Battery discharge branch control system and electronic equipment

Abstract

The invention relates to the technical field of battery management, in particular to a battery discharge branch control system and electronic equipment. The first input end of the main discharge module is connected with a battery, and the output end is connected with a load; the first input end of the pre-discharge module is connected with a battery, the output end is connected with a load, and the pre-discharge module comprises a current-limiting switch tube and is used for limiting discharge current through the current-limiting switch tube; the input end of the detection module is connected with a load, and the output end is connected with the input end of the control module; the first output end of the control module is connected with the second input end of the main discharging module, and the second output end of the control module is connected with the second input end of the pre-discharging module and used for adjusting the on-off state of the main discharging module and the pre-discharging module according to the load state. Performance and reliability of the whole power supply / battery product can be ensured, and burning-out of the pre-discharge resistor and failure of the product caused by frequent starting-up when the load is short-circuited are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of battery management, and in particular to a battery discharge branch control system and electronic equipment. Background Art

[0002] In the existing BMS (Battery Management System) system, when the load is connected, the capacitance of the load will generate a significant instantaneous large current, which may cause the connector to be damaged by electric shock. When pre-discharge is used, it is common to reduce the instantaneous current by connecting a current limiting resistor in series to protect the connector. However, this current limiting resistor has significant problems in practical applications. The output current of the current limiting resistor varies greatly under conditions of different battery capacities (the voltage difference between full and empty conditions is large, current = voltage / resistance, and when the resistance is fixed, the higher the voltage, the greater the current). It is impossible to accurately determine whether the load is a capacitive load or a resistive load or whether there is a short circuit state, which may cause large current to heat up, increase heat loss, and affect the reliability of the system.

[0003] In order to solve the current shock and equipment damage problems caused by directly closing the discharge switch when the load is short-circuited, the industry has proposed a pre-discharge circuit solution. This solution mainly outputs an initial small current through a current limiting resistor to evaluate the load status and avoid closing the discharge switch when the load is short-circuited, thereby protecting the switch and the battery. However, the problem with this solution is that when the battery capacity is different, the battery voltage is different, resulting in different output currents and different power consumption on the current limiting resistor. When the load is continuously short-circuited and repeatedly turned on, the current limiting resistor will be frequently consumed, causing it to fail quickly, which in turn affects the performance and reliability of the overall power supply / battery product.

[0004] Based on this, how to avoid frequent startup with different battery capacities (the more battery strings there are, the greater the voltage difference when the capacities are different) and load short circuit, which may cause the pre-discharge resistor to burn out and product failure, has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present application provides a battery discharge branch control system and electronic equipment to ensure the performance and reliability of the overall power supply / battery product, and avoid frequent startup when the load is short-circuited, resulting in pre-discharge resistor burning and product failure.

[0006] The technical solution adopted by this application to solve its technical problem is: In a first aspect, the present application provides a battery discharge branch control system, which is applied between a battery and a load, and includes: a main discharge module, a pre-discharge module, a detection module and a control module; The first input end of the main discharge module is connected to the battery, and the output end is connected to the load; The first input end of the pre-discharge module is connected to the battery, and the output end is connected to the load; the pre-discharge module includes a current limiting switch tube, which is used to limit the discharge current through the current limiting switch tube when the pre-discharge module is turned on; The input end of the detection module is connected to the load, and the output end is connected to the input end of the control module, and is used to sample the state of the load through the detection module; The first output end of the control module is connected to the second input end of the main discharge module, and the second output end of the control module is connected to the second input end of the pre-discharge module, so as to adjust the on-off state of the main discharge module and the pre-discharge module according to the load state through the control module.

[0007] Optionally, the main discharge module includes: a first switch tube, a first resistor, and a second resistor; The output end of the first switch tube is connected to the battery through a first current-sensing resistor, and the input end is connected to the load; The first resistor is connected in parallel between the trigger end and the output end of the first switch tube, and the trigger end of the first switch tube is also connected to the first output end of the control module through the second resistor.

[0008] Optionally, the main discharge module further includes a first diode; The cathode of the first diode is connected to the connection point between the first output end of the control module and the second resistor, and the anode of the first diode is connected to the connection point between the second resistor and the trigger end of the first switch tube.

[0009] Optionally, the main discharge module further includes a first voltage regulator tube; The positive electrode of the first voltage regulator is connected to the output end of the first switch tube, and the negative electrode is connected to the trigger end of the first switch tube.

[0010] Optionally, the pre-discharge module includes a second switch tube, a third switch tube, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second current detection resistor and a third current detection resistor; The battery is connected to the output end of the second switch tube through the first current detection resistor, the second current detection resistor and the third current detection resistor, and the input end of the second switch tube is connected to the load; The connection point between the first current detection resistor and the second current detection resistor is connected to the connection point between the second current detection resistor and the third current detection resistor through the third resistor and the fourth resistor connected in series; The output end of the third switch tube is connected to the connection point between the first current detection resistor and the third resistor, the trigger end is connected to the connection point between the third resistor and the fourth resistor, the input end is connected to the second output end of the control module through the fifth resistor, and the input end is also connected to the trigger end of the second switch tube through the sixth resistor; The seventh resistor is connected in parallel between the output end and the trigger end of the second switch tube.

[0011] Optionally, the pre-discharge module further includes: a second diode; The cathode of the second diode is connected to the connection between the second output terminal of the control module and the fifth resistor, and the anode of the second diode is connected to the connection between the fifth resistor and the input terminal of the third switch tube. Optionally, the pre-discharge module further includes: a second voltage regulator tube; The positive electrode of the second voltage regulator is connected to the output end of the second switch tube, and the negative electrode is connected to the trigger end of the second switch tube.

[0012] Optionally, the detection module includes an eighth resistor and a ninth resistor; One end of the eighth resistor is connected to the battery, and the other end is connected to one end of the ninth resistor and a sampling end of an external controller; The other end of the ninth resistor is connected to the connection point between the input end of the second switch tube and the load; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

[0013] Optionally, the detection module includes an eighth resistor, a ninth resistor, a fourth switch tube, a tenth resistor, an eleventh resistor and a fifth switch tube; The trigger end of the fourth switch tube is connected to one end of the eighth resistor and one end of the ninth resistor, the other end of the eighth resistor is connected to the output end of the fourth switch tube and the battery, the other end of the ninth resistor is connected to the load, and the input end of the fourth switch tube is connected to the first input end of the external controller; The trigger end of the fifth switch tube is connected to one end of the tenth resistor and one end of the eleventh resistor, the other end of the tenth resistor is connected to the battery and the output end of the fifth switch tube, the other end of the eleventh resistor is connected to the load, and the input end of the fifth switch tube is connected to the second input end of the controller; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

[0014] Optionally, the detection module includes: an eighth resistor, a ninth resistor, a tenth resistor, a capacitor, a twelfth resistor and a fourth switch tube; The trigger end of the fourth switch tube is connected to one end of the eighth resistor and one end of the ninth resistor, the other end of the eighth resistor is connected to the output end of the fourth switch tube and the battery, and the other end of the ninth resistor is connected to the load; The capacitor is connected in series with the tenth resistor and then connected in parallel to both ends of the ninth resistor; The input end of the fourth switch tube is connected to the sampling end of the external controller, and the sampling end of the controller is also connected to the external DC signal source through the twelfth resistor; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

[0015] In a second aspect, the present application provides a battery discharge branch control method, which is applied to the above-mentioned battery discharge branch control system, and the method includes: Acquiring a battery status to determine whether to allow the battery discharge branch control system to discharge according to the battery status; If the battery discharge branch control system is allowed to discharge, the pre-discharge module is turned on by the control module to enter the pre-discharge mode; in the pre-discharge mode, current-limited discharge is performed based on the current-limiting switch tube in the pre-discharge module; Sampling the load through the detection module to determine whether the load is abnormal according to the sampling result; If there is no abnormality in the load, the main discharge module is turned on and the pre-discharge module is turned off through the control module to enter the main discharge mode; otherwise, a load abnormality alarm is sent and the pre-discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

[0016] Optionally, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: When the pre-discharge module is turned on, voltage sampling is performed on the load to obtain an initial first voltage; After the first preset time, sampling the load again to obtain a current second voltage; Calculating a current load capacitance value of the load according to the first voltage, the second voltage and the first preset time; Determine whether the load capacitance value is within a preset capacitance value interval; if the load capacitance value is within the capacitance value interval, determine that there is no abnormality in the load; otherwise, determine that there is an abnormality in the load.

[0017] Optionally, the formula used to calculate the load capacitance value of the current load according to the first voltage, the second voltage and the first preset time is: ; in, is the load capacitance value, is the load current, is the voltage difference between the first voltage and the second voltage of the load, is the sampling time difference.

[0018] Optionally, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a first preset voltage threshold, a first level signal is sent to the control module through the detection module; The control module waits for a second level signal to be input in response to the first level signal, and sends the second level signal to the control module through the detection module if the load voltage drop is less than a second preset voltage threshold; Calculating a signal time difference between a time instant of acquiring the second level signal and a time instant of acquiring the first level signal, and determining whether the signal time difference is within a preset time interval; If the signal time difference is within the preset time interval, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

[0019] Optionally, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a preset voltage threshold, a first level signal is sent to the control module through the detection module; Determine whether the first level signal is updated to a second level signal within a preset time; If the first level signal is updated to the second level signal within the preset time, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

[0020] Optionally, the step of turning on the main discharge module and turning off the pre-discharge module by the control module to enter the main discharge mode includes: Detecting the current state of the load to obtain the load current; If the load current is less than the preset current threshold, the pre-discharge module is turned on and the main discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

[0021] By adopting the above technical solution, the present application turns off the main discharge module and the pre-discharge module in the initial state, firstly detects whether the battery is allowed to discharge (determines whether the battery voltage, temperature and other parameters meet the standards) through the relevant system, and if discharge is allowed, obtains the load state through the detection module. The load state includes a first state and a second state, the pre-discharge module is turned on in the first state, and the main discharge module is turned on in the second state.

[0022] Furthermore, if the load state acquired by the detection module is the first state, a conduction signal is sent through the second output terminal of the control module (external control system, such as a single-chip microcomputer MCU) to control the pre-discharge module to be turned on, in which case the main discharge module is disconnected. When the pre-discharge module is turned on, the current limiting switch tube in the pre-discharge module is started to limit the current passing through the pre-discharge module until the load state reaches the second state; Furthermore, if the load state acquired by the detection module is the second state, a conduction signal is sent through the first output terminal of the control module to control the main discharge module to be turned on, and in this case the pre-discharge module is disconnected. When the load state reaches the second state, the signal transmitted by the main discharge module has tended to be stable, thereby effectively avoiding the phenomenon of large current heating.

[0023] In summary, the present application has at least the following beneficial effects: According to the load status, the main discharge module and the pre-discharge module are switched in time, and a current limiting switch tube is added to the pre-discharge module. When the voltage drop is instantly increased when the load is connected, the pre-discharge module and its current limiting switch tube are turned on first to slowly reduce the voltage difference between the battery and the load. Then the pre-discharge module is turned off and the main discharge module is turned on for discharge. Based on this, damage to the main discharge circuit caused by excessive instantaneous current is avoided, the reliability of the system is improved, and heat loss is reduced. According to the load status, the probability of mis-opening of the discharge switches in the main discharge module and the pre-discharge module is reduced, and frequent startup when the load is short-circuited is avoided, which may cause the pre-discharge resistor to burn out and the product to fail, thereby improving the reliability of the system. Description of the drawings Figure 1 It is a module connection diagram of a battery discharge branch control system provided in an embodiment of the present application; Figure 2is a circuit schematic diagram of a battery discharge branch control system provided in the first embodiment of the present application; Figure 3 is a circuit schematic diagram of a battery discharge branch control system provided in the second embodiment of the present application; Figure 4 A schematic diagram of simulation of load drop voltage variation provided in the second embodiment of the present application; Figure 5 A simulation diagram of a load voltage drop voltage change and a control module provided in the second embodiment of the present application; Figure 6 is a circuit schematic diagram of a battery discharge branch control system provided in the third embodiment of the present application; Figure 7 It is a simulation schematic diagram of a load voltage drop voltage change and a control module provided in the third embodiment of the present application; Figure 8 It is a schematic diagram of the overall flow of the battery discharge branch control method provided in an embodiment of the present application.

[0024] Reference numerals: Q2, first switch tube; R7, first resistor; R3, second resistor; RS1, first current sensing resistor; D1, the first diode; ZD2, the first voltage regulator; B-, the negative terminal of the battery; D-, the negative terminal of the load; RS2, the second current-sensing resistor; RS3, the third current-sensing resistor; Q3, the second switch tube; R1, the third resistor; R2, the fourth resistor; Q1, the third switch tube; R4, the fifth resistor; R5, the sixth resistor; R6, the seventh resistor; D2, the second diode; ZD1, the second voltage-stabilizing tube; R8, the eighth resistor; R9, the ninth resistor; Q4, the fourth switch tube; R10, the tenth resistor; R11, the eleventh resistor; Q5, the fifth switch tube; C1, capacitor; R12, twelfth resistor; R13, thirteenth resistor. DETAILED DESCRIPTION

[0025] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0026] The following will clearly and completely describe the concept, specific structure and technical effects of the present application in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. Based on the embodiments of the present application, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the present application. In addition, all the connection / connection relationships involved in the patent do not simply refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features created in this application can be combined interactively without conflicting with each other.

[0027] Reference Figure 1 , Figure 1 : This is a module connection diagram of a battery discharge branch control system provided in an embodiment of the present application. The system includes a main discharge module, a pre-discharge module, a detection module and a control module. Each module is specifically described below: Regarding the main discharge module: the first input end of the main discharge module is connected to the negative terminal B- of the battery, and the output end is connected to the negative terminal D- of the load.

[0028] Among them, the battery discharge branch control system provided by the present application is applied between the battery and the load, including but not limited to between the negative terminal B- of the battery and the negative terminal D- of the load, and between the positive terminal B+ of the battery and the positive terminal D+ of the load. For the convenience of explanation, the following embodiments of the present application take the application of the system between the negative terminal B- of the battery and the negative terminal D- of the load as an example, but do not limit the location where the system is applied. Technical personnel familiar with the field can also make various equivalent deformations or substitutions without violating the spirit of the present application, which should all fall within the scope of protection defined by the claims of the present application.

[0029] Specifically, the main discharge module serves as the main discharge branch of the system discharge. The main discharge branch is mainly responsible for the discharge process of the battery under normal working conditions, including providing power for electric vehicles or outputting electrical energy for energy storage systems. It ensures that the battery can release electrical energy safely and efficiently, while monitoring key parameters such as current and voltage to prevent problems such as over-discharge and overheating. It includes at least one switch tube, and an external control system (such as a single-chip microcomputer MCU) can control the on-off state of the main discharge module by controlling the on-off of the switch tube. It is worth noting that all the switch tubes mentioned in this solution include but are not limited to MOS tubes, IGBTs, and relays.

[0030] Regarding the pre-discharge module: the first input end of the pre-discharge module is connected to the negative terminal B- of the battery, and the output end is connected to the negative terminal D- of the load; the pre-discharge module includes a current limiting switch tube, which is used to limit the discharge current through the current limiting switch tube when the pre-discharge module is turned on.

[0031] Specifically, the pre-discharge module is a pre-discharge branch of the battery system. The pre-discharge branch is mainly used for pre-charging before the battery is connected to the external circuit to ensure that the voltage at both ends of the battery matches the voltage of the external circuit, thereby avoiding the current shock and voltage mutation generated when directly connected. In addition, the pre-discharge branch can also maintain the voltage of the battery system when the battery needs to be discharged, playing a buffering role. In an embodiment of the present application, the pre-discharge module includes at least two switch tubes, one of which is used to control the on-off state of the pre-discharge module, and the other switch tube is a current limiting switch tube, which is used to adjust the conduction degree of the aforementioned switch tube to achieve the effect of current limiting and constant current, and avoid excessive instantaneous current and damage to related devices.

[0032] Regarding the detection module: the input end of the detection module is connected to the negative end D- of the load, and the output end is connected to the input end of the control module, and is used to sample the load state of the negative end D- of the load through the detection module; Specifically, the detection module includes at least two sampling resistors for sampling. The two resistors are connected in series and then in parallel between the battery and the load. By detecting the voltage value between the sampling resistors, the current load state can be determined. The load state will be recognized by the external control system, and a control signal will be sent accordingly to adjust the on-off state of the main discharge module and the on-off state of the pre-discharge module.

[0033] Regarding the control module: the first output end of the control module is connected to the second input end of the main discharge module, and the second output end of the control module is connected to the second input end of the pre-discharge module, which is used to adjust the on-off state of the main discharge module and the pre-discharge module according to the load state through the control module.

[0034] Specifically, the control module refers to an external controller / control system, such as an MCU, which includes a first output terminal (main discharge control pin) and a second output terminal (pre-discharge control pin), and controls the corresponding main discharge module or pre-discharge module to be turned on or off by outputting high and low level electrical signals. In the embodiment of the present application, the discharge mode is adjusted by the control module, which includes three discharge modes: Main discharge mode: the main discharge module is turned on and the pre-discharge module is turned off. In this case, discharge is performed normally. Pre-discharge mode: The pre-discharge module is turned on and the main discharge module is turned off. In this case, the load voltage drop is large. Constant current pre-discharge is performed through the current limiting switch tube in the pre-discharge module until the voltage drop is lower than a specific threshold before the main discharge mode is turned on. Unstarted mode: Both the main discharge module and the pre-discharge module are disconnected.

[0035] By adopting the above technical solution, combined with the attached Figure 1The working principle of the battery discharge branch control system provided in this application is explained as follows: Step S1: In the initial state, the control module turns off the main discharge module and the pre-discharge module through the first output terminal and the second output terminal; Step S2: an external control system (also referred to as a control module) obtains a battery status, including but not limited to voltage and temperature parameters, so as to determine whether discharge is allowed under the current circumstances; Step S3, if discharge is allowed, the pre-discharge module is turned on through the second output end of the control module, and the state of the load is continuously sampled through the detection module. In this case, the load state is in the first state; after the pre-discharge module is turned on, the current limiting switch tube therein is turned on, so that the current limiting switch tube enters the amplification state, generating a current limiting constant current effect, thereby improving the stability and reliability of the pre-discharge module transmission signal; Specifically, a preset delay time is required during the process from allowing discharge to turning on the pre-discharge module. The delay time is set during the process from allowing discharge to turning on the pre-discharge module for many reasons, including system stability, safety, energy management, control accuracy, and preventing misoperation. These factors work together to ensure that the system can operate safely, stably, and efficiently.

[0036] More specifically, the first state of the load state is determined according to the preset of relevant personnel, including but not limited to voltage value, capacitance value, timing, etc. If it is a sampled voltage, when the load voltage drop voltage is greater than a preset voltage threshold, the load state is determined to be in the first state; if it is timing, the timing starts from the moment when the load state sampling starts until the timing setting of the second state described below is reached; if the sampled capacitance value is similar to the voltage value, it will not be repeated here.

[0037] More specifically, if discharging is not allowed, the relevant system enters a shutdown state.

[0038] Step S4, when the load state sampled by the detection module changes from the first state to the second state, in this case the control module will determine whether to allow the main discharge module to be turned on according to the sampling result of the detection module; If the current circuit is abnormal according to the sampling result, a corresponding load abnormality alarm is sent. For example, a timer, capacitor voltage calculation, etc. can be used for judgment, and the sampling result is compared with the preset interval. If it exceeds the preset interval, the main discharge module is not allowed to be turned on and an error is reported.

[0039] Step S5: If the main discharge module is allowed to be turned on, the main discharge module is controlled to be turned on through the first output end of the control module, and the pre-discharge module is disconnected through the second output end of the control module.

[0040] On the other hand, if the main discharge module is not allowed to be turned on, it means that there is a load abnormality. In this case, a load abnormality alarm is issued, including but not limited to voice, text, etc., and the pre-discharge module is turned off, and the preset delay time is adjusted. Generally speaking, each time a load abnormality occurs, the preset delay time will be increased accordingly.

[0041] By adopting the above technical solution and combining it with the system provided by the present application, the switching between the main discharge module and the pre-discharge module can be completed. In actual operation, after step S5, the main discharge module can also be continuously tested to determine whether the discharge needs to be stopped. Specifically: Step S6: sampling the main discharge module to obtain a load current, and comparing the load current with a preset current threshold to determine whether the main discharge module needs to be shut down; Step S7: If the load current is lower than the preset current threshold, the pre-discharge branch is reopened, and the main discharge branch is closed, and the process returns to step S1.

[0042] Specifically, when the load current is lower than a preset current threshold (eg, 15 mA), it can be considered that the load is removed or turned off, and the product can enter a pre-discharge mode and sleep in standby mode to wait for the next power-on wake-up, thereby saving power.

[0043] Further, refer to Figure 2 , Figure 2 The circuit schematic diagram of the battery discharge branch control system provided by the first embodiment of the present application includes a main discharge module, a pre-discharge module, a detection module and a control module. Figure 2 The first embodiment provided in this application is described in detail: Regarding the main discharge module: the main discharge module includes: a first switch tube Q2, a first resistor R7, and a second resistor R3; The output end of the first switch tube Q2 is connected to the negative terminal B- of the battery through the first current detection resistor RS1, and the input end is connected to the negative terminal D- of the load; The first resistor R7 is connected in parallel between the trigger end and the output end of the first switch tube Q2, and the trigger end of the first switch tube Q2 is also connected to the first output end of the control module through the second resistor R3.

[0044] Specifically, when the first output terminal DSG of the control module sends a high-level signal, the trigger terminal of the first switch tube Q2 is pulled high so that the input terminal and the output terminal of the first switch tube Q2 are turned on. Among them, all the switch tubes mentioned in this application (the first switch tube Q2 to the fifth switch tube Q5) include but are not limited to IGBT, relay, MOS tube, triode, etc. In the embodiment of this application, the first switch tube Q2 is a MOS tube. After the first switch tube Q2 is turned on, the signal is output from the negative terminal D- of the load through the first switch tube Q2 and the first current detection resistor RS1 to the negative terminal B- of the battery.

[0045] Furthermore, the main discharge module further includes a first diode D1; The cathode of the first diode D1 is connected to the connection point between the first output terminal of the control module and the second resistor R3 , and the anode of the first diode D1 is connected to the connection point between the second resistor R3 and the trigger terminal of the first switch tube Q2 .

[0046] Specifically, between the first output terminal of the control module and the second input terminal of the main discharge module, a first diode D1 may be connected in parallel to both ends of the second resistor R3 to perform accelerated discharge shutdown to protect the circuit.

[0047] Furthermore, the main discharge module further includes a first voltage regulator tube ZD2; The positive electrode of the first voltage regulator tube ZD2 is connected to the output end of the first switch tube Q2, and the negative electrode is connected to the trigger end of the first switch tube Q2.

[0048] Specifically, a first voltage regulator ZD2 is connected in parallel between the trigger end and the output end of the switch tube. In this embodiment, a voltage regulator is connected in parallel between the gate and the source of the MOS tube to perform voltage regulation protection and protect the device from overvoltage shock.

[0049] Regarding the pre-discharge module: the pre-discharge module includes a second switch tube Q3, a third switch tube Q1, a third resistor R1, a fourth resistor R2, a fifth resistor R4, a sixth resistor R5, a seventh resistor R6, a second current detection resistor RS2 and a third current detection resistor RS3; wherein the current limiting switch tube is the third switch tube Q1; The negative terminal B- of the battery is connected to the output terminal of the second switch tube Q3 through the first current detection resistor RS1, the second current detection resistor RS2 and the third current detection resistor RS3, and the input terminal of the second switch tube Q3 is connected to the negative terminal D- of the load; The connection point between the first current detection resistor RS1 and the second current detection resistor RS2 is connected to the connection point between the second current detection resistor RS2 and the third current detection resistor RS3 through the third resistor R1 and the fourth resistor R2 connected in series; The output end of the third switch tube Q1 is connected to the connection between the first current detection resistor RS1 and the third resistor R1, the trigger end is connected to the connection between the third resistor R1 and the fourth resistor R2, the input end of the third switch tube Q1 is connected to the second output end of the control module through the fifth resistor R4, and the input end is also connected to the trigger end of the second switch tube Q3 through the sixth resistor R5; The seventh resistor R6 is connected in parallel between the output end and the trigger end of the second switch tube Q3.

[0050] Specifically, when the second output terminal of the control module starts to send a high-level signal, the trigger terminal of the second switch tube Q3 is pulled up through the fifth resistor R4 and the sixth resistor R5 (in this embodiment, the second switch tube Q3 is a MOS tube, and the trigger terminal is a gate), so that the second switch tube Q3 starts to be turned on, and the negative end D- of the load outputs the electrical signal to the negative end B- of the battery through the second switch tube Q3, the third current sensing resistor RS3, the second current sensing resistor RS2, and the first current sensing resistor RS1, forming a signal loop; Then, between the second current-sensing resistor RS2 and the third current-sensing resistor RS3, the voltage is pulled up from low due to the conduction of the second switch tube Q3, so that the third switch tube Q1 is turned on (in this embodiment, the third switch tube Q1 is an NPN triode, and the trigger end is the base). After the third switch tube Q1 is turned on, its collector potential is pulled down (i.e., the potential between the fifth resistor R4 and the sixth resistor R5), so that the trigger end of the second switch tube Q3 is pulled down to enter the amplification state. In the amplification state, the drain current of the second switch tube Q3 no longer changes with the change of the drain voltage, but remains constant, thereby realizing constant current limiting and avoiding the device from overheating or damaging the device due to the instantaneous excessive current.

[0051] More specifically, when the pre-discharge module is turned on, the control module can synchronously start the timer to record the start time of the pre-discharge mode, so as to facilitate subsequent determination of whether there is an abnormality in the load state.

[0052] Furthermore, the pre-discharge module further includes: a second diode D2; The cathode of the second diode D2 is connected to the connection point between the second output terminal of the control module and the fifth resistor R4, and the anode of the second diode D2 is connected to the connection point between the fifth resistor R4 and the input terminal of the third switch tube Q1.

[0053] Specifically, similar to the function of the first diode D1 mentioned above, a diode is connected to the second output terminal of the control module to accelerate the discharge shutdown, thereby protecting the circuit.

[0054] Furthermore, the pre-discharge module further includes: a second voltage regulator tube ZD1; The positive electrode of the second voltage regulator tube ZD1 is connected to the output end of the second switch tube Q3 , and the negative electrode is connected to the trigger end of the second switch tube Q3 .

[0055] Specifically, similar to the above-mentioned first voltage regulator tube ZD2, the second switch tube Q3 in the embodiment of the present application adopts a MOS tube, and a voltage regulator tube is connected in parallel between the gate and the source of the second switch tube Q3 to provide voltage regulation protection.

[0056] Regarding the detection module: In the embodiment of the present application, the detection module includes an eighth resistor R8 and a ninth resistor R9; One end of the eighth resistor R8 is connected to the negative terminal B- of the battery, and the other end is connected to one end of the ninth resistor R9 and a sampling end of an external controller; The other end of the ninth resistor R9 is connected to the connection point between the input end of the second switch tube Q3 and the negative end D- of the load; The first output end of the controller is connected to the trigger end of the first switch tube Q2 through the second resistor R3, and the second output end is connected to the connection point between the third switch tube Q1 and the sixth resistor R5 through the fifth resistor R4.

[0057] Specifically, after the eighth resistor R8 and the ninth resistor R9 are connected in series, one end is connected to the negative terminal D- of the load, and the other end is connected to the negative terminal B- of the battery, so as to perform voltage division processing. By collecting the voltage value of the potential point VTH_DET, the load state can be obtained, and the load state will be obtained by the control module, thereby correspondingly controlling the on and off states of the main discharge module and the pre-discharge module.

[0058] More specifically, in the first embodiment provided by the present application, when the pre-discharge module starts to conduct, the load voltage is sampled to obtain the load voltage V0, and the timer is started at the same time; when the timer count reaches the preset value, the load voltage is sampled again to obtain the load voltage V1, and then the load capacitance value is calculated based on the voltage difference between the two moments, so as to determine whether the current load state is normal, and thus determine whether to allow the main discharge module to be turned on. Specifically, the formula used to calculate the load capacitance value is: ; in, is the load capacitance value, is the load current, is the voltage difference between the load at two times, The first preset time preset for the timer, that is, the time change.

[0059] Furthermore, since the current parameters can be limited and constant by the pre-discharge module, the current parameters can be fixed; the time parameters can be fixed by fixing the sampling time (that is, the timer preset value is fixed), it is only necessary to judge the load voltage values ​​collected at two moments to determine the current load state.

[0060] Further, refer to Figure 3 , Figure 3 It is a circuit schematic diagram of a battery discharge branch control system provided by the second embodiment of the present application, including a main discharge module, a pre-discharge module, a detection module and a control module. Compared with the first embodiment, the second embodiment is mainly improved in the control module part, so only the control module part is described, and the remaining modules are not repeated. The following is a specific description: The detection module includes an eighth resistor R8, a ninth resistor R9, a fourth switch tube Q4, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13 and a fifth switch tube Q5; The trigger end of the fourth switch tube Q4 is connected to one end of the eighth resistor R8 and one end of the ninth resistor R9, the other end of the eighth resistor R8 is connected to the output end of the fourth switch tube Q4 and the negative terminal B- of the battery, the other end of the ninth resistor R9 is connected to the negative terminal D- of the load, the input end of the fourth switch tube Q4 is connected to the first input end of the external controller and one end of the twelfth resistor R12, and the other end of the twelfth resistor R12 is connected to the external DC signal source VDD; The trigger end of the fifth switch tube Q5 is connected to one end of the tenth resistor R10 and one end of the eleventh resistor R11, the other end of the tenth resistor R10 is connected to the negative terminal B- of the battery and the output end of the fifth switch tube Q5, the other end of the eleventh resistor R11 is connected to the negative terminal D- of the load, the input end of the fifth switch tube Q5 is connected to the second input end of the controller and one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is connected to the DC signal source VDD; The first output end of the controller is connected to the trigger end of the first switch tube Q2 through the second resistor R3, and the second output end is connected to the connection point between the third switch tube Q1 and the sixth resistor R5 through the fifth resistor R4.

[0061] Specifically, the eighth resistor R8 to the eleventh resistor R11 are used for voltage division, and the fourth switch tube Q4 and the fifth switch tube Q5 adopt NPN type triodes in the embodiment of the present application, wherein the collector of the fourth switch tube Q4 is connected to the VTH1_INT pin of the control module, and the collector of the fifth switch tube Q5 is connected to the VTH2_INT pin of the control module. When the fourth switch tube Q4 is disconnected, the signal sent by the DC signal source VDD is output to VTH1_INT through the twelfth resistor, thereby pulling up VTH1_INT, and when it is turned on, the signal sent by the DC signal source VDD is output to the battery through the twelfth resistor and the fourth switch tube Q4, thereby pulling down VTH1_INT; when the fifth switch tube Q5 is disconnected, the signal sent by the DC signal source VDD is output to VTH2_INT through the thirteenth resistor, thereby pulling up VTH2_INT, and when the fifth switch tube Q5 is turned on, the signal sent by the DC signal source VDD is output to the battery through the thirteenth resistor and the fifth switch tube Q5, thereby pulling down VTH2_INT. The bases of the fourth switch tube Q4 and the fifth switch tube Q5 are both connected to the negative end D− of the load, and are turned on or off according to the load voltage drop of the negative end D− of the load.

[0062] More specifically, when the load voltage drop is greater than the first preset voltage threshold VTH1, the fourth switch tube Q4 is turned on. In this case, a low level signal is sent to the control module (such as MCU) through VTH1_INT, and the control module is awakened based on the low level signal, and the timer is started at the same time; after the fourth switch tube Q4 is turned on, as the pre-discharge module gradually charges the load capacitor due to current limiting, the load voltage drop gradually decreases. When the load voltage drop is less than the second preset voltage threshold VTH2, the fifth switch tube Q5 is turned off, so that the collector of the fifth switch tube Q5 is pulled high, and the control module recognizes the high level of the collector VTH2_INT of the fifth switch tube Q5, and obtains the time based on the high level of VTH2_INT to determine whether the load is abnormal.

[0063] By adopting the above circuit design, the working principle of the second embodiment provided by this application is described as follows: After the pre-discharge module starts to conduct, when the load current rises (the voltage at the negative end D- of the load rises synchronously after the current is divided by multiple current-sensing resistors), for example, when the load is connected in the embodiment of the present application, since the load itself can be regarded as a capacitor, hereinafter referred to as the load capacitor, the voltage at the positive end of the load capacitor is synchronized with the voltage at the positive end of the battery when the battery is connected to the load. Based on the characteristic that the voltage at both ends of the capacitor cannot suddenly change, the voltage difference between the positive end P+ of the load capacitor and the negative end D- of the load capacitor is large, and the voltage at both ends of the load capacitor will experience a transition process from the initial large voltage difference to a new stable voltage difference, that is, the load voltage drop voltage is instantly changed to B+ (positive end of the battery)\P+ (positive end of the load capacitor) voltage because the voltage of the load capacitor cannot suddenly change. In this case, it is equivalent to the voltage of B+ (positive end of the battery)\P+ (positive end of the load capacitor) directly acting on the resistor on the base of the fourth switch tube Q4 and the base of the fifth switch tube Q5. In this case, the load voltage drop voltage is greater than the first preset voltage threshold VTH1, so that the fourth switch tube Q4 is turned on. After the fourth switch tube Q4 is turned on, its collector potential is lowered, so that VTH1_INT is a low level. The control module is awakened when it recognizes that VTH1_INT is at a low level, and the timer is turned on and counting is started; Then, because the pre-discharge module discharges by constant current, the load drop voltage at the negative end D- of the load gradually decreases, and finally decreases to below the second preset voltage threshold VTH2. In this case, the fifth switch tube Q5 is disconnected, so that the potential of the VTH2_INT point is pulled up. When the control module recognizes that the VTH2_INT potential is high, it stops the timer timing and obtains the acquisition time difference between the two signals, that is, the accumulated time from the start of the timer to the end. It is determined whether the accumulated time is within the preset time interval. If it is not timed out, the main discharge module can be controlled to start conducting through the first output end of the control module.

[0064] For example, VTH1 is set to about 1.4V, that is, when D-voltage>1.4V, VTH1_INT will be pulled low. When D-voltage<1.4V, VTH1_INT will be pulled high; VTH2 is set to about 15V, that is, when D-voltage>15V, VTH2_INT will be pulled low. That is, when D-voltage<15V, VTH2_INT will be pulled high. When VTH1_INT is high, the system enters sleep standby. When it is detected that VTH1_INT is pulled low, the system wakes up and starts the 1S timer (taking the timer 1S timing as an example). If VTH2_INT is high in the next 1S, the main discharge circuit is opened and the main discharge logic cycle is entered.

[0065] More specifically, refer to Figure 4 , Figure 4The simulation schematic diagram of the load voltage drop change provided in the second embodiment of the present application shows that when the load is turned on, the voltage drop increases slightly due to the small current at the start-up; when the load is fully turned on and starts working, the voltage increases again and enters a stable state; When the load capacitor with 0V voltage is connected, that is, when the internal charge of the load capacitor is balanced, the load is electrically connected to the battery. At this time, since the voltage across the load will not change suddenly, the voltage will be instantly pulled up to produce a peak value. However, since the present application provides a current limiting switch tube to limit the discharge current, the current will not be too large instantaneously, thereby limiting the peak value of the load voltage, and the load voltage will enter a stable state for a certain period of time; in this process, the battery gradually charges the load end capacitor; As the battery charges the load-end capacitor, the load voltage drop gradually decreases, making it impossible to maintain a stable voltage value, causing the waveform to go downhill until the load is fully charged.

[0066] Reference Figure 5 , Figure 5 The simulation diagram of the load voltage drop voltage change and control module provided in the second embodiment of the present application, wherein VF2 is the load voltage at the negative terminal D- of the load, and the specific description can refer to the above Figure 4 It can be seen that when the load is turned on and then on, VTH1_INT is pulled down earlier than VTH2_INT, that is, the fourth switch tube Q4 is turned on earlier than the fifth switch tube Q5. In the process of charging the load capacitor, the load voltage continues to decrease, and VTH2_INT is pulled up earlier than VTH1_INT, that is, the fifth switch tube Q5 is turned off. In this cycle, it is determined whether the time difference between the moment when VTH1_INT changes from high to low and the moment when VTH2_INT changes from low to high is within the preset time range, that is, whether the time required from the start of the load to the load voltage dropping to the threshold corresponding to VTH2_INT is exceeded, so as to determine whether the load is abnormal.

[0067] It is worth noting that in the embodiments of the present application Figure 4 , Figure 5 and Figure 7 In the simulation schematic diagram shown, the horizontal axis represents time (t), the unit is second (s), and the vertical axis represents voltage (U), the unit is volt (V).

[0068] Furthermore, if there is no abnormality in the load, the main discharge module is turned on through the first output terminal of the control module. In this embodiment, a high-level signal is sent through the DSG to turn on the first switch tube Q2. Then, the load current on the main discharge module is detected, and a preset current threshold (for example, 15mA) is preset. If the load current is continuously less than the preset current threshold, it is considered that the load is removed or turned off, and the product enters pre-discharge standby sleep, waiting for the next power-on wake-up to save power.

[0069] By adopting the above technical solution, it is only necessary to obtain the time difference between the two signals to determine whether the load is abnormal. Compared with the first embodiment, the second embodiment does not need to perform AD sampling on the system, thereby simplifying the above load capacitance calculation process and having stronger real-time performance and reliability.

[0070] Further, refer to Figure 6 , Figure 6 : is a circuit schematic diagram of a battery discharge branch control system provided in the third embodiment of the present application. Similar to the second embodiment, the third embodiment also includes a main discharge module, a pre-discharge module, a detection module and a control module. Compared with the first and second embodiments, the third embodiment is mainly improved in the detection module part. Therefore, only the detection module part is described, and the other modules are not repeated. The following is a specific description: The detection module includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a capacitor C1, a twelfth resistor R12 and a fourth switch tube Q4; The trigger end of the fourth switch tube Q4 is connected to one end of the eighth resistor R8 and one end of the ninth resistor R9, the other end of the eighth resistor R8 is connected to the output end of the fourth switch tube Q4 and the negative terminal B- of the battery, and the other end of the ninth resistor R9 is connected to the negative terminal D- of the load; The capacitor C1 is connected in series with the tenth resistor R10 and then connected in parallel to both ends of the ninth resistor R9; The input end of the fourth switch tube Q4 is connected to the sampling end of the external controller, and the sampling end of the controller is also connected to the external DC signal source through the twelfth resistor R12; The first output end of the controller is connected to the trigger end of the first switch tube Q2 through the second resistor R3, and the second output end is connected to the connection point between the third switch tube Q1 and the sixth resistor R5 through the fifth resistor R4.

[0071] Specifically, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10 and the twelfth resistor R12 are used for voltage division. When the fourth switch tube Q4 is disconnected, the external DC signal source VDD pulls up VTH1_INT through the twelfth resistor R12, and the level state of VTH1_INT is sensed by the control module (such as MCU); when the load voltage at the negative end D- of the load is connected or turned on, since the two ends of the capacitor C1 cannot suddenly change, the voltage of the load voltage that changes sharply will directly act on the tenth resistor R10, and the fourth switch tube Q4 is driven to turn on quickly through the current limiting of the tenth resistor R10. After the fourth switch tube Q4 is turned on, the external DC signal source VDD is output to the negative end B- of the battery through the twelfth resistor R12, so that VTH1_INT is pulled down, and the control module wakes up the system after sampling, and starts the timer for timing.

[0072] More specifically, if the load is currently in a short-circuit state, the load current will also rise sharply. After the current is divided by multiple current-sensing resistors, the load voltage at the negative terminal D- of the load will rise sharply synchronously, which will also wake up the system and start the timer. However, during the counting time of the timer, the negative terminal D- of the load is always at a high level, causing the fourth switch tube Q4 to continue to be turned on. After the timer times out, it is determined that the load is abnormal, and the corresponding load abnormality alarm is issued.

[0073] Reference Figure 7 , Figure 7 1 is a simulation diagram of the load voltage drop voltage change and control module provided in the third embodiment of the present application, wherein VF2 in the upper part of the figure shows the change of the load voltage, and its voltage change can refer to the above Figure 4 The following figure shows the description of Figure 6 The voltage change diagram of VTH1_INT shown in the figure adopts the above circuit design and combines Figure 6 It can be seen that the working principle of the third embodiment provided by this application is: If the system determines that discharge is allowed and the pre-discharge module is turned on, the load current rises sharply. After the current is divided by the first current detection resistor, the second current detection resistor and the third current detection resistor, the D- voltage rises sharply synchronously. Because the two ends of the capacitor C1 cannot change suddenly, the voltage directly acts on the tenth resistor R10. After the tenth resistor R10 limits the current, the fourth switch tube Q4 is driven to turn on quickly and start the timing, corresponding to Figure 7 The part at the bottom of the figure where the high level changes rapidly to a low level; After the timer is started, it is determined whether the voltage of VTH1_INT changes from a low level to a high level again within a certain period of time, that is, whether the fourth switch tube Q4 returns to the disconnected state within a certain period of time. If it is not timed out, the main discharge module is allowed to be turned on, and the first switch tube Q2 is controlled to be turned on through DSG. Otherwise, it is determined that the load is abnormal.

[0074] By adopting the technical solution provided by the third embodiment, the above-mentioned second embodiment is further optimized. While having the beneficial effects of the above-mentioned second embodiment that there is no need to sample the load voltage, the amount of calculation is reduced, and the real-time performance is improved, the components used are further reduced, thereby reducing the circuit cost, saving the hardware resource optimization cost, and further improving the practicality of the system.

[0075] In a second aspect, the present application provides a battery discharge branch control method, which is applied to the above-mentioned battery discharge branch control system, referring to Figure 1 and Figure 8 , Figure 8 This is a schematic diagram of the overall flow of the battery discharge branch control method provided in an embodiment of the present application, which specifically includes the following steps: In step S1, a battery status is acquired to determine whether the battery discharge branch control system is allowed to discharge according to the battery status.

[0076] Specifically, in the starting state, the control module turns off the main discharge module and the pre-discharge module through the first output terminal and the second output terminal, and determines whether discharge is allowed through parameters such as battery voltage and temperature identified by an external control system (or control module). If the preset discharge standard is met, discharge is allowed.

[0077] In step S2, if the battery discharge branch control system is allowed to discharge, the pre-discharge module is turned on by the control module to enter the pre-discharge mode.

[0078] Wherein, in the pre-discharge mode, current-limited discharge is performed based on the current-limited switch tube in the pre-discharge module.

[0079] Specifically, if discharge is allowed, the pre-discharge module is turned on through the second output terminal of the control module. After the pre-discharge module is turned on, the current limiting switch tube therein is triggered to enter the pre-discharge mode. In the pre-discharge mode, taking the negative end of the load connected to the negative end of the battery as an example, the electrical signal is output from the negative end of the load through the current limiting switch tube in the pre-discharge module to the negative end of the battery in a constant current limiting manner. The specific circuit principle can refer to the detailed description of the pre-discharge module above.

[0080] In step S3, the load is sampled by the detection module to determine whether the load is abnormal according to the sampling result.

[0081] Specifically, the detection module can continuously sample the state of the load after the pre-discharge module is turned on, and collect the load voltage to determine whether the load is abnormal. Specifically, the present application provides three embodiments for the step S3, that is, provides a variety of detection methods for determining whether the load is abnormal, which are specifically described below: In the first embodiment provided in this application, refer to Figure 2 As shown in the circuit schematic diagram, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: When the pre-discharge module is turned on, voltage sampling is performed on the load to obtain an initial first voltage; Specifically, the first voltage refers to the voltage at which the pre-discharge module is turned on. Figure 2 The voltage value obtained by voltage sampling at the potential point VTH_DET shown is used to start the related timer while performing the first voltage sampling.

[0082] Further, after the first preset time, the load is sampled again to obtain a current second voltage; Specifically, after the first preset time of the timer is started in the above step, the timer is stopped and the voltage of the potential point VTH_DET is sampled again, and the voltage obtained by this sampling is used as the second voltage. It is worth noting that the first voltage and the second voltage sampled in the first embodiment of the present application involve the calculation of the load capacitance value, and need to be AD sampled by a controller such as an MCU microcontroller for subsequent calculations.

[0083] Furthermore, a load capacitance value of the current load is calculated according to the first voltage, the second voltage and the first preset time.

[0084] Specifically, the formula used to calculate the load capacitance value of the current load according to the first voltage, the second voltage and the first preset time is: ; in, is the load capacitance value, is the load current, is the voltage difference between the first voltage and the second voltage of the load, The first preset time.

[0085] Furthermore, since the current parameters can be limited and constant through the pre-discharge module, the parameters of the load current are fixed; the time parameters can be fixed by fixing the sampling time (that is, the timer preset value is fixed), it is only necessary to judge the voltage difference between the load voltage values ​​collected at two moments to determine the current load state.

[0086] Further, it is determined whether the load capacitance value is within a preset capacitance value interval; if the load capacitance value is within the capacitance value interval, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

[0087] Specifically, the load capacitance value calculated by the above formula can be compared with the capacitance value range preset according to actual needs to determine whether the load capacitance value falls within the preset capacitance value range. If it does, it is determined that the current load is normal, and the control module is subsequently allowed to turn on the main discharge module for discharge; otherwise, it is determined that the load is abnormal. In this case, a series of abnormal situations such as error reporting can be responded to, and the system returns to the starting state.

[0088] In the second embodiment provided in this application, refer to Figure 3 As shown in the circuit schematic diagram, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a first preset voltage threshold, a first level signal is sent to the control module through the detection module.

[0089] The first level signal provided in the embodiment of the present application is a low level signal. It should be understood that the first level signal can be modified to a high level signal through a specific circuit deformation. In this embodiment, only a low level signal is used as an example, which should not limit the present application in any way.

[0090] The first preset voltage threshold can be adjusted by adjusting the resistance of the eighth resistor R8, adjusting the resistance of the ninth resistor R9, or replacing the model of the fourth switch tube Q4.

[0091] Specifically, when the load drop voltage is greater than the first preset voltage threshold VTH1, the fourth switch tube Q4 is turned on. In this case, a low level signal is sent to the control module (such as MCU) through VTH1_INT. The control module is awakened based on the low level signal and the timer is started at the same time.

[0092] Furthermore, the control module waits for input of a second level signal in response to the first level signal, and sends the second level signal to the control module through the detection module if the load voltage drop is less than a second preset voltage threshold.

[0093] The second preset voltage threshold is adjusted by adjusting the resistance of the tenth resistor R10, adjusting the resistance of the eleventh resistor R11, and replacing the model of the fifth switch tube Q5.

[0094] Specifically, after receiving the first level signal, as the pre-discharge module gradually discharges the current limit, the load voltage drop gradually decreases. When the load voltage drop is less than the second preset voltage threshold VTH2, the fifth switch tube Q5 is disconnected, so that the collector of the fifth switch tube Q5 is pulled high, thereby sending a high level signal (i.e., the second level signal) through VTH2_INT. The control module recognizes the high level of the collector VTH2_INT of the fifth switch tube Q5, and determines whether there is an abnormality in the load based on the high level acquisition time of VTH2_INT.

[0095] Further, calculating a signal time difference between a time instant of acquiring the second level signal and a time instant of acquiring the first level signal, and determining whether the signal time difference is within a preset time interval; If the signal time difference is within the preset time interval, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

[0096] Specifically, since the pre-discharge module gradually reduces the load drop voltage at the negative terminal D- of the load through constant current discharge, and finally reduces it to below the second preset voltage threshold VTH2, in this case, the fifth switch tube Q5 is disconnected, so that the potential of the VTH2_INT point is pulled up, and when the control module recognizes that the VTH2_INT potential is high, the timer is stopped and the acquisition signal time difference between the two signals is obtained, that is, the cumulative time from the start of the timer to the end. It is determined whether the cumulative time is within the preset time interval. If it is not timed out, it is determined that the current load is normal. On the contrary, if it is timed out, it is determined that the load is abnormal.

[0097] Compared with the first embodiment, the second embodiment determines whether there is an abnormality in the load by obtaining the time difference between the two signals. There is no need to calculate the load capacitance value, and there is no need to perform AD sampling of the load voltage through the controller, thereby simplifying the above-mentioned calculation process of the load capacitance and having stronger real-time performance and reliability.

[0098] In the third embodiment provided in this application, refer to Figure 6 As shown in the circuit schematic diagram, the step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a preset voltage threshold, a first level signal is sent to the control module through the detection module.

[0099] The first level signal and the second level signal provided in this embodiment are not related to the first level signal and the second level signal provided in the above-mentioned second embodiment.

[0100] The preset voltage threshold can be adjusted according to the device selection involved in the detection module.

[0101] Specifically, when the load voltage drop is greater than the preset voltage threshold, the fourth switch tube Q4 is driven to turn on quickly through the current limiting of the tenth resistor R10. After the fourth switch tube Q4 is turned on, the external DC signal source VDD is output to the negative terminal B- of the battery through the twelfth resistor R12, so that VTH1_INT is pulled low, that is, the first level signal (low level signal) is sent. In this embodiment, the first level signal is also used to start the timer.

[0102] Furthermore, it is determined whether the first level signal is updated to a second level signal within a preset time.

[0103] The preset time may be set in the timer mentioned above, for example, 1 second; the second level signal should be a signal with a level state different from that of the first level signal, and is a high level signal in this embodiment.

[0104] Further, if the first level signal is updated to the second level signal within the preset time, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

[0105] Specifically, in this embodiment, after the timer starts timing, it is determined whether the level state of VTH1_INT changes from a low level to a high level within a preset time (e.g., within 1 second) from the start of timing, so as to determine whether the load state is abnormal in the current situation. If the first level signal changes to the second level signal within the preset time, it is determined that the load state is normal; otherwise, it is determined that the load state is abnormal and subsequent corresponding abnormality handling steps are performed.

[0106] Compared with the above-mentioned second embodiment, the third embodiment provided by the present application has the beneficial effects of the above-mentioned second embodiment without sampling the load voltage, reducing the amount of calculation, and improving the real-time performance. At the same time, it only needs to judge the signal transformation of the same potential (VTH1_INT), which obviously reduces the number of devices, thereby reducing the components used, thereby reducing the circuit cost, saving hardware resource optimization costs, and further improving the practicality of the system.

[0107] In step S41, if there is no abnormality in the load, the main discharge module is turned on and the pre-discharge module is turned off through the control module to enter the main discharge mode.

[0108] Specifically, if the load state is normal, the control module turns on the main discharge module through the corresponding output terminal and turns off the pre-discharge module based on the signal collected by the detection module to enter the main discharge mode.

[0109] Furthermore, after step S41, the method further includes: In step S5, the current state of the load is detected to obtain the load current.

[0110] In step S6, if the load current is less than the preset current threshold, the pre-discharge module is turned on and the main discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

[0111] Specifically, after the main discharge mode is turned on, the load current on the main discharge module is detected, and a preset current threshold (for example, 15mA) is preset. If the load current is continuously less than the preset current threshold, it is considered that the load is removed or turned off, and the product enters pre-discharge standby sleep (pre-discharge module is turned on, main discharge module is turned off), waiting for the next power-on wake-up to save power.

[0112] In step S42, otherwise, a load abnormality alarm is sent and the pre-discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

[0113] Specifically, if the load status is determined to be abnormal through the above steps, the corresponding abnormality handling step is entered. In the embodiment provided in the present application, it includes but is not limited to alarming the load abnormality through one or more error reporting methods such as voice broadcast and information prompt, and returning to the step of obtaining the battery status to wait for a new round of determination.

[0114] The above is a specific description of the preferred implementation of the present application, but the invention of the present application is not limited to the described embodiments. Technical personnel familiar with the field can also make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A battery discharge branch control system, applied between a battery and a load, characterized in that: include: Main discharge module, pre-discharge module, detection module and control module; The first input end of the main discharge module is connected to the battery, and the output end is connected to the load; The first input end of the pre-discharge module is connected to the battery, and the output end is connected to the load; the pre-discharge module includes a current limiting switch tube, which is used to limit the discharge current through the current limiting switch tube when the pre-discharge module is turned on; The input end of the detection module is connected to the load, and the output end is connected to the input end of the control module, and is used to sample the state of the load through the detection module; The first output end of the control module is connected to the second input end of the main discharge module, and the second output end of the control module is connected to the second input end of the pre-discharge module, so as to adjust the on-off state of the main discharge module and the pre-discharge module according to the state of the load through the control module.

2. The battery discharge branch control system according to claim 1, characterized in that: The main discharge module includes: a first switch tube, a first resistor, and a second resistor; The output end of the first switch tube is connected to the battery through a first current-sensing resistor, and the input end is connected to the load; The first resistor is connected in parallel between the trigger end and the output end of the first switch tube, and the trigger end of the first switch tube is also connected to the first output end of the control module through the second resistor.

3. The battery discharge branch control system according to claim 2, characterized in that: The main discharge module also includes a first diode; The cathode of the first diode is connected to the connection point between the first output end of the control module and the second resistor, and the anode of the first diode is connected to the connection point between the second resistor and the trigger end of the first switch tube.

4. The battery discharge branch control system according to claim 2, characterized in that: The main discharge module also includes a first voltage regulator tube; The positive electrode of the first voltage regulator is connected to the output end of the first switch tube, and the negative electrode is connected to the trigger end of the first switch tube.

5. The battery discharge branch control system according to claim 2, characterized in that: The pre-discharge module includes a second switch tube, a third switch tube, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second current detection resistor and a third current detection resistor; wherein the current limiting switch tube is the third switch tube; The battery is connected to the output end of the second switch tube through the first current detection resistor, the second current detection resistor and the third current detection resistor, and the input end of the second switch tube is connected to the load; The connection point between the first current detection resistor and the second current detection resistor is connected to the connection point between the second current detection resistor and the third current detection resistor through the third resistor and the fourth resistor connected in series; The output end of the third switch tube is connected to the connection point between the first current detection resistor and the third resistor, the trigger end is connected to the connection point between the third resistor and the fourth resistor, the input end is connected to the second output end of the control module through the fifth resistor, and the input end is also connected to the trigger end of the second switch tube through the sixth resistor; The seventh resistor is connected in parallel between the output end and the trigger end of the second switch tube.

6. The battery discharge branch control system according to claim 5, characterized in that: The pre-discharge module further includes: a second diode and a second voltage regulator tube; The cathode of the second diode is connected to the connection point between the second output terminal of the control module and the fifth resistor, and the anode of the second diode is connected to the connection point between the fifth resistor and the input terminal of the third switch tube; The positive electrode of the second voltage regulator is connected to the output end of the second switch tube, and the negative electrode is connected to the trigger end of the second switch tube.

7. The battery discharge branch control system according to claim 5, characterized in that: The detection module includes an eighth resistor and a ninth resistor; One end of the eighth resistor is connected to the battery, and the other end is connected to one end of the ninth resistor and a sampling end of an external controller; The other end of the ninth resistor is connected to the connection point between the input end of the second switch tube and the load; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

8. The battery discharge branch control system according to claim 5, characterized in that: The detection module includes an eighth resistor, a ninth resistor, a fourth switch tube, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor and a fifth switch tube; The trigger end of the fourth switch tube is connected to one end of the eighth resistor and one end of the ninth resistor, the other end of the eighth resistor is connected to the output end of the fourth switch tube and the battery, the other end of the ninth resistor is connected to the load, the input end of the fourth switch tube is connected to the first input end of the external controller and one end of the twelfth resistor, and the other end of the twelfth resistor is connected to an external DC signal source; The trigger end of the fifth switch tube is connected to one end of the tenth resistor and one end of the eleventh resistor, the other end of the tenth resistor is connected to the battery and the output end of the fifth switch tube, the other end of the eleventh resistor is connected to the load, the input end of the fifth switch tube is connected to the second input end of the controller and one end of the thirteenth resistor, and the other end of the thirteenth resistor is connected to the DC signal source; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

9. The battery discharge branch control system according to claim 5, characterized in that: The detection module includes: an eighth resistor, a ninth resistor, a tenth resistor, a capacitor, a twelfth resistor and a fourth switch tube; The trigger end of the fourth switch tube is connected to one end of the eighth resistor and one end of the ninth resistor, the other end of the eighth resistor is connected to the output end of the fourth switch tube and the battery, and the other end of the ninth resistor is connected to the load; The capacitor is connected in series with the tenth resistor and then connected in parallel to both ends of the ninth resistor; The input end of the fourth switch tube is connected to the sampling end of the external controller, and the sampling end of the controller is also connected to the external DC signal source through the twelfth resistor; The first output end of the controller is connected to the trigger end of the first switch tube through the second resistor, and the second output end is connected to the connection point between the third switch tube and the sixth resistor through the fifth resistor.

10. A battery discharge branch control method, characterized in that: The method comprises: Acquiring a battery state to determine whether to allow the battery discharge branch control system to discharge according to the battery state; If the battery discharge branch control system is allowed to discharge, the pre-discharge module is turned on by the control module to enter the pre-discharge mode; in the pre-discharge mode, current-limited discharge is performed based on the current-limiting switch tube in the pre-discharge module; Sampling the load through the detection module to determine whether the load is abnormal according to the sampling result; If there is no abnormality in the load, the main discharge module is turned on and the pre-discharge module is turned off through the control module to enter the main discharge mode; otherwise, a load abnormality alarm is sent and the pre-discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

11. The battery discharge branch control method according to claim 10, characterized in that: The step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: When the pre-discharge module is turned on, voltage sampling is performed on the load to obtain an initial first voltage; After the first preset time, sampling the load again to obtain a current second voltage; Calculating a current load capacitance value of the load according to the first voltage, the second voltage and the first preset time; Determine whether the load capacitance value is within a preset capacitance value interval; if the load capacitance value is within the capacitance value interval, determine that there is no abnormality in the load; otherwise, determine that there is an abnormality in the load.

12. The battery discharge branch control method according to claim 11, characterized in that: The formula used to calculate the load capacitance value of the current load according to the first voltage, the second voltage and the first preset time is: ； in, is the load capacitance value, is the load current, is the voltage difference between the first voltage and the second voltage of the load, The first preset time.

13. The battery discharge branch control method according to claim 10, characterized in that: The step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a first preset voltage threshold, a first level signal is sent to the control module through the detection module; The control module waits for a second level signal to be input in response to the first level signal, and sends the second level signal to the control module through the detection module if the load voltage drop is less than a second preset voltage threshold; Calculating a signal time difference between a time instant of acquiring the second level signal and a time instant of acquiring the first level signal, and determining whether the signal time difference is within a preset time interval; If the signal time difference is within the preset time interval, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

14. The battery discharge branch control method according to claim 10, characterized in that: The step of sampling the load by the detection module to determine whether the load is abnormal according to the sampling result includes: Sampling the voltage of the load to obtain a load voltage drop; If the load voltage drop is greater than a preset voltage threshold, a first level signal is sent to the control module through the detection module; Determine whether the first level signal is updated to a second level signal within a preset time; If the first level signal is updated to the second level signal within the preset time, it is determined that there is no abnormality in the load; otherwise, it is determined that there is an abnormality in the load.

15. The battery discharge branch control method according to claim 10, characterized in that: After the step of turning on the main discharge module and turning off the pre-discharge module by the control module to enter the main discharge mode, the method includes: Detecting the current state of the load to obtain the load current; If the load current is less than the preset current threshold, the pre-discharge module is turned on and the main discharge module is turned off through the control module, and the process returns to the step of obtaining the battery status.

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