Battery pack charging and discharging regulation device and method

Abstract

The application relates to the technical field of battery packs, and particularly discloses a charging and discharging regulation and control device and method for a battery pack. The device comprises a temperature detection element, a correction module and a control module, the temperature detection element is arranged at a preset position of the battery pack through a heat conductor; the correction module is connected with the temperature detection element and is used for correcting detection data of the temperature detection element to obtain correction data; the control module is connected with the correction module and is used for determining the temperature of the battery pack according to the correction data and regulating and controlling the charging and discharging process of the battery pack according to the temperature of the battery pack. The detection data of the temperature detection element is corrected through the correction module, and then the real temperature of the battery pack can be obtained according to the corrected data, so that the charging and discharging process of the battery pack can be regulated and controlled according to the real temperature of the battery pack in a timely manner, and the situation that the regulation and control is failed due to inaccurate temperature measurement of the battery pack can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery pack, in particular to a battery pack charging and discharging regulation device and method. BACKGROUND

[0002] With the development of energy storage technology, battery pack emerges as the times require. The battery pack is to encapsulate multiple batteries together, and through the combination of series or parallel connection of a plurality of batteries, the output voltage of different requirements is realized. In the use process of the battery, a series of safety hazards will be caused due to the temperature being too high. If the working process of the battery pack cannot be regulated in time when the temperature is too high, safety accidents are prone to occur.

[0003] The traditional way is to set a heat conduction element on the surface of the battery pack, and measure the temperature of the heat conduction element through the temperature sensing element, and then take the temperature of the heat conduction element as the temperature of the battery pack. However, there is a large deviation between the temperature of the heat conduction element and the actual temperature of the battery pack, which leads to the inaccuracy of the collected temperature of the battery pack, and further affects the regulation process. SUMMARY

[0004] Therefore, in view of the above problems, the present application provides a battery pack charging and discharging regulation device and method.

[0005] A battery pack charging and discharging regulation device, the battery pack is connected to an external device, the battery pack is discharged to the external device or charged through the external device, and the charging and discharging regulation device is used to regulate the charging and discharging process of the battery pack; the charging and discharging regulation device comprises:

[0006] A temperature detection element is arranged at a predetermined position of the battery pack through a heat conductor;

[0007] A correction module is connected to the temperature detection element, and is used to correct the detection data of the temperature detection element to obtain correction data;

[0008] A control module is connected to the correction module, and is used to determine the temperature of the battery pack according to the correction data, and regulate the charging and discharging process of the battery pack according to the temperature of the battery pack.

[0009] In one embodiment, the correction module comprises a correction element, the correction element is connected in series in the charging and discharging circuit of the battery pack and the external device, one end of the correction element is grounded, and the other end is connected to the negative electrode of the battery pack.

[0010] In one of the embodiments, the temperature detecting element comprises a thermistor, the correction element comprises a linear resistor, the control module collects the current value on the charging and discharging circuit of the battery pack and the external device to obtain the voltage across the correction element, and corrects the voltage at the first end of the thermistor according to the voltage across the correction element, and then determines the temperature of the battery pack according to the voltage at the first end of the thermistor after correction.

[0011] In one of the embodiments, the correction module and the control module are arranged in the external device.

[0012] In one of the embodiments, the correction module and the control module are arranged in the battery pack.

[0013] The correction module is configured to determine a first temperature variation parameter corresponding to the temperature detecting element according to the detection data of the temperature detecting element, determine a temperature variation parameter difference between the first temperature variation parameter and a second temperature variation parameter corresponding to the battery pack according to the first temperature variation parameter and a preset mapping relationship, determine a temperature difference between the battery pack and the detection data of the temperature detecting element according to the temperature variation parameter difference and a preset relationship, and correct the detection data according to the temperature difference.

[0014] In one of the embodiments, the battery pack comprises a shell, the shell comprises at least one battery cell, the preset position of the battery pack is the surface of the battery cell or any position of the shell, and the temperature of the battery pack comprises the temperature of the battery cell or the temperature of the shell.

[0015] A charging and discharging regulation method of a battery pack, the battery pack is connected to an external device, the battery pack is discharged to the external device or charged by the external device, and a temperature detecting element is arranged at a preset position of the battery pack; the charging and discharging regulation method comprises:

[0016] obtaining detection data of the temperature detecting element;

[0017] correcting the detection data to obtain corrected data;

[0018] determining the temperature of the battery pack according to the corrected data, and regulating the charging and discharging process of the battery pack according to the temperature of the battery pack.

[0019] In one of the embodiments, the step of correcting the detection data to obtain corrected data comprises:

[0020] determining a first temperature variation parameter corresponding to the temperature detecting element according to the detection data;

[0021] determine a temperature variation parameter difference between the first temperature variation parameter and a second temperature variation parameter corresponding to the battery pack according to the first temperature variation parameter and a preset mapping relationship, the preset mapping relationship representing a corresponding relationship between the first temperature variation parameter and the temperature variation parameter difference;

[0022] determine a temperature difference between a temperature of the battery pack and the temperature detection element detection data according to the temperature variation parameter difference and a preset relationship, the preset relationship representing a corresponding relationship between the temperature variation parameter difference and the temperature difference;

[0023] correct the detection data according to the temperature difference.

[0024] In one of the embodiments, the step of obtaining the temperature detection element detection data comprises:

[0025] sampling a plurality of temperature detection element detection data according to a preset time interval;

[0026] The step of determining the first temperature variation parameter corresponding to the temperature detection element according to the detection data comprises:

[0027] determining the first temperature variation parameter of the temperature detection element in a time interval according to the temperature detection element detection data sampled at a current sampling time and a previous sampling time and the time interval.

[0028] In one of the embodiments, before the step of determining the first temperature variation parameter corresponding to the temperature detection element according to the detection data, the charging and discharging regulation method comprises:

[0029] setting a plurality of reference temperatures;

[0030] when the detection data reaches any of the reference temperatures, obtaining a time interval between a current sampling time and a previous sampling time, the previous sampling time being a time when the temperature detection element detection data reaches a previous reference temperature;

[0031] The step of determining the first temperature variation parameter corresponding to the temperature detection element according to the detection data comprises:

[0032] determining the first temperature variation parameter of the temperature detection element in a time interval according to a current reference temperature, a previous reference temperature and a time interval between a current sampling time and a previous sampling time.

[0033] In one of the embodiments, before the step of determining a temperature variation parameter difference between the first temperature variation parameter and a second temperature variation parameter corresponding to the battery pack according to the first temperature variation parameter and a preset mapping relationship, the method further comprises:

[0034] obtaining a discharge current of the battery pack;

[0035] determining a preset mapping relationship between the first temperature variation parameter and the temperature variation parameter difference according to the discharge current.

[0036] In one embodiment, in the step of determining the temperature difference between the temperature of the battery pack and the temperature detection element detection data according to the temperature variation parameter difference and a preset relationship, the preset relationship is:

[0037] ΔT n = (t n -t n-1 )*ΔK n +ΔT n-1

[0038] wherein, ΔT n is the temperature difference between the temperature of the battery pack and the temperature detection element detection data at the nth sampling moment, t n is the nth sampling moment, t n-1 is the (n-1)th sampling moment, ΔK n is the temperature variation parameter difference between the battery pack and the temperature detection element at the nth sampling moment, ΔT n-1 is the temperature difference between the battery pack and the temperature detection element at the (n-1)th sampling moment.

[0039] In one embodiment, the first temperature variation parameter is the temperature variation slope of the temperature detection element, and the second temperature variation parameter is the temperature variation slope of the battery pack.

[0040] In one embodiment, the step of determining the temperature of the battery pack according to the correction data and regulating the charging and discharging process of the battery pack according to the temperature of the battery pack comprises:

[0041] judging whether the temperature of the battery pack is out of a preset range;

[0042] if the temperature of the battery pack is out of the preset range, stopping the charging and discharging of the battery pack.

[0043] The charging and discharging regulation device of the battery pack is used for regulating the charging and discharging process of the battery pack, and comprises a temperature detection element, a correction module and a control module. The temperature detection element is arranged at a preset position of the battery pack through a heat conductor. The correction module corrects the detection data output by the temperature detection element to obtain correction data. The control module determines the temperature of the battery pack according to the correction data, and regulates the charging and discharging process of the battery pack according to the temperature of the battery pack. That is, the correction module is arranged, the detection data of the temperature detection element is corrected through the correction module, and then the real temperature of the battery pack can be obtained according to the corrected data. Therefore, the charging and discharging process of the battery pack can be regulated in time according to the real temperature of the battery pack, and the regulation failure caused by inaccurate temperature measurement of the battery pack can be avoided. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 A schematic diagram of the connection of the charger and the battery pack is shown in FIG. 1.

[0045] Figure 2 A schematic diagram of the external device as the power tool is shown in FIG. 2.

[0046] Figure 3 A schematic diagram of the charging and discharging regulation device of the battery pack provided by the embodiment one of the application is shown in FIG. 3.

[0047] Figure 4 And 5 A schematic diagram of the assembly of the temperature detection element is shown in FIG. 4.

[0048] Figure 6 A schematic diagram of one embodiment of the correction module in the charging and discharging regulation device of the battery pack provided by the embodiment one of the application is shown in FIG. 5.

[0049] Figure 7 A specific example diagram of the correction module in the charging and discharging regulation device of the battery pack provided by the embodiment one of the application is shown in FIG. 6.

[0050] Figure 8 A flowchart of the charging and discharging regulation method of the battery pack provided by the embodiment two of the application is shown in FIG. 7.

[0051] Figure 9 A flowchart of step S200 in the charging and discharging regulation method of the battery pack provided by the embodiment two of the application is shown in FIG. 8.

[0052] BRIEF DESCRIPTION OF DRAWINGS

[0053] 100, battery pack; 111, end cover; 112, wrapping support; 113, accommodating cavity; 120, battery cell; 130, heat conductor; 200, external device; 300, temperature detection element; 400, correction module; 410, sampling unit; 420, correction element; 500, control module. DETAILED DESCRIPTION

[0054] For the purpose of clarity, the present application will be described in greater detail below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0055] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0056] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0058] In order to enable the direct current power tool to achieve the large power of the traditional gasoline or AC power supply, a plurality of lithium battery elements are currently combined to form a lithium battery pack, and the lithium battery pack is used to supply power to the power tool. For example, the lithium battery pack is internally provided with a plurality of lithium batteries in parallel, the capacity of which is greater than or equal to 2AH, and the voltage is nominally 4V. The lithium batteries are connected in series by 15 series, so that the battery pack has a nominal voltage of 60V and an electric quantity greater than or equal to 120WH. In addition, the charger can also charge the lithium battery pack.

[0059] When the battery pack is in the process of charging or discharging, the temperature of the battery pack will change, and if it is not regulated in time when its temperature exceeds the safe range, it will often bring a series of safety hazards. Among them, the detection result of the temperature of the battery pack is more critical, if the detected temperature of the battery pack is not accurate, it will affect the timeliness of the regulation. At present, the main way to detect the temperature of the battery pack is to measure the temperature of the battery pack through the temperature sensing element. In actual application, due to the shape limitation of the battery pack and the temperature sensing element, the temperature sensing element cannot completely adhere to the battery, and the contact area with the battery pack is small, so that the heat of the battery pack cannot be conducted to the temperature sensing element in time. Therefore, a heat conducting element, such as heat conducting glue, is usually coated on the surface of the battery pack, and the temperature sensing element is wrapped in the heat conducting element to indirectly realize the measurement of the temperature of the battery pack by the temperature sensing element. However, there is a deviation between the temperature of the heat conducting element and the actual temperature of the battery pack. For example, the heat conducting glue, due to the influence of the characteristics (thermal conductivity, thermal resistance, viscosity, etc.) of the heat conducting glue, actual test shows that when the battery pack generates a lot of heat within a certain period of time, the temperature rise of the heat conducting glue lags behind the actual temperature rise of the battery pack, which causes the temperature detected by the temperature sensing element to be less than the actual temperature of the battery pack.

[0060] In order to obtain the actual temperature of the battery pack, the following two schemes are currently mainly included: (1) coating a heat conducting element with high thermal conductivity on the surface of the battery pack, increasing the heat conducting power of the heat conducting element, reducing the thermal resistance of the heat conducting glue, increasing the adhesion of the heat conducting element and the battery surface, etc.; (2) reducing the discharge power of the battery pack to slow down the temperature rise of the battery. However, the above two schemes have defects, in the first scheme, the cost of the heat conducting element is often increased, and the temperature lag problem still exists, which cannot completely solve the problem of inaccurate temperature detection; in the second scheme, reducing the discharge power of the battery pack will cause the user experience to be poor, and will affect the normal and efficient use of the battery pack.

[0061] Based on the above problems, the present application provides a battery pack charging and discharging regulation device and a charging and discharging regulation method for regulating the charging and discharging process of the battery pack.

[0062] Embodiment one

[0063] The present embodiment provides a battery pack 100 charging and discharging regulation device, referring to Figure 1 and 2 The battery pack 100 is connected to the external device 200, and the battery pack 100 is discharged to the external device 200 or charged through the external device 200, and the charging and discharging regulation device is used for regulating the charging and discharging process of the battery pack 100.

[0064] Referring to Figure 3The charging and discharging regulation device provided by the embodiment comprises a temperature detection element 300, a correction module 400 and a control module 500. The temperature detection element 300 is arranged at a preset position of the battery pack 100 through a heat conductor 130. The correction module 400 is connected to the temperature detection element 300 and is used for correcting the detection data of the temperature detection element 300 to obtain corrected data. The control module 500 is connected to the correction module 400 and is used for determining the temperature of the battery pack 100 according to the corrected data and regulating the charging and discharging process of the battery pack 100 according to the temperature of the battery pack 100.

[0065] The charging and discharging regulation device of the battery pack 100 is arranged at a preset position of the battery pack 100 through a heat conductor 130. The correction module 400 corrects the detection data output by the temperature detection element 300 to obtain corrected data. The control module 500 determines the temperature of the battery pack 100 according to the corrected data and regulates the charging and discharging process of the battery pack 100 according to the temperature of the battery pack 100. That is, the correction module 400 is arranged to correct the detection data of the temperature detection element 300, and the real temperature of the battery pack 100 can be obtained according to the corrected data. Therefore, the charging and discharging process of the battery pack 100 can be regulated according to the real temperature of the battery pack 100 in time, and the situation that the regulation fails due to the failure to detect the real temperature of the battery pack 100 can be avoided.

[0066] In the embodiment, the external device 200 can comprise any one of a power tool and a charger. When the external device 200 is a power tool, the battery pack 100 supplies power to the power tool, the battery pack 100 discharges, Figure 2 for a grass trimmer, the battery pack 100 can be connected to the grass trimmer through an electrode seat, and the battery pack 100 supplies power to the grass trimmer; when the external device 200 is a charger, the charger supplies power to the battery pack 100, and the battery pack 100 charges, Figure 1 for a charger, the battery pack 100 can be connected to the charger through an electrode seat. The charging regulation device is used for regulating the charging process or the discharging process of the battery pack 100.

[0067] In one of the embodiments, the battery pack 100 comprises a shell, the shell comprises at least one battery cell 120, the preset position of the battery pack 100 is any position of the surface of the battery cell 120 or the shell, and the temperature of the battery pack 100 comprises the temperature of the battery cell 120 or the temperature of the shell.

[0068] Specifically, the shell can include a plurality of battery cells 120 assembled in a whole by means of series connection and / or parallel connection. The heat conductor 130 can be coated on the surface of the battery cell 120, and the shell at the position of the heat conductor 130 has a through hole communicating the inside and the outside, and the temperature detecting element 300 extends to the heat conductor 130 through the through hole and is wrapped in the heat conductor 130. The heat conductor 130 can also be coated at any position on the surface of the shell, and the temperature detecting element 300 is wrapped in the heat conductor 130.

[0069] In one embodiment, referring to Figure 4 and 5 , the shell can include an end cap 111 and a wrapping support 112, and the battery cell 120 is arranged in the internal space formed by the end cap 111 and the wrapping support 112. Meanwhile, the joint of the end cap 111 and the wrapping support 112 has a receiving cavity 113 capable of communicating with the outside and the battery cell 120, and the receiving cavity 113 has the heat conductor 130 coated on the surface of the battery cell 120, and the temperature detecting element 300 extends into the receiving cavity 113 and is wrapped in the heat conductor 130. The heat conductor 130 and the temperature detecting element 300 can also be located on the surface of the wrapping support 112 or the end cap 111.

[0070] The heat conductor 130 can be a conventional and relatively economical heat-conducting glue in the art, and does not need to be invested in a large cost; and the temperature detecting element 300 can be an electronic component with a negative temperature coefficient (NTC, Negative Temperature Coefficient), i.e., an electronic component whose resistance decreases exponentially with the increase of temperature, such as a thermistor.

[0071] Since the temperature detected by the temperature detecting element 300 deviates from the actual temperature of the battery pack 100, the detection data of the temperature detecting element 300 is corrected by the correction module 400, and then the actual temperature of the battery pack 100 is determined based on the corrected result.

[0072] In one embodiment, referring to Figure 6 , the correction module 400 includes a correction element 420 connected in series in the charge-discharge circuit of the battery pack 100 and the external device 200, one end of the correction element 420 is grounded, and the other end is connected to the negative electrode of the battery pack 100.

[0073] Taking the electric tool as an example, in actual application, the battery pack 100 is used to supply power for the electric tool, when the electric tool works, the current flows out from the positive pole of the battery pack 100, passes through the load device and the correction element 420 in the electric tool, and then flows into the negative pole of the battery pack 100. The temperature detection element 300 is attached to the preset position of the battery pack 100 through the heat conductor 130, and is connected with the control module 500, and a sampling unit 410 connected to the power supply end is connected between the control module 500 and the temperature detection element 300. The control module 500 is used to collect the voltage of one end of the sampling unit 410 connected with the temperature detection element 300 (i.e. the first end of the temperature detection element 300), and then the resistance value of the temperature detection element 300 can be obtained. Since the temperature detection element 300 can be an electronic component with a negative temperature coefficient, the corresponding temperature value can be determined according to the resistance value of the temperature detection element 300, i.e. the temperature of the battery pack 100.

[0074] The above is the general process of determining the temperature of the battery pack 100. Since there is a deviation between the temperature measured by the temperature detection element 300 and the actual temperature of the battery pack 100, when the battery pack 100 charges the electric tool, the actual temperature of the battery pack 100 is generally greater than the temperature measured by the temperature detection element 300, i.e. the temperature value finally determined by the control module 500 is less than the actual temperature of the battery pack 100. Based on this, the embodiment sets the correction element 420 on the loop formed by the battery pack 100 and the electric tool, so as to increase the resistance on the loop. When the battery pack 100 charges the electric tool, with the increase of the current on the loop, the voltage across the correction element 420 increases, the voltage at the first end of the sampling unit 410 decreases, i.e. the resistance value of the temperature detection element 300 decreases, and the temperature value increases. That is, after setting the correction element 420, the temperature value finally determined by the control module 500 is greater than the temperature value determined when the correction element 420 is not set. Thus, the deviation between the temperature detection element 300 and the actual temperature of the battery can be offset, the problem of temperature rise lag can be solved, and the finally determined temperature value is closer to the actual temperature of the battery pack 100.

[0075] In one of the embodiments, the sampling unit 410 includes a sampling resistor, the correction element 420 includes a linear resistor, and the temperature detection element 300 includes a thermistor. The control module 500 collects the current value on the charge-discharge loop of the battery pack 100 and the external device 200 to obtain the voltage across the correction element 420, and corrects the voltage at the first end of the thermistor according to the voltage across the correction element 420, and then determines the temperature of the battery pack 100 according to the voltage at the first end of the corrected thermistor.

[0076] The following is described with a specific example:

[0077] Figure 7The left side of the middle is the battery pack 100PACK, and the right side is the electric tool TOOL. When the electric tool works, the current flows out from the total positive (P+) of the battery pack 100, passes through the load device M and the linear resistor R3, and then flows into the total negative (P-) of the battery pack 100. The thermistor T1 is attached to the surface of the battery cell 120 in the battery pack 100 through the heat-conducting glue. The sampling resistor R2 is pulled up to the power supply end VCC in the electric tool, the sampling resistor R2 is connected with the thermistor T1, and the node is point A. The control module 500MCU in the electric tool collects the voltage of point A, determines the resistance value of the thermistor T1, and then converts the temperature of the battery.

[0078] The conventional detection method of the battery pack temperature is that the control module detects the upper end voltage of the thermistor T1. When the linear resistor R3 is not set, Vcc takes point B as the reference ground, With the increase of the battery temperature, the resistance value RT1 of the thermistor decreases, and there is a temperature rise lag phenomenon due to the influence of the heat-conducting glue, that is, the battery pack temperature finally determined by the control module is less than the actual battery pack temperature.

[0079] In the present application, the temperature rise lag problem can be compensated by the linear resistor R3 connected in series in the loop. Specifically, referring to Figure 7 , Vcc takes point C as the reference ground, and the potential of the upper end A of the thermistor T1 is Wherein, I is the discharge current in the charging and discharging loop. As can be seen from the formula, when the battery discharge current increases, the voltage across the linear resistor R3 increases, and the voltage of point A decreases. Since the upper end voltage of the thermistor T1 is positively correlated with the resistance value and negatively correlated with the temperature, the detected temperature value is greater than the temperature value measured by the conventional method, and is closer to the actual battery pack temperature, thereby offsetting the deviation between the thermistor T1 and the actual temperature of the battery. That is, in this specific example, the purpose of temperature compensation is achieved by setting the linear resistor R3 in the loop.

[0080] When the control module 500 determines the actual temperature of the battery pack 100, it can be judged whether the actual temperature of the battery pack 100 exceeds the safe temperature range. If it exceeds, the charging and discharging process of the battery pack 100 is stopped.

[0081] In one embodiment, the correction module 400 and the control module 500 are arranged in the external device 200. For example, the sampling unit 410, the correction element 420 and the control module 500 are arranged in the electric tool. When the control module 500 judges that the actual temperature of the battery pack 100 exceeds the safe temperature range, the operation of the load device in the electric tool is stopped, or a stop charging and discharging command is sent to the battery pack 100 to stop the charging and discharging work of the battery pack 100. The above can achieve the purpose of regulating and controlling the charging and discharging process of the battery pack 100.

[0082] The above is a correction of the battery pack 100 temperature by hardware. In another embodiment, the battery pack 100 temperature can also be corrected by an internal program.

[0083] The correction module 400 and the control module 500 can be disposed in the battery pack 100. The correction module 400 can be a battery management system (BMS) in the battery pack 100.

[0084] The correction module 400 is configured to determine a first temperature change parameter corresponding to the temperature detection element 300 according to the detection data of the temperature detection element 300, determine a temperature change parameter difference between the first temperature change parameter and a second temperature change parameter corresponding to the battery pack 100 according to the first temperature change parameter and a preset mapping relationship, and determine a temperature difference between the battery pack 100 and the detection data of the temperature detection element 300 according to the temperature change parameter difference and a preset relationship, and correct the detection data according to the temperature difference.

[0085] The temperature change parameter refers to a parameter reflecting temperature change. The first temperature change parameter is a parameter reflecting the temperature change detected by the temperature detection element 300, and the second temperature change parameter is a parameter reflecting the temperature change of the battery pack 100. In this embodiment, the temperature change slope is preferably used as the temperature change parameter, i.e., the first temperature change parameter is the temperature change slope of the temperature detection element 300, and the second temperature change parameter is the temperature change slope of the battery pack 100. Of course, other parameters can also be used as the temperature change parameter, which is not limited herein.

[0086] According to actual tests, it is found that in the initial state without charging and discharging, the temperature of the battery pack 100 is consistent with the detection temperature of the temperature detection element 300. When the battery pack 100 is discharged at a constant current, the temperature of the battery pack 100 and the detection temperature of the temperature detection element 300 gradually rise. Due to the presence of the heat conductor 130, the deviation between the actual temperature of the battery pack 100 and the detection temperature of the temperature detection element 300 becomes larger and larger, i.e., the first temperature change parameter of the temperature detection element 300 and the second temperature change parameter of the battery pack 100 are different. The inventors have found that the difference between the first temperature change parameter and the second temperature change parameter (referred to as the temperature change parameter difference herein) and the first temperature change parameter have a corresponding relationship, and thus a preset mapping relationship between the first temperature change parameter and the temperature change parameter difference is formed.

[0087] In the correction, the correction module 400 first acquires the first temperature change parameter of the temperature detection element 300, and then determines the temperature change parameter difference between the first temperature change parameter and the second temperature change parameter according to the mapping relationship between the first temperature change parameter and the temperature change parameter difference. After the temperature change parameter difference is acquired, since there is a corresponding relationship between the temperature difference between the data detected by the battery pack 100 and the temperature detection element 300 and the temperature change parameter difference, a relationship is formed in advance, and the temperature difference between the data detected by the battery pack 100 and the temperature detection element 300 can be determined according to the temperature change parameter difference and the preset relationship. Then, the detection data is corrected according to the temperature difference, and the control module 500 can acquire the actual temperature of the battery pack 100 accordingly. When the control module 500 judges that the actual temperature of the battery pack 100 exceeds the safe temperature range, a stop charging and discharging instruction is sent to the battery pack 100 to stop the charging and discharging of the battery pack 100, or a shutdown signal is sent to the external device 200 to stop the operation of the external device 200.

[0088] For the specific correction method of the correction module 400 in this embodiment, refer to the specific description in Embodiment 2.

[0089] Embodiment 2

[0090] The embodiment provides a charging and discharging regulation method of a battery pack 100. The battery pack 100 is connected to an external device 200. The battery pack 100 discharges to the external device 200 or is charged by the external device 200. A temperature detection element 300 is arranged at a preset position of the battery pack 100. The external device 200 can be a power tool or a charger. When the external device 200 is a power tool, the battery pack 100 charges the power tool. When the external device 200 is a charger, the charger supplies power to the battery pack 100, and the battery pack 100 is charged. The temperature detection element 300 can be arranged at the preset position of the battery pack 100 through a heat conductor 130. For the specific arrangement of the temperature detection element 300, refer to the corresponding description in Embodiment 1, which is not described here.

[0091] Reference Figure 8 The charging and discharging regulation method provided by the embodiment comprises the following steps:

[0092] Step S100, acquiring detection data of the temperature detection element 300;

[0093] Step S200, correcting the detection data to obtain corrected data;

[0094] Step S300, determining the temperature of the battery pack 100 according to the corrected data, and regulating the charging and discharging process of the battery pack 100 according to the temperature of the battery pack 100.

[0095] The above charging and discharging regulation method does not directly use the detection data of the temperature detection element 300 as the temperature of the battery pack 100, but corrects the detection data of the temperature detection element 300 to obtain corrected data, then determines the temperature of the battery pack 100 according to the corrected data, and regulates the charging and discharging process of the battery pack 100 according to the temperature of the battery pack 100. In actual application, the charging and discharging of the battery pack 100 can be stopped when the temperature of the battery pack 100 exceeds the safe temperature range. Due to the presence of the heat conductor 130, there is a deviation between the detection data of the temperature detection element 300 and the actual temperature of the battery pack 100. By correcting the monitoring data, the real temperature of the battery pack 100 can be obtained, so that the charging and discharging process of the battery pack 100 can be regulated in time according to the real temperature of the battery pack 100, and the situation of regulation failure due to the failure to detect the real temperature of the battery pack 100 can be avoided.

[0096] In one embodiment, referring to Figure 9 , the step S200 of correcting the detection data to obtain the corrected data includes:

[0097] Step S210, determining a first temperature change parameter corresponding to the temperature detection element 300 according to the detection data.

[0098] In actual application, a plurality of detection data of the temperature detection element 300 can be obtained, and then the first temperature change parameter of the temperature detection element 300 can be determined according to the obtained plurality of detection data. The first temperature change parameter is used to represent the change of the temperature data detected by the temperature detection element 300, which can be a temperature change slope or other parameters that can represent the change of the temperature data.

[0099] Step S220, determining a temperature change parameter difference between the first temperature change parameter and a second temperature change parameter corresponding to the battery pack 100 according to the first temperature change parameter and a preset mapping relationship, the preset mapping relationship representing the corresponding relationship between the first temperature change parameter and the temperature change parameter difference.

[0100] According to actual tests, it is found that, in the initial state without charging and discharging, the temperature of the battery pack 100 is consistent with the detection temperature of the temperature detection element 300, when the battery pack 100 is discharged at a constant current, the temperature of the battery pack 100 and the detection temperature of the temperature detection element 300 gradually rise, and due to the presence of the heat conductor 130, the deviation between the actual temperature of the battery pack 100 and the detection temperature of the temperature detection element 300 becomes larger and larger, that is, there is a difference between the first temperature change parameter of the temperature detection element 300 and the second temperature change parameter of the battery pack 100. The inventor has found that there is a corresponding relationship between the difference between the first temperature change parameter and the second temperature change parameter (hereinafter referred to as the temperature change parameter difference) and the first temperature change parameter, and thus first forms a preset mapping relationship between the first temperature change parameter and the temperature change parameter difference. In step S220, the temperature change parameter difference is determined according to the determined first temperature change parameter and the preset mapping relationship between the first temperature change parameter and the temperature change parameter difference.

[0101] In one embodiment, the first temperature change parameter is the temperature change slope of the temperature detection element 300, the second temperature change parameter is the temperature change slope of the battery pack 100, and the temperature change parameter difference is the difference between the temperature change slope of the battery pack 100 and the temperature change slope of the temperature detection element 300.

[0102] In step S230, the temperature difference between the temperature of the battery pack 100 and the detection data of the temperature detection element 300 is determined according to the temperature change parameter difference and a preset relationship, which represents the corresponding relationship between the temperature change parameter difference and the temperature difference.

[0103] After the temperature change parameter difference is determined, the temperature difference between the temperature of the battery pack 100 and the detection data of the temperature detection element 300 can be calculated according to the preset relationship between the temperature change parameter difference and the temperature difference. The preset relationship is formed in advance to represent the corresponding relationship between the temperature change parameter difference and the temperature difference.

[0104] In step S240, the detection data is corrected according to the temperature difference.

[0105] Since the rising speed of the detection data is often lagging behind the actual temperature rising speed of the battery pack 100, that is, the detection data is lower than the actual temperature of the battery pack 100, in actual application, after the temperature difference is determined, the temperature difference obtained on the basis of the detection data can be added to the detection data, so as to realize the correction of the detection data.

[0106] In one of the embodiments, the step S100 of obtaining the detection data of the temperature detection element 300 comprises: sampling a plurality of detection data of the temperature detection element 300 according to a preset time interval. A time interval can be preset, for example, 20s or 30s or 35s, etc., and the detection data is sampled once every time interval.

[0107] The step S210 of determining the first temperature change parameter corresponding to the temperature detection element 300 according to the detection data comprises:

[0108] The step S211 of determining the first temperature change parameter of the temperature detection element 300 in the time interval according to the detection data of the temperature detection element 300 sampled at the current sampling time and the last sampling time and the time interval.

[0109] For example, when the first temperature change parameter is the temperature change slope, the difference between the detection data sampled at the adjacent two sampling times is divided by the preset time interval, and the temperature change slope is obtained.

[0110] In addition to the above-mentioned manner of obtaining a plurality of detection data according to a preset time interval, the detection data can also be obtained when a preset reference temperature is reached. For example, in another embodiment, before the step S210 of determining the first temperature change parameter corresponding to the temperature detection element 300 according to the detection data, the charging and discharging control method provided by the embodiment further comprises:

[0111] The step S201 of setting a plurality of reference temperatures.

[0112] A plurality of reference temperature values can be set, for example, 25℃, 45℃, 50℃, 55℃, 60℃, 65℃, etc. The setting of the reference temperature means that during the charging and discharging process of the battery pack 100, when it is determined that the detection data of the temperature detection element 300 reaches the reference temperature, the current detection data is taken as the input for subsequent calculation.

[0113] The step S203 of obtaining the time interval between the current sampling time and the last sampling time when the detection data reaches any reference temperature, and the last sampling time is the time when the detection data of the temperature detection element 300 reaches the last reference temperature.

[0114] At the initial moment, the battery pack 100 has not started charging and discharging, and assuming that the reference temperature is 25℃, the initial moment is taken as the first sampling moment. As the battery pack 100 charges and discharges, its temperature gradually rises, and when the detection data reaches 45℃, it is the second sampling moment, and the time interval between the current sampling moment and the first sampling moment is determined; when the detection data reaches 50℃, it is the third sampling moment, and the time interval between the current sampling moment and the second sampling moment is determined, and so on.

[0115] Step S210, i.e. the step of determining the first temperature change parameter corresponding to the temperature detection element 300 according to the detection data, includes:

[0116] Step S213, according to the current reference temperature, the last reference temperature, and the time interval between the current sampling moment and the last sampling moment, the first temperature change parameter of the temperature detection element 300 in the time interval is determined.

[0117] For example, when the first temperature change parameter is the temperature change slope, the difference between the current reference temperature and the last reference temperature divided by the time interval between the current sampling moment and the last sampling moment can be used to determine the first temperature change slope in the time interval. At each sampling moment, the first temperature change parameter of the temperature detection element 300 in the corresponding time interval can be determined by this method.

[0118] In one embodiment, before step S220, i.e. the step of determining the temperature change parameter difference between the first temperature change parameter and the second temperature change parameter corresponding to the battery pack 100 according to the first temperature change parameter and the preset mapping relationship, the charging and discharging control method provided in this embodiment further includes the following steps:

[0119] Obtaining the discharge current of the battery pack 100; and determining the preset mapping relationship between the first temperature change parameter and the temperature change parameter difference according to the discharge current.

[0120] According to the actual measurement data, the mapping relationship between the first temperature change parameter and the temperature change parameter difference is different when the discharge current of the battery pack 100 is different. That is, the discharge current of the current battery pack 100 can be obtained first, and the preset mapping relationship between the first temperature change parameter and the temperature change parameter difference is determined according to the discharge current.

[0121] In addition, the heat conduction power of the heat conductor 130 also affects the preset mapping relationship between the first temperature change parameter and the temperature change parameter difference.

[0122] The following table is a specific example of the mapping relationship between the heat conduction power of the heat conductor 130, the discharge current of the battery pack 100, the temperature change slope of the detection data, and the temperature change parameter difference:

[0123]

[0124] Kntc is the temperature change slope of the detection data, and AK is the temperature variation parameter difference. Assuming that the discharge current of the battery pack 100 is 25 A and the heat conduction power of the heat conductor 130 is 2 W, when the obtained temperature change slope of the detection data is greater than or equal to 0.2085, it can be determined that the temperature variation parameter difference AK is 0.0800, when the obtained temperature change slope of the detection data is between 0.1569 and 0.2085, it can be determined that the temperature variation parameter difference AK is 0.0391, when the obtained temperature change slope of the detection data is between 0.1179 and 0.1569, it can be determined that the temperature variation parameter difference AK is 0.0223, and so on. The temperature variation parameter difference can be determined through the above mapping relationship, and subsequent calculation is further performed.

[0125] In one of the embodiments, in the step S230, that is, the step of determining the temperature difference between the temperature of the battery pack 100 and the detection data of the temperature detection element 300 according to the temperature variation parameter difference and the preset relationship, the preset relationship is:

[0126] ΔT n = (t n -t n-1 )*AK n +ΔT n-1

[0127] ΔT n is the temperature difference between the temperature of the battery pack 100 and the detection data of the temperature detection element 300 at the nth sampling moment, t n is the nth sampling moment, t n-1 is the (n-1)th sampling moment, AK n is the temperature variation parameter difference between the battery pack 100 and the temperature detection element 300 at the nth sampling moment, and ΔT n-1 is the temperature difference between the battery pack 100 and the temperature detection element 300 at the (n-1)th sampling moment.

[0128] According to the above formula, the temperature difference between the battery pack 100 and the temperature detection element 300 can be quickly and accurately obtained in combination with the temperature variation parameter difference.

[0129] The following is the derivation process of the above preset relationship:

[0130] It is assumed that the temperature change slope of the battery pack 100 temperature in the sampling time interval between adjacent sampling moments is fixed, and the temperature change slope of the temperature detection element 300 is also fixed. The temperature detection element 300 is a negative temperature coefficient NTC.

[0131] Tn: actual temperature of the battery cell 120 at time n; Tntcn: temperature detected by the temperature detection element 300 NTC at time n; Kntc: temperature change slope of the temperature detection element 300 NTC in a sampling time interval; K: temperature change slope of the battery pack 100 in a sampling time interval; AK: difference between the temperature change slope of the battery pack 100 and the temperature change slope of the temperature detection element 300 NTC in a sampling time interval, i.e., AK = K - Kntc.

[0132] The temperature of the battery pack 100 at the initial time is equal to the temperature of the temperature detection element 300 NTC. Assuming that the initial temperature is T0, T0 = Tntc0, AT 0 = 0;

[0133] At time t1, the temperature change slopes of the battery pack 100 and the temperature detection element 300 NTC in the time interval t0-t1 are Kt1 and Kntct1, respectively, so Tntct1 = Kntct1 * t1 + T0, Tt1 = Kt1 * t1 + T0, and Tt1 = Tntct1 + AT 1 . Combining the three equations gives:

[0134] Kt1 * t1 + T0 = Kntct1 * t1 + T0 + AT 1 → AT 1 = t1 * (Kt1 - Kntct1) = t1 * AK1

[0135] At time t2, the temperature change slopes of the battery pack 100 and the temperature detection element 300 NTC in the time interval t2-t1 are Kt2 and Kntct2, respectively, so Tntct2 = Kntct2 * (t2-t1) + Tntc1, Tt2 = Kt2 * (t2-t1) + Tt1, and Tt2 = Tntct2 + AT 2 . Combining the three equations gives:

[0136] Kt2 * (t2-t1) + Tt1 = Kntct2 * (t2-t1) + Tntct1 + AT 2 → AT 2 = (t2-t1) * (Kt2 - Kntct2) + AT 1 = (t2-t1) * AK2 + AT 1

[0137] From the above derivation, at time n,

[0138] ΔT n = (t n -t n-1 )*(Kt n -Kntct n )+ΔTn-1 = (t n -t n-1 )*ΔK n +ΔT n-1

[0139] The charging and discharging regulation method provided by the embodiment is described below with a specific example.

[0140] Suppose the preset time interval is 30 seconds, according to the preset mapping relationship, when the temperature change slope Kntcof the temperature detection element 300NTC is greater than or equal to 0.15, ΔK=0.06.

[0141] At time t0, T0=Tntc0=25℃, ΔT 0 =0.

[0142] After 30 seconds, at time t1, the temperature of the temperature detection element 300NTC is 30.0℃, and the temperature change slope Kntct1of the temperature detection element 300NTC in 30 seconds is calculated as (30.0-25) / 30≈0.17, then ΔK=0.06, according to the preset relationship, ΔT 1 =0.06*30+ΔT 0 =1.8℃.

[0143] Therefore, the actual temperature Tt1of the battery pack 100 is Tntct1+ΔT 1 =30.0+1.8=31.8℃.

[0144] After another 30 seconds, at time t2, the temperature of the temperature detection element 300NTC is 35.3℃, and the temperature change slope Kntct2of the temperature detection element 300NTC in 30 seconds is calculated as (35.3-30.0) / 30≈0.18, then,

[0145] ΔK=0.06, ΔT 2 =0.06*30+ΔT 1 =3.6℃.

[0146] Therefore, the actual temperature Tt2of the battery pack 100 is Tntct2+ΔT 2 =35.3+3.6=38.9℃.

[0147] In one of the embodiments, step S300, i.e., determining the temperature of the battery pack 100 according to the correction data, and regulating the charging and discharging process of the battery pack 100 according to the temperature of the battery pack 100, includes:

[0148] Step S310, determining whether the temperature of the battery pack 100 exceeds the preset range;

[0149] Step S320, if the preset range is exceeded, stopping the battery pack 100 from charging and discharging externally.

[0150] The preset range is a safety temperature range of the battery pack 100, for example, if it is judged that the actual temperature of the battery pack 100 exceeds 75℃, the battery pack 100 is stopped from charging and discharging externally. If the actual temperature of the battery pack 100 is within the preset range, the current charging and discharging process of the battery pack 100 is continued.

[0151] The technical features of the above embodiments can be combined arbitrarily. To make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the description.

[0152] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be pointed out that, for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A charge-discharge regulating device of a battery pack, characterized by, The battery pack is connected with an external device, the battery pack discharges to the external device or charges through the external device, and the charging and discharging regulation device is used for regulating the charging and discharging process of the battery pack; the charging and discharging regulation device comprises: A temperature detection element is arranged at a preset position of the battery pack through a heat conductor, and is used for obtaining detection data; A correction module is connected with the temperature detection element, and is used for correcting the deviation of the detection data of the temperature detection element relative to actual temperature data to obtain correction data, wherein the deviation includes a deviation caused by the heat conductor; A control module is connected with the correction module, and is used for determining the temperature of the battery pack according to the correction data, and regulating the charging and discharging process of the battery pack according to the temperature of the battery pack; The correction module comprises a correction element, and the correction element comprises a linear resistor; the temperature detection element comprises a thermistor, the control module collects the current value on the charging and discharging loop of the battery pack and the external device to obtain the voltage across the correction element, and corrects the voltage at the first end of the thermistor according to the voltage across the correction element, and then determines the temperature of the battery pack according to the voltage at the first end of the thermistor after correction.

2. The battery pack charge-discharge regulating device according to claim 1, wherein The correction element is connected in series on the charging and discharging loop of the battery pack and the external device, one end of the correction element is grounded, and the other end is connected with the negative electrode of the battery pack.

3. The battery pack charge-discharge regulating device according to claim 2, wherein The correction module and the control module are arranged in the external device.

4. The battery pack charge-discharge regulating device according to claim 1, wherein The correction module and the control module are arranged in the battery pack. The correction module is used for determining a first temperature change parameter corresponding to the temperature detection element according to the detection data of the temperature detection element, determining a temperature change parameter difference between the first temperature change parameter and a second temperature change parameter corresponding to the battery pack according to the first temperature change parameter and a preset mapping relationship, and determining a temperature difference between the battery pack and the detection data of the temperature detection element according to the temperature change parameter difference and a preset relationship, and correcting the detection data according to the temperature difference. The battery pack comprises a shell, at least one battery cell is arranged in the shell, the preset position of the battery pack is the surface of the battery cell or any position of the shell, and the temperature of the battery pack includes the temperature of the battery cell or the temperature of the shell.

5. The battery pack charge-discharge regulating device according to claim 1, wherein The battery pack is connected with an external device, the battery pack discharges to the external device or charges through the external device, and the battery pack is provided with a temperature detection element at a preset position, the temperature detection element is arranged at the preset position of the battery pack through a heat conductor, the temperature detection element comprises a thermistor, and a correction module is arranged in the battery pack, the correction module comprises a correction element, and the correction element comprises a linear resistor; 6. A method for regulating the charging and discharging of a battery pack, characterized in that, The charging and discharging regulation method comprises: Obtaining the detection data of the temperature detection element; Correcting the deviation of the detection data relative to actual temperature data to obtain correction data, wherein the deviation includes a deviation caused by the heat conductor; ​ Collecting a current value on a charge-discharge circuit of the battery pack and the external device to obtain a voltage across the correction element, correcting the voltage at the first end of the thermistor according to the voltage across the correction element, determining the temperature of the battery pack according to the corrected voltage at the first end of the thermistor, and regulating the charge-discharge process of the battery pack according to the temperature of the battery pack.

7. The charge-discharge control method according to claim 6, wherein The step of correcting the detection data to obtain corrected data comprises: determining a first temperature change parameter corresponding to the temperature detection element according to the detection data; determining a temperature change parameter difference between the first temperature change parameter and a second temperature change parameter corresponding to the battery pack according to the first temperature change parameter and a preset mapping relationship, the preset mapping relationship representing a corresponding relationship between the first temperature change parameter and the temperature change parameter difference; determining a temperature difference between the temperature of the battery pack and the detection data of the temperature detection element according to the temperature change parameter difference and a preset relationship, the preset relationship representing a corresponding relationship between the temperature change parameter difference and the temperature difference; correcting the detection data according to the temperature difference.

8. The charge-discharge control method according to claim 7, wherein The step of obtaining the detection data of the temperature detection element comprises: sampling a plurality of detection data of the temperature detection element according to a preset time interval; The step of determining a first temperature change parameter corresponding to the temperature detection element according to the detection data comprises: determining the first temperature change parameter of the temperature detection element in a time interval according to the detection data of the temperature detection element sampled at a current sampling time and a previous sampling time and the time interval.

9. The charge-discharge control method according to claim 7, wherein Before the step of determining a first temperature change parameter corresponding to the temperature detection element according to the detection data, the charge-discharge regulation method comprises: setting a plurality of reference temperatures; when the detection data reaches any of the reference temperatures, obtaining a time interval between a current sampling time and a previous sampling time, the previous sampling time being a time when the detection data of the temperature detection element reaches a previous reference temperature; The step of determining a first temperature change parameter corresponding to the temperature detection element according to the detection data comprises: determining the first temperature change parameter of the temperature detection element in a time interval according to the current reference temperature, the previous reference temperature, and the time interval between the current sampling time and the previous sampling time.

10. The charge / discharge regulation method according to claim 8 or 9, characterized in that, Before the step of determining a temperature change parameter difference between the first temperature change parameter and a second temperature change parameter corresponding to the battery pack according to the first temperature change parameter and a preset mapping relationship, the method further comprises: obtaining a discharge current of the battery pack; determining a preset mapping relationship between the first temperature change parameter and the temperature change parameter difference according to the discharge current.

11. The charge-discharge control method according to claim 8 or 9, wherein In the step of determining a temperature difference between the temperature of the battery pack and the detection data of the temperature detection element according to the temperature change parameter difference and a preset relationship, the preset relationship is: ΔT n = (t n -t n-1 )*ΔK n +ΔT n-1 wherein ΔT n is a temperature difference between the temperature of the battery pack and the temperature detection element detection data at the nth sampling time, t n is the nth sampling time, t n-1 is the n-1th sampling time, ΔK n is a temperature variation parameter difference between the battery pack and the temperature detection element at the nth sampling time, ΔT n-1 is a temperature difference between the battery pack and the temperature detection element at the n-1th sampling time.

12. The charge-discharge control method according to claim 11, wherein The first temperature change parameter is a temperature change slope of the temperature detection element, and the second temperature change parameter is a temperature change slope of the battery pack.

13. The charge-discharge control method according to claim 7, wherein The step of determining the temperature of the battery pack according to the correction data and regulating the charging and discharging process of the battery pack according to the temperature of the battery pack comprises: judging whether the temperature of the battery pack exceeds a preset range; if the temperature of the battery pack exceeds the preset range, stopping the charging and discharging of the battery pack.

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