BMS short circuit protection method and device based on echelon turn-off strategy
By using a tiered shutdown strategy to disconnect the main control switch and shutdown unit step by step, the output circuit current changes are controlled, which solves the problems of high cost and poor current limiting effect in existing BMS short-circuit protection methods, and improves the stability and efficiency of the circuit.
Patent Information
- Application Number
- CN202610122365.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-01
AI Technical Summary
In existing BMS short-circuit protection methods, adding a TVS surge absorption device increases costs and has no significant current limiting effect. Selecting a high-voltage electronic control switch is even more expensive and has a high probability of circuit component failure.
A tiered shutdown strategy is adopted. By detecting the output load current, multiple shutdown units are used to disconnect the main control switch step by step, thereby controlling the change of output circuit current, avoiding voltage spikes, and reducing the voltage withstand requirements of circuit components.
It effectively avoids excessively high peak voltages in the circuit, reduces circuit costs, and improves circuit stability and charge/discharge conversion efficiency.
Smart Images
Figure CN121965907A_ABST
Abstract
Description
A BMS short-circuit protection method and device based on a tiered shutdown strategy Technical Field
[0001] This invention relates to the field of power control technology, and in particular to a BMS short-circuit protection method, device, and readable storage medium based on a tiered shutdown strategy. Background Technology
[0002] In some high-power electronic devices, multiple rechargeable batteries are connected in series to form a high-power power supply to meet the high power requirements. This high-power power supply is connected to the output load via a control circuit. When the output load experiences an overcurrent or short circuit, the connection between the power supply and the output load needs to be disconnected. To protect the power supply and circuit components, a Battery Management System (BMS) and an electronic control switch are included in the control circuit. When the output load current is normal, the electronic control switch is closed; when the output load experiences an overcurrent or short circuit, the BMS controls the electronic control switch to quickly open. Based on the back electromotive force principle, a voltage spike is generated across the electronic control switch, which can easily damage the electronic control switch and other circuit components. To ensure the performance of the electronic control switch, a TVS surge absorber needs to be added at the electronic control switch to absorb the voltage spike, or a electronic control switch and other components with a higher voltage rating must be selected. However, the addition of a TVS surge absorber increases the overall circuit cost and reduces the charge-discharge conversion efficiency. Furthermore, the current limiting effect is not significant; when the total voltage of the power supply exceeds 100V, the probability of circuit component failure remains high. The forced selection of electronic switches and other components with higher voltage ratings significantly increases the cost of the entire circuit. In particular, the probability of circuit component failure is generally higher when the total voltage of the power supply exceeds the set value (such as 100V).
[0003] In view of this, it is necessary to propose improvements to the BMS short-circuit protection method. Summary of the Invention
[0004] To address at least one of the aforementioned technical problems, the main objective of this invention is to provide a BMS short-circuit protection method and apparatus based on a tiered shutdown strategy.
[0005] To achieve the above objectives, the present invention provides a BMS short-circuit protection method based on a tiered shutdown strategy, applied to a BMS short-circuit protection circuit. The BMS short-circuit protection circuit includes a power supply, an AFE unit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load via the main control switch. The AFE unit is electrically connected to the main control switch. The shutdown unit is connected in parallel with the main control switch. The shutdown unit is electrically connected to the MCU unit. The MCU unit is electrically connected to the AFE unit. The method includes: continuously detecting the output current data of the output load; when the output current data of the output load exceeds a set threshold, determining the output current as overcurrent or short circuit, and generating a first control signal; controlling the main control switch to quickly disconnect according to the first control signal, at which time the shutdown unit is in a conducting state; continuously acquiring the output current data of the output circuit; when the output current data of the output circuit reaches a preset value, determining the output current as a safe shutdown current, and generating a second control signal; controlling the shutdown unit to disconnect according to the second control signal to cut off the power supply to the output load, wherein the current value of the set threshold is greater than the preset value.
[0006] As one implementation of this solution, the shutdown unit includes at least two groups; the step of determining the output current as the safe shutdown current and generating a second control signal when the output current data of the output circuit reaches a preset value, and controlling the shutdown unit to disconnect according to the second control signal, specifically includes: when the output current data of the output circuit reaches a first preset value, determining the output current as the first-level shutdown current and generating a first-level shutdown signal, and shutting down any group of shutdown units according to the first-level shutdown signal, at which time, other shutdown units are in the conducting state; when the output current data of the output circuit reaches a target preset value, determining the output current as the safe shutdown current and generating a safe shutdown signal, and shutting down all remaining shutdown units according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
[0007] As one implementation of this solution, the shutdown unit includes at least two groups. Each group of shutdown units includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The internal resistance of the current-limiting branch is distributed from large to small according to the serial number of the shutdown unit. When the output current data of the output circuit reaches a preset value, the output current is determined as the safe shutdown current, and a second control signal is generated. The shutdown unit is controlled to disconnect according to the second control signal. Specifically, this includes: when the output current data of the output circuit reaches a first preset value, the output current is determined as the first-level shutdown current, and a first-level shutdown signal is generated. The first group of shutdown units is shut down according to the first-level shutdown signal. At this time, other shutdown units are in the conducting state. When the output current data of the output circuit reaches a target preset value, the output current is determined as the safe shutdown current, and a safe shutdown signal is generated. All shutdown units in the remaining groups are shut down according to the safe shutdown signal. The current value of the first preset value is greater than the target preset value.
[0008] As one implementation of this solution, the internal resistance of the current-limiting branch in the at least two sets of shutdown units is distributed in multiples.
[0009] As one implementation of this solution, after continuously acquiring the output current data of the output circuit, the method further includes: when the output current data of the output load does not exceed a set threshold, both the main control switch and the shutdown unit are in a closed state, and the output current is transmitted from the main control switch to the output load.
[0010] To achieve the above objectives, another technical solution adopted by the present invention is as follows: A BMS short-circuit protection device based on a tiered shutdown strategy is provided, applied to a BMS short-circuit protection circuit. The BMS short-circuit protection circuit includes a power supply, an AFE unit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load through the main control switch. The AFE unit is electrically connected to the main control switch. The shutdown unit is connected in parallel with the main control switch. The shutdown unit is electrically connected to the MCU unit. The MCU unit is electrically connected to the AFE unit. The method includes: a detection module for continuously detecting the output current data of the output load. The first control module is used to determine the output current as overcurrent or short circuit when the output current data of the output load exceeds a set threshold, and generate a first control signal. According to the first control signal, the main control switch is quickly disconnected. At this time, the shutdown unit is in the on state. The acquisition module is used to continuously acquire the output current data of the output circuit. The second control module is used to determine the output current as the safe shutdown current when the output current data of the output circuit reaches a preset value, and generate a second control signal. According to the second control signal, the shutdown unit is disconnected to cut off the power supply to the output load. The current value of the set threshold is greater than the preset value.
[0011] To achieve the above objectives, another technical solution adopted by the present invention is as follows: a power control system is provided, including a BMS short-circuit protection circuit. The BMS short-circuit protection circuit includes a power supply, an AFE unit, a sampling circuit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load through the main control switch. The AFE unit is electrically connected to the main control switch and is also electrically connected to the output load through the sampling circuit. The shutdown unit is connected in parallel with the main control switch and is electrically connected to the MCU unit. The MCU unit is also electrically connected to the AFE unit. The power control system further includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is electrically connected to both the MCU unit and the AFE unit. When the processor executes the computer program, it implements the steps in the above method.
[0012] In one implementation of this solution, the AFE unit and the main control switch form an output control circuit, the MCU unit and the shutdown unit form a current limiting circuit, and both the control circuit and the current limiting circuit are located between the positive terminal of the power supply and the output load, or both the control circuit and the current limiting circuit are located between the negative terminal of the power supply and the output load.
[0013] As one implementation of this solution, the shutdown unit includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The shutdown switch is a MOSFET, a relay, or a thyristor-controlled switch, and the current-limiting branch is a current-limiting power resistor or a constant current circuit.
[0014] To achieve the above objectives, another technical solution adopted by the present invention is to provide a readable storage medium on which a computer program is stored, wherein when the computer program is executed by a processor, the steps in the above method are implemented.
[0015] The technical solution of this invention mainly employs continuous monitoring of the output current data of the output load. When the output current data exceeds a set threshold, the output current is determined to be an overcurrent or short circuit, and a first control signal is generated. Based on the first control signal, the main control switch is quickly disconnected. At this time, the shutdown unit is in a conducting state, and the power supply and output load are connected through the shutdown unit. A certain operating current is still maintained in the output circuit, which can effectively control the current variation in the output circuit and avoid excessively high peak voltages. The output current data of the output circuit is continuously acquired. When the output current data of the output circuit reaches a preset value, the output current is determined as a safe shutdown current, and a second control signal is generated. Based on the second control signal, the shutdown unit is disconnected to cut off the power supply to the output load. When the output current data of the output circuit reaches the preset value, the shutdown current of the output circuit is small, and the peak voltage can be controlled within a safe range. In summary, this solution can avoid excessively high peak voltages in the circuit, greatly reduce the withstand voltage level of circuit components, help reduce circuit costs, and ensure the stability of the entire circuit. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0017] Figure 1 is a flowchart of a BMS short-circuit protection method based on a tiered shutdown strategy according to an embodiment of the present invention; Figure 2 is a block diagram of a BMS short-circuit protection device based on a tiered shutdown strategy according to an embodiment of the present invention; Figure 3 is a circuit diagram of a BMS short-circuit protection circuit according to an embodiment of the present invention; Figure 4 is a circuit diagram of a BMS short-circuit protection circuit according to another embodiment of the present invention; Figure 5 is a block diagram of a power control system according to an embodiment of the present invention.
[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0020] It should be noted that the descriptions involving "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.
[0021] Unlike existing technologies that add TVS surge absorption devices or force the selection of electronically controlled switches and other components with higher withstand voltage ratings in BMS short-circuit protection circuits, resulting in higher circuit costs and poor current limiting effects, this solution proposes a BMS short-circuit protection method based on a tiered shutdown strategy. This aims to avoid excessively high peak voltages, reduce the voltage rating requirements of circuit components, and lower circuit costs. The specific method of this tiered shutdown strategy-based BMS short-circuit protection method is described in the following embodiments.
[0022] Please refer to Figures 1, 3, and 4. Figure 1 is a flowchart of a BMS short-circuit protection method based on a tiered shutdown strategy according to an embodiment of the present invention; Figure 3 is a circuit diagram of a BMS short-circuit protection circuit according to an embodiment of the present invention; and Figure 4 is a circuit diagram of a BMS short-circuit protection circuit according to another embodiment of the present invention. In the embodiments of the present invention, the BMS short-circuit protection method based on a tiered shutdown strategy is applied to a BMS short-circuit protection circuit, specifically in unmanned aerial vehicles (UAVs), including agricultural UAVs and heavy-duty UAVs. The BMS short-circuit protection circuit includes a power supply 101, an AFE unit 102, a main control switch S1, a shutdown unit, an MCU unit 103, and an output load RL. The power supply 101 is electrically connected to the output load RL through the main control switch S1. The AFE unit 102 is electrically connected to the main control switch S1. The shutdown unit is connected in parallel with the main control switch S1. The shutdown unit is electrically connected to the MCU unit 103. The MCU unit 103 is electrically connected to the AFE unit 102. The power supply 101 includes multiple rechargeable batteries connected in series, such as lithium-ion batteries and non-lithium-ion batteries. The voltage of the series-connected power supply 101 is between 40V and 130V. For other high-power electronic devices, the voltage of power supply 101 can be appropriately reduced or increased. The AFE (Analog Front End) unit can detect the output current of the output load RL and then control the main control switch S1 to open. The main control switch S1 can be a MOSFET, relay, thyristor, or other electronically controlled switches. The output load RL can be a capacitive or inductive load. During the operation of the shutdown unit, the MCU unit 103 continuously acquires the output current of the output circuit and then controls the shutdown unit to open. The BMS short-circuit protection method based on the tiered shutdown strategy specifically includes the following steps: S110, continuously detect the output current data of the output load RL.
[0023] When the circuit is operating normally, both the main control switch S1 and the switches in the shutdown unit are closed, the power supply 101 continuously supplies power to the output load RL, and the AFE unit 102 continuously monitors the output current data of the output load RL. Understandably, when the circuit is operating normally, the output current data of the output load RL is less than or equal to a set threshold.
[0024] S120. When the output current data of the output load RL exceeds the set threshold, the output current is determined to be overcurrent or short circuit, and a first control signal is generated. According to the first control signal, the main control switch S1 is quickly disconnected. At this time, the shutdown unit is in the conducting state.
[0025] When the output current of the output load RL exceeds a set threshold, the output current of the output load RL can be determined to be either overcurrent or short-circuited. That is, the output circuit of the output load RL is in an abnormal state. The AFE unit 102 generates a corresponding first control signal and controls the main control switch S1 to quickly turn off according to the first control signal. After the main control switch S1 is turned off, the power supply 101 forms an output loop with the output load RL through the shutdown unit. The entire circuit still continues to operate. Due to the current limiting effect of the shutdown unit, the circuit still has a certain operating current, effectively controlling the change amplitude of the loop current and avoiding excessively high peak voltages.
[0026] S130: Continuously acquire the output current data of the output circuit.
[0027] During the operation of the shutdown unit, the MCU unit 103 continuously reads the output current data of the output circuit from the AFE unit 102. The output current data of the output circuit continues to decrease. When the output current data of the output circuit is greater than the preset value, the shutdown unit remains in the closed state.
[0028] S140. When the output current data of the output circuit reaches a preset value, the output current is determined as the safe shutdown current, and a second control signal is generated. The shutdown unit is controlled to disconnect according to the second control signal to cut off the power supply 101 from supplying power to the output load RL. The current value of the set threshold is greater than the preset value.
[0029] When power supply 101 is connected to output load RL through the shutdown unit to form an output circuit, the output current in the output circuit gradually decreases. When the output current data of the output circuit reaches a preset value, MCU unit 103 can regard the output current as a safe shutdown current. At this time, the shutdown current is small, and MCU unit 103 generates a second control signal and controls the shutdown unit to disconnect according to the second control signal. At this time, the disconnection of the shutdown unit has little impact on the current of the output circuit, and the reverse peak voltage can be controlled within a safe range, thereby avoiding excessively high peak voltage. This scheme avoids excessively high peak voltage in the circuit by using a tiered shutdown of the main control switch S1 and the shutdown unit. The voltage withstand rating of the main control switch S1 and the output load RL is more flexible, which helps to save costs and ensure the stability of the circuit.
[0030] In one specific embodiment, the shutdown unit includes at least two groups, each group connected in parallel with the main control switch S1. The step of determining the output current as a safe shutdown current and generating a second control signal when the output current data of the output circuit reaches a preset value, and controlling the shutdown unit to disconnect according to the second control signal, specifically includes: determining the output current as a first-level shutdown current and generating a first-level shutdown signal when the output current data of the output circuit reaches a first preset value; shutting off any group of shutdown units according to the first-level shutdown signal, at which time the other shutdown units are in a conducting state; and determining the output current as a safe shutdown current and generating a safe shutdown signal when the output current data of the output circuit reaches a target preset value, shutting off all remaining shutdown units according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
[0031] When the voltage of power supply 101 is high or the short-circuit current is large, multiple sets of shutdown units can be connected in parallel. By sequentially turning off the shutdown units, the output current of the output circuit can be gradually reduced, effectively controlling the peak voltage in the circuit. The specific number of shutdown units can be designed according to the actual circuit requirements. As shown in Figures 3 and 4, S2-S4 are three shutdown switches connected in parallel, and R1-R3 are three current-limiting resistors connected in parallel. The MCU unit 103 continuously reads the output current data of the output circuit from the AFE unit 102. When the output current data of the output circuit reaches the first preset value, the output current is determined to be the first-level shutdown current, and a corresponding first-level shutdown signal is generated. Based on the first-level shutdown signal, any set of shutdown units can be turned off. Correspondingly, when the output current data of the output circuit reaches the second preset value, the output current is determined to be the second-level shutdown current, and a corresponding second-level shutdown signal is generated. Based on the second-level shutdown signal, any set of shutdown units in the remaining groups can be turned off. Until the output current data of the output circuit reaches the target preset value, the output current is determined as the safe shutdown current, and a safe shutdown signal is generated. Based on the safe shutdown signal, all shutdown units in the remaining group are shut down. Through hierarchical control of multiple shutdown units, the variation amplitude of the output current in the output circuit can be quickly controlled, keeping the peak voltage within a safe range. In the above scheme, the current magnitude of the set threshold is greater than the first preset value, the current magnitude of the first preset value is greater than the second preset value, and the current magnitude of the second preset value is greater than the target preset value.
[0032] It should be noted that the number of turn-off units can be greater than or equal to the number of turn-off current stages. In the above scheme, the number of turn-off current stages includes the first-stage turn-off current, the second-stage turn-off current, and the safety turn-off current. Preferably, the number of turn-off units is equal to the number of turn-off current stages to optimize the circuit structure.
[0033] In one specific embodiment, the shutdown unit includes at least two groups. Each group of shutdown units includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The internal resistance of the current-limiting branch is distributed from largest to smallest according to the shutdown unit number; that is, the resistance of the current-limiting branch in the first group of shutdown units is the largest, the resistance of the current-limiting branch in the second group of shutdown units is the second largest, and the resistance of the current-limiting branch in the last group of shutdown units is the smallest. When the output current data of the output circuit reaches a preset value, the output current is determined as the safe shutdown current, and a second control signal is generated. The control signal controls the shutdown unit to disconnect, specifically including: when the output current data of the output circuit reaches a first preset value, the output current is determined as the first-level shutdown current, and a first-level shutdown signal is generated. The first group of shutdown units is shut down according to the first-level shutdown signal. At this time, other shutdown units are in the conducting state. When the output current data of the output circuit reaches a target preset value, the output current is determined as the safe shutdown current, and a safe shutdown signal is generated. All remaining shutdown units are shut down according to the safe shutdown signal. The current value of the first preset value is greater than the target preset value.
[0034] Based on at least two sets of shutdown units connected in parallel, the internal resistance of the current-limiting branch can be changed to further reduce the variation in the output current of the output circuit. As shown in Figures 3 and 4, S2-S4 are three shutdown switches connected in parallel, and R1-R3 are three current-limiting resistors connected in parallel. The resistance relationship of R1-R3 is R1>R2>R3. Specifically, the resistance of the current-limiting branch in the first set of shutdown units is the largest, the resistance of the current-limiting branch in the second set of shutdown units is the second largest, and the resistance of the current-limiting branch in the last set of shutdown units is the smallest. Thus, when the output current data of the output circuit decreases to the first preset value, the output current is determined as the first-level shutdown current, and a first-level shutdown signal is generated. The first group of shutdown units is shut down according to the first-level shutdown signal. When the output current data of the output circuit decreases to the second preset value, the output current is determined as the second-level shutdown current, and a second-level shutdown signal is generated. The second group of shutdown units is shut down according to the second-level shutdown signal. This continues until the output current data of the output circuit reaches the target preset value, at which point the output current is determined as the safe shutdown current, and a safe shutdown signal is generated. All remaining shutdown units are shut down according to the safe shutdown signal. Through the above scheme, the output current can be reduced in stages, ensuring the safety of the circuit devices.
[0035] In one embodiment, the internal resistances of the current-limiting branches in the at least two sets of shutdown units are distributed in multiples. By setting the internal resistances of the current-limiting branches in a multiple relationship, current limiting can be achieved quickly. The specific multiples can be flexibly set according to the current-limiting requirements of the circuit.
[0036] In one embodiment, after continuously acquiring the output current data of the output circuit, the method further includes: when the output current data of the output load RL does not exceed a set threshold, both the main control switch S1 and the shutdown unit are in a closed state, and the output current is supplied from the main control switch S1 to the output load RL. When the power supply 101 normally supplies power to the output load RL, both the main control switch S1 and the shutdown unit are in a closed state. At this time, the output current data of the output load RL does not exceed the set threshold. To ensure the power supply efficiency of the power supply 101, the output current of the power supply 101 is supplied from the main control switch S1 to the output load RL. At this time, although the shutdown unit is in a closed state, it is in a standby state. When the output current data of the output load RL exceeds the set threshold, the main control switch S1 is opened, and the power supply 101 forms an output circuit with the output load RL through the shutdown unit.
[0037] In summary, this solution has at least the following advantages: 1. By sequentially disconnecting the switching unit, component damage can be effectively avoided, improving product reliability; 2. Lower voltage rating components can be selected, effectively reducing costs and improving charge / discharge conversion efficiency; 3. The device can also achieve a pre-discharge function, effectively reducing output current surges and improving product stability; 4. It can be added to existing circuits, resulting in strong product compatibility; 5. The circuit parameters of this device are flexibly adjustable and can be adjusted according to different scenarios, covering a wide range of applications; 6. The above-mentioned switching sequence control is implemented by MCU software, or by parameters preset to the AFE when the MCU starts.
[0038] Please refer to Figures 2 to 4. Figure 2 is a block diagram of a BMS short-circuit protection device based on a tiered shutdown strategy according to an embodiment of the present invention; Figure 3 is a circuit diagram of a BMS short-circuit protection circuit according to an embodiment of the present invention; and Figure 4 is a circuit diagram of a BMS short-circuit protection circuit according to another embodiment of the present invention. In the embodiments of the present invention, the BMS short-circuit protection device based on a tiered shutdown strategy is applied to a BMS short-circuit protection circuit. The BMS short-circuit protection circuit includes a power supply 101, an AFE unit 102, a main control switch S1, a shutdown unit, an MCU unit 103, and an output load RL. The power supply 101 is electrically connected to the output load RL through the main control switch S1. The AFE unit 102 is electrically connected to the main control switch S1. The shutdown unit is connected in parallel with the main control switch S1 and is electrically connected to the MCU unit 103. The MCU unit 103 is electrically connected to the AFE unit 102. The method includes: a detection module 110, used to continuously detect the output of the output load RL. The system includes: a first control module 120, which determines the output current as overcurrent or short circuit when the output current data of the output load RL exceeds a set threshold, and generates a first control signal to control the main control switch S1 to quickly disconnect according to the first control signal. At this time, the shutdown unit is in the on state. The acquisition module 130 is used to continuously acquire the output current data of the output circuit. The second control module 140 is used to determine the output current as a safe shutdown current when the output current data of the output circuit reaches a preset value, and generates a second control signal to control the shutdown unit to disconnect according to the second control signal, so as to cut off the power supply 101 from supplying power to the output load RL. The current value of the set threshold is greater than the preset value.
[0039] In one embodiment, the shutdown unit includes at least two groups; the second control module 140 is specifically used for: when the output current data of the output circuit reaches a first preset value, determining the output current as the first-level shutdown current and generating a first-level shutdown signal, and shutting off any group of shutdown units according to the first-level shutdown signal, at which time, other shutdown units are in the conducting state; when the output current data of the output circuit reaches a target preset value, determining the output current as the safe shutdown current and generating a safe shutdown signal, and shutting off all remaining shutdown units according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
[0040] In one embodiment, the shutdown unit includes at least two groups, each group of shutdown units includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch, the internal resistance of the current-limiting branch is distributed from large to small according to the serial number of the shutdown unit; the second control module 140 is specifically used for: when the output current data of the output circuit reaches a first preset value, determining the output current as the first-level shutdown current and generating a first-level shutdown signal, shutting down the first group of shutdown units according to the first-level shutdown signal, at which time, other shutdown units are in the conducting state; when the output current data of the output circuit reaches a target preset value, determining the output current as the safe shutdown current and generating a safe shutdown signal, shutting down all shutdown units in the remaining group according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
[0041] Please refer to Figures 3 and 4. Figure 3 is a circuit diagram of a BMS short-circuit protection circuit according to one embodiment of the present invention; Figure 4 is a circuit diagram of a BMS short-circuit protection circuit according to another embodiment of the present invention. In an embodiment of this solution, the power control system includes a BMS short-circuit protection circuit. The BMS short-circuit protection circuit includes a power supply 101, an AFE unit 102, a sampling circuit 104, a main control switch S1, a shutdown unit, an MCU unit 103, and an output load RL. The power supply 101 is electrically connected to the output load RL through the main control switch S1. The AFE unit 102 is electrically connected to the main control switch S1 and is also electrically connected to the output load RL through the sampling circuit 104. The shutdown unit is connected in parallel with the main control switch S1 and is electrically connected to the MCU unit 103. The MCU unit 103 is also electrically connected to the AFE unit 102. The power control system further includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is electrically connected to both the MCU unit 103 and the AFE unit 102. When the processor executes the computer program, it implements the steps in the above method.
[0042] In this embodiment, the sampling circuit 104 can sample the output current data of the output resistor in real time and transmit the collected output current data to the AFE unit 102. The AFE unit 102 can process the sampled output current data in real time to control whether the main control switch S1 is disconnected from the circuit. The sampling interval is between 1ms and 400ms. The smaller the sampling interval, the better the continuity of the output current and the better the real-time performance of the output current. The MCU unit 103 can continuously read the sampled output current data from the AFE unit 102 and process the sampled output current data in real time to control whether the shutdown unit is disconnected from the circuit.
[0043] In one embodiment, the AFE unit 102 and the main control switch S1 form an output control circuit, and the MCU unit 103 and the shutdown unit form a current limiting circuit. The control circuit and the current limiting circuit are both located between the positive terminal of the power supply 101 and the output load RL, or the control circuit and the current limiting circuit are both located between the negative terminal of the power supply 101 and the output load RL.
[0044] The output control circuit and current limiting circuit can be located simultaneously between the positive terminal of power supply 101 and the output load RL, or between the negative terminal of power supply 101 and the output load RL, which is beneficial for the layout design of the entire circuit.
[0045] In one embodiment, the shutdown unit includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The shutdown switch is a MOSFET, a relay, or a thyristor-controlled switch, and the current-limiting branch is a current-limiting power resistor or a constant current circuit. For ease of control, both the shutdown switch and the main control switch S1 can be any one of a MOSFET, a relay, or a thyristor-controlled switch, or other controlled switches can be selected.
[0046] Please refer to Figure 5, which is a block diagram of a power control system according to an embodiment of the present invention. This power control system can be used to implement the BMS short-circuit protection method based on a tiered shutdown strategy as described in the foregoing embodiments. As shown in Figure 5, the power control system includes a memory 301, a processor 302, a bus 303, and a computer program stored in the memory 301 and executable on the processor 302. The memory 301 and the processor 302 are connected via the bus 303. When the processor 302 executes the computer program, it implements the BMS short-circuit protection method based on a tiered shutdown strategy as described in the foregoing embodiments. The number of processors can be one or more.
[0047] The memory 301 can be a high-speed random access memory (RAM) or a non-volatile memory, such as a disk storage device. The memory 301 is used to store executable program code, and the processor 302 is coupled to the memory 301.
[0048] Furthermore, this application embodiment also provides a computer-readable storage medium, which may be disposed in the power control system of the above embodiments, and the computer-readable storage medium may be the memory in the embodiment shown in FIG5 above.
[0049] The computer-readable storage medium stores a computer program that, when executed by a processor, implements the BMS short-circuit protection method based on a tiered shutdown strategy described in the foregoing embodiments. Furthermore, the computer-readable storage medium can also be a USB flash drive, external hard drive, read-only memory (ROM), RAM, magnetic disk, or optical disk, or any other medium capable of storing program code.
[0050] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.
[0051] The modules described as separate components may or may not be physically separate. Similarly, the components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment, depending on actual needs.
[0052] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.
[0053] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, external hard drives, ROM, RAM, magnetic disks, or optical disks.
[0054] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.
[0055] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0056] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.
Claims
1. A BMS short-circuit protection method based on a tiered shutdown strategy, applied to a BMS short-circuit protection circuit, characterized in that, The BMS short-circuit protection circuit includes a power supply, an AFE unit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load through the main control switch. The AFE unit is electrically connected to the main control switch. The shutdown unit is connected in parallel with the main control switch. The shutdown unit is electrically connected to the MCU unit. The MCU unit is electrically connected to the AFE unit. The method includes: continuously detecting the output current data of the output load; when the output current data of the output load exceeds a set threshold, determining the output current as overcurrent or short circuit, and generating a first control signal; controlling the main control switch to quickly disconnect according to the first control signal, at which time the shutdown unit is in the conducting state; continuously acquiring the output current data of the output circuit; when the output current data of the output circuit reaches a preset value, determining the output current as a safe shutdown current, and generating a second control signal; controlling the shutdown unit to disconnect according to the second control signal to cut off the power supply to the output load, wherein the current value of the set threshold is greater than the preset value.
2. The BMS short-circuit protection method based on a tiered shutdown strategy as described in claim 1, characterized in that, The shutdown unit comprises at least two groups; the step of determining the output current as a safe shutdown current and generating a second control signal when the output current data of the output circuit reaches a preset value, and controlling the shutdown unit to disconnect according to the second control signal, specifically includes: determining the output current as a first-level shutdown current and generating a first-level shutdown signal when the output current data of the output circuit reaches a first preset value, and shutting off any group of shutdown units according to the first-level shutdown signal, at which time the other shutdown units are in the conducting state; determining the output current as a safe shutdown current and generating a safe shutdown signal when the output current data of the output circuit reaches a target preset value, and shutting off all remaining shutdown units according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
3. The BMS short-circuit protection method based on a tiered shutdown strategy as described in claim 1, characterized in that, The shutdown unit comprises at least two groups, each group comprising a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The internal resistance of the current-limiting branch is distributed from largest to smallest according to the shutdown unit number. When the output current data of the output circuit reaches a preset value, the output current is determined as the safe shutdown current, and a second control signal is generated. The shutdown unit is then controlled to disconnect according to the second control signal. Specifically, this includes: when the output current data of the output circuit reaches a first preset value, the output current is determined as the first-level shutdown current, and a first-level shutdown signal is generated. The first group of shutdown units is shut down according to the first-level shutdown signal, at which time the other shutdown units are in the conducting state; when the output current data of the output circuit reaches a target preset value, the output current is determined as the safe shutdown current, and a safe shutdown signal is generated. All remaining shutdown units are shut down according to the safe shutdown signal, wherein the current value of the first preset value is greater than the target preset value.
4. The BMS short-circuit protection method based on a tiered shutdown strategy as described in claim 3, characterized in that, The internal resistances of the current-limiting branches in the at least two sets of shutdown units are distributed in multiples.
5. The BMS short-circuit protection method based on a tiered shutdown strategy as described in claim 1, characterized in that, After continuously acquiring the output current data of the output circuit, the method further includes: when the output current data of the output load does not exceed a set threshold, both the main control switch and the shutdown unit are in a closed state, and the output current is transmitted from the main control switch to the output load.
6. A BMS short-circuit protection device based on a tiered shutdown strategy, applied to a BMS short-circuit protection circuit, characterized in that, The BMS short-circuit protection circuit includes a power supply, an AFE unit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load through the main control switch. The AFE unit is electrically connected to the main control switch. The shutdown unit is connected in parallel with the main control switch. The shutdown unit is electrically connected to the MCU unit. The MCU unit is electrically connected to the AFE unit. The method includes: a detection module for continuously detecting the output current data of the output load; a first control module for determining the output current as overcurrent or short circuit when the output current data of the output load exceeds a set threshold, generating a first control signal, and controlling the main control switch to quickly disconnect according to the first control signal, at which time the shutdown unit is in a conducting state; an acquisition module for continuously acquiring the output current data of the output circuit; and a second control module for determining the output current as a safe shutdown current when the output current data of the output circuit reaches a preset value, generating a second control signal, and controlling the shutdown unit to disconnect according to the second control signal to cut off the power supply to the output load, wherein the current value of the set threshold is greater than the preset value.
7. A power control system, including a BMS short-circuit protection circuit, characterized in that, The BMS short-circuit protection circuit includes a power supply, an AFE unit, a sampling circuit, a main control switch, a shutdown unit, an MCU unit, and an output load. The power supply is electrically connected to the output load through the main control switch. The AFE unit is electrically connected to the main control switch and to the output load through the sampling circuit. The shutdown unit is connected in parallel with the main control switch and electrically connected to the MCU unit. The MCU unit is electrically connected to the AFE unit. The power control system further includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor is electrically connected to both the MCU unit and the AFE unit. When the processor executes the computer program, it implements the steps of the method according to any one of claims 1-5.
8. The power control system as described in claim 7, characterized in that, The AFE unit and the main control switch form an output control circuit, and the MCU unit and the shutdown unit form a current limiting circuit. The control circuit and the current limiting circuit are both located between the positive terminal of the power supply and the output load, or the control circuit and the current limiting circuit are both located between the negative terminal of the power supply and the output load.
9. The power control system as described in claim 7, characterized in that, The shutdown unit includes a shutdown switch and a current-limiting branch electrically connected to the shutdown switch. The shutdown switch is a MOSFET, a relay, or a thyristor-controlled switch, and the current-limiting branch is a current-limiting power resistor or a constant current circuit.
10. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1-5.