A battery pack discharge overcurrent detection circuit and method

Abstract

The application discloses a battery pack discharge overcurrent detection circuit, which is characterized in that a battery pack is connected with a control module, the control module is connected with an electronic load and a discharge module respectively, the control module increases the discharge current of the battery pack according to a delay time and a step current, a current detection module detects a maximum overcurrent protection current, and the battery pack appears overcurrent protection, the detected step current can be used as an overcurrent protection value of the battery pack, the current detection module adopts a Hall sensor to accurately detect the discharge current in the circuit, and flexible adjustment of the configuration parameters of the electronic load and the discharge module can realize effective detection of the overcurrent of the battery pack, the control module comprises a first control board and a second control board, a filter unit is arranged in each of the first control board and the second control board, a clock circuit and a filter unit are arranged in the second control board and the discharge module, the accuracy of the overcurrent protection detection of the battery pack is improved, the operation is convenient, and the overcurrent detection cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of battery overcurrent detection, and particularly relates to a battery pack discharge overcurrent detection circuit and method. BACKGROUND

[0002] With the vigorous development of the lithium battery industry in the market, the safety and service life of the battery are paid more and more attention. Before the battery is shipped, various tests will be carried out on the battery overcharge protection performance to prevent unnecessary damage to the battery caused by overcharge. However, after the battery discharges the internal stored power and the voltage reaches a certain value, over-discharge will occur if the discharge continues. The discharge cutoff voltage is usually determined according to the discharge current. Since there is currently a lack of testing on the battery discharge current protection performance, the battery pack discharge overcurrent will also affect the working performance of the battery, and even have a direct impact on the safety and service life of the battery. Therefore, it is necessary to accurately and conveniently detect the battery pack discharge overcurrent. SUMMARY

[0003] Therefore, the present application provides a battery pack discharge overcurrent detection circuit and method, which can accurately detect the discharge current of the battery pack and has the characteristics of convenient operation. The following technical solutions are used to realize the present application.

[0004] In a first aspect, the present application provides a battery pack discharge overcurrent detection circuit, which comprises a control module, a battery pack, an electronic load, a discharge module and a current detection module. The battery pack, the current detection module and the control module are connected. The discharge module and the electronic load are connected to the control module.

[0005] The control module comprises a first control board and a second control board. The first control board comprises a first chip, a first interface arranged on the first chip and a first filter unit connected to the first chip. The second control board comprises a second chip, a first clock circuit connected to the second chip, a second filter unit adjacent to the first clock circuit and connected to the second chip, a second interface connected to the first interface, and a communication unit.

[0006] The discharge module comprises a third chip connected to the communication unit, a second clock circuit arranged on the third chip, a third filter unit arranged corresponding to the second clock circuit, and a driving unit connected to the third chip.

[0007] The control module sets the time delay of the first clock circuit and the second clock circuit and the configuration parameters of the electronic load and the discharge module according to the voltage to obtain a stepping current, and adjusts the discharge current of the battery pack according to the time delay and the stepping current until the battery pack appears overcurrent protection.

[0008] As a further improvement of the above technical solution, the setting of the time delay of the first clock circuit and the second clock circuit and the configuration parameters of the electronic load and the discharge module according to the voltage to obtain a stepping current comprises:

[0009] When the discharge current is less than or equal to the starting current of the discharge module, the driving unit does not work, and the electronic load normally works.

[0010] As a further improvement of the above technical solution, when the discharge current is greater than the starting current, the driving unit is turned on to make the discharge module work, and the electronic load normally works, wherein the starting current is 10A.

[0011] As a further improvement of the above technical solution, the current detection module is a first Hall sensor, the voltage input end of the first Hall sensor is connected to a second capacitor, the voltage output end of the first Hall sensor is connected to a first capacitor, and the ground end of the first Hall sensor is connected to a first resistor and a second resistor respectively.

[0012] As a further improvement of the above technical solution, the ground end of the first Hall sensor is also connected to a fourth filter unit, and the fourth filter unit is connected to the battery pack and the control module, wherein the fourth filter unit comprises a third resistor and a third capacitor connected in parallel.

[0013] As a further improvement of the above technical solution, the first filter unit comprises a fourth resistor and a fourth capacitor, the number of the first interface and the second interface is seven, the first interfaces are arranged in sequence on the same end of the first chip, and the second interfaces are distributed at intervals on the second chip.

[0014] As a further improvement of the above technical solution, the first clock circuit comprises a fifth capacitor and a sixth capacitor connected in parallel and a first crystal oscillator connected to the second chip, the second filter unit comprises a fifth resistor and a seventh capacitor connected in parallel, the third filter unit comprises a sixth resistor and an eighth capacitor connected in parallel, and the second clock circuit comprises a ninth capacitor and a tenth capacitor connected in parallel and a second crystal oscillator connected to the third chip.

[0015] As a further improvement of the above technical solution, the driving unit comprises a driving isolation module connected with the third chip, a power switch tube, a seventh resistor and a second Hall sensor, the input end of the power switch tube is connected with the driving isolation module, and the output end of the power switch tube is connected with the seventh resistor and the second Hall sensor in sequence.

[0016] In a second aspect, the application further provides a battery pack discharge overcurrent detection method, comprising the following steps:

[0017] Obtaining configuration parameters of an electronic load and a discharge module;

[0018] The control module performs voltage testing on the battery pack according to the configuration parameters, and controls the electronic load and the discharge module to adjust the current according to the voltage;

[0019] According to the set delay time and the value of the step current, the discharge current of the battery pack is increased until the current detection module detects the maximum overcurrent protection current of the circuit where the control module is located.

[0020] As a further improvement of the above technical solution, when the control module detects that the battery pack has overcurrent protection, the current detection module takes the step current as the discharge overcurrent protection value of the battery pack.

[0021] The application further provides a battery pack discharge overcurrent detection circuit and method, by connecting the battery pack with the control module, the control module is connected with the electronic load and the discharge module respectively, the circuit current can be flexibly adjusted, the control module increases the discharge current of the battery pack according to the delay time and the step current, the current detection module detects the maximum overcurrent protection current, and when the battery pack has overcurrent protection, the detected step current can be taken as the discharge overcurrent protection value of the battery pack, the current detection module adopts the Hall sensor to accurately detect the discharge current in the circuit, and the configuration parameters of the electronic load and the discharge module can be flexibly adjusted to realize effective detection of the discharge overcurrent of the battery pack. The control module comprises a first control board and a second control board, a filtering unit is arranged in each of the first control board and the second control board, a clock circuit and a filtering unit are arranged in the second control board and the discharge module, which can reduce interference and ensure the working stability of the circuit. The delay time and the step current can be reasonably set according to the electronic load, the discharge module and the battery pack, the accuracy of the discharge overcurrent protection detection of the battery pack is improved, the operation is convenient, and the overcurrent detection cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. Other related drawings can also be obtained by those of ordinary skill in the art without creative labor.

[0023] Figure 1 Structure block diagram of the battery pack discharge overcurrent detection circuit of the present application;

[0024] Figure 2 Principle diagram of the battery pack discharge overcurrent detection circuit of the present application;

[0025] Figure 3 Circuit diagram of the first control board of the present application;

[0026] Figure 4 Circuit diagram of the second control board of the present application;

[0027] Figure 5 Circuit diagram of the discharge module of the present application;

[0028] Figure 6 Circuit diagram of the driving unit of the present application;

[0029] Figure 7 Flow chart of the battery pack discharge overcurrent detection method of the present application.

[0030] The main element symbols are explained as follows:

[0031] 100-control module; 110-battery pack; 120-electronic load; 130-discharge module; 140-current detection module; 150-first control board; 160-second control board; 170-first filter unit; 180-second filter unit; 190-third filter unit; 200-fourth filter unit; 210-first clock circuit; 220-second clock circuit; 230-driving unit. DETAILED DESCRIPTION

[0032] The embodiments of the present application will be described in detail below, and the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and should not be understood as a limitation to the present application.

[0033] It should be noted that when an element is said to be "fixed" to another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly" on another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] See Figure 1 The present invention provides a battery pack discharge overcurrent detection circuit, including a control module 100, a battery pack 110, an electronic load 120, a discharge module 130 and a current detection module 140. The battery pack 130 and the current detection module 140 are connected to the control module 100, and the discharge module 130 and the electronic load 120 are connected to the control module 100.

[0036] The control module 100 includes a first control board 150 and a second control board 160. The first control board 150 includes a first chip denoted as U1, a first interface denoted as ADC_D0 to ADC_D6 disposed on the first chip U1, and a first filter unit 170 connected to the first chip U1. The second control board 160 includes a second chip denoted as U2, a first clock circuit 210 connected to the second chip U2, a second filter unit 180 connected to the second chip U2 and adjacent to the first clock circuit 210, a second interface corresponding to the first interface, and a communication unit.

[0037] The discharge module 130 includes a third chip denoted as U3 connected to the communication unit, a second clock circuit 220 disposed on the third chip U3, a third filter unit 190 disposed corresponding to the second clock circuit 220, and a drive unit 230 connected to the third chip U3.

[0038] The control module 100 sets the time delay of the first clock circuit 210 and the second clock circuit 220 and the configuration parameters of the electronic load 120 and the discharge module 130 according to the voltage of the battery pack 110 to obtain a stepping current when testing the voltage of the battery pack 110, and adjusts the discharge current of the battery pack 110 according to the time delay and the stepping current until the battery pack 110 appears over-current protection, and the current detection module 140 receives the discharge current to complete the over-current detection of the battery pack 110.

[0039] Referring to Figure 2 , Figure 3 , Figure 4 and Figure 5 In the embodiment, when the discharge current is less than or equal to the starting current of the discharge module 130, the driving unit 230 does not work, and the electronic load 120 normally works; when the discharge current is greater than the starting current, the driving unit 230 is turned on to make the discharge module 130 work, and the electronic load 120 normally works, wherein the starting current is 10A. The current detection module is a first Hall sensor, which is recorded as Hall sensor 1-A. The voltage input end of the first Hall sensor, i.e. the voltage, is connected to a second capacitor, which is recorded as C2. The voltage output end of the first Hall sensor, i.e. the voltage, is connected to a first capacitor, which is recorded as C1. The ground end of the first Hall sensor is recorded as GND and is connected to a first resistor, which is recorded as R1, and a second resistor, which is recorded as R2, respectively. The ground end of the first Hall sensor is also connected to a fourth filter unit 200, which is connected to the battery pack 110 and the control module 100. The fourth filter unit 200 includes a third resistor, which is recorded as R3, and a third capacitor, which is recorded as C3, in parallel. The IN-51 and IN-52 pins of a first chip U1 are connected to the battery pack.

[0040] It should be noted that the first filter unit 170 includes a fourth resistor R4 and a fourth capacitor C4, the number of the first interface and the second interface is seven, the first interface is arranged on the same end of the first chip, and the second interface is distributed on the second chip. The first clock circuit 210 includes a fifth capacitor C5 and a sixth capacitor C6 connected in parallel, and a first crystal oscillator Y1 connected with the second chip. The second filter unit 180 includes a fifth resistor R5 and a seventh capacitor C7 connected in parallel. The third filter unit 190 includes a sixth resistor R6 and an eighth capacitor C8 connected in parallel. The second clock circuit 220 includes a ninth capacitor C9 and a tenth capacitor C10 connected in parallel, and a second crystal oscillator Y2 connected with the third chip. The electronic load can be equipped with a 2.8-inch liquid crystal display, support double-channel completely independent test, also can be a wide power measurement range, voltage and current measurement speed up to 40kHz, test resolution up to 1mV / 1mA, configuration RS232 communication module, control interface module, with stable operation, adapt to the characteristics of the test function demand, test function value can be directly fed back to the computer interface. The discharge module tests the overall load of the battery, the overcurrent test, the short circuit protection test, monitors whether there is protection under the specified load, and the power increases, then the number of discharge modules needs to be increased.

[0041] It should be understood that during the discharge process of the battery to the external load, the voltage of the battery will gradually decrease during the discharge process. When the battery voltage drops to 2.5V, its capacity has been completely discharged, at this time, if the battery continues to discharge to the load, it may cause permanent damage to the battery. The control module includes a first control board and a second control board, and a filter unit is arranged in the first control board and the second control board. The second control board and the discharge module are provided with clock circuits and filter units, which can reduce interference and ensure the working stability of the circuit. The delay time and the step current can be reasonably set according to the electronic load, the discharge module and the battery pack, and the accuracy of the battery pack discharge overcurrent protection detection is improved.

[0042] Referring to Figure 6 , the driving unit 230 includes a driving isolation module connected with the third chip U3, a power switch tube Q1, a seventh resistor R7 and a second Hall sensor Hall sensor 1-B. The input end of the power switch tube is connected with the driving isolation module, and the output end of the power switch tube is connected with the seventh resistor and the second Hall sensor in sequence.

[0043] In this embodiment, the delay time can be preset, and the step current is adjusted according to the operating status of the discharge module. That is, the second Hall sensor can detect the operating current of the discharge module, making the discharge detection of the battery pack more convenient. The drive isolation module can determine the starting current of the discharge module, which can also be understood as the on-state voltage drop, thereby enabling rapid and effective detection of the battery pack discharge overcurrent protection value.

[0044] See Figure 7 The present invention also provides a method for detecting overcurrent discharge in a battery pack, comprising the following steps:

[0045] S1: Obtain the configuration parameters of the electronic load and discharge module;

[0046] S2: The control module performs a voltage test on the battery pack according to the configuration parameters, and controls the electronic load and the discharge module to adjust the current according to the voltage.

[0047] S3: Increase the discharge current of the battery pack according to the set delay time and step current values ​​until the current detection module detects the maximum overcurrent protection current of the circuit where the control module is located.

[0048] S4: When the control module detects that the battery pack has overcurrent protection, the current detection module uses the step current as the discharge overcurrent protection value of the battery pack.

[0049] In this embodiment, a parameter range is set on the electronic load. After clicking "Start Test," three 200A 12V relays close. These relays are connected between the control module and the battery pack, between the control module and the electronic load, and between the control module and the discharge module, respectively. The control module tests the battery pack voltage, while the electronic load and discharge module adjust the current by increasing the discharge current according to the set delay time and step current values ​​until the maximum overcurrent protection current range is reached. If the battery pack trips protection during the test, the measured step current is the battery pack discharge overcurrent protection value. The current is measured by a Hall sensor. For discharge currents below 10A (including 10A), the electronic load operates independently; for discharge currents above 10A, the electronic load and discharge module operate together.

[0050] It should be noted that by connecting the battery pack and the control module, and the control module to the electronic load and the discharge module respectively, the circuit current can be flexibly adjusted. The control module increases the discharge current of the battery pack according to the delay time and step current. The current detection module detects the maximum overcurrent protection current and the battery pack is in overcurrent protection mode. The detected step current can be used as the discharge overcurrent protection value of the battery pack. The current detection module uses a Hall sensor to accurately detect the discharge current in the circuit. The configuration parameters of the electronic load and the discharge module can be flexibly adjusted to achieve effective detection of battery pack discharge overcurrent.

[0051] In all of the examples shown and described herein, any specific values should be interpreted as merely exemplary and not limiting, and thus other examples of the example embodiments can have different values.

[0052] It should be noted that like reference numerals and letters refer to like items throughout the several views, and as a result, further defining and explaining of such items is not required in subsequent views once such items have been defined in one view.

[0053] The above-described embodiments are merely illustrative of several embodiments of the present application and do not limit the scope of the present application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present application, and such modifications and improvements should be construed as falling within the scope of the present application.

Claims

1. A battery pack discharge overcurrent detection circuit, characterized by comprising: The application relates to a battery pack testing device, which comprises a control module, a battery pack, an electronic load, a discharge module and a current detection module, wherein the battery pack, the current detection module and the control module are connected, and the discharge module and the electronic load are connected with the control module. The control module comprises a first control board and a second control board, the first control board comprises a first chip, a first interface arranged on the first chip and a first filter unit connected with the first chip, the second control board comprises a second chip, a first clock circuit connected with the second chip, a second filter unit adjacent to the first clock circuit and connected with the second chip, a second interface connected with the first interface and a communication unit. The discharge module comprises a third chip connected with the communication unit, a second clock circuit arranged on the third chip, a third filter unit arranged correspondingly with the second clock circuit and a driving unit connected with the third chip. When the control module tests the voltage of the battery pack, the delay time of the first clock circuit and the second clock circuit and the configuration parameters of the electronic load and the discharge module are set according to the voltage to obtain a step current, the control module adjusts the discharge current of the battery pack according to the delay time and the step current until the battery pack appears overcurrent protection, and the current detection module receives the discharge current to complete the overcurrent detection of the battery pack.

2. The battery pack discharge overcurrent detection circuit according to claim 1, characterized by, The delay time of the first clock circuit and the second clock circuit and the configuration parameters of the electronic load and the discharge module are set according to the voltage to obtain a step current, which comprises: When the discharge current is less than or equal to the starting current of the discharge module, the driving unit does not work, and the electronic load normally works.

3. The battery pack discharge overcurrent detection circuit according to claim 2, characterized by, When the discharge current is greater than the starting current, the driving unit is turned on to make the discharge module work, and the electronic load normally works, wherein the starting current is 10A.

4. The battery pack discharge overcurrent detection circuit according to claim 1, characterized by, The current detection module is a first Hall sensor, the voltage input end of the first Hall sensor is connected with a second capacitor, the voltage output end of the first Hall sensor is connected with a first capacitor, and the ground end of the first Hall sensor is connected with a first resistor and a second resistor respectively.

5. The battery pack discharge overcurrent detection circuit according to claim 4, characterized by, The ground end of the first Hall sensor is also connected with a fourth filter unit, and the fourth filter unit is connected to the battery pack and the control module, wherein the fourth filter unit comprises a third resistor and a third capacitor connected in parallel.

6. The battery pack discharge overcurrent detection circuit according to claim 1, wherein The first filter unit comprises a fourth resistor and a fourth capacitor, the number of the first interface and the second interface is seven, the first interfaces are arranged in sequence on the same end of the first chip, and the second interfaces are distributed at intervals on the second chip.

7. The battery pack discharge overcurrent detection circuit according to claim 1, wherein The first clock circuit comprises a fifth capacitor and a sixth capacitor connected in parallel and a first crystal oscillator connected with the second chip, the second filter unit comprises a fifth resistor and a seventh capacitor connected in parallel, the third filter unit comprises a sixth resistor and an eighth capacitor connected in parallel, and the second clock circuit comprises a ninth capacitor and a tenth capacitor connected in parallel and a second crystal oscillator connected with the third chip.

8. The battery pack discharge overcurrent detection circuit according to claim 1, wherein The driving unit comprises a driving isolation module connected with the third chip, a power switch tube, a seventh resistor and a second Hall sensor, an input end of the power switch tube is connected with the driving isolation module, and an output end of the power switch tube is connected with the seventh resistor and the second Hall sensor in sequence.

9. A battery discharge overcurrent detection method for a battery discharge overcurrent detection circuit according to any one of claims 1 to 8, characterized by, The method comprises the following steps: Obtaining configuration parameters of an electronic load and a discharge module; A control module performs voltage testing on a battery pack according to the configuration parameters, and controls the electronic load and the discharge module to adjust current according to voltage; The discharge current of the battery pack is increased according to a set delay time and a value of a step current until a current detection module detects a maximum overcurrent protection current of a circuit where the control module is located.

10. The battery pack discharge overcurrent detection method according to claim 9, wherein Further comprising: When the control module detects overcurrent protection of the battery pack, the current detection module takes the step current as an overcurrent protection value of the battery pack.

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