Cell voltage detection circuit and system

Abstract

The embodiment of the utility model discloses a cell voltage detection circuit and system. The circuit comprises a rectification module, an instantaneous voltage acquisition module, a steady-state voltage acquisition module and a processing module. The rectifier module is connected with the switch transformer and is used for dividing, rectifying and filtering the voltage input by the switch transformer to generate a voltage acquisition signal; the rectifier module is connected with the instantaneous voltage acquisition module, and the instantaneous voltage acquisition module is used for acquiring the voltage acquisition signal to generate an instantaneous voltage signal; the instantaneous voltage acquisition module is connected with the steady-state voltage acquisition module, and the steady-state voltage acquisition module is used for performing signal processing on the instantaneous voltage signal to obtain a steady-state voltage signal; the instantaneous voltage acquisition module and the steady-state voltage acquisition module are both connected with the processing module, and the processing module is used for determining whether an instantaneous overvoltage and undervoltage fault occurs or not according to the instantaneous voltage signal and determining whether a steady-state overvoltage and undervoltage fault occurs or not according to the steady-state voltage signal. The over-voltage and under-voltage state of the battery can be accurately detected.

Description

Technical Field

[0001] The embodiments of the present utility model relate to the technical field of battery detection, and in particular to a cell voltage detection circuit and system. Background Art

[0002] If the externally applied voltage of the battery is too high, higher than the voltage window that the electrolyte can withstand, it will exacerbate the decomposition process of the electrolyte. The decomposition products also include combustible gases, which damage the conductivity of the electrolyte and shorten the battery life. Figure 1 For a relationship curve between the battery cycle life and the cell charging cut-off voltage when the externally applied voltage of the battery is too high provided by the prior art, as Figure 1 shown, when the externally applied voltage of the battery is too high, it has a great impact on the battery life. In addition, if the battery discharges under-voltage, the lead layer of the battery plate will be gradually peeled off until the plate is damaged, shortening the battery life. Summary of the Utility Model

[0003] The embodiments of the present utility model provide a cell voltage detection circuit and system to accurately and quickly detect the over- and under-voltage faults of the battery, thereby reducing battery loss and improving the service life of the battery.

[0004] In a first aspect, the embodiments of the present utility model provide a cell voltage detection circuit, which includes a rectification module, an instantaneous voltage acquisition module, a steady-state voltage acquisition module, and a processing module;

[0005] The rectification module is connected to the switching transformer, and the rectification module is used to divide, rectify, and filter the voltage input by the switching transformer to generate a voltage acquisition signal;

[0006] The rectification module is connected to the instantaneous voltage acquisition module, and the instantaneous voltage acquisition module is used to acquire the voltage acquisition signal to generate an instantaneous voltage signal;

[0007] The instantaneous voltage acquisition module is connected to the steady-state voltage acquisition module, and the steady-state voltage acquisition module is used to process the signal of the instantaneous voltage to obtain a steady-state voltage signal;

[0008] Both the instantaneous voltage acquisition module and the steady-state voltage acquisition module are connected to the processing module. The processing module is used to determine whether an instantaneous over- and under-voltage fault occurs according to the instantaneous voltage signal, and determine whether a steady-state over- and under-voltage fault occurs according to the steady-state voltage signal.

[0009] Optionally, the rectification module includes a first rectification unit and a second rectification unit;

[0010] The first end of the first rectifying unit and the first end of the second rectifying unit are both connected to the first end of the switching transformer. The second end of the first rectifying unit and the second end of the switching transformer are grounded together. The third end of the first rectifying unit is connected to a first fixed potential, and the second end of the second rectifying unit is connected to the instantaneous voltage acquisition module;

[0011] The first rectifying unit is used to filter and rectify the output voltage of the switching transformer, and the second rectifying unit is used to divide, rectify, and filter the output voltage of the switching transformer to generate a voltage acquisition signal.

[0012] Optionally, the first rectifying unit includes a first diode, a first capacitor, and a second capacitor;

[0013] The second rectifying unit includes a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor, a fourth capacitor, and a fifth capacitor;

[0014] The cathode of the first diode serves as the first end of the first rectifying unit. The first poles of the first capacitor, the second capacitor, and the anode of the first diode are connected and serve as the third end of the first rectifying unit. The second poles of the first capacitor and the second capacitor are connected and serve as the second end of the first rectifying unit;

[0015] The anode of the second diode serves as the first end of the second rectifying unit. The cathode of the second diode is connected to the first end of the first resistor. The second end of the first resistor and the first end of the second resistor are both connected to the first end of the third capacitor. The second end of the second capacitor is grounded. The second end of the second resistor is connected to the first end of the third resistor. The second end of the third resistor is connected to the first end of the fourth resistor. The second end of the fourth resistor and the first end of the fifth resistor are both connected to the first end of the fourth capacitor. The second end of the fourth capacitor is grounded. The second end of the fifth resistor is connected to the first end of the sixth resistor. The second end of the sixth resistor, the first end of the seventh resistor, and the first end of the fifth capacitor are connected and serve as the second end of the second rectifying unit. The second end of the seventh resistor and the second end of the fifth capacitor are grounded together.

[0016] Optionally, the instantaneous voltage acquisition module includes a voltage division and filtering unit and an amplification unit;

[0017] The first end of the voltage division and filtering unit is connected to the rectifying module. The second end of the voltage division and filtering unit is connected to the first end of the amplification unit. The second end and the third end of the amplification unit are connected to the steady-state voltage acquisition module and the processing module.

[0018] Optionally, the voltage dividing and filtering unit includes an eighth resistor, a ninth resistor, and a sixth capacitor;

[0019] The amplifying unit includes a dual operational amplifier;

[0020] The first end of the eighth resistor and the first end of the ninth resistor are connected and serve as the first end of the voltage dividing and filtering unit. The second end of the eighth resistor is grounded. The second end of the ninth resistor and the first end of the sixth capacitor are connected and serve as the second end of the voltage dividing and filtering unit. The second end of the sixth capacitor is grounded;

[0021] The first end of the dual operational amplifier serves as the first end of the amplifying unit, the second end of the dual operational amplifier serves as the second end of the amplifying unit, and the third end of the dual operational amplifier serves as the third end of the amplifying unit.

[0022] Optionally, the steady-state voltage acquisition module includes a steady-state undervoltage acquisition unit and a steady-state overvoltage acquisition unit;

[0023] The first ends of both the steady-state undervoltage acquisition unit and the steady-state overvoltage acquisition unit are connected to the instantaneous voltage acquisition module, and the second ends of both the steady-state undervoltage acquisition unit and the steady-state overvoltage acquisition unit are connected to the processing module.

[0024] Optionally, the steady-state undervoltage acquisition unit includes a tenth resistor, a third diode, a fourth diode, and a seventh capacitor;

[0025] The first end of the tenth resistor serves as the first end of the steady-state undervoltage acquisition unit. The cathode of the third diode is connected to a second fixed potential. The second end of the tenth resistor, the anode of the third diode, the cathode of the fourth diode, and the first end of the seventh capacitor are connected and serve as the second end of the steady-state undervoltage acquisition unit. The anode of the fourth diode and the second end of the seventh capacitor are grounded together.

[0026] Optionally, the steady-state overvoltage acquisition unit includes a reference subunit, a comparison subunit, a voltage dividing and filtering subunit, and a voltage stabilizing subunit;

[0027] The first end of the comparison subunit serves as the first end of the steady-state overvoltage acquisition unit. The second end of the comparison subunit is connected to the first end of the reference subunit. The third end of the comparison subunit is connected to the first end of the voltage dividing and filtering subunit. The second end of the voltage dividing and filtering subunit is connected to the first end of the voltage stabilizing subunit. The second end of the voltage stabilizing subunit serves as the second end of the steady-state overvoltage acquisition unit.

[0028] Optionally, the comparison subunit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, an eighth capacitor, a ninth capacitor, and a comparator;

[0029] The reference subunit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, and a tenth capacitor;

[0030] The voltage division and filtering subunit includes an eighteenth resistor, a nineteenth resistor, a fifth diode, a sixth diode, and an eleventh capacitor;

[0031] The voltage stabilization subunit includes a Schmitt inverter;

[0032] The first end of the eleventh resistor serves as the first end of the comparison subunit. The second end of the eleventh resistor and the first end of the eighth capacitor are both connected to the first end of the twelfth resistor. The second end of the eighth capacitor is grounded. The second end of the twelfth resistor, the first end of the thirteenth resistor, and the first end of the comparator are all connected to the first end of the ninth capacitor. The second end of the ninth capacitor and the second end of the comparator are connected and serve as the second end of the comparison subunit. The second end of the thirteenth resistor and the third end of the comparator are connected and serve as the third end of the comparison subunit;

[0033] The first end of the fourteenth resistor is connected to a third fixed potential. The second end of the fourteenth resistor, the first end of the tenth capacitor, and the first end of the fifteenth resistor are all connected to the first end of the seventeenth resistor. The second end of the seventeenth resistor serves as the first end of the reference subunit. The second end of the fifteenth resistor and the first end of the sixteenth resistor are connected. The second end of the tenth capacitor and the second end of the sixteenth resistor are grounded together;

[0034] The first end of the eighteenth resistor serves as the first end of the voltage division and filtering subunit. The second end of the eighteenth resistor, the anode of the fifth diode, the cathode of the sixth diode, the first end of the nineteenth resistor, and the first end of the eleventh capacitor are connected and serve as the second end of the voltage division and filtering subunit. The cathode of the fifth diode and the second end of the nineteenth resistor are connected to a fourth fixed potential. The anode of the sixth diode and the second end of the eleventh capacitor are grounded together;

[0035] The first end of the Schmitt inverter serves as the first end of the voltage stabilization subunit. The second end of the Schmitt inverter serves as the second end of the voltage stabilization subunit.

[0036] In a second aspect, an embodiment of the present invention further provides a cell voltage detection system, and the cell voltage detection system includes the cell voltage detection circuit provided in any embodiment of the present invention.

[0037] The cell voltage detection circuit provided by the embodiment of the present utility model collects an instantaneous voltage signal through an instantaneous voltage acquisition module, and feeds the instantaneous voltage signal back to a processing module, so that the processing module determines whether the instantaneous voltage of the battery is within a normal instantaneous voltage range, to quickly determine whether the battery has an instantaneous over-voltage or under-voltage fault, and give an early warning in time when the battery has an instantaneous over-voltage or under-voltage fault. The steady-state voltage signal is collected through a steady-state voltage acquisition module, and the steady-state voltage signal is fed back to the processing module, so that the processing module determines whether the steady-state voltage of the battery is within a normal steady-state voltage range, to accurately determine whether the battery has a steady-state over-voltage or under-voltage fault, and give an early warning in time when the battery has a steady-state over-voltage or under-voltage fault. Thus, through the differential detection of the instantaneous voltage and the steady-state voltage, this solution can quickly and accurately monitor and alarm the charge and discharge faults of the battery, adjust the charge and discharge of the battery in time, thereby reducing the battery loss and increasing the service life of the battery. Description of the Drawings

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a relationship curve between the battery cycle life and the cell charging cut-off voltage when the external voltage of the battery provided by the prior art is too high;

[0040] Figure 2 It is a schematic structural diagram of a cell voltage detection circuit provided by the embodiment of the present utility model;

[0041] Figure 3 It is a schematic structural diagram of another cell voltage detection circuit provided by the embodiment of the present utility model. Detailed Embodiments

[0042] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0043] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present utility model are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] Figure 2 FIG. is a schematic structural diagram of a cell voltage detection circuit provided by an embodiment of the present utility model. As Figure 2 shown, the cell voltage detection circuit includes a rectification module 110, an instantaneous voltage acquisition module 120, a steady-state voltage acquisition module 130, and a processing module 140;

[0045] The rectification module 110 is connected to the switching transformer 210. The rectification module 110 is configured to divide, rectify, and filter the voltage input by the switching transformer 210 to generate a voltage acquisition signal. The rectification module 110 is connected to the instantaneous voltage acquisition module 120. The instantaneous voltage acquisition module 120 is configured to acquire the voltage acquisition signal to generate an instantaneous voltage signal. The instantaneous voltage acquisition module 120 and the steady-state voltage acquisition module 130 are connected. The steady-state voltage acquisition module 130 is configured to process the instantaneous voltage signal to obtain a steady-state voltage signal. Both the instantaneous voltage acquisition module 120 and the steady-state voltage acquisition module 130 are connected to the processing module 140. The processing module 140 is configured to determine whether an instantaneous over-voltage or under-voltage fault occurs according to the instantaneous voltage signal, and determine whether a steady-state over-voltage or under-voltage fault occurs according to the steady-state voltage signal.

[0046] Among them, the rectification module 110 can perform voltage division processing, rectification processing, and filtering processing on the battery voltage collected by the switching transformer 210 to collect the battery voltage and obtain a voltage acquisition signal. The instantaneous voltage acquisition module 120 can instantaneously acquire the voltage acquisition signal to obtain an instantaneous voltage signal. The steady-state voltage acquisition module 130 can process the instantaneous voltage signal (such as filtering processing, etc.) to obtain a steady-state voltage signal. The processing module 140 can perform real-time monitoring on the collected instantaneous voltage signal to determine whether the instantaneous voltage of the battery is within the normal instantaneous voltage range, and further determine whether an instantaneous over-voltage or under-voltage fault occurs in the battery. The processing module 140 can perform real-time monitoring on the collected steady-state voltage signal to determine whether the steady-state voltage of the battery is within the normal steady-state voltage range, and further determine whether a steady-state over-voltage or under-voltage fault occurs in the battery.

[0047] During the charging and discharging process of a battery, it may enter a state of instantaneous overcharging or over-discharging due to the influence of certain factors, resulting in an instantaneous overvoltage or instantaneous undervoltage of the battery voltage. Currently, when the battery management system detects the battery sensitively, once an instantaneous overvoltage or instantaneous undervoltage is detected, there may be a false alarm of the charging and discharging fault of the battery. When the battery management system detects the battery insensitively, it is unable to alarm the charging and discharging fault of the battery in a timely manner.

[0048] The cell voltage detection circuit provided by the embodiment of the present utility model collects an instantaneous voltage signal through the instantaneous voltage acquisition module 120 and feeds the instantaneous voltage signal back to the processing module 140, so that the processing module 140 determines whether the instantaneous voltage of the battery is within the normal instantaneous voltage range, quickly judges whether the battery has an instantaneous over-undervoltage fault, and gives a timely warning when the battery has an instantaneous over-undervoltage fault. The steady-state voltage acquisition module 130 collects a steady-state voltage signal and feeds the steady-state voltage signal back to the processing module 140, so that the processing module 140 determines whether the steady-state voltage of the battery is within the normal steady-state voltage range, accurately judges whether the battery has a steady-state over-undervoltage fault, and gives a timely warning when the battery has a steady-state over-undervoltage fault. Thus, this solution can quickly and accurately monitor and alarm the charging and discharging faults of the battery by distinguishing and detecting the instantaneous voltage signal and the steady-state voltage signal, timely adjust the charging and discharging of the battery, thereby reducing battery loss and increasing the service life of the battery.

[0049] Based on the above embodiment, optionally, Figure 3 is a schematic structural diagram of another cell voltage detection circuit provided by the embodiment of the present utility model. As Figure 3 shown, the rectification module 110 includes a first rectification unit 111 and a second rectification unit 112;

[0050] The first end of the first rectification unit 111 and the first end of the second rectification unit 112 are both connected to the first end of the switching transformer 210. The second end of the first rectification unit 111 and the second end of the switching transformer 210 are grounded together. The third end of the first rectification unit 111 is connected to the first fixed potential V1, and the second end of the second rectification unit 112 is connected to the instantaneous voltage acquisition module 120;

[0051] The first rectification unit 111 is used to filter and rectify the output voltage of the switching transformer 210, and the second rectification unit 112 is used to divide, rectify and filter the output voltage of the switching transformer 210 to generate a voltage acquisition signal.

[0052] Among them, through the first rectification unit 111 and the second rectification unit 112, a more accurate and stable voltage acquisition signal can be generated, so that the subsequent acquisition of the instantaneous voltage signal and the steady-state voltage signal is more accurate.

[0053] Specifically, the first rectification unit 111 includes a first diode D1, a first capacitor C1, and a second capacitor C2;

[0054] The second rectification unit 112 includes a second diode D2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5;

[0055] The cathode of the first diode D1 serves as the first end of the first rectification unit 111. The first pole of the first capacitor C1, the first pole of the second capacitor C2, and the anode of the first diode D1 are connected and serve as the third end of the first rectification unit 111. The second pole of the first capacitor C1 and the second pole of the second capacitor C2 are connected and serve as the second end of the first rectification unit 111;

[0056] The anode of the second diode D2 serves as the first end of the second rectification unit 112. The cathode of the second diode D2 and the first end of the first resistor R1 are connected. The second end of the first resistor R1 and the first end of the second resistor R2 are both connected to the first end of the third capacitor C3. The second end of the second capacitor C2 is grounded. The second end of the second resistor R2 and the first end of the third resistor R3 are connected. The second end of the third resistor R3 and the first end of the fourth resistor R4 are connected. The second end of the fourth resistor R4 and the first end of the fifth resistor R5 are both connected to the first end of the fourth capacitor C4. The second end of the fourth capacitor C4 is grounded. The second end of the fifth resistor R5 and the first end of the sixth resistor R6 are connected. The second end of the sixth resistor R6, the first end of the seventh resistor R7, and the first end of the fifth capacitor C5 are connected and serve as the second end of the second rectification unit 112. The second end of the seventh resistor R7 and the second end of the fifth capacitor C5 are grounded together.

[0057] Wherein, the cathode of the first diode D1 and the anode of the second diode D2 are both connected to the first end of the switching transformer 210. The second pole of the first capacitor C1 and the second pole of the second capacitor C2 are both connected to the second end of the switching transformer 210. The second end of the sixth resistor R6, the first end of the seventh resistor R7, and the first end of the fifth capacitor C5 are all connected to the instantaneous voltage acquisition module 120.

[0058] Based on the above embodiments, optionally, continue to refer to Figure 3 , the instantaneous voltage acquisition module 120 includes a voltage division and filtering unit 121 and an amplification unit 122;

[0059] The first end of the voltage dividing and filtering unit 121 is connected to the rectification module 110, the second end of the voltage dividing and filtering unit 121 is connected to the first end of the amplification unit 122, and the second and third ends of the amplification unit 122 are connected to the steady-state voltage acquisition module 130 and the processing module 140.

[0060] Among them, the voltage dividing and filtering unit 121 is used for voltage dividing and filtering processing of the voltage acquisition signal. The amplification unit 122 is used for signal amplification of the input signal to obtain an instantaneous voltage signal.

[0061] Specifically, the voltage dividing and filtering unit 121 includes an eighth resistor R8, a ninth resistor R9, and a sixth capacitor C6;

[0062] The amplification unit 122 includes a dual operational amplifier U1;

[0063] The first ends of the eighth resistor R8 and the ninth resistor R9 are connected and serve as the first end of the voltage dividing and filtering unit 121. The second end of the eighth resistor R8 is grounded. The second end of the ninth resistor R9 and the first end of the sixth capacitor C6 are connected and serve as the second end of the voltage dividing and filtering unit 121. The second end of the sixth capacitor C6 is grounded;

[0064] The first end of the dual operational amplifier U1 serves as the first end of the amplification unit 122, the second end of the dual operational amplifier U1 serves as the second end of the amplification unit 122, and the third end of the dual operational amplifier U1 serves as the third end of the amplification unit 122.

[0065] Among them, the first ends of the eighth resistor R8 and the ninth resistor R9 are both connected to the rectification module 110. The second end of the ninth resistor R9 and the first end of the sixth capacitor C6 are both connected to the first end of the dual operational amplifier U1. The second and third ends of the dual operational amplifier U1 are connected to the steady-state voltage acquisition module 130 and the processing module 140.

[0066] Based on the above embodiments, optionally, continue to refer to Figure 3 , the steady-state voltage acquisition module 130 includes a steady-state undervoltage acquisition unit 131 and a steady-state overvoltage acquisition unit 132;

[0067] The first ends of the steady-state undervoltage acquisition unit 131 and the steady-state overvoltage acquisition unit 132 are both connected to the instantaneous voltage acquisition module 120. The second ends of the steady-state undervoltage acquisition unit 131 and the steady-state overvoltage acquisition unit 132 are both connected to the processing module 140.

[0068] Among them, the steady-state undervoltage acquisition unit 131 is used to generate a steady-state undervoltage signal according to the instantaneous voltage, and the steady-state overvoltage acquisition unit 132 is used to generate a steady-state overvoltage signal according to the instantaneous voltage. The processing module 140 is used to determine whether a steady-state undervoltage fault occurs according to the steady-state undervoltage signal, and determine whether a steady-state overvoltage fault occurs according to the steady-state overvoltage signal.

[0069] Specifically, the steady-state undervoltage acquisition unit 131 includes a tenth resistor R10, a third diode D3, a fourth diode D4, and a seventh capacitor C7;

[0070] The first end of the tenth resistor R10 serves as the first end of the steady-state undervoltage acquisition unit 131. The cathode of the third diode D3 is connected to the second fixed potential V2. The second end of the tenth resistor R10, the anode of the third diode D3, the cathode of the fourth diode D4, and the first end of the seventh capacitor C7 are connected and serve as the second end of the steady-state undervoltage acquisition unit 131. The anode of the fourth diode D4 and the second end of the seventh capacitor C7 are grounded together.

[0071] Among them, the first end of the tenth resistor R10 is connected to the instantaneous voltage acquisition module 120, and the anode of the third diode D3, the cathode of the fourth diode D4, and the first end of the seventh capacitor C7 are connected to the processing module 140.

[0072] Based on the above embodiments, optionally, continue to refer to Figure 3 , the steady-state overvoltage acquisition unit 132 includes a reference sub-unit 1321, a comparison sub-unit 1322, a voltage division and filtering sub-unit 1323, and a voltage stabilization sub-unit 1324;

[0073] The first end of the comparison sub-unit 1322 serves as the first end of the steady-state overvoltage acquisition unit 132. The second end of the comparison sub-unit 1322 is connected to the first end of the reference sub-unit 1321. The third end of the comparison sub-unit 1322 is connected to the first end of the voltage division and filtering sub-unit 1323. The second end of the voltage division and filtering sub-unit 1323 is connected to the first end of the voltage stabilization sub-unit 1324. The second end of the voltage stabilization sub-unit 1324 serves as the second end of the steady-state overvoltage acquisition unit 132.

[0074] Among them, the reference sub-unit 1321 is used to generate a reference voltage signal, and the voltage of the reference voltage signal is equal to the overvoltage threshold of the battery. The comparison sub-unit 1322 is used to divide and filter the acquired instantaneous voltage, and compare the divided signal with the reference voltage signal to generate a steady-state overvoltage signal. The voltage division and filtering sub-unit 1323 is used to divide and filter the steady-state overvoltage signal to generate a signal within the recognizable range of the processing module 140. The voltage stabilization sub-unit 1324 is used to stabilize the signal output by the voltage division and filtering sub-unit 1323 to make the recognition of the signal by the processing module 140 more accurate.

[0075] Specifically, the comparison subunit 1322 includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, an eighth capacitor C8, a ninth capacitor C9, and a comparator U2;

[0076] The reference subunit 1321 includes a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, and a tenth capacitor C10;

[0077] The voltage division and filtering subunit 1323 includes an eighteenth resistor R18, a nineteenth resistor R19, a fifth diode D5, a sixth diode D6, and an eleventh capacitor C11;

[0078] The voltage regulation subunit 1324 includes a Schmitt inverter U3;

[0079] The first end of the eleventh resistor R11 serves as the first end of the comparison subunit 1322. The second end of the eleventh resistor R11 and the first end of the eighth capacitor C8 are both connected to the first end of the twelfth resistor R12. The second end of the eighth capacitor C8 is grounded. The second end of the twelfth resistor R12, the first end of the thirteenth resistor R13, and the first end of the comparator U2 are all connected to the first end of the ninth capacitor C9. The second end of the ninth capacitor C9 and the second end of the comparator U2 are connected and serve as the second end of the comparison subunit 1322. The second end of the thirteenth resistor R13 and the third end of the comparator U2 are connected and serve as the third end of the comparison subunit 1322;

[0080] The first end of the fourteenth resistor R14 is connected to the third fixed potential V3. The second end of the fourteenth resistor R14, the first end of the tenth capacitor C10, and the first end of the fifteenth resistor R15 are all connected to the first end of the seventeenth resistor R17. The second end of the seventeenth resistor R17 serves as the first end of the reference subunit 1321. The second end of the fifteenth resistor R15 and the first end of the sixteenth resistor R16 are connected. The second end of the tenth capacitor C10 and the second end of the sixteenth resistor R16 are grounded together;

[0081] The first end of the eighteenth resistor R18 serves as the first end of the voltage division and filtering subunit 1323. The second end of the eighteenth resistor R18, the anode of the fifth diode D5, the cathode of the sixth diode D6, the first end of the nineteenth resistor R19, and the first end of the eleventh capacitor C11 are connected and serve as the second end of the voltage division and filtering subunit 1323. The cathode of the fifth diode D5 and the second end of the nineteenth resistor R19 are connected to the fourth fixed potential V4. The anode of the sixth diode D6 and the second end of the eleventh capacitor C11 are grounded together;

[0082] The first end of the Schmitt inverter U3 serves as the first end of the voltage regulation subunit 1324. The second end of the Schmitt inverter U3 serves as the second end of the voltage regulation subunit 1324.

[0083] Among them, the first end of the eleventh resistor R11 is connected to the instantaneous voltage acquisition module 120, the second end of the ninth capacitor C9 and the second end of the comparator U2 are both connected to the second end of the seventeenth resistor R17, the second end of the thirteenth resistor R13 and the third end of the comparator U2 are connected to the first end of the eighteenth resistor R18, the first end of the nineteenth resistor R19 and the first end of the eleventh capacitor C11 are connected to the first end of the Schmitt inverter U3, and the second end of the Schmitt inverter U3 is connected to the processing module 140.

[0084] The embodiment of the present invention also provides a cell voltage detection system, which includes the cell voltage detection circuit provided by any embodiment of the present invention. Therefore, it has the beneficial effects of the cell voltage detection circuit provided by any embodiment of the present invention, and details are not described herein again.

[0085] The cell voltage detection system further includes a DC braking circuit, and the DC braking circuit is connected to the processing module. The processing module is used to control the DC braking circuit to adjust the charging and discharging voltage of the battery when it is determined that an instantaneous over-voltage or under-voltage fault occurs.

[0086] The working process of the cell voltage detection system is as follows:

[0087] 1) The cell voltage detection circuit collects an instantaneous voltage signal and sends the instantaneous voltage signal to the processing module, and the processing module determines whether an instantaneous over-voltage or under-voltage fault occurs in the battery. If an instantaneous over-voltage or under-voltage fault occurs in the battery, step 2) is executed; if no instantaneous over-voltage or under-voltage fault occurs in the battery, step 3) is executed.

[0088] 2) The DC braking circuit adjusts the charging and discharging voltage of the battery;

[0089] 3) The cell voltage detection circuit collects a steady-state voltage signal and sends the steady-state voltage signal to the processing module, and the processing module determines whether a steady-state over-voltage or under-voltage fault occurs in the battery. If a steady-state over-voltage or under-voltage fault occurs, step 4) is executed; if no steady-state over-voltage or under-voltage fault occurs, step 1) is executed.

[0090] 4) Perform shutdown protection.

[0091] It should be understood that various forms of the flow shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0092] The above specific embodiments do not constitute a limitation on the protection scope of the present utility model. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A cell voltage detection circuit, characterized in that: It includes a rectifier module, an instantaneous voltage acquisition module, a steady-state voltage acquisition module and a processing module; The rectifier module is connected to the switch transformer, and is used to divide, rectify and filter the voltage input by the switch transformer to generate a voltage acquisition signal; The rectifier module is connected to the instantaneous voltage acquisition module, and the instantaneous voltage acquisition module is used to collect the voltage acquisition signal to generate an instantaneous voltage signal; The instantaneous voltage acquisition module is connected to the steady-state voltage acquisition module, and the steady-state voltage acquisition module is used to perform signal processing on the instantaneous voltage signal to obtain a steady-state voltage signal; The instantaneous voltage acquisition module and the steady-state voltage acquisition module are both connected to the processing module, and the processing module is used to determine whether an instantaneous over- or under-voltage fault occurs according to the instantaneous voltage signal, and determine whether a steady-state over- or under-voltage fault occurs according to the steady-state voltage signal.

2. The cell voltage detection circuit according to claim 1, characterized in that: The rectifier module includes a first rectifier unit and a second rectifier unit; The first end of the first rectifier unit and the first end of the second rectifier unit are both connected to the first end of the switch transformer, the second end of the first rectifier unit and the second end of the switch transformer are grounded, the third end of the first rectifier unit is connected to a first fixed potential, and the second end of the second rectifier unit is connected to an instantaneous voltage acquisition module; The first rectifying unit is used to filter and rectify the output voltage of the switching transformer, and the second rectifying unit is used to divide, rectify and filter the output voltage of the switching transformer to generate a voltage acquisition signal.

3. The cell voltage detection circuit according to claim 2, characterized in that: The first rectifying unit includes a first diode, a first capacitor and a second capacitor; The second rectifying unit includes a second diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third capacitor, a fourth capacitor and a fifth capacitor; The cathode of the first diode serves as the first end of the first rectifying unit, the first electrode of the first capacitor, the first electrode of the second capacitor, and the anode of the first diode are connected and serve as the third end of the first rectifying unit, and the second electrode of the first capacitor and the second electrode of the second capacitor are connected and serve as the second end of the first rectifying unit; The anode of the second diode serves as the first end of the second rectifier unit, the cathode of the second diode is connected to the first end of the first resistor, the second end of the first resistor and the first end of the second resistor are both connected to the first end of the third capacitor, the second end of the second capacitor is grounded, the second end of the second resistor is connected to the first end of the third resistor, the second end of the third resistor is connected to the first end of the fourth resistor, the second end of the fourth resistor and the first end of the fifth resistor are both connected to the first end of the fourth capacitor, the second end of the fourth capacitor is grounded, the second end of the fifth resistor is connected to the first end of the sixth resistor, the second end of the sixth resistor, the first end of the seventh resistor and the first end of the fifth capacitor are connected and serve as the second end of the second rectifier unit, and the second end of the seventh resistor and the second end of the fifth capacitor are commonly grounded.

4. The cell voltage detection circuit according to claim 1, characterized in that: The instantaneous voltage acquisition module includes a voltage division and filtering unit and an amplification unit; The first end of the voltage-dividing filter unit is connected to the rectifier module, the second end of the voltage-dividing filter unit is connected to the first end of the amplifying unit, and the second and third ends of the amplifying unit are connected to the steady-state voltage acquisition module and the processing module.

5. The cell voltage detection circuit according to claim 4, characterized in that: The voltage dividing and filtering unit comprises an eighth resistor, a ninth resistor and a sixth capacitor; The amplification unit includes a dual operational amplifier; The first end of the eighth resistor is connected to the first end of the ninth resistor and serves as the first end of the voltage-dividing filter unit, the second end of the eighth resistor is grounded, the second end of the ninth resistor is connected to the first end of the sixth capacitor and serves as the second end of the voltage-dividing filter unit, and the second end of the sixth capacitor is grounded; The first end of the dual operational amplifier serves as the first end of the amplifying unit, the second end of the dual operational amplifier serves as the second end of the amplifying unit, and the third end of the dual operational amplifier serves as the third end of the amplifying unit.

6. The cell voltage detection circuit according to claim 1, characterized in that: The steady-state voltage acquisition module includes a steady-state undervoltage acquisition unit and a steady-state overvoltage acquisition unit; The first end of the steady-state undervoltage acquisition unit and the first end of the steady-state overvoltage acquisition unit are both connected to the instantaneous voltage acquisition module, and the second end of the steady-state undervoltage acquisition unit and the second end of the steady-state overvoltage acquisition unit are both connected to the processing module.

7. The cell voltage detection circuit according to claim 6, characterized in that: The steady-state undervoltage acquisition unit includes a tenth resistor, a third diode, a fourth diode and a seventh capacitor; The first end of the tenth resistor serves as the first end of the steady-state undervoltage acquisition unit, the cathode of the third diode is connected to the second fixed potential, the second end of the tenth resistor, the anode of the third diode, the cathode of the fourth diode and the first end of the seventh capacitor are connected and serve as the second end of the steady-state undervoltage acquisition unit, and the anode of the fourth diode and the second end of the seventh capacitor are commonly grounded.

8. The cell voltage detection circuit according to claim 6, characterized in that: The steady-state overvoltage acquisition unit includes a reference subunit, a comparison subunit, a voltage division and filtering subunit, and a voltage stabilization subunit; The first end of the comparison subunit serves as the first end of the steady-state overvoltage acquisition unit, the second end of the comparison subunit is connected to the first end of the reference subunit, the third end of the comparison subunit is connected to the first end of the voltage divider and filter subunit, the second end of the voltage divider and filter subunit is connected to the first end of the voltage stabilizing subunit, and the second end of the voltage stabilizing subunit serves as the second end of the steady-state overvoltage acquisition unit.

9. The cell voltage detection circuit according to claim 8, characterized in that: The comparison subunit includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, an eighth capacitor, a ninth capacitor and a comparator; The reference subunit includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor and a tenth capacitor; The voltage-dividing filter subunit includes an eighteenth resistor, a nineteenth resistor, a fifth diode, a sixth diode and an eleventh capacitor; The voltage stabilizing subunit includes a Schmitt inverter; The first end of the eleventh resistor serves as the first end of the comparison subunit, the second end of the eleventh resistor and the first end of the eighth capacitor are both connected to the first end of the twelfth resistor, the second end of the eighth capacitor is grounded, the second end of the twelfth resistor, the first end of the thirteenth resistor, and the first end of the comparator are all connected to the first end of the ninth capacitor, the second end of the ninth capacitor is connected to the second end of the comparator and serves as the second end of the comparison subunit; the second end of the thirteenth resistor is connected to the third end of the comparator and serves as the third end of the comparison subunit; The first end of the fourteenth resistor is connected to the third fixed potential, the second end of the fourteenth resistor, the first end of the tenth capacitor and the first end of the fifteenth resistor are all connected to the first end of the seventeenth resistor, the second end of the seventeenth resistor serves as the first end of the reference subunit, the second end of the fifteenth resistor is connected to the first end of the sixteenth resistor, and the second end of the tenth capacitor and the second end of the sixteenth resistor are grounded; The first end of the eighteenth resistor serves as the first end of the voltage-dividing filter subunit, the second end of the eighteenth resistor, the anode of the fifth diode, the cathode of the sixth diode, the first end of the nineteenth resistor and the first end of the eleventh capacitor are connected and serve as the second end of the voltage-dividing filter subunit, the cathode of the fifth diode and the second end of the nineteenth resistor are connected to the fourth fixed potential, and the anode of the sixth diode and the second end of the eleventh capacitor are grounded; The first end of the Schmitt inverter serves as the first end of the voltage stabilizing subunit, and the second end of the Schmitt inverter serves as the second end of the voltage stabilizing subunit.

10. A battery cell voltage detection system, characterized in that: A cell voltage detection circuit comprising the cell voltage detection circuit according to any one of claims 1 to 9.

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