Detection device, equipment and method for detecting liquid leakage of battery pack

Abstract

The embodiment of the invention discloses a detection device, equipment and method for detecting liquid leakage of a battery pack, and a switching module in the detection device controls the conduction of a first path, a second path or a third path according to a first signal from a control module. The detection module determines a first measuring range, a second measuring range and a third measuring range which need to be used by the conditions of the first passage, the second passage and the third passage respectively. The control module calculates a first voltage at two ends of the battery pack in the first path under the first measuring range, a second voltage at two ends of the first positive switching resistor in the second path under the second measuring range and a third voltage at two ends of the first negative switching resistor in the third path under the third measuring range; and according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor and the resistance value of the first negative switching resistor, calculating an equivalent resistance between the reference port and the target detection point, wherein the equivalent resistance is used for describing the liquid leakage condition of the battery pack. The detection device can rapidly and efficiently check the battery leakage condition, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of battery monitoring, and in particular to a detection device, equipment and method for detecting battery pack leakage. Background Art

[0002] As an energy storage device, batteries are widely used in various electronic devices, automobiles, aerospace and other fields. However, during long-term use, batteries may fail or leak due to internal chemical reactions, physical damage or external environmental factors. These problems will not only cause battery performance to deteriorate and affect the normal operation of equipment, but may also cause a series of safety hazards.

[0003] In related technologies, battery safety inspections mainly rely on manual on-site inspections, but the inspection cycle is long or the inspection is not in place, and the concealment of battery leakage makes it difficult to detect and troubleshoot hidden dangers in a timely manner. In addition, in some industries, lithium battery packs usually install the cells in a relatively closed PAKC space, making the inspection work more difficult. Summary of the invention

[0004] The embodiments of the present application provide a detection device, equipment and method for detecting battery leakage, which are used to quickly and efficiently troubleshoot battery leakage and improve battery life.

[0005] In a first aspect, an embodiment of the present application provides a battery pack leakage detection device, comprising: a control module, a detection module and a switching module; the switching module is connected to the battery pack to be detected, and the detection module is connected to the switching module and the control module; the switching module includes M positive switching resistors and M negative switching resistors;

[0006] The switching module is used to: control the first path, the second path or the third path to be turned on according to the first signal from the control module; wherein, in the first path, the first positive switching resistor and the first negative switching resistor are not connected; in the second path, the first positive switching resistor is connected between the positive electrode and the reference port of the battery pack; in the third path, the first negative switching resistor is connected between the negative electrode and the reference port of the battery pack; the reference port is a contact point on the reference surface formed by the peripheral metal parts of the battery pack; the first positive switching resistor is one of the M positive switching resistors, and the first negative switching resistor is one of the M negative switching resistors;

[0007] The detection module is used to: determine the first range to be used for the first channel, the second range to be used for the second channel, and the third range to be used for the third channel according to the second signal from the control module that matches the first signal;

[0008] The control module is used to calculate a first voltage across the battery pack in a first path under a first range, a second voltage across the first positive switching resistor in a second path under a second range, and a third voltage across the first negative switching resistor in a third path under a third range;

[0009] The control module is also used to calculate the equivalent resistance between the reference port and the target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor and the resistance value of the first negative switching resistor; wherein the equivalent resistance is used to describe the leakage of the battery pack, and the target detection point is any position on any single cell in the battery pack.

[0010] In a second aspect, an embodiment of the present application provides a battery pack leakage detection method, which is applied to the battery pack leakage detection device of the first aspect, and the method includes:

[0011] Calculate a first voltage across the battery pack in the first path in a first range, a second voltage across the first positive switching resistor in the second path in a second range, and a third voltage across the first negative switching resistor in the third path in a third range;

[0012] Calculate the equivalent resistance between the reference port and the target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor and the resistance value of the first negative switching resistor; wherein the target detection point is any position on any single cell in the battery pack;

[0013] If the equivalent resistance is less than the set resistance threshold, it is determined that the battery pack is leaking.

[0014] In the embodiment of the present application, the peripheral metal parts of the battery pack form a reference surface, and a contact point on the reference surface is called a reference port. The detection device is connected to the reference port, and the reference port and the target detection point of the battery pack (which can be any single cell) can be equivalent to a resistor. The leakage of the battery pack can be determined by the size of the equivalent resistance. The detection device is connected to the battery pack to be detected, and the access status of the first positive switching resistor and the first negative switching resistor in the switching module is controlled by the control module, thereby forming three paths in three states. In the first path, the first positive switching resistor and the first negative switching resistor are not connected; in the second path, the first positive switching resistor is connected between the positive pole of the battery pack and the reference port; in the third path, the first negative switching resistor is connected between the negative pole of the battery pack and the reference port. In addition, in order to improve the accuracy, the detection module determines the first range to be used in the calculation of the first path, the second range to be used in the second path, and the third range to be used in the third path. The control module calculates the first voltage across the battery pack in the first path under the first range, the second voltage across the first positive switching resistor in the second path under the second range, and the third voltage across the first negative switching resistor in the third path under the third range; the control module is also used to: calculate the equivalent resistance between the reference port and the target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor and the resistance value of the first negative switching resistor, and then determine the leakage of the battery pack according to the resistance value of the equivalent resistance. Therefore, the detection device can realize automatic detection of the leakage of the battery pack without manual intervention, without affecting the normal working condition of the battery pack in use, and can timely discover the potential leakage risk of the battery pack and trigger an alarm, thereby improving the safety and reliability of the battery pack and ensuring the safe operation of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings introduced below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic diagram of the structure of a battery leakage detection system provided in one embodiment of the present application;

[0017] Figure 2 A schematic diagram of the structure of a battery pack leakage detection device provided in one embodiment of the present application;

[0018] Figure 3 A circuit diagram of a switching module provided in one embodiment of the present application;

[0019] Figure 4 A circuit diagram of a battery leakage detection device provided in one embodiment of the present application;

[0020] Figure 5 A circuit diagram for selecting a first path provided in an embodiment of the present application;

[0021] Figure 6 A circuit diagram for selecting a second path provided in an embodiment of the present application;

[0022] Figure 7 A circuit diagram for selecting a third path provided in one embodiment of the present application;

[0023] Figure 8 A circuit diagram of a detection module provided in one embodiment of the present application;

[0024] Fig. 9 A circuit diagram of a complete battery detection device provided in one embodiment of the present application;

[0025] Fig.10 A flow chart of a method for detecting battery leakage provided in one embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0027] (1) Switching resistor: a resistor used to realize the switching function. The switching function of the resistor refers to the resistor being connected to the brake unit and short-circuited from the brake unit.

[0028] (2) Computer room level: The ABCD classification standard for computer room levels is mainly based on factors such as the reliability, security, and facility configuration of the computer room. Computer rooms of different levels are suitable for different business scenarios and needs. When selecting a computer room, you should make a reasonable choice based on actual business needs and budget. Generally, a Class D computer room is the lowest level of computer room, with the following characteristics:

[0029] Facility requirements: Usually there is only a single power supply, and there may be no uninterruptible power supply or system (Uninterruptible Power Supply, UPS) to provide uninterruptible power supply.

[0030] Security: Basic security management system, which may only have a simple monitoring system.

[0031] Reliability: The average annual failure time may exceed 8 hours, and the system availability is low.

[0032] Application scenarios: Suitable for small businesses, offices and other places with low requirements for data security.

[0033] As an important device for energy storage and supply, the safety of battery packs is of vital importance. Battery leakage is one of the common faults of battery packs. Battery leakage refers to the leakage of electrolyte or other chemicals inside the battery from the battery shell. If not discovered and handled in time, it may cause serious safety accidents such as short circuit, fire, or even explosion.

[0034] At present, most battery products on the market contain liquid electrolytes. Battery leakage is usually caused by the following reasons: manufacturing defects during the production and use of battery products, external extrusion and collision, overcharging, over-discharging, long-term use, long-term low-current discharge, electrolyte decomposition, etc. These factors can easily cause the electrolyte inside the battery to leak.

[0035] Battery leakage may cause the following hazards:

[0036] Equipment damage: Battery leakage may corrode the battery casing and surrounding electronic equipment, causing equipment damage or functional failure; Safety hazards: Battery leakage may cause serious safety accidents such as fire and explosion, posing a threat to personnel and equipment; Environmental pollution: Chemical substances in battery leakage may pollute the environment and ecosystem, affecting the ecological balance and human health.

[0037] Given the prevalence and harmfulness of battery leakage, it is of great significance to conduct leakage detection on battery packs. Through timely leakage detection, potential problems in the battery pack can be discovered and dealt with in a timely manner, thereby avoiding equipment damage, safety hazards and environmental pollution. In addition, battery pack leakage detection can also improve battery reliability and service life, reduce maintenance costs, and improve the overall performance of the equipment.

[0038] A large number of lead-acid batteries are installed as backup power sources in communication rooms and data center production sites, and the energy storage industry uses lithium batteries as the main storage medium. In the field of communication, battery safety inspections mainly rely on manual on-site inspections, especially in Class D rooms. Due to the long inspection cycle and even inadequate inspections, coupled with the hidden nature of battery leakage, it is difficult to detect and troubleshoot hidden dangers in a timely manner. In the energy storage industry, most lithium battery packs install the cells in a relatively closed PACK space, and the inspection work after battery leakage is also difficult.

[0039] To this end, the present application provides a detection device, equipment and method for detecting battery pack leakage. In the present application, the plane formed by the peripheral metal parts (battery rack, battery cabinet or battery PACK box metal shell) used to install the battery pack is called the neutral ground reference plane (hereinafter referred to as the reference plane), and the impedance between the target detection point (any position on any single cell in the battery pack) and the reference plane is called the equivalent resistance RL. The detection device is connected to the positive and negative poles of the battery pack and the reference port (a contact point on the reference plane) through three detection cables, that is, the detection device only needs to be connected in parallel to the busbars of the positive and negative poles of the battery pack, without adding an external power supply and anti-reverse diodes. In this way, the equivalent resistance between the reference port and the detection point is calculated. If the equivalent resistance is less than the set resistance threshold, the target detection point leakage can be determined. In this way, without affecting the normal use of the battery pack, the potential leakage risk of the battery pack can be discovered in time and an alarm can be triggered to ensure the safe operation of the battery pack.

[0040] After introducing the design ideas of the embodiments of the present application, the following briefly introduces the application scenarios to which the technical solutions of the embodiments of the present application can be applied. It should be noted that the application scenarios introduced below are only used to illustrate the embodiments of the present application and are not limited. In specific implementation, the technical solutions provided by the embodiments of the present application can be flexibly applied according to actual needs.

[0041] refer to Figure 1 , which is a structural schematic diagram of a battery leakage detection system provided in an embodiment of the present application, the system includes a detection device, a battery pack (including n single cells) and peripheral metal parts (battery rack, battery cabinet or battery PACK box metal shell, here taking the battery cabinet as an example). Figure 1 The reference port and the target detection point (suspected battery leakage point) are shown in FIG.

[0042] Of course, the method provided in the embodiment of the present application is not limited to Figure 1 The application scenarios shown can also be used in other possible application scenarios, and the embodiments of the present application are not limited thereto. Figure 1 The functions that can be implemented by each device in the application scenario shown will be described in the subsequent method embodiments, and will not be described in detail here.

[0043] To further illustrate the technical solution provided by the embodiment of the present application, this is described in detail below in conjunction with the accompanying drawings and specific implementation methods. Although the embodiment of the present application provides the method operation steps shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative labor. In the steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiment of the present application.

[0044] Combine the following Figure 1 The application scenario shown illustrates the technical solution provided by the embodiment of the present application.

[0045] refer to Figure 2 The embodiment of the present application provides a battery pack leakage detection device, comprising a control module 21, a detection module 22 and a switching module 23. The switching module 23 is connected to the battery pack to be detected, and the detection module 21 is connected to the switching module 23 and the control module 21.

[0046] Optionally, the first input terminal of the switching module 23 is connected to the positive electrode V+ of the battery pack; the second input terminal of the switching module 23 is connected to the negative electrode V- of the battery pack; and the third input terminal of the switching module 23 is connected to the reference port PE. The first output terminal of the switching module 23 is connected to the first input terminal VS+ of the detection module 22, and the first output terminal of the switching module 23 is connected to the second input terminal VS- of the detection module 22. The output terminal Vo_AD of the detection module 22 is connected to the input terminal of the control module 21, and the control terminals S0 and S1 of the detection module 22 are connected to the signal output terminal of the control module 21.

[0047] In order to adapt to the detection requirements of battery packs with different voltages, the switching module 23 includes M positive switching resistors and M negative switching resistors. Figure 3 A circuit diagram of a switching module provided in an embodiment of the present application, in this example, M is 4, and the switching switches K1, K2, K7, K8, K9, K10, K11, K12, K13, and K14 are controlled by the control module 21. Any one of the four groups of positive switching resistors and negative switching resistors can be selected to be connected to the detection module 22. At the same time, one positive switching resistor and one negative switching resistor are allowed to be put into use. In the embodiment of the present application, the positive switching resistor put into use at the current moment is called the first positive switching resistor (the switching switch matched by it is K1), and the negative switching resistor put into use at the current moment is called the first negative switching resistor (the switching switch matched by it is K2). The four groups of switching resistors use high-precision resistance values, and the resistance values ​​use step differences to meet the adaptive detection requirements of different battery pack voltages.

[0048] In the embodiment of the present application, the control module 21 controls the corresponding switching switch to select the corresponding best matching switching resistor to meet the application requirements of different battery pack voltages. This can be used to improve the detection accuracy and sensitivity of battery leakage and also increase the adaptability of the detection device to application scenarios.

[0049] The switching module 23 further includes a third switch K3, a fourth switch K4, a fifth switch K5 and a sixth switch K6, and is used to control the first path, the second path or the third path to be turned on according to a first signal from the control module 21. The first signal here can be a signal for controlling the switch to be turned on or off.

[0050] Figure 4 A circuit diagram of a battery leakage detection device provided in an embodiment of the present application, wherein the states of each switch are disconnected, and the Figure 4 To illustrate the connection relationship between each switch. Figure 4 The battery pack in is represented by four single resistors (BT1, BT2, BT3, BT4).

[0051] Among them, the first end of the third switch K3 is connected to the first end of the first switch K1, the second end of the third switch K3 is connected to the first end of the fourth switch K4, the second end of the first switch K1 is connected to the first end of the first positive switching resistor RP1; the second end of the fourth switch K4 is connected to the second end of the first positive switching resistor RP1; the first end of the fifth switch K5 is connected to the second end of the fourth switch K4 and the first end of the first negative switching resistor RN1, the second end of the fifth switch K5 is connected to the first end of the sixth switch K6, and the second end of the first negative switching resistor RN1 is connected to the second end of the sixth switch K6; the first end of the first switch K1 is the first input end of the switching module 23; the second end of the second switch K2 is the second input end of the switching module 23; the second end of the first positive switching resistor RP1 is the third input end of the switching module 23.

[0052] Optionally, the control module 21 can control the opening and closing of the first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5 and the sixth switch K6 in the switching module 23, thereby realizing three different states of the electric measuring device, each state being called a path. Next, the three states corresponding to the three paths are described.

[0053] Optionally, in the first path, the first positive switching resistor RP1 and the first negative switching resistor RN1 are not connected.

[0054] Figure 5 A circuit diagram for selecting a first path provided in an embodiment of the present application is shown in FIG. Figure 5In the first path, the control module 21 controls the third switch K3 and the sixth switch K6 to be closed, and the first switch K1, the second switch K2, the fourth switch K4 and the fifth switch K5 to be opened. At this time, VS+ and the positive electrode voltage V+ of the battery pack are at the same potential, and VS- and the negative electrode voltage V- of the battery pack are at the same potential. Therefore, the first voltage Vbus at both ends of the battery pack is the voltage difference between the voltage VS+ of the first output end of the switching module 23 and the voltage VS- of the second output end of the switching module 23 in the first path.

[0055] That is to say, through Figure 5 A first voltage Vbus across the battery pack may be calculated.

[0056] Optionally, in the second path, the control module 21 controls the first switch K1 to close, so that the first forward switching resistor RP1 is connected between the positive electrode V+ of the battery pack and the reference port PE.

[0057] Figure 6 A circuit diagram for selecting a second path provided in an embodiment of the present application is shown in FIG. Figure 6 In the second path, the control module 21 controls the third switch K3 and the fifth switch K5 to close, and the second switch K2, the fourth switch K4 and the sixth switch K6 to open. At this time, VS+ and the reference plane PE are at the same potential, and VS- and the reference plane PE are at the same potential. Therefore, the second voltage Vrp across the first positive switching resistor RP1 is the voltage difference between the voltage VS+ at the first output end of the switching module 23 and the voltage VS- at the second output end of the switching module 23 in the second path.

[0058] That is to say, through Figure 6 The second voltage Vrp across the first forward switching resistor RP1 can be calculated. Figure 7 It can be seen that when the first switch K1 is closed, a current loop is automatically formed between the positive electrode V+ of the battery pack -> the first forward switching resistor RP1 -> the equivalent resistor RL -> the target detection point -> the negative electrode V- of the battery pack. At this time, the voltage VP1 between the positive electrode V+ of the battery pack and the target detection point is equal to the sum of the voltage Vrp across the first forward switching resistor RP1 and the voltage Vrl across the equivalent resistor RL, that is, VP1 = Vrp + Vrl; since RP1 and RL are in a current loop at this time, the current flowing through them is the same, that is, Irp = Irl, so it can be obtained that: VP1 = Vrp + (Vrp / RP) * RL.

[0059] Optionally, in the third path, the control module 21 controls the second switch K2 to close, so that the first negative switching resistor RN1 is connected between the negative electrode V- of the battery pack and the reference port PE.

[0060] Figure 7 A circuit diagram for selecting a third path provided in an embodiment of the present application is shown in FIG. Figure 7 In the third path, the control module 21 controls the first switch K1, the third switch K3, and the fifth switch K5 to be disconnected, and the fourth switch K4 and the sixth switch K6 to be closed. At this time, VS+ is at the same potential as the reference plane PE, and VS- is at the same potential as the negative electrode VS- of the battery pack. Therefore, the third voltage Vrn across the first negative switching resistor RN1 is the voltage difference between the voltage VS+ at the first output end of the switching module 23 and the voltage VS- at the second output end of the switching module 23 in the third path.

[0061] That is to say, through Figure 7 The third voltage Vrn across the first negative switching resistor RN1 can be calculated. Figure 7 It can be seen that when the second switch K2 is closed, a current loop is automatically formed between the positive electrode V+ of the battery pack -> target detection point -> equivalent resistor RL -> first negative switching resistor RN1 -> negative electrode V- of the battery pack. At this time, the voltage VP2 between the positive electrode V+ of the battery pack and the target detection point is equal to the voltage Vbus across the battery pack minus the sum of the voltage Vrn across the first negative switching resistor RN1 and the voltage Vrl across the equivalent resistor RL, that is, VP2 = Vbus-(Vrl+Vrn); since RN and RL are in a current loop at this time, the current flowing through them is the same, that is, Irn = Irl, so it can be obtained: VP2 = Vbus-(Vrn / RN)*RL-Vrn.

[0062] Combination Figure 5-Figure 7 After calculating the first voltage Vbus across the battery pack, the second voltage Vrp across the first positive switching resistor RP1, and the third voltage Vrn across the first negative switching resistor RN1, the control module 21 can also calculate the equivalent resistance RL between the reference port and the target detection point according to the first voltage Vbus, the second voltage Vrp, the third voltage Vrn, the resistance value of the first positive switching resistor RP1, and the resistance value of the first negative switching resistor RN1.

[0063] Optionally, considering that in the embodiment of the present application, the positive switching resistor and the auxiliary switching resistor in the detection module 22 are known high-precision resistors, if the resistance values ​​of the first positive switching resistor RP1 and the first negative switching resistor RN1 are set to be the same, then RP1=RN1, and they are uniformly set to Rtq, so the following expression is obtained:

[0064] VP1=Vrp+(Vrp / Rtq)*RL; VP2=Vbus-(Vrn / Rtq)*RL-Vrn

[0065] In addition, since the target detection point is the same in the above three states, the voltage between the positive electrode V+ of the battery pack and the target detection point is the same in the two switching controls, that is, VP1 = VP2, so the following expression is obtained:

[0066] Vrp+(Vrp / Rtq)*RL=Vbus-(Vrn / Rtq)*RL-Vrn.

[0067] Therefore, it can be concluded that: RL = (Vbus-Vrp-Vrn)*Rtq / (Vrp+Vrn).

[0068] If the equivalent resistance is less than the set resistance threshold, it is determined that the battery pack has leakage.

[0069] In the above embodiment, a forward current loop is formed by controlling the first positive switching resistor to switch in, and a reverse current loop is formed by controlling the first negative switching resistor to switch in. By collecting and calculating the voltage Vrp across the first positive switching resistor RP1 and the voltage Vrn across the first negative switching resistor RN1 fed back from the two switching current loops, the value of the equivalent resistor RL can be calculated.

[0070] In addition, the control module 21 can also determine the location where the leakage occurs in the battery pack. Optionally, the process can be implemented through steps A1-A4:

[0071] A1: Determine the cell voltage of each cell according to the first voltage and the number of cells included in the battery pack.

[0072] The first voltage Vbus is the voltage across the battery pack, and the number of single cells included in the battery pack is N. Therefore, the single cell voltage Vbat of each single cell is Vbus / N.

[0073] A2: Calculate the target voltage between the positive terminal of the battery pack and the target detection point.

[0074] Optionally, since the real value RL of the equivalent resistance RL has been detected, the target voltage VP1 between the positive electrode V+ of the battery pack and the target detection point can be accurately calculated by the formula VP1=Vrp+(Vrp / Rtq)*RL.

[0075] A3: Calculate the order of the target detection points among the number of single battery cells according to the target voltage and the single cell voltage.

[0076] Therefore, the battery position of the target electrical test point relative to the positive electrode of the battery pack can be calculated, that is, the order of the target test point among the number of single batteries is Ptr=VP1 / Vbat=VP1*N / Vbus; the Ptr value can be rounded to an integer.

[0077] A4: Determine the location in the battery pack where the leakage occurs based on the sequence.

[0078] For example, N is 4, and Ptr is calculated to be 1.9, then the target detection point is determined to be the second single cell.

[0079] In the embodiment of the present application, the position of the target detection point can be accurately calculated by the voltage value between the target detection point and the positive or negative electrode of the battery pack. Therefore, the leakage state of any single cell can be detected in real time, and the single cell in the battery pack where the leakage occurs can be accurately located. Real-time detection of battery pack leakage and location of the leakage point are achieved.

[0080] On the basis of the above technical scheme, considering that in the process of measuring the first voltage, the second voltage and the third voltage, the range of each voltage is different, or the voltage range of different battery packs is different, for example, 0-1500V. Therefore, in order to improve the measurement accuracy, the detection module in the embodiment of the present application provides a detection scheme for a feedback signal with an adaptive adjustment range, and the feedback signal includes a first voltage at both ends of the electronic group, a second voltage at both ends of the first positive switching resistor, and a third voltage at both ends of the first negative switching resistor. Since the voltage of different battery packs will cause a large difference in the detection range of the feedback signal, the control module controls the opening and closing of the third switch, the fourth switch, the fifth switch, and the sixth switch to freely switch the first voltage, the second voltage and the third voltage to the first input terminal and the second input terminal of the detection module. Optionally, four detection ranges can be designed, and any one of the four detection ranges can be selected by controlling the electronic switches S0 and S1 of the detection module to meet the detection requirements of the feedback signal.

[0081] In this way, when calculating the first voltage, the detection module 22 can be set to the first range; when calculating the second voltage, the detection module 22 can be set to the second range; when calculating the third voltage, the detection module 22 can be set to the third range. The setting process can be that the control module 21 generates a second signal according to the first signal, and sends the second signal to the detection module 22 so that the detection module 22 performs the setting.

[0082] Optional, Figure 8 A circuit diagram of a detection module provided in an embodiment of the present application, the setting of different ranges can be implemented by the detection module 22 in the following manner:

[0083] The detection module 22 includes a power amplifier unit, a voltage divider unit and a range control chip. The negative input end of the power amplifier unit U7 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is the first input end of the detection module 22; the positive input end of the power amplifier unit U7 is connected to the first end of the second resistor R2; the second end of the second resistor R2 is the second input end of the detection module 22; the output end of the power amplifier unit U7 is connected to the first output pin (2Z) of the range control chip; the first end of each of the at least one range resistor (R3, R4, R5, R6) of the voltage divider unit is respectively connected to at least one channel selection pin of the range control chip. The selection pins (1Y0, 1Y1, 1Y2, 1Y3, 2Y0, 2Y1, 2Y2, 2Y3) are connected; the second end of each of the at least one range resistor of the voltage divider unit is connected to the first end of the first resistor R1; the second output pin (1Z) of the range control chip is grounded through the third resistor R3 and the first capacitor C1; wherein the connection point of the third resistor R3 and the first capacitor C1 is the output end of the detection module 22; the switch pins (S0 and S1, that is, the electronic switch of the aforementioned detection module 22) of the range control chip are the control ends of the detection module 22.

[0084] In a specific example, the electronic switches S0 and S1 are controlled by the control module 21, so that the input voltage Vbus is divided by the resistor R1 and the four range resistors R2, R3, R4, and R5, thereby obtaining four output signals of different sizes. The control module 21 intelligently selects the appropriate range to check Vbus, Vrp, and Vrn by detecting the output signal, thereby ensuring that the invention can adapt to the accuracy and reliability of various battery pack voltage leakage detection.

[0085] In the above embodiment, the detection module 22 can automatically adapt to battery packs with different voltage ranges, and then automatically identify the voltage range of the feedback signal, and select different ranges to measure voltages in different situations. Therefore, the embodiment of the present application can adapt to different battery pack voltage detection scenarios.

[0086] Fig. 9 A circuit diagram of a complete battery detection device provided in an embodiment of the present application. Fig. 9 It can be seen that the embodiment of the present application uses an equivalent method to make the battery rack, battery cabinet, battery PACK box and other peripheral metal parts of the battery pack equivalent to a neutral ground reference plane and connect it to the detection device. The impedance between the target detection point and the neutral reference plane is equivalent to an unknown resistance RL, and the leakage is determined by calculating the size of the equivalent resistance and comparing it with the set resistance threshold.

[0087] In addition, the present application also provides a battery leakage detection method, which is applied to the battery leakage detection device of the above embodiment. Fig.10A flow chart of a battery leakage detection method provided in an embodiment of the present application, Fig.10 At least the following steps are included:

[0088] S101: Calculate a first voltage across the battery pack in a first path under a first range, a second voltage across the first positive switching resistor in a second path under a second range, and a third voltage across the first negative switching resistor in a third path under a third range.

[0089] S102: Calculate an equivalent resistance between a reference port and a target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor, and the resistance value of the first negative switching resistor.

[0090] The target detection point is any position on any single battery in the battery pack.

[0091] S103: If the equivalent resistance is less than the set resistance threshold, it is determined that the battery pack has leakage.

[0092] The implementation method of each step can be found in the above-mentioned embodiment and will not be repeated here.

[0093] An embodiment of the present application also provides a device, which includes the detection device of the above embodiment, a battery pack and peripheral metal parts of the battery pack; the peripheral metal parts include a battery rack, a battery cabinet or a metal shell of a battery metal PACK box.

[0094] In the embodiment of the present application, the switching control is applied to the outside of the battery pack by means of an equivalent model, so that when the battery leaks, the equivalent leakage impedance and the applied switching resistance constitute two independent current loops with opposite currents. By detecting the voltage values ​​at both ends of the positive and negative switching resistances, the size of the leakage equivalent resistance can be accurately calculated, and the severity of the battery leakage can be judged by the size of the equivalent resistance. In addition, in the embodiment of the present application, the relative voltage of the battery leakage point from the battery pack bus terminal can also be detected at the same time, so that the relative position of the leakage point can be indirectly calculated. In addition, adaptive control logic is adopted to dynamically adjust the size of the switching resistance of the detection module 22 and the detection range of the feedback signal according to the battery pack bus voltage range. The detection method involved is not limited by the battery pack voltage and can be applied to applications with different battery pack voltage specifications: such as 48V, 240V, 336V, UPS battery packs, energy storage battery packs, etc.

[0095] The above embodiments are only used to introduce the technical solutions of the present application in detail, but the description of the above embodiments is only used to help understand the methods of the embodiments of the present application and should not be understood as limiting the embodiments of the present application. Any changes or substitutions that can be easily thought of by technicians in this technical field should be included in the protection scope of the embodiments of the present application.

Claims

1. A detection device for detecting battery leakage, characterized in that: It includes a control module, a detection module and a switching module; the switching module is connected to the battery pack to be detected, and the detection module is connected to the switching module and the control module; the switching module includes M positive switching resistors and M negative switching resistors; The switching module is used to control the first path, the second path or the third path to be turned on according to the first signal from the control module; wherein, in the first path, the first positive switching resistor and the first negative switching resistor are not connected; in the second path, the first positive switching resistor is connected between the positive electrode of the battery pack and the reference port; in the third path, the first negative switching resistor is connected between the negative electrode of the battery pack and the reference port; the reference port is a contact point on the reference surface formed by the peripheral metal parts of the battery pack; the first positive switching resistor is one of the M positive switching resistors, and the first negative switching resistor is one of the M negative switching resistors; The detection module is used to determine, according to a second signal from the control module that matches the first signal, a first measurement range to be used for the first path, a second measurement range to be used for the second path, and a third measurement range to be used for the third path; The control module is used to calculate the first voltage across the battery pack in the first path in the first range, the second voltage across the first positive switching resistor in the second path in the second range, and the third voltage across the first negative switching resistor in the third path in the third range; The control module is also used to calculate the equivalent resistance between the reference port and the target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor and the resistance value of the first negative switching resistor; wherein the equivalent resistance is used to describe the leakage of the battery pack, and the target detection point is any position on any single cell in the battery pack.

2. The detection device according to claim 1, characterized in that: The first input terminal of the switching module is connected to the positive electrode of the battery pack; the second input terminal of the switching module is connected to the negative electrode of the battery pack; the third input terminal of the switching module is connected to the reference port; The first output end of the switching module is connected to the first input end of the detection module, and the first output end of the switching module is connected to the second input end of the detection module; The output end of the detection module is connected to the input end of the control module, and the control end of the detection module is connected to the signal output end of the control module.

3. The detection device according to claim 1, characterized in that: The detection module includes a power amplification unit, a voltage divider unit and a range control chip; The negative input terminal of the power amplification unit is connected to the first end of the first resistor, and the second end of the first resistor is the first input terminal of the detection module; The positive input terminal of the power amplification unit is connected to the first end of the second resistor; the second end of the second resistor is the second input terminal of the detection module; The output end of the power amplification unit is connected to the first output pin of the range control chip; The first end of each of the at least one range resistor of the voltage divider unit is respectively connected to at least one channel selection pin of the range control chip; the second end of each of the at least one range resistor of the voltage divider unit is connected to the first end of the first resistor; The second output pin of the range control chip is grounded through a third resistor and a first capacitor; wherein the connection point of the third resistor and the first capacitor is the output end of the detection module; and the switch pin of the range control chip is the control end of the detection module.

4. The detection device according to claim 1, characterized in that: The switching module also includes a first switch, a second switch, a third switch, a fourth switch, a fifth switch and a sixth switch; The first end of the third switch is connected to the first end of the first switch, the second end of the third switch is connected to the first end of the fourth switch, the second end of the first switch is connected to the first end of the first positive switching resistor; the second end of the fourth switch is connected to the second end of the first positive switching resistor; The first end of the fifth switch is connected to the second end of the fourth switch and the first end of the first negative switching resistor, the second end of the fifth switch is connected to the first end of the sixth switch, and the second end of the first negative switching resistor is connected to the second end of the sixth switch; The first end of the first switch is the first input end of the switching module; The second end of the second switch is the second input end of the switching module; The second end of the first positive switching resistor is the third input end of the switching module.

5. The detection device according to claim 4, characterized in that: In the first path, the third switch and the sixth switch are closed, and the first switch, the second switch, the fourth switch and the fifth switch are opened; The first voltage is a voltage difference between a voltage at a first output end of the switching module and a voltage at a second output end of the switching module in the first path.

6. The detection device according to claim 4, characterized in that: In the second path, the first switch, the third switch, and the fifth switch are closed, and the second switch, the fourth switch, and the sixth switch are opened; The second voltage is a voltage difference between a voltage at a first output end of the switching module and a voltage at a second output end of the switching module in the second path.

7. The detection device according to claim 4, characterized in that: In the third path, the first switch, the third switch, and the fifth switch are opened, and the second switch, the fourth switch, and the sixth switch are closed; The third voltage is a voltage difference between a voltage at the first output end of the switching module and a voltage at the second output end of the switching module in the third path.

8. A device, characterized in that It comprises the detection device as claimed in any one of claims 1 to 7, the battery pack and the peripheral metal parts of the battery pack; the peripheral metal parts include the metal shell of a battery rack, a battery cabinet or a battery PACK box.

9. A method for detecting battery leakage, characterized in that: Using the detection device according to any one of claims 1 to 7, the method comprises: Calculate a first voltage across the battery pack in the first path in a first range, a second voltage across the first positive switching resistor in the second path in a second range, and a third voltage across the first negative switching resistor in the third path in a third range; Calculate the equivalent resistance between the reference port and a target detection point according to the first voltage, the second voltage, the third voltage, the resistance value of the first positive switching resistor, and the resistance value of the first negative switching resistor; wherein the target detection point is any position on any single battery in the battery pack; If the equivalent resistance is less than the set resistance threshold, it is determined that the battery pack has leakage.

10. The detection method according to claim 9, characterized in that: The method further comprises: Determine a cell voltage of each cell according to the first voltage and the number of cells included in the battery pack; Calculating a target voltage between the positive electrode of the battery pack and the target detection point; Calculating the order of the target detection points among the number of the single battery cells according to the target voltage and the single battery voltage; The location where the leakage occurs in the battery pack is determined according to the sequence.

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