CN115498730A - BMS protection circuit and method - Google Patents
BMS protection circuit and method Download PDFInfo
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- CN115498730A CN115498730A CN202211166152.XA CN202211166152A CN115498730A CN 115498730 A CN115498730 A CN 115498730A CN 202211166152 A CN202211166152 A CN 202211166152A CN 115498730 A CN115498730 A CN 115498730A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/18—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for batteries; for accumulators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/00032—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by data exchange
- H02J7/00038—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by data exchange using passive battery identification means, e.g. resistors or capacitors
- H02J7/00041—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by data exchange using passive battery identification means, e.g. resistors or capacitors in response to measured battery parameters, e.g. voltage, current or temperature profile
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
- H02J7/0036—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using connection detecting circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0063—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with circuits adapted for supplying loads from the battery
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0068—Battery or charger load switching, e.g. concurrent charging and load supply
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/007—Regulation of charging or discharging current or voltage
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- Protection Of Static Devices (AREA)
Abstract
The embodiment of the application discloses BMS protection circuit and method, and BMS protection circuit includes at least: the device comprises a battery, a micro control unit positioned on a protection board, a pre-discharge current-limiting loop and a discharge main loop; when the power-on initialization of the protection board is completed, the micro control unit is used for controlling the closing of the pre-discharge switch and the second switch so as to enable the pre-discharge current-limiting loop to be connected with the battery in series to form a pre-discharge loop; when the load is connected between the battery and the pre-discharge current-limiting loop, the pre-discharge loop is used for charging the load capacitor; the pre-discharge current limiting module in the pre-discharge current limiting loop is used for reducing the pre-discharge current of the pre-discharge loop, and the load at least comprises a load impedance and a load capacitor which are connected in parallel; when the charging of the load capacitor is completed, the micro control unit is used for controlling to disconnect the pre-discharge switch and close the first switch so that the main discharge loop is respectively connected with the battery and the load in series to form a discharge loop, and the discharge loop is used for supplying power to the load impedance.
Description
Technical Field
The present application relates to but not limited to the field of battery management technologies, and in particular, to a BMS protection circuit and method.
Background
The current global energy technology develops continuously, and the new energy product based on the lithium ion battery develops rapidly, and the battery management system BMS is needed by the lithium battery.
However, in situations such as power tool battery replacement systems, electric motorcycle battery replacement systems, and outdoor energy storage systems, which require frequent battery or load replacement, an access arc may occur. The high heat, flash, and detonation caused by the access arc can negatively impact the device circuitry, electrical interfaces, and structural appearance, and in severe cases can lead to device failure. Therefore, how to avoid the generation of the access arc when the battery is replaced becomes an urgent problem to be solved.
Disclosure of Invention
Based on the problems in the related art, the embodiments of the present application provide a BMS protection circuit and method.
The technical scheme of the embodiment of the application is realized as follows:
the embodiment of the application provides a BMS protection circuit, BMS protection circuit includes at least: the device comprises a battery, a micro control unit positioned on a protection board, a pre-discharge current-limiting loop and a discharge main loop;
wherein the battery is connected with the micro control unit; the pre-discharge current-limiting loop is connected with the discharge main loop in parallel; the pre-discharge current limiting loop at least comprises a pre-discharge current limiting module and a pre-discharge switch; the main discharging loop comprises a first switch and a second switch which are connected in series;
after the power-on initialization of the protection board is completed, the micro control unit is used for controlling the closing of the pre-discharge switch and the second switch so as to enable the pre-discharge current-limiting loop to be connected with the battery in series to form a pre-discharge loop;
when a load is connected between the battery and the pre-discharge current-limiting loop, the pre-discharge loop is used for charging the load capacitor; the pre-discharge current limiting module in the pre-discharge current limiting loop is used for reducing the pre-discharge current of the pre-discharge loop, and the load at least comprises a load impedance and a load capacitor which are connected in parallel;
when the charging of the load capacitor is completed, the micro control unit is used for controlling to disconnect the pre-discharge switch and close the first switch so that the main discharge loop is respectively connected with the battery and the load in series to form a discharge loop, and the discharge loop is used for supplying power to the load impedance.
In some embodiments, the pre-discharge current-limiting loop and the discharge main loop include a common second switch, the first switch is a discharge MOS transistor, and the second switch is a charge MOS transistor;
in the pre-discharge current-limiting loop, the charging MOS tube, the pre-discharge switch and the pre-discharge current-limiting module are connected in series;
in the discharge main loop, the charging MOS tube is connected with the discharge MOS tube in series; the pre-discharge switch and the pre-discharge current-limiting module which are connected in series in the pre-discharge current-limiting loop are connected in parallel with the discharge MOS tube in the discharge main loop.
In some embodiments, the protective plate comprises at least a standby state and a discharge state;
when the power-on initialization of the protection board is completed, the micro control unit is used for controlling the pre-discharge switch and the charging MOS tube to be closed and the discharging MOS tube to be disconnected, so that the protection board is in a standby state;
when the charging of the load capacitor is completed, the micro control unit is used for controlling the disconnection of the pre-discharge switch and the closing of the discharge MOS tube, so that the protection board is switched to the discharge state from the standby state.
In some embodiments, the circuit further comprises a current shunt connected to the battery; the current shunt is used for respectively detecting the current of the pre-discharge current-limiting loop and the current of the discharge main loop;
when the load is connected, the current divider is used for detecting the pre-discharge current in the pre-discharge loop;
when the charging of the load capacitor is completed, the current shunt is also used for detecting the discharging current in the discharging loop.
In some embodiments, the protective panel further comprises a protective condition;
the micro control unit is used for determining the discharge voltage of the battery, the pre-discharge current of the pre-discharge loop and the discharge current of the discharge loop;
when the discharge voltage is smaller than the protection voltage, and the pre-discharge current and the discharge current are smaller than the protection current, the pre-discharge switch is controlled to be closed, and the discharge MOS tube is switched off, so that the protection board is switched to the protection state from the discharge state or the standby state.
In some embodiments, the micro control unit is further configured to determine a battery temperature of the battery;
and when the temperature of the battery is higher than the protection temperature, controlling to close the pre-discharge switch and disconnect the discharge MOS tube so that the protection board is switched to the protection state from the discharge state or the standby state.
The embodiment of the application also provides a BMS protection method, which is applied to the BMS protection circuit; the method at least comprises the following steps:
acquiring a load access signal;
responding to the load access signal, and determining the pre-discharge current of the pre-discharge current-limiting loop;
when the pre-discharge current is larger than a preset threshold value, charging the load capacitor through the pre-discharge current limiting loop with a pre-discharge current limiting module;
and when the charging of the load capacitor is finished, the pre-discharge switch is switched off, and the load is supplied with power through the main discharge loop.
In some embodiments, before the load is connected, the pre-discharge switch and the charging MOS transistor are closed, the pre-discharge current limiting loop is communicated, and the protection board is in a standby state.
In some embodiments, the pre-discharge current limiting module is a current limiting resistor;
when the pre-discharge current is greater than a preset threshold value, charging the load capacitor through the pre-discharge current limiting loop with the pre-discharge current limiting module, including:
when the pre-discharge current is larger than a preset threshold value, reducing the pre-discharge current of the pre-discharge current-limiting loop through the current-limiting resistor to obtain a first pre-discharge current;
the pre-discharge current-limiting loop charges the load capacitor through the first pre-discharge current.
In some embodiments, said turning off said pre-discharge switch when said load capacitor is charged and supplying power to said load through said main discharge loop comprises:
when the charging of the load capacitor is finished, the pre-discharge switch is controlled to be switched off, the discharge MOS tube is closed, and the discharge main loop is communicated, so that the protection board is in a discharge state;
and supplying power to the load impedance through the discharge main loop.
The BMS protection circuit and the method provided by the embodiment of the application have the advantages that after the power-on initialization of the protection board is completed, the micro control unit closes the pre-discharge switch to form a pre-discharge loop, when a load is connected between the battery and the pre-discharge loop, the pre-discharge loop charges a load capacitor to reduce the pre-discharge current of the pre-discharge loop, at the moment, because the pre-discharge current-limiting module is connected in the pre-discharge loop, the pre-discharge loop is prevented from short-circuiting, the access electric arc cannot be generated due to the short-circuit current, the problem that the equipment is damaged by the access electric arc in a frequent battery replacement scene is solved, the stability and the safety of the battery are improved, the electric equipment and the human body safety can be effectively protected, and the service life of the equipment is prolonged.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.
Fig. 1 is a schematic circuit diagram of a BMS protection circuit according to an embodiment of the present application;
fig. 2 is a schematic circuit diagram of another BMS protection circuit provided by an embodiment of the present application;
fig. 3 is a schematic view illustrating a state transition of a protection board according to an embodiment of the present application;
FIG. 4 is a circuit diagram of a pre-discharge control circuit provided in an embodiment of the present application;
fig. 5 is a schematic circuit diagram of another BMS protection circuit provided by an embodiment of the present application;
fig. 6 is a schematic flowchart of a BMS protection method according to an embodiment of the present application;
fig. 7 is a schematic diagram of state transition of another protection board provided in an embodiment of the present application.
Detailed Description
In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in further detail with reference to the attached drawings, the described embodiments should not be considered as limiting the present application, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict.
In the following description, references to the terms "first \ second \ third" are only to distinguish similar objects and do not denote a particular order or importance, but rather "first \ second \ third" may, where permissible, be interchanged in a particular order or sequence so that embodiments of the present application described herein can be practiced in other than the order shown or described herein.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the present application only and is not intended to be limiting of the application.
Based on the problems in the related art, the embodiment of the present application provides a BMS protection circuit, and fig. 1 is a circuit schematic diagram of the BMS protection circuit provided by the embodiment of the present application. As shown in fig. 1, the BMS protection circuit includes at least a battery 101, a micro control unit located on a protection board, a pre-discharge current limiting loop 102, and a discharge main loop 103; wherein the battery 101 is connected to the micro control unit, which is not shown in fig. 1; the pre-discharge current-limiting loop 102 is connected with the discharge main loop 103 in parallel; the load 104 at least comprises a load impedance R1 and a load capacitor C1 connected in parallel; the pre-discharge current limiting loop 102 at least comprises a pre-discharge current limiting module R2 and a pre-discharge switch 1021; the main discharging loop 103 includes a first switch Q1 and a second switch Q2 connected in series. Wherein, B + is the anode of the battery, and B-is the cathode of the battery. P + and P-represent the positive and negative battery electrodes that are brought out through the BMS protection plate. The pre-release switch 1021 may be a MOS transistor, such as an NMOS transistor. Here, the protection board is a BMS protection board, the micro control Unit may be a single chip Microcomputer (MCU) or a component such as a control IC, and the micro control Unit is configured to control on/off of a switch in the BMS protection circuit.
In this embodiment, as shown in fig. 1, after the power-on initialization of the protection board is completed, the micro control unit is configured to control to close the pre-release switch 1021 and the second switch Q2, so that the pre-release current-limiting loop 102 is connected in series with the battery 101 to form a pre-release loop, as shown by a dotted arrow in fig. 1. When the load 104 is connected between the battery 101 and the pre-discharge current-limiting loop 102, the pre-discharge loop is used for charging the load capacitor C1; the pre-discharge current limiting module R2 in the pre-discharge current limiting loop is used for reducing the pre-discharge current of the pre-discharge loop; when the charging of the load capacitor C1 is completed, the micro control unit is configured to control to open the pre-release switch 1021, and close the first switch Q1, so that the main discharging loop 103 is connected in series with the battery 101 and the load 104, respectively, to form a discharging loop, as shown by a solid arrow in fig. 1, and the discharging loop is configured to supply power to the load impedance R1, so that the battery supplies power to the load.
In some embodiments, the load capacitor C1 can conduct direct current before being fully charged, and the capacitor blocks direct current and alternating current only when being fully charged, so that when a load is connected, the capacitor reduces current in a pre-discharge loop through the pre-discharge current-limiting module R2 of the pre-discharge loop, so that the pre-discharge loop is not short-circuited, an access arc cannot be generated due to short-circuit current, and the problem that the equipment is damaged by the access arc in a scene of frequent power exchange is solved.
In some embodiments, the pre-discharge current limiting loop and the discharge main loop include a common second switch Q2, the first switch Q1 may be a discharge MOS transistor, and the second switch Q2 may be a charge MOS transistor. As shown in fig. 2, fig. 2 is a schematic circuit diagram of another BMS protection circuit according to an embodiment of the present application, in the pre-discharging current limiting loop, a charging MOS transistor Q2, a pre-discharging switch 1021, and a pre-discharging current limiting module R2 are connected in series; in the discharge main loop, the charging MOS tube Q2 is connected with the discharge MOS tube Q1 in series; the pre-discharging switch 1021 and the pre-discharging current-limiting module R2 which are connected in series in the pre-discharging current-limiting loop are connected in parallel with a discharging MOS tube Q1 in the discharging main loop.
Based on the foregoing embodiment, fig. 3 is a schematic diagram illustrating state transition of a protection board provided in an embodiment of the present application, and as shown in fig. 3, states of the protection board at least include a standby state 301 and a discharging state 302; and after the power-on initialization of the protection board is completed, the micro control unit is used for controlling the closing of the pre-discharge switch and the charging MOS tube and the opening of the discharging MOS tube so as to enable the protection board to be in a standby state.
In some embodiments, fig. 4 is a circuit schematic diagram of a pre-discharge control circuit provided in the present application, and as shown in fig. 4, the pre-discharge control circuit at least includes a driving circuit, a pre-release switch Q66 (i.e., the pre-release switch in the above embodiments), and a pre-discharge current limiting module R2, where the driving circuit is used to control opening and closing of the pre-release switch Q66. The number of resistors in the pre-discharge current limiting module R2 may be set according to the size of the load capacitor and the load impedance, for example, the pre-discharge current limiting module R2 is formed by 6 resistors R21 to R26 connected in series or in parallel with each other in this embodiment of the application.
In some embodiments, the pre-discharge switch Q66 may be an NMOS transistor, the pre-discharge switch Q66 is connected in series with the pre-discharge current limiting module R2, the pre-discharge switch Q66 is connected to the negative electrode of the battery through a resistor R329, the resistor R329 is connected in parallel with the resistor R323, and the pre-discharge current limiting module R2 is connected to the source of the discharge MOS transistor Q1. The driving circuit at least comprises a triode Q65 connected with the grid of a pre-release switch Q66 through a resistor R321, the emitter of the triode Q65 is connected with a connection voltage VCC, and a resistor R315 is arranged between the emitter and the base of the triode Q65.
In some embodiments, when a load is connected, after a voltage of 13V is applied to VCC, the transistor Q65 is turned on, and then the pre-discharge switch Q66 is driven to be turned on, a pre-discharge loop is formed, so that a pre-discharge current is generated in the pre-discharge loop, when the current is greater than a threshold (the threshold may be 40 milliamperes), the protection board starts to enter a discharge state from a standby state, the current can charge a load capacitor after being limited by a pre-discharge resistor (a dotted arrow loop in fig. 1), the pre-discharge current at this time can be reduced due to the limitation of the pre-discharge current limiting module R2, the load capacitor is charged again by a small current limited at this time, a short circuit of the pre-discharge loop cannot be caused, the problem that a large current is formed in the pre-discharge loop to generate an access arc is avoided, and the problem of arc sparking which is generally formed by current energy storage and current replacement is solved.
In some embodiments, when the charging of the load capacitor is completed, the micro control unit is configured to control to open the pre-discharge switch and close the discharge MOS transistor, so that the state switching of the protection board is completed, and the protection board completely shifts from the standby state 301 to the discharge state 302.
In some embodiments, the protective plate further comprises a protective state 303; the micro control unit is used for determining the discharge voltage of the battery, the pre-discharge current of the pre-discharge loop and the discharge current of the discharge loop; when the discharge voltage is smaller than the protection voltage, and the pre-discharge current and the discharge current are smaller than the protection current, controlling to close the pre-discharge switch and disconnect the discharge MOS tube, so that the protection board is switched from the discharge state 302 or the standby state 301 to the protection state 303.
In some embodiments, the micro control unit is further configured to determine a battery temperature of the battery; when the battery temperature is higher than a protection temperature (for example, the protection temperature may be 40 ℃), controlling to close the pre-discharge switch and open the discharge MOS transistor, so that the protection board is switched from the discharge state or the standby state to the protection state.
In some embodiments, fig. 5 is a schematic circuit diagram of another BMS protection circuit provided in the embodiments of the present application, and as shown in fig. 5, the BMS protection circuit may further include a current shunt Rs connected to the battery; the current divider Rs is used for respectively detecting the currents of the pre-discharge current-limiting loop and the discharge main loop; when the load is connected, the current divider is used for detecting the pre-discharge current in the pre-discharge loop, and if the pre-discharge current is larger than a threshold value, the state of the protection board enters a discharge state; when the charging of the load capacitor is completed, the current shunt is also used for detecting the discharging current in the discharging loop. The current shunt Rs detects the currents of the pre-discharge current-limiting loop and the discharge main loop, so that the loop overcurrent can be avoided, and the stability of the protection board is improved.
The embodiment of the application provides a BMS protection circuit, after the electricity initialization is accomplished on the protection board, little the closed pre-discharge switch of control unit, form the pre-discharge circuit, when the load inserts between battery and the pre-discharge circuit, the pre-discharge circuit charges load capacitance, in order to reduce the pre-discharge current of pre-discharge circuit, at this moment, because be connected with the pre-discharge current limiting module in the pre-discharge circuit, make the pre-discharge circuit can not take place the short circuit, just also can not produce the access electric arc because of short-circuit current, the problem of the access electric arc damage equipment under the scene of frequently trading the electricity has been solved, the stability and the security of battery have been improved, can effectual protection consumer and human safety, the life-span of equipment has been prolonged.
Based on the BMS protection circuit, the embodiment of the application provides a BMS protection method, and an execution main body of the BMS protection method is a micro control unit of a protection board. Fig. 6 is a schematic flowchart of a BMS protection method according to an embodiment of the present application, and as shown in fig. 6, the BMS protection method is implemented through steps S601 to S604:
and step S601, acquiring a load access signal.
In the embodiment of the application, before the load is connected, the pre-discharge switch and the charging MOS tube in the BMS protection circuit are closed, the pre-discharge current limiting loop is communicated, and the protection board is in a standby state.
In some embodiments, the micro control Unit may be a single chip Microcomputer (MCU) or a control IC. When the load is accessed, the micro control unit is used for acquiring a load access signal.
Step S602, determining a pre-discharge current of the pre-discharge current-limiting loop in response to the load access signal.
Step S603, when the pre-discharge current is greater than a preset threshold, charging the load capacitor through the pre-discharge current limiting loop having the pre-discharge current limiting module.
In this embodiment of the present application, the preset threshold may be 40 milliamperes (mA), when the pre-discharge current of the pre-discharge current-limiting loop is greater than the preset threshold, the pre-discharge current of the pre-discharge current-limiting loop is reduced by the current-limiting resistor in the pre-discharge current-limiting loop to obtain a first pre-discharge current, and the pre-discharge current-limiting loop charges the load capacitor by the first pre-discharge current.
And step S604, when the charging of the load capacitor is finished, disconnecting the pre-discharge switch and supplying power to the load through the discharge main loop.
In the embodiment of the application, when the charging of the load capacitor of the load is completed, the micro control unit controls to open the pre-discharge switch, close the discharge MOS transistor, and connect the discharge main circuit, so that the protection board is in a discharge state; and supplying power to the load impedance through the main discharging loop so as to supply power to the load.
The BMS protection method provided by the embodiment of the application, when the load is connected, the pre-discharging current-limiting loop charges the load capacitor, so that the pre-discharging current of the pre-discharging current-limiting loop is reduced, at the moment, because the pre-discharging current-limiting module is connected in the pre-discharging current-limiting loop, the pre-discharging loop is not short-circuited, the access electric arc cannot be generated due to the short-circuit current, the problem that the equipment is damaged by the access electric arc in the scene of frequently changing the battery is solved, the stability and the safety of the battery are improved, the electric equipment and the human body safety can be effectively protected, and the service life of the equipment is prolonged.
In some embodiments, fig. 7 is a schematic diagram of state transition of another protection board provided in this embodiment of the application, as shown in fig. 7, when the protection board is in a standby state, and when a charger is connected to a battery, and a current is greater than a threshold, the protection board enters a charging state 702 from the standby state 701, a charging MOS transistor is closed, a pre-discharge current limiting module is opened, and a current flows through the charging MOS transistor and a discharging MOS transistor, at this time, state switching is completed, and the charger is normally powered.
In some embodiments, in any state, when the discharge voltage of the battery is less than the protection voltage (e.g. 2.5V), the pre-discharge current of the pre-discharge loop and the discharge current of the discharge loop are less than the protection current (e.g. 40 mA), or the battery temperature is greater than the protection temperature (e.g. 40 degrees celsius), i.e. the micro control unit receives the protection signal, the protection board enters the protection state 703.
In some embodiments, the charging MOS open-type protection signal may be an overcharge protection, and the micro control unit controls to open the charging MOS transistor and the discharging MOS transistor and close the pre-discharge switch (i.e., the pre-discharge MOS transistor). The discharging MOS disconnection type protection signal can be over-discharge protection, and the micro control unit controls to disconnect the pre-discharge switch and the discharging MOS tube and close the charging MOS tube. The protection plate is in a corresponding state, for example, the discharge state 704 is the discharge state when the protection plate is released, the charge state 702 is the charge state when the protection plate is released, and the standby state 701 is the non-current state when the protection plate is released, wherein the non-current state means that the protection plate is released due to recovery of voltage, current or temperature.
The pre-discharge current limiting module in the embodiment of the application is used as a current limiting function, and is combined with multiple control states of the protection plate, so that the effect of arc extinction when a load or a battery is frequently connected is achieved, and the problem that an electric arc damages equipment in a scene of frequently changing the battery is solved; according to the embodiment of the application, the overall cost is reduced without additionally adding a module, and the development and the maintenance are easy; meanwhile, the basic framework of the protection plate is utilized, the pre-discharge loop is added, the arc ignition problem is solved through multi-module cooperation processing and protection plate state conversion strategies, electric equipment and human body safety can be effectively protected, and the service life of the equipment is prolonged.
It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of another like element in a process, method, article, or apparatus that comprises the element.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, all the functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.
The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall cover the scope of the present application.
Claims (10)
1. A BMS protection circuit, characterized in that the BMS protection circuit comprises at least: the device comprises a battery, a micro control unit positioned on a protection board, a pre-discharge current-limiting loop and a discharge main loop;
wherein the battery is connected with the micro control unit; the pre-discharge current-limiting loop is connected with the discharge main loop in parallel; the pre-discharge current-limiting loop at least comprises a pre-discharge current-limiting module and a pre-discharge switch; the main discharging loop comprises a first switch and a second switch which are connected in series;
after the power-on initialization of the protection board is completed, the micro control unit is used for controlling the closing of the pre-discharge switch and the second switch so as to enable the pre-discharge current-limiting loop to be connected with the battery in series to form a pre-discharge loop;
when a load is connected between the battery and the pre-discharge current-limiting loop, the pre-discharge loop is used for charging the load capacitor; the pre-discharge current limiting module in the pre-discharge current limiting loop is used for reducing the pre-discharge current of the pre-discharge loop, and the load at least comprises a load impedance and a load capacitor which are connected in parallel;
when the charging of the load capacitor is completed, the micro control unit is used for controlling to disconnect the pre-discharge switch and close the first switch so that the main discharge loop is respectively connected with the battery and the load in series to form a discharge loop, and the discharge loop is used for supplying power to the load impedance.
2. The circuit of claim 1, wherein the pre-discharge current-limiting loop and the discharge main loop comprise a common second switch, the first switch is a discharge MOS transistor, and the second switch is a charge MOS transistor;
in the pre-discharge current-limiting loop, the charging MOS tube, the pre-discharge switch and the pre-discharge current-limiting module are connected in series;
in the discharge main loop, the charging MOS tube is connected with the discharge MOS tube in series; the pre-discharge switch and the pre-discharge current limiting module which are connected in series in the pre-discharge current limiting loop are connected in parallel with a discharge MOS tube in the discharge main loop.
3. The circuit of claim 2, wherein the protection board comprises at least a standby state and a discharge state;
when the power-on initialization of the protection board is completed, the micro control unit is used for controlling the pre-discharge switch and the charging MOS tube to be closed and the discharging MOS tube to be disconnected, so that the protection board is in a standby state;
when the charging of the load capacitor is completed, the micro control unit is used for controlling the disconnection of the pre-discharge switch and the closing of the discharge MOS tube, so that the protection board is switched from the standby state to the discharge state.
4. A circuit according to any of claims 1 to 3, further comprising a current shunt connected to the battery; the current shunt is used for respectively detecting the currents of the pre-discharge current-limiting loop and the discharge main loop;
when the load is connected, the current divider is used for detecting the pre-discharge current in the pre-discharge loop;
when the charging of the load capacitor is completed, the current shunt is also used for detecting the discharging current in the discharging loop.
5. The circuit of claim 4, wherein the protection board further comprises a protection state;
the micro control unit is used for determining the discharge voltage of the battery, the pre-discharge current of the pre-discharge loop and the discharge current of the discharge loop;
when the discharge voltage is smaller than the protection voltage, and the pre-discharge current and the discharge current are smaller than the protection current, the pre-discharge switch is controlled to be closed, and the discharge MOS tube is switched off, so that the protection board is switched to the protection state from the discharge state or the standby state.
6. The circuit of claim 5, wherein said micro-control unit is further configured to determine a battery temperature of said battery;
and when the temperature of the battery is higher than the protection temperature, controlling to close the pre-discharge switch and disconnect the discharge MOS tube so that the protection plate is switched to the protection state from the discharge state or the standby state.
7. A BMS protection method characterized in that the method is applied to the BMS protection circuit of any one of claims 1 to 6; the method at least comprises the following steps:
acquiring a load access signal;
responding to the load access signal, and determining the pre-discharge current of the pre-discharge current-limiting loop;
when the pre-discharge current is larger than a preset threshold value, charging the load capacitor through the pre-discharge current limiting loop with a pre-discharge current limiting module;
and when the charging of the load capacitor is finished, the pre-discharge switch is switched off, and the load is supplied with power through the main discharge loop.
8. The method as claimed in claim 7, wherein before the load is connected, the pre-discharge switch and the charging MOS transistor are closed, the pre-discharge current limiting loop is connected, and the protection board is in a standby state.
9. The method of claim 8, wherein the pre-discharge current limiting module is a current limiting resistor;
when the pre-discharge current is greater than a preset threshold value, charging the load capacitor through the pre-discharge current limiting loop with the pre-discharge current limiting module, including:
when the pre-discharge current is larger than a preset threshold value, reducing the pre-discharge current of the pre-discharge current-limiting loop through the current-limiting resistor to obtain a first pre-discharge current;
the pre-discharge current-limiting loop charges the load capacitor through the first pre-discharge current.
10. The method of claim 9, wherein said step of opening said pre-discharge switch to supply power to said load through said main discharge loop when said load capacitor is fully charged comprises:
when the charging of the load capacitor is finished, the pre-discharge switch is controlled to be switched off, the discharge MOS tube is closed, and the discharge main loop is communicated, so that the protection board is in a discharge state;
and supplying power to the load impedance through the discharge main loop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211166152.XA CN115498730A (en) | 2022-09-23 | 2022-09-23 | BMS protection circuit and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211166152.XA CN115498730A (en) | 2022-09-23 | 2022-09-23 | BMS protection circuit and method |
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| CN115498730A true CN115498730A (en) | 2022-12-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202211166152.XA Pending CN115498730A (en) | 2022-09-23 | 2022-09-23 | BMS protection circuit and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116488310A (en) * | 2023-06-21 | 2023-07-25 | 深圳市华芯控股有限公司 | Management circuit and device for BMS incapable of removing load charger due to current limiting module |
-
2022
- 2022-09-23 CN CN202211166152.XA patent/CN115498730A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116488310A (en) * | 2023-06-21 | 2023-07-25 | 深圳市华芯控股有限公司 | Management circuit and device for BMS incapable of removing load charger due to current limiting module |
| CN116488310B (en) * | 2023-06-21 | 2023-12-15 | 深圳市华芯控股有限公司 | Management circuit and device for BMS incapable of removing load charger due to current limiting module |
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