Load throwing protection circuit suitable for lithium battery

Abstract

The utility model relates to the technical field of load throwing of a lithium battery, in particular to a load throwing protection circuit suitable for the lithium battery, which comprises an MOS (Metal Oxide Semiconductor) tube Q6 and an MOS tube Q8, the grid electrode of the MOS tube Q6 is coupled with a resistor R16, the source electrode of the MOS tube Q6 is coupled with a resistor R47, the grid electrode of the MOS tube Q8 is coupled with a resistor R56, the resistor R56 and the resistor R47 are connected in series, the drain electrode of the grid electrode of the MOS tube Q8 is coupled with a resistor R57, and the drain electrode of the MOS tube Q8 is coupled with a resistor R57. According to the utility model, a hardware version battery management system is adopted, and a super electrolytic capacitor group is connected in parallel with a bus, so that the surge generated by'load throwing 'is eliminated, the'load throwing' suppression and instantaneous large current smoothing technology of a battery pack is mastered, and the'load throwing 'problem of the battery is fundamentally solved; the problems of over-current optimization and protection of instant large current are solved, a new achievable technical approach is provided, and meanwhile starting and parking power supply integrated engineering application is achieved.

Description

Technical Field

[0001] This utility model relates to the field of load dumping technology for lithium batteries, and in particular to a load dumping protection circuit suitable for lithium batteries. Background Technology

[0002] The current electrification transformation of the traditional automotive industry has led to rapid technological advancements in the lithium battery industry. Battery pack load dump suppression and instantaneous high-current smoothing technologies remain challenging issues in the industry. A 12V start-stop battery pack may suddenly activate its protection mechanism during a full charge overvoltage event. This causes the onboard alternator to suddenly transition from a heavy load to a light load, generating surges during voltage regulation. Instantaneous high currents can exceed 1000A, while the battery management system (BMS) has a continuous overcurrent capacity of only 100-200A. These instantaneous high currents can cause significant damage to the BMS and other onboard equipment. The key technology for addressing the issue of equipment damage due to load dumping is battery pack load dump suppression technology.

[0003] Based on the above background, a new "load dumping" suppression technology and instantaneous current smoothing technology suitable for parking start-stop lithium batteries are proposed. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a load dump protection circuit suitable for lithium batteries, thereby solving the technical problem in the prior art that "the vehicle generator will generate surges during voltage regulation, with instantaneous high currents reaching over 1000A, while the BMS's continuous overcurrent capacity is only 100-200A, and the instantaneous high currents will cause impact damage to the BMS and other vehicle equipment".

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A load dump protection circuit suitable for lithium batteries includes MOSFETs Q6 and Q8. The gate of MOSFET Q6 is coupled to a resistor R16, the source of MOSFET Q6 is coupled to a resistor R47, the gate of MOSFET Q8 is coupled to a resistor R56, the resistors R56 and R47 are connected in series, the drain of the gate of MOSFET Q8 is coupled to a resistor R57, the other end of the resistor R57 is coupled to a diode D17, the cathode of the diode D17 is coupled to a resistor R27, the other end of the resistor R27 is coupled to a diode D18, and the diode D18 is coupled to the drain of the gate of MOSFET Q6.

[0007] As a preferred embodiment of this utility model, the source of the MOS transistor Q8 is coupled to a resistor R99, the other end of the resistor R99 is coupled to an electrolytic capacitor C12, the other end of the electrolytic capacitor C12 is coupled to an electrolytic capacitor C14, and the electrolytic capacitor C14 is coupled to the drain of the MOS transistor.

[0008] As a preferred embodiment of this invention, a diode D16 is connected in series across the two ends of the MOS transistor Q6.

[0009] As a preferred embodiment of this invention, diodes D15 are coupled to both ends of the MOS transistor Q8.

[0010] This invention provides a load dump protection circuit suitable for lithium batteries, which has the following features:

[0011] Beneficial effects:

[0012] This solution employs a hardware-based battery management system, connecting a super-electrolytic capacitor bank in parallel on the bus to absorb surges generated by "load dumping." It masters technologies for suppressing battery "load dumping" and smoothing instantaneous high current. This fundamentally solves the battery "load dumping" problem, addresses the challenges of optimizing and protecting against instantaneous high current overcurrent, proposes a new and feasible technical approach, and simultaneously enables integrated engineering applications for starting and parking power supplies.

[0013] Other advantages, objectives and features of the utility model will be set forth in part in the description which follows, and in part will be obvious to those skilled in the art based on an examination of the following description, or may be taught from the practice of the utility model. Attached Figure Description

[0014] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation

[0015] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the present invention, and does not imply that every embodiment of the present invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0017] The principle and circuit elements of this utility model will be described in detail below with reference to the accompanying drawings and embodiments:

[0018] refer to Figure 1A load dump protection circuit suitable for lithium batteries includes MOSFETs Q6 and Q8. The MOSFET Q6 has a gate coupled to a resistor R16, a source coupled to a resistor R47, and a gate coupled to a resistor R56. Resistors R56 and R47 are connected in series. The drain of the gate of the MOSFET Q8 is coupled to a resistor R57. The other end of resistor R57 is coupled to a diode D17. The cathode of diode D17 is coupled to a resistor R27, and the other end of resistor R27 is coupled to a diode D18. Diode D18 is coupled to the drain of the gate of MOSFET Q6.

[0019] Specifically, the source of MOSFET Q8 is coupled to a resistor R99, the other end of which is coupled to an electrolytic capacitor C12, the other end of which is coupled to an electrolytic capacitor C14, and the electrolytic capacitor C14 is coupled to the drain of the MOSFET.

[0020] Specifically, diode D16 is connected in series across the two ends of MOSFET Q6.

[0021] Specifically, diode D15 is coupled to both ends of MOSFET Q8.

[0022] The working principle of this utility model:

[0023] First, MOSFET Q6 in CHG and MOSFET Q8 in MOS_TLP are connected via a NOT gate circuit, meaning their signals are NOT related. During battery charging, MOSFET Q6 in CHG is turned on, while MOSFET Q8 in MOS_TLP is turned off. The current flows from P- through MOSFET Q6 to C-. When the battery is fully charged and the protection board experiences overvoltage, MOSFET Q6 is turned off (at this point, the charger acts as the power source, and the battery acts as the load; at the instant the CHG MOSFET turns off, the load changes from heavy to light, resulting in a very large instantaneous current). Because the signals in MOS_TLP and CHG are NOT related, when MOSFET Q6 turns off, MOSFET Q8 turns on. The current flows from P- through electrolytic capacitors C14 and C12, through MOSFET Q8, to C-, charging electrolytic capacitors C14 and C12, thus greatly suppressing the large current.

[0024] Secondly, at the moment of discharge (the battery is the power source, while the vehicle engine or other equipment is the load), the current flows from C- to P-, requiring MOSFET Q8 to be turned off and MOSFET Q6 to be turned on. Meanwhile, electrolytic capacitors C14 and C12 dissipate electrical energy through resistor R99.

[0025] This utility model adopts a hardware-based battery management system, which connects a super electrolytic capacitor bank in parallel on the bus to absorb the surge generated by "load dump". It masters the technology of battery pack "load dump" suppression and instantaneous high current smoothing, fundamentally solves the battery "load dump" problem, solves the problem of instantaneous high current overcurrent optimization and protection, proposes a new feasible technical approach, and realizes the integrated engineering application of starting and parking power supply.

[0026] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model 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 utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A throw load protection circuit suitable for a lithium battery, comprising a MOS transistor Q6 and a MOS transistor Q8, characterized in that, The gate of the MOS tube Q6 is coupled with a resistor R16, the source of the MOS tube Q6 is coupled with a resistor R47, the gate of the MOS tube Q8 is coupled with a resistor R56, the resistor R56 and the resistor R47 are connected in series, the drain of the gate of the MOS tube Q8 is coupled with a resistor R57, the other end of the resistor R57 is coupled with a diode D17, the cathode of the diode D17 is coupled with a resistor R27, the other end of the resistor R27 is coupled with a diode D18, the diode D18 is coupled at the drain of the gate tube Q6.

2. A throw load protection circuit for a lithium battery according to claim 1, wherein, The source of the MOS tube Q8 is coupled with a resistor R99, the other end of the resistor R99 is coupled with an electrolytic capacitor C12, the other end of the electrolytic capacitor C12 is coupled with an electrolytic capacitor C14, the electrolytic capacitor C14 is coupled at the drain of the MOS tube.

3. A throw-off load protection circuit for a lithium battery according to claim 1, characterized in that, The two ends of the MOS tube Q6 are connected in series with a diode D16.

4. The throw-off load protection circuit for lithium batteries according to claim 1, characterized in that, The two ends of the MOS tube Q8 are coupled with a diode D15.

Images