Battery pack voltage acquisition circuit, method, device, apparatus and storage medium

Abstract

The application discloses a kind of voltage acquisition circuit, method, device, equipment and storage medium of battery pack, it is related to energy storage technical field, including: battery management chip, first power supply and first controllable switch;Wherein, the two ends of first controllable switch are respectively connected the negative electrode power supply input end of battery management chip and the 1st voltage acquisition end, or respectively connect the positive electrode power supply input end of battery management chip and the n+1 voltage acquisition end;The present application is set by first power supply and first controllable switch, so that first controllable switch is disconnected, first power supply can replace 1st single battery or n single battery to battery management chip and carry out power supply, so that battery management chip can collect accurate 1st single battery or n single battery battery voltage, to realize the voltage correction of the 1st single battery and n single battery of acquisition, avoid the voltage acquisition error caused by power supply current, improve the accuracy of battery pack voltage acquisition.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a voltage acquisition circuit, method, device and equipment of a battery pack and a computer readable storage medium. BACKGROUND

[0002] At present, energy storage technologies include electrochemical energy storage and pumped storage, and electrochemical energy storage mainly uses lithium battery technology. For electrochemical energy storage, safety is the top priority, and battery fires are mainly caused by battery thermal runaway. The battery management system (BMS) is a system for managing and maintaining batteries, while ensuring maximum battery life and preventing overcharging and discharging. Through the BMS, the status of the battery can be obtained in real time, including single battery voltage, single battery temperature, total battery voltage, charging and discharging current, battery health status and other information.

[0003] In a large ground energy storage system, the BMS is generally divided into three levels, including total control, main control and slave control. The slave control is directly connected to the single battery and can collect the single battery voltage, temperature and perform balancing on the single battery. The slave control is installed in the battery pack and connected to the single battery through a wire harness. As shown in Figure 1 , for example, a forced air-cooled battery pack composed of 16 series-connected single batteries, a total of 17 wires (such as Figure 1 B0-B16) will be drawn from the single batteries, i.e. the negative electrode of the first single battery and the positive electrode of each single battery; 16 channels of AFE (Analog Front End, analog front end) chips are used on the slave control to collect the voltage of the 16 single batteries, i.e. 17 battery voltage acquisition points (such as Figure 1 C0-C16) of the AFE chip are connected to the 17 wires drawn from the battery pack, and at the same time, the V- point of the AFE chip is connected to the negative electrode of the first single battery, and the V+ point is connected to the positive electrode of the last single battery; in this case, since the power supply of the AFE chip is supplied by the battery pack, the power supply current will flow through the first and 17th wires, and since there is impedance in the wire harness and connectors (connectors 1 and 2), plugs, etc., a voltage drop will be generated when the current flows, which will in turn cause voltage acquisition errors.

[0004] Therefore, how to avoid voltage acquisition errors caused by power supply current of the battery management chip (such as AFE chip) and improve the accuracy of battery pack voltage acquisition is a problem that needs to be solved urgently. SUMMARY

[0005] The application aims to provide a battery pack voltage acquisition circuit, method, device, equipment and computer readable storage medium to avoid voltage acquisition error of a battery management chip caused by power supply current and improve the accuracy of battery pack voltage acquisition.

[0006] To solve the above technical problems, the application provides a battery pack voltage acquisition circuit, which comprises a battery management chip, a first power supply and a first controllable switch.

[0007] The first voltage acquisition end to the n-th voltage acquisition end of the battery management chip are respectively connected to the negative poles of the first single battery to the n-th single battery of the battery pack, the n+1-th voltage acquisition end of the battery management chip is connected to the positive pole of the n-th single battery, the battery pack comprises n single batteries connected in series, and n is a positive integer greater than 2.

[0008] The two ends of the first controllable switch are respectively connected to the negative pole power supply input end of the battery management chip and the first voltage acquisition end or the positive pole power supply input end of the battery management chip and the n+1-th voltage acquisition end; if the two ends of the first controllable switch are respectively connected to the negative pole power supply input end and the first voltage acquisition end, the common end connected to the first controllable switch and the negative pole power supply input end is connected to the negative pole output end of the first power supply, and the positive pole output end of the first power supply is connected to the i-th voltage acquisition end of the battery management chip, i is a positive integer greater than or equal to 3 and less than or equal to n.

[0009] If the two ends of the first controllable switch are respectively connected to the positive pole power supply input end and the n+1-th voltage acquisition end, the common end connected to the first controllable switch and the positive pole power supply input end is connected to the positive pole output end of the first power supply, and the negative pole output end of the first power supply is connected to the j-th voltage acquisition end of the battery management chip, j is a positive integer greater than or equal to 2 and less than or equal to n-1.

[0010] In some embodiments, i is 3 and j is n-1.

[0011] In some embodiments, the first power supply is specifically an isolation power supply.

[0012] In some embodiments, the control end of the first controllable switch is connected to the control output end of the battery management chip.

[0013] In some embodiments, the first controllable switch is specifically a MOS tube.

[0014] In some embodiments, the battery management chip is specifically an analog front-end chip.

[0015] In some embodiments, the voltage acquisition circuit further comprises a second power supply and a second controllable switch.

[0016] The two ends of the first controllable switch are connected to the negative power input end and the first voltage acquisition end, respectively, and the two ends of the second controllable switch are connected to the positive power input end and the (n+1)th voltage acquisition end, respectively. The common end connected to the second controllable switch and the positive power input end is connected to the positive output end of the second power supply, and the negative output end of the second power supply is connected to the jth voltage acquisition end.

[0017] In some embodiments, the values of i and j are different.

[0018] The application further provides a voltage acquisition method of a battery pack, applied to the voltage acquisition circuit of the battery pack as described above, comprising:

[0019] When the first controllable switch is closed in the voltage acquisition circuit, the single battery voltage acquired by the battery management chip in the voltage acquisition circuit is obtained. The single battery voltage includes the voltage of n single batteries in the battery pack in the voltage acquisition circuit.

[0020] The first controllable switch is controlled to be opened, and the target single battery voltage acquired by the battery management chip is obtained. The target single battery voltage is the voltage of a target single battery in the single batteries. If the two ends of the first controllable switch are connected to the negative power input end and the first voltage acquisition end of the battery management chip, respectively, the target single battery includes the first single battery in the battery pack. If the two ends of the first controllable switch are connected to the positive power input end and the (n+1)th voltage acquisition end of the battery management chip, respectively, the target single battery includes the n single battery in the battery pack.

[0021] According to the target single battery voltage, the voltage of the first single battery and the voltage of the n single battery in the single battery voltage are corrected, and the corrected voltage of the first single battery and the n single battery is obtained.

[0022] In some embodiments, the two ends of the first controllable switch are connected to the negative power input end and the first voltage acquisition end of the battery management chip, respectively, and the correction of the voltage of the first single battery and the voltage of the n single battery in the single battery voltage according to the target single battery voltage to obtain the corrected voltage of the first single battery and the n single battery includes:

[0023] The voltage of the first single battery in the target single battery voltage is determined as the corrected voltage of the first single battery.

[0024] According to the voltage of the first single battery in the single battery voltage and the target single battery voltage, an error voltage is calculated;

[0025] According to the voltage of the first single battery in the single battery voltage and the target single battery voltage, an error voltage is calculated;

[0026] In some embodiments, the first power supply of the voltage acquisition circuit is an isolated power supply, and before the first controllable switch is controlled to be turned off, the method further comprises:

[0027] Controlling the first power supply to start working.

[0028] In some embodiments, the voltage acquisition circuit further comprises a second controllable switch and a second power supply, and the control of the first controllable switch being turned off and the acquisition of the target single battery voltage collected by the battery management chip comprises:

[0029] Controlling the first controllable switch to be turned off and the second controllable switch to be turned off to acquire the target single battery voltage; wherein the target single battery voltage comprises the voltages of the first single battery and the nth single battery;

[0030] According to the target single battery voltage, the voltages of the first single battery and the nth single battery in the single battery voltage are corrected to acquire the corrected voltages of the first single battery and the nth single battery, comprising:

[0031] The voltages of the first single battery and the nth single battery in the target single battery voltage are determined as the corrected voltages of the first single battery and the nth single battery, respectively.

[0032] The application also provides a voltage acquisition device of a battery pack, which is applied to the voltage acquisition circuit of the battery pack as described above, and comprises:

[0033] The normal acquisition module is configured to acquire the single battery voltage collected by the battery management chip in the voltage acquisition circuit when the first controllable switch in the voltage acquisition circuit is turned on; wherein the single battery voltage comprises the voltages of n single batteries in the battery pack in the voltage acquisition circuit;

[0034] The correction acquisition module is configured to control the first controllable switch to be turned off, and acquire a target single battery voltage collected by the battery management chip, wherein the target single battery voltage is a voltage of a target single battery in the single batteries; if two ends of the first controllable switch are connected to a negative supply input end and a first voltage acquisition end of the battery management chip respectively, the target single battery includes a first single battery in the battery pack; if two ends of the first controllable switch are connected to a positive supply input end and an (n+1)th voltage acquisition end of the battery management chip respectively, the target single battery includes an nth single battery in the battery pack.

[0035] The voltage correction module is configured to correct voltages of the first single battery and the nth single battery in the single battery voltages according to the target single battery voltage, and acquire corrected voltages of the first single battery and the nth single battery.

[0036] The application further provides a voltage acquisition device of a battery pack, which comprises:

[0037] The memory is configured to store a computer program.

[0038] The processor is configured to execute the computer program to realize the steps of the voltage acquisition method of the battery pack.

[0039] The application further provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is executed by a processor to realize the steps of the voltage acquisition method of the battery pack.

[0040] The voltage acquisition circuit of the battery pack provided by the application comprises a battery management chip, a first power supply and a first controllable switch.

[0041] It can be seen that, by means of the first power supply and the first controllable switch, when the first controllable switch is turned off, the first power supply can replace the first single battery or the nth single battery to supply power to the battery management chip, so that the power supply current does not pass through the battery voltage acquisition point of the first single battery or the nth single battery, and the battery management chip can acquire the accurate battery voltage of the first single battery or the nth single battery, thereby realizing voltage correction of the acquired first single battery and nth single battery, avoiding voltage acquisition errors caused by the power supply current, and improving the accuracy of battery pack voltage acquisition. In addition, the application also provides a battery pack voltage acquisition method, device, equipment and computer readable storage medium, which also have the above beneficial effects. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the application, and for those skilled in the art, other drawings can be obtained from the provided drawings without creative labor.

[0043] Figure 1 A typical circuit schematic diagram of the connection relationship between a 16-section battery pack and a BMS in the prior art;

[0044] Figure 2 A circuit diagram of a voltage acquisition circuit for a battery pack provided in an embodiment of the present invention;

[0045] Figure 3 A circuit diagram of another voltage acquisition circuit for a battery pack provided in an embodiment of the present invention;

[0046] Figure 4 for Figure 3 A flowchart illustrating the voltage correction process of the voltage acquisition circuit for the battery pack shown.

[0047] Figure 5 A circuit diagram of another voltage acquisition circuit for a battery pack provided in an embodiment of the present invention;

[0048] Figure 6 This is a flowchart of a battery pack voltage acquisition method provided in an embodiment of the present invention;

[0049] Figure 7 This is a structural block diagram of a voltage acquisition device for a battery pack provided in an embodiment of the present invention;

[0050] Figure 8 This is a schematic diagram of the structure of a voltage acquisition device for a battery pack provided in an embodiment of the present invention;

[0051] Figure 9 This is a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Please refer to Figure 2 , Figure 2 This is a circuit diagram of a voltage acquisition circuit for a battery pack provided in an embodiment of the present invention. The circuit may include: a battery management chip 10, a first power supply 20, and a first controllable switch 30;

[0054] Among them, the first voltage acquisition terminal (C0) to the nth voltage acquisition terminal (Cn-1) of the battery management chip 10 are respectively used to connect to the negative terminals of the first to the nth individual cells of the battery pack, and the (n+1)th voltage acquisition terminal (Cn) of the battery management chip 10 is used to connect to the positive terminal of the nth individual cell. The battery pack includes n individual cells connected in series, where n is a positive integer greater than 2.

[0055] The two ends of the first controllable switch 30 are connected with the negative power supply input end (V-) and the first voltage collection end of the battery management chip 10, or the positive power supply input end (V+) and the (n+1)th voltage collection end of the battery management chip 10, respectively; if the two ends of the first controllable switch 30 are connected with the negative power supply input end and the first voltage collection end, respectively, then the common end connected with the first controllable switch 30 and the negative power supply input end is connected with the negative output end of the first power supply 20, and the positive output end of the first power supply 20 is connected with the ith voltage collection end of the battery management chip 10, where i is a positive integer greater than or equal to 3 and less than or equal to n;

[0056] If the two ends of the first controllable switch 30 are connected with the positive power supply input end and the (n+1)th voltage collection end, respectively, then the common end connected with the first controllable switch 30 and the positive power supply input end is connected with the positive output end of the first power supply 20, and the negative output end of the first power supply 20 is connected with the jth voltage collection end of the battery management chip 10, where j is a positive integer greater than or equal to 2 and less than or equal to n-1.

[0057] It can be understood that, in some cases, as shown in FIG. 1, the first controllable switch 30 can be arranged between the negative power supply input end (i.e., the ground end) of the battery management chip 10 and the first voltage collection end, and the first power supply 20 can be connected in parallel between the first voltage collection end and the ith voltage collection end of the battery management chip 10 through the first controllable switch 30, so that when the first controllable switch 30 is turned off, the first power supply 20 can replace the first single battery to the (i-1)th single battery of the battery pack to supply power to the battery management chip 10; so that the power supply current of the battery management chip 10 flows from the ith connection line (such as B2 in FIG. 1) connected with the battery pack, and does not pass through the first connection line to the ith connection line, so that the voltages collected by the first voltage collection end and the second voltage collection end can be the voltage of the first single battery without line voltage drop. Moreover, since the length of the wire harness connected with the battery pack is basically the same, the connectors are also the same, that is, the line impedance is basically the same, and the error of the voltage of the nth single battery collected by the nth voltage collection end and the (n+1)th voltage collection end can be corrected by software. Figure 2 Figure 2

[0058] ​​Correspondingly, in other cases, the first controllable switch 30 can be arranged between the positive supply input end (i.e. the power supply point) of the battery management chip 10 and the (n+1)th voltage collection end, and the first power supply 20 can be connected in parallel between the jth voltage collection end and the nth voltage collection end of the battery management chip 10 through the first controllable switch 30, so that when the first controllable switch 30 is turned off, the first power supply 20 can replace the jth single battery to the nth single battery of the battery pack to supply power to the battery management chip 10; so that the power supply current of the battery management chip 10 flows from the jth connecting line (such as B14 in FIG. 1) of the battery pack, and does not pass through the (j+1)th connecting line to the (n+1)th connecting line, so that the voltage collected by the nth voltage collection end and the (n+1)th voltage collection end can be the voltage of the nth single battery without line voltage drop. And since the wire harness length of the battery pack is basically the same, the connector is also the same, that is, the line impedance is basically the same, and the error of the voltage of the first single battery collected by the first voltage collection end and the second voltage collection end can be corrected by software. Figure 4

[0059] Further, in order to reduce the power supply demand of the first power supply 20, i in the embodiment can be 3, so that when the first controllable switch 30 is turned off, the first power supply 20 can replace the first single battery and the second single battery of the battery pack to supply power to the battery management chip 10 in the case that the two ends of the first controllable switch 30 are connected to the negative supply input end and the first voltage collection end of the battery management chip 10 respectively; j in the embodiment can be n-1, so that when the first controllable switch 30 is turned off, the first power supply 20 can replace the (n-1)th single battery and the nth single battery of the battery pack to supply power to the battery management chip 10 in the case that the two ends of the first controllable switch 30 are connected to the positive supply input end and the (n+1)th voltage collection end of the battery management chip 10 respectively.

[0060] Wherein, as Figure 3 ​As shown, when n is 16 and i is 3, a switch 1 (i.e., the first controllable switch 30) is added between the negative supply input (V-) of the AFE chip (i.e., the battery management chip 10) and the first voltage collection terminal (C0), and the switch 1 can be controlled by the AFE chip or other processors such as an MCU (Microcontroller Unit). Meanwhile, an isolation power supply 1 (i.e., the first power supply 20) is connected in parallel between the first voltage collection terminal (C0) and the third voltage collection terminal (C2). The isolation power supply 1 replaces the first and second single batteries of the battery pack, so that the power supply current of the AFE chip flows from the connection line B2 connected to the battery pack, without passing through the connection line B0 and the connection line B1. In this way, the first voltage collection terminal (C0) and the second voltage collection terminal (C1) collect the voltage of the first single battery (i.e., the first single battery) without line voltage drop. Moreover, since the wire harness length of the connection battery pack is basically the same, the connector is also the same, i.e., the line impedance is basically the same, and the error of the voltage of the 16th single battery collected by the 16th voltage collection terminal (C15) and the 17th voltage collection terminal (C16) can be eliminated by a software correction method.

[0061] As shown in FIG. 2, Figure 3 and Figure 4 When the system is working normally, the switch 1 is closed, and the AFE chip normally collects the voltages at C0-C16 to obtain the voltages of the 16 single batteries. When performing voltage correction, the AFE chip (i.e., the battery management chip 10) or other processors such as an MCU can first enable the isolation power supply 1 to make the isolation power supply 1 work. Then, the switch 1 is opened, and the isolation power supply 1 replaces the first and second single batteries to supply power to the AFE chip. The AFE chip reads the voltages at C0-C16 again. At this time, the voltage of the first single battery read is the error-free voltage after eliminating the error of the power supply current of the AFE chip on the line. The difference between the two times of voltage collection of the first single battery is the error of voltage collection caused by the power supply current of the AFE chip. After obtaining this error value, since the connection conditions are the same, the voltage of the 16th single battery can be corrected, such as subtracting the error value from the voltage of the 16th single battery collected when the switch 1 is closed or opened.

[0062] As shown in FIG. 2, Figure 5 When n is 16 and j is 3, the isolation power supply 1 (i.e., the first power supply 20) can be placed on the high side, and Figure 3The circuit shown is similar, a switch 1 (i.e. a first controllable switch 30) is added between the positive supply input (V+) of the AFE chip (i.e. the battery management chip 10) and the 17th voltage collection terminal (C16), the switch 1 can be controlled by the AFE chip or other processors such as MCU (Microcontroller Unit, microcontroller unit), and an isolation power supply 1 (i.e. a first power supply 20) is connected in parallel between the 15th voltage collection terminal (C14) and the 17th voltage collection terminal (C16), which replaces the 15th and 16th single batteries of the battery pack, so that the power supply current of the AFE chip flows from the connection line B14 connected to the battery pack, without passing through the connection line B15 and the connection line B16, so that the 17th voltage collection terminal (C16) and the 16th voltage collection terminal (C15) collect the voltage of the 16th single battery (i.e. the 16th single battery) without line voltage drop; and since the wire harness length connected to the battery pack is basically the same, the connector is also the same, that is, the line impedance is basically the same, which can be eliminated by the method of software correction, and the error of the voltage collected by the 1st voltage collection terminal (C0) and the 2nd voltage collection terminal (C1) of the 1st single battery.

[0063] Specifically, as shown in Figure 3 and Figure 5 The voltage collection circuit of the battery pack provided by the embodiment can further include a connector (connector 2); the 1st voltage collection terminal to the n-1th voltage collection terminal of the battery management chip 10 are connected to the n single batteries in the battery pack through the connector.

[0064] Further, the voltage collection circuit of the battery pack provided by the embodiment can further include a second power supply and a second controllable switch; wherein the two ends of the first controllable switch 30 are respectively connected to the negative supply input and the 1st voltage collection terminal, that is, the common terminal connected to the first controllable switch 30 and the negative supply input is connected to the negative output terminal of the first power supply 20, and the positive output terminal of the first power supply 20 is connected to the i-th voltage collection terminal of the battery management chip 10; the two ends of the second controllable switch are respectively connected to the positive supply input and the n+1th voltage collection terminal, the common terminal connected to the second controllable switch and the positive supply input is connected to the positive output terminal of the second power supply, and the negative output terminal of the second power supply is connected to the j-th voltage collection terminal.

[0065] Correspondingly, the first controllable switch 30 and the second controllable switch in the embodiment can be disconnected separately to detect the voltages of the 1st single battery and the 16th single battery with the voltage drop of the wireless line, respectively. The first controllable switch 30 and the second controllable switch in the embodiment can also be disconnected simultaneously to detect the voltages of the 1st single battery and the 16th single battery with the voltage drop of the wireless line simultaneously. Correspondingly, in order to avoid the influence of the power supply of the first power supply 20 and the second power supply on the voltage collection of the 1st single battery and the 16th single battery when the first controllable switch 30 and the second controllable switch are disconnected simultaneously, the values of i and j in the embodiment can be different.

[0066] It should be noted that the specific types of the circuit elements in the voltage collection circuit of the battery pack provided in the embodiment can be set by the designer according to the practical scene and user demand, such as the battery management chip 10 in the embodiment can be an AFE chip or other voltage collection chip for collecting the voltage of the single battery in the battery pack. The first power supply 20 and the second power supply can be an isolation power supply or a battery (such as a button cell) respectively. Correspondingly, when the first power supply 20 and the second power supply are isolation power supplies, the power supply of the isolation power supply can also be used to avoid the influence of the power supply current of the battery management chip 10 on the self-discharge rate of the battery pack and the influence on the long-term storage of the battery.

[0067] Correspondingly, the first controllable switch 30 and the second controllable switch can be MOS tubes, transistors or relays, respectively. The control ends of the first controllable switch 30 and the second controllable switch can be connected to the battery management chip 10 or other processors such as MCUs to control the disconnection and connection of the first controllable switch 30 and the second controllable switch. For example, the control end of the first controllable switch 30 is connected to the control output end of the battery management chip 10.

[0068] In the embodiment, the first controllable switch 30 is disconnected, and the first power supply 20 can replace the 1st single battery or the n-th single battery to supply power to the battery management chip 10, so that the power supply current does not pass through the battery voltage collection point of the 1st single battery or the n-th single battery, and the battery management chip 10 can collect the accurate battery voltage of the 1st single battery or the n-th single battery, thereby realizing the voltage correction of the collected 1st single battery and n-th single battery, avoiding the voltage collection error caused by the power supply current, improving the accuracy of the voltage collection of the battery pack, and optimizing the error from ±10mV to ±3mV. The circuit provided in the embodiment does not need to change the wiring of the existing battery pack, and can realize the board-level replacement and upgrade for the slave control board of the battery pack without reserving additional power supply and location.

[0069] Corresponding to the above circuit embodiment, the embodiment of the present application also provides a battery pack voltage acquisition method. The battery pack voltage acquisition method described below can be correspondingly referred to the battery pack voltage acquisition circuit described above.

[0070] Please refer to Figure 6 , Figure 6 The flowchart of the battery pack voltage acquisition method provided by the embodiment of the present application. The method can include:

[0071] Step 101: When the first controllable switch in the voltage acquisition circuit is closed, the battery management chip in the voltage acquisition circuit acquires the single battery voltage.

[0072] Wherein, the single battery voltage includes the voltage of n single batteries in the battery pack in the voltage acquisition circuit.

[0073] It can be understood that the voltage acquisition method provided by the embodiment can be applied to the battery management chip in the voltage acquisition circuit, that is, by controlling the closing and opening of the first controllable switch, the voltage of the first single battery and the nth single battery in the battery pack acquired by itself is corrected. The method provided by the embodiment can also be applied to other processors connected to the battery management chip (such as the MCU of the BMS), such as the MCU of the BMS, which can correct the voltage of the first single battery and the nth single battery in the battery pack acquired by the battery management chip by controlling the closing and opening of the first controllable switch.

[0074] Correspondingly, in the embodiment, the specific way of acquiring the single battery voltage acquired by the battery management chip in the voltage acquisition circuit when the first controllable switch in the voltage acquisition circuit is closed can be set by the designer, such as the battery management chip can control the first controllable switch in the voltage acquisition circuit to close, and normally acquire the voltage of n single batteries in the battery pack. Correspondingly, when the voltage acquisition circuit further includes a second controllable switch and a second power supply, the battery management chip can control the first controllable switch and the second controllable switch in the voltage acquisition circuit to close, and normally acquire the voltage of n single batteries in the battery pack (i.e. single battery voltage).

[0075] Step 102: Control the first controllable switch to open, and acquire the target single battery voltage acquired by the battery management chip.

[0076] Wherein, the target single battery voltage is the voltage of the target single battery in the single battery; if the two ends of the first controllable switch are connected to the negative power supply input end and the first voltage acquisition end of the battery management chip, respectively, the target single battery includes the first single battery in the battery pack; if the two ends of the first controllable switch are connected to the positive power supply input end and the nth voltage acquisition end of the battery management chip, respectively, the target single battery includes the nth single battery in the battery pack.

[0077] It can be understood that in this step, the first controllable switch can be controlled to be turned off, and the power supply of the first power supply is used to enable the battery management chip to collect the voltage of the 1st single battery or the nth single battery corresponding to the first controllable switch (i.e. the target single battery voltage), so that the voltage of the 1st single battery and the nth single battery collected by the battery management chip is corrected when the first controllable switch is turned off.

[0078] Correspondingly, for the specific way of controlling the first controllable switch to be turned off in this step to obtain the target single battery voltage collected by the battery management chip, the designer can set it according to the practical scene and user demand, for example, when the voltage collection circuit does not include the second controllable switch and the second power supply, the battery management chip can control the first controllable switch in the voltage collection circuit to be turned off, and collect the target single battery voltage including the voltage of the 1st single battery or the nth single battery corresponding to the first controllable switch; correspondingly, when the first power supply in the voltage collection circuit is an isolation power supply, the battery management chip can first control the first power supply to start working, and then control the first controllable switch to be turned off, so as to ensure that the first power supply can work normally.

[0079] Correspondingly, when the voltage collection circuit further includes the second controllable switch and the second power supply, the battery management chip can control the first controllable switch and the second controllable switch to be turned off in sequence or simultaneously in this step, and obtain the target single battery voltage including the voltage of the 1st single battery collected when the first controllable switch is turned off and the voltage of the nth single battery collected when the second controllable switch is turned off; for example, the battery management chip can control the first controllable switch and the second controllable switch to be turned off, and obtain the target single battery voltage collected by the battery management chip; wherein the target single battery voltage includes the voltage of the 1st single battery and the voltage of the nth single battery.

[0080] Step 103: According to the target single battery voltage, the voltage of the 1st single battery and the nth single battery in the single battery voltage is corrected to obtain the corrected voltage of the 1st single battery and the nth single battery.

[0081] In this embodiment, the voltage of the 1st single battery and the nth single battery in the single battery voltage collected when the first controllable switch is turned on can be corrected according to the target single battery voltage collected when the first controllable switch is turned off, to obtain the voltage of the 1st single battery and the nth single battery with the wireless line voltage drop.

[0082] Correspondingly, for the specific way of correcting the voltages of the first and nth single batteries in the single battery voltages according to the target single battery voltages in the present embodiment, the designer can set it by himself / herself. For example, when the voltage acquisition circuit does not include the second controllable switch and the second power supply, and the two ends of the first controllable switch are connected to the negative power supply input end and the first voltage acquisition end of the battery management chip respectively, the battery management chip can determine the voltage of the first single battery in the target single battery voltages as the corrected voltage of the first single battery; according to the voltage of the first single battery in the single battery voltages and the target single battery voltages, the error voltage is calculated; according to the voltage of the nth single battery in the single battery voltages and the error voltage, the corrected voltage of the nth single battery is calculated; for example, when the error voltage is the difference between the voltage of the first single battery in the single battery voltages and the voltage of the first single battery in the target single battery voltages, the difference between the voltage of the nth single battery in the single battery voltages and the error voltage can be determined as the corrected voltage of the nth single battery. Correspondingly, the battery management chip can also use the error voltage to correct the voltages of the first and nth single batteries collected by the battery management chip when the first controllable switch is closed subsequently.

[0083] Correspondingly, when the voltage acquisition circuit includes the second controllable switch and the second power supply, the battery management chip can directly determine the voltage of the first single battery collected when the first controllable switch is disconnected in the target single battery voltages and the voltage of the nth single battery collected when the second controllable switch is disconnected in the target single battery voltages as the corrected voltages of the first and nth single batteries respectively. Correspondingly, the battery management chip can also calculate the difference between the voltage of the first single battery in the single battery voltages and the voltage of the first single battery collected when the first controllable switch is disconnected as the first error voltage, calculate the difference between the voltage of the nth single battery in the single battery voltages and the voltage of the nth single battery collected when the second controllable switch is disconnected as the second error voltage, and use the first and second error voltages to correct the voltages of the first and nth single batteries collected by the battery management chip when the first and second controllable switches are closed subsequently.

[0084] Further, when the first power supply and the second power supply in the embodiment are specifically isolation power supplies, the battery management chip can correct the voltage of the first single battery or the nth single battery in the target single battery voltage according to the target single battery voltage and the single battery voltage when the voltage acquisition circuit does not include the second controllable switch and the second power supply, and obtain the corrected voltage of the first single battery or the nth single battery. Correspondingly, the battery management chip can also correct the voltage of the first single battery or the nth single battery collected by the battery management chip when the first controllable switch is turned off by using the error voltage obtained during correction, that is, the normal voltage collection of the battery pack by the battery management chip can be in a state of being powered by the first power supply when the first controllable switch is turned off, so as to reduce the self-discharge rate of the battery.

[0085] In the embodiment, the first controllable switch is turned off, and the first power supply can replace the first single battery or the nth single battery to supply power to the battery management chip, so that the power supply current does not pass through the battery voltage collection point of the first single battery or the nth single battery, and the battery management chip can collect the accurate battery voltage of the first single battery or the nth single battery, thereby realizing the voltage correction of the collected first single battery and nth single battery, avoiding the voltage collection error caused by the power supply current, improving the accuracy of the battery pack voltage collection, and optimizing the error from ±10mV to ±3mV. The circuit provided in the embodiment does not need to change the wiring of the existing battery pack, and can realize board-level replacement and upgrading for the slave control board of the battery pack without reserving additional power supply and location.

[0086] Corresponding to the above method embodiment, the embodiment of the application also provides a battery pack voltage acquisition device. The battery pack voltage acquisition device described below can be mutually corresponding and referred to the battery pack voltage acquisition method described above.

[0087] Please refer to Figure 7 , Figure 7 The structure block diagram of the battery pack voltage acquisition device provided in the embodiment of the application. The device can include:

[0088] The normal collection module 100 is used to acquire the single battery voltage collected by the battery management chip in the voltage acquisition circuit when the first controllable switch in the voltage acquisition circuit is turned on. The single battery voltage includes the voltage of the n single batteries in the battery pack in the voltage acquisition circuit.

[0089] The correction acquisition module 200 is configured to control the first controllable switch to be turned off, and acquire a target single battery voltage collected by the battery management chip; wherein the target single battery voltage is a voltage of a target single battery in the single batteries; if two ends of the first controllable switch are connected to a negative supply input end and a first voltage acquisition end of the battery management chip respectively, the target single battery includes a first single battery in the battery pack; if two ends of the first controllable switch are connected to a positive supply input end and an (n+1)th voltage acquisition end of the battery management chip respectively, the target single battery includes an nth single battery in the battery pack.

[0090] The voltage correction module 300 is configured to correct voltages of the first single battery and the nth single battery in the single battery voltage according to the target single battery voltage, and acquire correction voltages of the first single battery and the nth single battery.

[0091] In some embodiments, two ends of the first controllable switch are connected to the negative supply input end and the first voltage acquisition end of the battery management chip respectively, and the voltage correction module 300 can include:

[0092] The determination sub-module is configured to determine the voltage of the first single battery in the target single battery voltage as the correction voltage of the first single battery.

[0093] The error calculation sub-module is configured to calculate an error voltage according to the voltage of the first single battery in the single battery voltage and the target single battery voltage.

[0094] The correction calculation sub-module is configured to calculate the correction voltage of the nth single battery according to the voltage of the nth single battery in the single battery voltage and the error voltage.

[0095] In some embodiments, the first power supply of the voltage acquisition circuit is an isolation power supply, and the correction acquisition module 200 is further configured to control the first power supply to start working before the first controllable switch is turned off.

[0096] In some embodiments, the voltage acquisition circuit further includes a second controllable switch and a second power supply, and the normal acquisition module 100 can be specifically configured to control the first controllable switch and the second controllable switch to be turned off, and acquire the target single battery voltage; wherein the target single battery voltage includes the voltages of the first single battery and the nth single battery.

[0097] The voltage correction module 300 can be specifically configured to determine the voltages of the first single battery and the nth single battery in the target single battery voltage as the correction voltages of the first single battery and the nth single battery respectively.

[0098] In the embodiment, the first controllable switch is set in the voltage acquisition circuit, and the first power supply can replace the first single battery or the nth single battery to supply power to the battery management chip when the first controllable switch is turned off, so that the power supply current does not pass through the battery voltage acquisition point of the first single battery or the nth single battery, and the battery management chip can acquire the accurate battery voltage of the first single battery or the nth single battery, thereby realizing voltage correction of the acquired first single battery and nth single battery, avoiding voltage acquisition error caused by power supply current, improving the accuracy of battery pack voltage acquisition, and optimizing the error from ±10 mV to ±3 mV. The circuit provided in the embodiment does not need to change the wiring of the existing battery pack, and can realize board-level replacement and upgrading for the slave board of the battery pack without reserving additional power supply and location.

[0099] Corresponding to the above method embodiment, the embodiment of the application also provides a battery pack voltage acquisition device. The battery pack voltage acquisition device described below can be referred to in conjunction with the battery pack voltage acquisition method described above.

[0100] Please refer to Figure 8 , Figure 8 The battery pack voltage acquisition device provided by the embodiment of the application has the structure shown in the figure. The battery pack voltage acquisition device can include:

[0101] The memory D1 is used to store the computer program.

[0102] The processor D2 is used to execute the computer program to realize the steps of the battery pack voltage acquisition method provided by the above method embodiment.

[0103] Corresponding to the above method embodiment, the embodiment of the application also provides a computer readable storage medium. The computer readable storage medium described below can be referred to in conjunction with the battery pack voltage acquisition method described above.

[0104] Please refer to Figure 9 , Figure 9 The structure of the computer readable storage medium provided by the embodiment of the application is shown in the figure. The computer readable storage medium 40 stores a computer program 41. When the computer program 41 is executed by the processor, the steps of the battery pack voltage acquisition method provided by the above method embodiment are realized.

[0105] The computer readable storage medium 40 can be a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various storage media that can store program codes.

[0106] The various embodiments described in the specification are presented for purposes of illustration and description. Each of the embodiments highlight a different aspect of the application. The embodiments are not mutually exclusive, and aspects of each embodiment can be combined with aspects of other embodiments. The embodiments disclosed for the apparatus, device, and computer readable storage medium are merely exemplary and do not limit the scope of the application. The methods disclosed for the apparatus, device, and computer readable storage medium are merely exemplary and do not limit the scope of the application.

[0107] The above provides a detailed introduction to the voltage acquisition circuit, method, device, apparatus, and computer readable storage medium of the battery pack. The principles and implementation manners of the application are described by applying specific examples. The above embodiment description is only used to help understand the method of the application and its core idea. It should be pointed out that, for those skilled in the art, without departing from the principles of the application, the application can be improved and modified in several ways. These improvements and modifications also fall within the protection scope of the claims of the application.

Claims

1. A voltage acquisition circuit for a battery pack, characterized in that, include: Battery management chip, first power supply, and first controllable switch; Wherein, the first voltage acquisition terminal to the nth voltage acquisition terminal of the battery management chip are respectively used to connect to the negative terminals of the first to the nth individual cells of the battery pack, and the (n+1)th voltage acquisition terminal of the battery management chip is used to connect to the positive terminal of the nth individual cell. The battery pack includes n individual cells connected in series, where n is a positive integer greater than 2. The two ends of the first controllable switch are respectively connected to the negative power supply input terminal of the battery management chip and the first voltage acquisition terminal, or respectively connected to the positive power supply input terminal of the battery management chip and the (n+1)th voltage acquisition terminal; if the two ends of the first controllable switch are respectively connected to the negative power supply input terminal and the first voltage acquisition terminal, then the common terminal connected to the first controllable switch and the negative power supply input terminal is connected to the negative output terminal of the first power supply, and the positive output terminal of the first power supply is connected to the i-th voltage acquisition terminal of the battery management chip, where i is a positive integer greater than or equal to 3 and less than or equal to n; If the two ends of the first controllable switch are respectively connected to the positive power supply input terminal and the (n+1)th voltage acquisition terminal, then the common terminal connected to the first controllable switch and the positive power supply input terminal is connected to the positive output terminal of the first power supply, and the negative output terminal of the first power supply is connected to the jth voltage acquisition terminal of the battery management chip, where j is a positive integer greater than or equal to 2 and less than or equal to n-1.

2. The voltage acquisition circuit for the battery pack according to claim 1, characterized in that, i is 3, j is n-1.

3. The voltage acquisition circuit for the battery pack according to claim 1, characterized in that, The first power supply is specifically an isolated power supply.

4. The voltage acquisition circuit for the battery pack according to claim 1, characterized in that, The control terminal of the first controllable switch is connected to the control output terminal of the battery management chip.

5. The voltage acquisition circuit for the battery pack according to claim 1, characterized in that, The first controllable switch is specifically a MOSFET.

6. The voltage acquisition circuit for the battery pack according to claim 1, characterized in that, The battery management chip is specifically an analog front-end chip.

7. The voltage acquisition circuit for the battery pack according to any one of claims 1 to 6, characterized in that, Also includes: Second power supply and second controllable switch; The first controllable switch is connected to the negative power supply input terminal and the first voltage acquisition terminal at both ends, and the second controllable switch is connected to the positive power supply input terminal and the (n+1)th voltage acquisition terminal at both ends, respectively. The common terminal connecting the second controllable switch and the positive power supply input terminal is connected to the positive output terminal of the second power supply, and the negative output terminal of the second power supply is connected to the jth voltage acquisition terminal.

8. The voltage acquisition circuit for the battery pack according to claim 7, characterized in that, The values ​​of i and j are different.

9. A method for acquiring the voltage of a battery pack, characterized in that, A voltage acquisition circuit applied to a battery pack as described in any one of claims 1 to 7, comprising: When the first controllable switch in the voltage acquisition circuit is closed, the voltage of a single battery cell acquired by the battery management chip in the voltage acquisition circuit is obtained; wherein, the voltage of a single battery cell includes the voltages of n single batteries cells in the battery pack in the voltage acquisition circuit; The first controllable switch is controlled to open, and the target single-cell battery voltage collected by the battery management chip is obtained; wherein, the target single-cell battery voltage is the voltage of the target single-cell battery; if the two ends of the first controllable switch are respectively connected to the negative power supply input terminal and the first voltage acquisition terminal of the battery management chip, then the target single-cell battery includes the first single-cell battery in the battery pack; if the two ends of the first controllable switch are respectively connected to the positive power supply input terminal and the (n+1)th voltage acquisition terminal of the battery management chip, then the target single-cell battery includes the nth single-cell battery in the battery pack; Based on the target single cell voltage, the voltages of the first single cell and the nth single cell are corrected to obtain the corrected voltages of the first single cell and the nth single cell.

10. The voltage acquisition method for a battery pack according to claim 9, characterized in that, The two ends of the first controllable switch are respectively connected to the negative power supply input terminal of the battery management chip and the first voltage acquisition terminal. The step of correcting the voltages of the first and nth individual cells based on the target individual cell voltage to obtain the corrected voltages of the first and nth individual cells includes: The voltage of the first single cell in the target single cell voltage is determined as the correction voltage of the first single cell; The error voltage is calculated based on the voltage of the first single cell in the single cell voltage and the target single cell voltage; The correction voltage of the nth cell is calculated based on the voltage of the nth cell and the error voltage.

11. The voltage acquisition method for a battery pack according to claim 9, characterized in that, The first power supply for the voltage acquisition circuit is an isolated power supply. Before the controllable switch is disconnected, the circuit further includes: Control the first power supply to start working.

12. The voltage acquisition method for a battery pack according to claim 9, characterized in that, The voltage acquisition circuit further includes a second controllable switch and a second power supply. Controlling the first controllable switch to open and acquiring the target single-cell battery voltage acquired by the battery management chip includes: The first controllable switch and the second controllable switch are opened to obtain the target single cell voltage; wherein, the target single cell voltage includes the voltage of the first single cell and the nth single cell; The step of correcting the voltages of the first and nth individual cells based on the target individual cell voltage to obtain the corrected voltages of the first and nth individual cells includes: The voltages of the first and nth individual cells in the target individual cell voltage are respectively determined as the correction voltages of the first and nth individual cells.

13. A voltage acquisition device for a battery pack, characterized in that, A voltage acquisition circuit applied to a battery pack as described in any one of claims 1 to 7, comprising: A normal acquisition module is used to acquire the individual cell voltage acquired by the battery management chip in the voltage acquisition circuit when the first controllable switch in the voltage acquisition circuit is closed; wherein, the individual cell voltage includes the voltages of n individual cells in the battery pack in the voltage acquisition circuit; A calibration acquisition module is used to control the first controllable switch to open and acquire the target single-cell battery voltage acquired by the battery management chip; wherein, the target single-cell battery voltage is the voltage of the target single-cell battery in the single-cell battery; if the two ends of the first controllable switch are respectively connected to the negative power supply input terminal and the first voltage acquisition terminal of the battery management chip, then the target single-cell battery includes the first single-cell battery in the battery pack; if the two ends of the first controllable switch are respectively connected to the positive power supply input terminal and the (n+1)th voltage acquisition terminal of the battery management chip, then the target single-cell battery includes the nth single-cell battery in the battery pack; A voltage correction module is used to correct the voltages of the first and nth individual cells in the individual cell voltages based on the target individual cell voltage, and to obtain the corrected voltages of the first and nth individual cells.

14. A voltage acquisition device for a battery pack, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the voltage acquisition method for the battery pack as described in any one of claims 9 to 12.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the voltage acquisition method for the battery pack as described in any one of claims 9 to 12.

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