack may exist energy mutation load short circuit and other conditions, so the vehicle manufacturer requires that the battery management system needs to have overcurrent detection and fuse driving functions within a period of time when the 12V storage battery loses power, and the fuse in series in the high-voltage battery loop is detonated to make the high-voltage loop circuit break, avoiding the risk of thermal runaway caused by battery pack short circuit. UTILITARIAN CONTENT

[0003] In view of the above problems, the utility model provides a battery management system, which has the functions of overcurrent detection and fuse driving of battery loop after power failure, and avoids the risk of thermal runaway caused by battery pack short circuit.

[0004] In order to realize the above technical purpose and achieve the above technical effect, the utility model realizes the following technical scheme:

[0005] A battery management system, comprising: a flyback isolation switching power supply, a transformer, a detection chip and an energy storage capacitor;

[0006] The input end of the flyback isolation switching power supply is used to be connected with the storage battery, and the output end thereof is connected with the input end of the transformer;

[0007] The output end of the transformer is connected with the detection chip, and is used to power the detection chip;

[0008] The detection chip comprises a MOS tube, an analog-to-digital converter and a switch controller; the MOS tube is connected with the energy storage capacitor, and charges the energy storage capacitor when the flyback isolation switching power supply is normally connected with the storage battery; the analog-to-digital converter is used to be connected with a shunt, and is used to collect the battery current passing through the shunt; and the switch controller is used to be connected with a fuse;

[0009] When the flyback isolation switching power supply cannot be connected with the storage battery, the energy storage capacitor powers the detection chip, and when the battery current passing through the shunt collected by the analog-to-digital converter exceeds the set threshold value, the switch controller directly detonates the fuse connected therewith.

[0010] In the scheme, the flyback isolation switch power supply is used in cooperation with the transformer to realize conversion of low voltage into the power supply voltage required by the detection chip, to supply power for the detection chip, and when the flyback isolation switch power supply is normally connected with the storage battery, the energy storage capacitor is used for energy storage, the energy stored on the energy storage capacitor is used to supply power for the detection chip during power failure, and after the battery overcurrent is detected, the fuse connected in series on the battery load loop is directly blown, so that the risk of thermal runaway caused by battery pack short circuit can be avoided.

[0011] Optionally, the design principle of the capacitance value of the energy storage capacitor is that when the flyback isolation switch power supply cannot obtain electric energy from the storage battery, the time for the energy storage capacitor to supply power for the detection chip is greater than a set time threshold.

[0012] In the scheme, by specifically setting the capacitance value of the energy storage capacitor, the normal operation of the battery management system can be ensured, and the safety of the battery management system is improved.

[0013] Optionally, the model of the detection chip is MC33777ATA1AE.

[0014] In the scheme, the components are easy to purchase, and the production cost of the battery management system is reduced.

[0015] Optionally, the output voltage of the battery is 12V, the required power supply voltage of the detection chip is 24V, and the transformer is used to convert the 12V voltage into a 24V voltage.

[0016] In the scheme, the flyback isolation switch power supply and the transformer are used to convert the 12V output voltage of the battery into a 24V voltage, so as to supply power for the detection chip with the model of MC33777ATA1AE, without the need to convert the voltage of several hundred volts from the battery into a 24V voltage through a DCDC converter, the voltage withstand value of the components is low, and the transformer has a small size.

[0017] Optionally, the transformer is an isolation transformer.

[0018] In the scheme, since the 12V voltage provided by the storage battery is low voltage, and the battery voltage and the battery current collected by the detection chip are both high voltage, the electrical isolation of low voltage and high voltage can be realized through the transformer.

[0019] Optionally, the fuse is an explosion fuse or a high-temperature fuse.

[0020] In the scheme, by setting the fuse as an explosion fuse or a high-temperature fuse, the power supply can be cut off in a very short time (such as a few milliseconds), and the response speed is fast.

[0021] Compared with the prior art, the utility model has the beneficial effects of:

[0022] In the utility model, use the flyback isolation switch power supply and cooperate with the transformer, realize the low pressure conversion for high pressure, power supply for the detection chip of high voltage side, and when the flyback isolation switch power supply and the storage battery connection are normal, use the energy storage capacitor to store energy, the energy stored on the energy storage capacitor is used to power supply for the detection chip in the power failure time, and after detecting the overcurrent, directly point the fuse connected in series on the battery load loop.

[0023] In addition, the components used in the utility model are easy to purchase, low in cost, and convenient for modular design of the power failure detection overcurrent diagnosis circuit. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to make the content of the utility model more easily understood clearly, the following is according to specific embodiment and combining with the drawings, and the utility model is further detailed, wherein:

[0025] Figure 1 It is the circuit schematic diagram of the battery management system of one embodiment of the utility model. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the following combining with embodiment, the utility model is further detailed.It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the protection scope of the utility model.

[0027] In the description of the utility model patent, it should be explained that the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "horizontal" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model patent and simplifying the description, and is not indicative or implicit of the device or element indicated must have a particular orientation, a particular orientation and operation, therefore, it cannot be understood as the limitation of the utility model patent.

[0028] In the description of the utility model patent, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, can be fixed connection, can be detachable connection, or integrally connected, can be mechanical connection, can be electrical connection, can be directly connected, can be indirectly connected through intermediate medium, can be the communication inside two elements.The above-mentioned terms in the utility model can be understood by the person skilled in the art according to the specific circumstances.

[0029] The application principle of the utility model will be described in detail in combination with the drawings.

[0030] As Figure 1 shown, the utility model discloses a battery management system, comprising: flyback isolating switch power supply, transformer, detection chip and energy storage capacitor C1;

[0031] The input end of flyback isolating switch power supply is used to be connected with storage battery, and its output end is connected with the input end of transformer;

[0032] The output end of transformer is connected with detection chip and is used to power supply detection chip;

[0033] Detection chip includes MOS tube Q1, analog-digital converter and switch controller;MOS tube Q1 is connected with energy storage capacitor C1, and when flyback isolating switch power supply is connected normally with storage battery, charges energy storage capacitor C1;Analog-digital converter is used to be connected with shunt and is used to gather battery current passing through shunt, and in the specific application process, shunt is connected with battery;Switch controller is used to be connected with fuse (i.e. Pyrofuse);In the specific implementation process, analog-digital converter gathers the size of battery current calculated from battery voltage on shunt, and the calculation process is prior art, therefore, the utility model does not make too much repetition;

[0034] When flyback isolating switch power supply cannot be connected with storage battery, energy storage capacitor C1 powers detection chip, and when the current passing through shunt gathered by analog-digital converter exceeds the set threshold value (in the specific application process, the set threshold value is stored in the event manager of detection chip in advance), then switch controller directly explodes fuse (i.e. Pyrofuse) connected with it, and does not need to pass through other controller.

[0035] The working principle of battery management system in the utility model is:

[0036] The power is taken from a 12V battery, and a flyback isolation switching power supply and a transformer are used to output 24V to supply power to a detection chip, and a MOS tube Q1 controlled by a charging current is used to charge an energy storage capacitor C1, and the energy stored in the energy storage capacitor C1 is used to consume the fuse blowing and the working current consumption of the detection chip in the power-off process. After the 12V power-off, the energy storage capacitor C1 supplies power to the detection chip through the body diode inside the MOS tube Q1, and the capacitance value of the energy storage capacitor C1 is adjusted to adapt to the preset duration T_alive of the battery management system after the 12V power-off. After the 12V power-off, the detection chip continuously detects the battery current within the duration T_alive, and when the detected battery current exceeds the set threshold, the fuse is blown directly through the switch controller inside the detection chip without the need for other controllers.

[0037] In the above scheme, the flyback isolation switching power supply is used in cooperation with the transformer to convert low voltage into high voltage to supply power to the detection chip on the high voltage side, and when the flyback isolation switching power supply is normally connected with the battery, the energy storage capacitor C1 is used for energy storage, and the energy stored in the energy storage capacitor C1 is used to supply power to the detection chip during the power-off time and directly blow the fuse connected in series on the battery load loop after overcurrent is detected. The circuit structure is simple and has high reliability.

[0038] In a specific embodiment of the utility model, the design principle of the capacitance value of the energy storage capacitor C1 is that when the flyback isolation switching power supply cannot obtain power from the battery, the time for the energy storage capacitor C1 to supply power to the detection chip is greater than the set time threshold.

[0039] In the above scheme, by designing the capacitance value of the energy storage capacitor C1, the normal operation of the battery management system can be ensured, and the safety of the battery management system is improved.

[0040] In a specific embodiment of the utility model, in order to realize easy purchase of components and reduce the production cost of the battery management system, the model of the detection chip is MC33777ATA1AE.

[0041] In a specific embodiment of the utility model, the output voltage of the battery is 12V, the required power supply voltage of the detection chip is 24V, and the transformer is used to convert the 12V voltage into a 24V voltage. The flyback isolation switching power supply and the transformer are used to convert the 12V output voltage of the battery into a 24V voltage to supply power to the detection chip with the model of MC33777ATA1AE, without the need for taking power from the battery (several hundred volts) and converting the several hundred volts into a 24V voltage through a DCDC converter. The voltage withstand value of the components is low, and the transformer has a small size.

[0042] In a specific embodiment of the utility model, the transformer is an isolation transformer. Since the 12V voltage provided by the battery is low voltage, and the battery voltage and battery current collected by the detection chip are both high voltage, the electrical isolation of low voltage and high voltage can be realized through the transformer.

[0043] In a specific embodiment of the utility model, the fuse is an explosion fuse or a high-temperature fuse, which can cut off the power supply within a very short time (such as a few milliseconds) and has a fast response speed.

[0044] Compared with the traditional power supply scheme, the utility model has the advantages of low voltage resistance of the used components, small size of the whole battery management system, saving of board size, low cost, etc. The topology structure of the battery management system in the utility model is simple, which greatly reduces the difficulty of EMC rectification.

[0045] The basic principle and main features of the utility model and the advantages of the utility model are shown and described above. Those skilled in the art should understand that the utility model is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model can have various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A battery management system, characterized by, The utility model relates to a battery, a flyback isolation switch power supply, a transformer, a detection chip and an energy storage capacitor. The input end of the flyback isolation switch power supply is connected with the battery, and the output end is connected with the input end of the transformer. The output end of the transformer is connected with the detection chip, and is used for powering the detection chip. The detection chip comprises a MOS tube, an analog-digital converter and a switch controller; the MOS tube is connected with the energy storage capacitor, and the energy storage capacitor is charged when the flyback isolation switch power supply is normally connected with the battery. The analog-digital converter is used for being connected with a shunt, and is used for collecting the battery current passing through the shunt; and the switch controller is used for being connected with a fuse. When the flyback isolation switch power supply cannot be connected with the battery, the energy storage capacitor is used for powering the detection chip; when the battery current passing through the shunt collected by the analog-digital converter exceeds a set threshold value, the switch controller directly blows the fuse connected with the switch controller. The design principle of the capacity of the energy storage capacitor is that the time for the energy storage capacitor to power the detection chip after the flyback isolation switch power supply cannot obtain the electric energy from the battery is greater than a set time threshold value.

2. The battery management system of claim 1, wherein: The model of the detection chip is MC33777ATA1AE.

3. The battery management system of claim 1, wherein: The output voltage of the battery is 12V, the required power supply voltage of the detection chip is 24V, and the transformer is used for converting the 12V voltage into the 24V voltage.

4. The battery management system of claim 3, wherein: The transformer is an isolation transformer.

5. The battery management system of claim 1, wherein: The fuse is an explosion fuse or a high-temperature fuse.

6. The battery management system of claim 1, wherein: ​

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