CN117833417A - A battery pack constant power control circuit, method, terminal and readable storage medium - Google Patents

Abstract

The invention relates to a constant power control circuit, a method, a terminal and a readable storage medium of a battery pack, wherein the control circuit comprises a main control circuit, M abnormal control circuits and M equalization circuits, two ends of each battery are connected in parallel with one abnormal control circuit and one equalization circuit, the main control circuit is connected with each battery and each abnormal control circuit and is used for detecting the voltage at two ends of each battery, judging whether each battery is abnormal according to the voltage, the charging state and the discharging state of each battery, shorting out the battery when determining that one battery is abnormal, equalizing the electric quantity of a high-voltage battery to a low-voltage battery when determining that the voltage of one battery is higher than the voltage of other batteries in the battery pack, and controlling the duty ratio in the transfer process so as to control the equalizing current and realize equalization. The method bypasses the abnormal battery and realizes balance among the batteries, so that self-adaptive balance of the battery pack is realized, and the service life of the battery pack is prolonged.

Description

A battery pack constant power control circuit, method, terminal and readable storage medium

Technical Field

The present invention relates to the field of new energy technology, and in particular to a battery pack constant power control circuit, method, terminal and readable storage medium.

Background technique

New energy technologies have been widely developed and applied in all aspects of life. In the field of new energy, the most basic is the battery pack, which includes M batteries, a series-parallel combination of batteries to achieve various requirements for voltage and current. However, various problems may arise during the production and use of batteries. Even batteries from the same batch may have inconsistent internal resistance, different capacities, and different cycle lives. During the charging and discharging process of the battery, the charging and discharging rates will also be different. Therefore, a balancing method is used to keep the battery cells within the expected range.

There are many balancing methods at present, including active balancing and passive balancing. Balancing management includes voltage balancing, current balancing and temperature balancing. Passive balancing generally discharges lithium-powered batteries with higher voltages through resistance discharge, releasing electricity in the form of heat, and buying more charging time for other lithium-powered batteries. Active balancing is a form developed on the basis of passive balancing. It transfers the electricity of a high-voltage battery in the battery pack to a battery with lower electricity through energy conversion, avoiding the energy loss caused by passive balancing. However, the active balancing circuit is more complicated. It is not a simple task to accurately realize energy transfer, and the phenomenon of energy transfer exceeding the limit often occurs.

At present, conventional battery balancing circuits use series resistors to control the opening and closing of MOS to balance the batteries. Intermittent balancing, due to the fixed resistance value, will make it impossible to accurately collect the battery voltage during balancing. Due to the inconsistent battery voltage difference, affected by the fluctuation of the balancing current, the balancing current will be large or small according to the size of the battery voltage difference. When the battery voltage difference is large, the balancing current is relatively large, the power is large, and the heat is large. When the battery voltage difference is small, the balancing current is relatively small, the power is small, and the heat is small, which causes the life of its components to decline. When the heat is large, it causes a series of instabilities.

Therefore, how to ensure the constant power of the battery pack is a problem that needs to be solved urgently.

Summary of the invention

The purpose of the present invention is to provide a constant power control circuit, method, terminal and readable storage medium for a battery pack, wherein an abnormal control circuit and a balancing circuit are connected in parallel at both ends of each battery, a main control circuit detects the voltage at both ends of each battery, compares the voltage of each battery, opens the balancing circuit of the high-voltage battery, and charges the low-voltage battery to achieve battery pack balance; when a battery abnormality is detected, the abnormal control circuit is opened, the battery is short-circuited, and the battery pack is ensured to operate normally.

In a first aspect, a constant power control circuit of a battery pack of the present invention is implemented by the following technical solutions:

A constant power control circuit for a battery pack, wherein a resistor group includes M batteries, a main control circuit and M abnormal control circuits, wherein both ends of each battery are connected in parallel with an abnormal control circuit, the main control circuit is connected with each battery and each abnormal control circuit, and is used to detect the voltage at both ends of each battery, and judge whether each battery has an abnormality according to the voltage, current, charging state, voltage drop during discharge state and internal resistance of each battery. When a battery is determined to be abnormal, the main control circuit discharges the abnormal battery, and after the discharge is completed, controls the abnormal control circuit connected in parallel with the abnormal battery to conduct, bypasses the abnormal battery, and makes the power supply of the entire battery pack normal.

The present invention is further configured as follows: the abnormal control circuit comprises a first switch circuit, which is turned on or off according to the abnormal control signal of the main control circuit.

The present invention is further configured as follows: the first switch circuit includes two docked power tubes, the control electrode of the first power tube and the control electrode of the second power tube are connected together, connected to the abnormal signal output end of the main control circuit, the input end of the first power tube is connected to the positive end of the battery, and its output end is connected to the output end of the second power tube, and the input end of the second power tube is connected to the negative end of the battery.

In a second aspect, a constant power control circuit of a battery pack of the present invention is implemented by the following technical solutions:

A constant power control circuit for a battery pack, wherein a resistor group includes M batteries, a main control circuit and M balancing circuits, two ends of each battery are connected in parallel with an balancing circuit, the main control circuit is connected with each battery and each balancing circuit, and is used to detect the voltage at both ends of each battery, and to determine whether there is a battery voltage higher than the voltages of other batteries according to the voltage of each battery, and when it is determined that the voltage of a certain battery is high, the balancing circuit controls the high-voltage battery to charge the low-voltage battery in the group.

The present invention is further configured such that the equalization circuit includes a second switch circuit, which is turned on or off according to the equalization signal of the main control circuit to transmit the power of the high-voltage battery to the next connected low-voltage battery.

The present invention is further configured as follows: the second switch circuit includes a third power tube and a current limiting resistor, the input end of the third power tube is connected to the positive end of the battery through the current limiting resistor, the output end is connected to the negative end of the battery, and the control end is connected to the balanced signal output end of the main control circuit through the resistor.

In a third aspect, a constant power control circuit of a battery pack of the present invention is implemented by the following technical solutions:

A constant power control circuit for a battery pack, wherein a resistor group includes M batteries, a main control circuit, M abnormal control circuits, M balancing circuits and a battery pack abnormal control circuit, wherein an abnormal control circuit and a balancing circuit are connected in parallel at both ends of a battery, one end of the battery pack abnormal control circuit is connected to the negative end of the battery pack, the other end of the battery pack abnormal control circuit is connected to the negative end of the first battery in the battery pack, the control end of the battery pack abnormal control circuit is connected to the main control circuit, and when the main control circuit detects abnormal charging and discharging of the battery pack, the current flow direction of the battery pack is controlled.

In a fourth aspect, a constant power control method of a battery pack of the present invention is implemented by the following technical solutions:

A constant power control method for a battery pack, wherein a control circuit detects the voltage, charging state and discharging state at both ends of each battery, and compares the voltage of each battery. If the voltage of a battery is higher than that of the other batteries, the duty cycle of the power tube control signal in the equalization circuit is controlled according to the voltage difference between the upper and lower batteries, thereby controlling the size of the equalization current, transferring the power of the high-voltage battery to the low-voltage battery, and achieving equalization; if the voltage of a battery is lower than that of the other batteries in the battery pack, the battery is charged or discharged, and when the battery is detected to be abnormal, the abnormal control circuit of the battery is controlled to open, short-circuiting the battery, so that the abnormal battery is bypassed.

In a fifth aspect, a battery pack constant power control circuit terminal of the present invention is implemented by the following technical solutions:

A battery pack constant power control circuit terminal comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the method described in the present application is implemented when the processor executes the computer program.

In a sixth aspect, a computer-readable storage medium of the present invention is implemented by the following technical solution:

A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in the present application is implemented.

Compared with the prior art, the beneficial technical effects of this application are:

1. This application ensures that the impedance of the battery pack is normal by short-circuiting the abnormal battery;

2. Furthermore, the present application ensures the balance of power of each battery by transferring the power of the overcharged battery to the undercharged battery;

3. Furthermore, the present application realizes power balancing by controlling the duty cycle of the switch according to the voltage difference during the power transfer process and adaptively controlling the balancing current.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a control circuit of a specific embodiment of the present application;

FIG2 is a schematic diagram of an abnormal control circuit according to a specific embodiment of the present application;

FIG3 is a schematic diagram of a balancing control circuit according to a specific embodiment of the present application;

FIG. 4 is a schematic diagram of a battery pack abnormality control circuit according to a specific embodiment of the present application.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

A battery pack constant power control circuit of the present application, assuming that the battery pack includes M batteries, each battery is connected in series, as shown in FIG1, the battery pack constant power control circuit includes a main control circuit (not shown), M abnormal control circuits and M balancing circuits, and each battery is provided with an abnormal control circuit and a balancing circuit. The abnormal control circuit is connected in parallel with the battery, and the balancing circuit is connected in parallel with the battery.

The present application is described by including both an abnormal control circuit and a balancing circuit. In a specific embodiment of the present application, the constant power control circuit of the battery pack only includes a main control circuit and M abnormal control circuits, or only includes a main control circuit and M balancing circuits. In these two cases, the structure and working mode of the abnormal control circuit and the balancing circuit, and so on, are not repeated here.

The abnormal control circuit is used to short-circuit a battery when an abnormality occurs, so as to ensure the normal operation of the entire battery pack.

The balancing circuit is used to transfer the power of the high-voltage battery to the low-voltage battery when a certain battery has a high voltage, so as to achieve power balance between the batteries.

In the present application, the abnormal control circuit of each battery works in the same way, and the balancing circuit works in the same way. The following is explained with one battery, and the same applies to multiple batteries, which will not be repeated.

The abnormal control circuit includes a first switch circuit. The main control circuit detects the voltage across each battery. If it is determined that the voltage of the battery is greater than the set value than the voltage of other batteries, the main control circuit charges or discharges the battery to detect whether the battery is abnormal. The abnormality includes that the battery voltage rises relatively quickly during the charging process and the battery voltage drops relatively quickly during the discharging process, indicating that the battery's own storage capacity for electricity decreases, the internal resistance increases, and the temperature rise increases during operation, causing safety hazards.

The main control circuit charges and discharges each battery three times to determine whether each battery is abnormal. After confirming that a battery is abnormal, it performs abnormal processing. The abnormal processing method includes:

First, the abnormal battery voltage is discharged through the balancing circuit connected in parallel with the abnormal battery. When the abnormal battery voltage is about to reach 0V, the main control circuit turns on the abnormal control circuit connected in parallel with the abnormal battery, so that the abnormal control circuit is turned on and the abnormal circuit is bypassed, so that the entire battery pack is connected normally without abnormal batteries in the middle, and the power supply to the entire battery pack is in a stable state.

Determine whether each battery is abnormal. Abnormalities include charging and discharging too fast or too slow, and charging voltage not meeting the conditions. When the main control circuit determines that the battery is abnormal, it discharges the abnormal battery voltage through the balancing circuit in parallel with the abnormal battery. When the voltage of the abnormal battery is about to reach 0V, the main control circuit controls the abnormal control circuit in parallel with the abnormal battery to conduct, short-circuit the abnormal battery, and bypass the abnormal battery from the battery pack to make the current path of the entire battery pack run with normal resistance, ensuring the normal operation of electrical equipment, and the normal operation of the whole machine with power supply when the battery PACK N+1 fails.

The battery pack has a certain voltage space, that is, the battery pack can work normally within a certain voltage range. Generally, this voltage space is plus or minus 15% of the nominal voltage value. That is, if the battery pack is composed of 100 batteries connected in series, if 15 batteries are damaged, the battery pack can still work normally after these 15 batteries are bypassed and connected.

The first switch circuit includes two butt-jointed power tubes, as shown in FIG2 , the input end of the first power tube Q1 is connected to the positive end B-AD1 of the battery, and the output end thereof is connected to the output end of the second power tube Q2, the input end of the second power tube Q2 is connected to the negative end of the battery, the control end of the first power tube Q1 and the control end of the second power tube Q2 are connected together, and connected to the abnormal control signal output end EN of the main control circuit through the resistor R1.

When the abnormal control signal EN is valid, the first power tube Q1 and the second power tube Q2 are turned on at the same time, short-circuiting the two ends of the battery; when the abnormal control signal EN is invalid, the body diode of the first power tube Q1 and the body diode of the second power tube Q2 ensure that the first switch circuit is completely cut off to prevent leakage current from being generated and current loss.

The balancing circuit includes a second switch circuit. The main control circuit detects the voltage at both ends of the battery, compares the voltage of each battery in the battery pack, and determines whether there is a battery voltage higher than the voltage of most batteries, or a battery voltage lower than the voltage of most batteries according to the setting range of the battery voltage. When the battery voltage is higher than the voltage of most batteries, the balancing circuit is turned on, and the power of the high-voltage battery is used to charge the next low-voltage battery. When the battery voltage is lower than the voltage of some batteries, the balancing circuit of the previous battery of the battery is turned on, and the battery is charged with the power of the previous battery. After the charging and discharging of each battery in the battery pack, the voltage of each battery in the battery pack is relatively balanced, and the battery pack is balanced.

The equalization circuit is turned on or off according to the equalization signal of the main control circuit to provide charging current to the low-voltage battery.

The second switch circuit, as shown in FIG3 , includes a third power tube Q3 and a current limiting resistor R4. One end of the resistor R2 is connected to the output end of the main control circuit equalization signal CB1, and the other end thereof is connected to one end of the resistor R3 and the control end of the third power tube Q3. The input end of the third power tube Q3 is connected to one end of the current limiting resistor R4, and the other end of the current limiting resistor R4 is connected to the positive end B-AD1 of the battery. The output end of the third power tube Q3 and the other end of the resistor R3 are connected to the negative end B-AD0 of the battery.

When the equalization signal CB1 is valid, the third power tube Q3 is turned on, and the current limiting resistor R4 controls the current flowing through the power tube to transfer the battery power to the next battery.

When the equalization signal is invalid, the third power tube Q3 is turned off to prevent battery power loss.

The main control circuit controls the duty cycle of the balancing signal CB1 according to the voltage difference across the battery, so that the balancing current can be adaptively adjusted according to the voltage difference, and the balancing power and battery heating are controlled within a reasonable range, ensuring that the working path of the entire battery pack is more stable and the heating is uniform.

In a specific embodiment of the present application, when the main control circuit detects a battery abnormality, the balancing circuit connected in parallel with the battery is first turned on to balance the residual battery power to the next battery. After the battery power is 0, the abnormal control circuit is controlled to be turned on to bypass the battery to prevent the situation where high heat is generated by direct conduction when there is residual power in the battery.

The M batteries in the battery pack are connected in series, and a battery pack abnormality control circuit is set between the negative electrode of the first battery and the negative electrode of the battery pack, and the positive electrode of the Mth battery serves as the positive electrode of the battery pack.

The battery pack abnormality control circuit is used to control the battery pack when an abnormality occurs in the battery pack during the charging and discharging process.

During the charging process of the battery pack, when abnormal charging conditions such as abnormal charging, charging overvoltage, charging overcurrent, etc. occur, the battery pack abnormal control circuit prevents current from flowing from the negative electrode of the battery to the negative electrode of the battery pack.

During the discharge process of the battery pack, when an abnormal discharge state such as discharge overcurrent, discharge short circuit, abnormal discharge temperature, etc. occurs, the battery pack abnormal control circuit prevents current from flowing from the negative electrode of the battery pack to the negative electrode of the battery.

The battery pack abnormality control circuit includes a third switch circuit and a fourth switch circuit. The control end of the third switch circuit and the control end of the fourth switch circuit are respectively connected to the main control circuit. The input end of the third switch circuit is connected to the negative electrode of the battery through a resistor, and its output end is connected to the output end of the fourth switch circuit. The input end of the fourth switch circuit is connected to the negative electrode of the battery pack.

The battery pack abnormality control circuit is shown in FIG4 . The third switch circuit includes a fourth power tube Q4 , the fourth switch circuit includes a fifth power tube Q5 , and the resistor R5 is used for current limiting.

The control electrode G1 of the fourth power tube Q4 is connected to the discharge abnormality signal output terminal of the main control circuit, its input terminal is connected to the negative electrode B- of the first battery through the resistor R5, and its output terminal is connected to the output terminal of the fifth power tube Q5. The control electrode G2 of the fifth power tube Q5 is connected to the charging abnormality signal output terminal of the main control circuit, and its input terminal is connected to the negative electrode P- of the battery pack.

When the main control circuit detects abnormal discharge, it outputs a control signal to turn off the fourth power tube Q4 and turn on the fifth power tube Q5. The current flows from the negative electrode B of the battery to the body diode of the fourth power tube Q4, the fifth power tube Q5 and the negative electrode P- of the battery pack.

When the main control circuit detects abnormal charging, it outputs a control signal to turn off the fifth power tube Q5 and turn on the fourth power tube Q4. The current flows from the negative electrode P- of the battery pack to the body diode of the fifth power tube Q5---the fourth power tube Q4-the negative electrode B- of the battery.

A constant power control method for a battery pack of the present application confirms whether there is an abnormal battery in the battery pack by charging and discharging the battery level at least once, and performs abnormal processing on the battery pack when an abnormal situation is detected in a battery in the battery pack.

Assuming that an abnormality occurs in the third battery, the voltage of the third battery is discharged through the third balancing circuit. When the voltage of the third battery drops to about 0V, it indicates that the discharge is completed. Then the third abnormal control circuit is turned on to short-circuit the third battery. After the entire battery pack loses one battery, the voltage of the entire battery pack still meets the output voltage requirement, and the entire battery pack is powered normally.

The same applies to any other abnormal situation of the battery and no further explanation is given.

Taking the third battery as an example, the following is explained:

Since the single-channel balancing circuit includes a current limiting resistor R5 and a balancing power tube (MOS tube Q4/Q5), the balancing current is the largest when the balancing power tube is normally open, and the balancing stops when the balancing power tube is closed. In this way, when the balancing power tube is turned on, the temperature rise of the current limiting resistor is relatively large. If the ambient temperature is 25°C, the temperature rise of the current limiting resistor is still acceptable. When the ambient temperature rises, for example, reaching more than 50 degrees Celsius, coupled with the temperature rise generated by the current limiting resistor during balancing, the temperature of the balancing circuit will reach more than 100°C, causing unstable operation and thus causing safety hazards. NTC is used to detect the ambient temperature, and the balancing power tube control signal is adjusted based on the ambient temperature. The switching duty cycle of the power tube control signal PWM is adjusted to reduce the balancing current, thereby reducing the resistance temperature rise, so that the balancing circuit works within a reasonable temperature range.

Since the balancing resistor is fixed, the current passing through the current limiting resistor is also different when the battery voltage is different. By adjusting the balancing power tube switch, the PWM switch duty cycle is adjusted to make the balancing power the same and control the heating temperature. The balancing power will not be inconsistent with the battery voltage.

Abnormalities include the battery voltage rising quickly during charging and falling quickly during discharging, which indicates that the battery's ability to store electricity decreases, the internal resistance increases, and the temperature rise increases during operation, causing safety hazards. The main control chip performs three charges and discharges to confirm that there is an abnormality in the battery pack. When a battery abnormality is detected in the battery pack, the abnormality is handled as follows: First, the abnormal battery voltage is discharged through the balancing circuit of the present application. When the abnormal battery voltage reaches the 0V voltage range, the power tube connected in parallel with the abnormal battery is turned on to short-circuit the abnormal battery, so that the entire battery pack is connected normally, there is no abnormal battery in the battery pack, and the battery pack is in a stable state of power supply to the whole machine.

It includes a main control circuit that detects the voltage at both ends of each battery. When the voltage at both ends of the battery is lower than the voltage of most of the batteries in the group, the battery is charged or discharged, and whether there is any abnormality in charging or discharging, such as a rapid voltage rise during charging and a rapid voltage drop during discharging. If the battery is abnormal, the power on the battery is first transferred to the next battery through the balancing circuit. When the power on the battery is 0, the abnormal control circuit is turned on, and the battery is bypassed and connected to ensure the normal operation of the entire battery pack.

When the main control circuit detects that the voltage of a battery in the battery pack is significantly higher than the voltage of most batteries in the group, it turns on the balancing circuit corresponding to the battery, controls the duty cycle of the balancing circuit according to the voltage difference between the upper and lower batteries, and adaptively adjusts the balancing current to transfer part of the power on the battery to the next battery, thereby ensuring that the power of each battery is balanced and extending the life of the battery pack.

An embodiment of the present invention provides a battery pack constant power control terminal device. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as an exception control program. When the processor executes the computer program, the method described in this application is implemented.

Exemplarily, the computer program may be divided into one or more modules/units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules/units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the battery pack constant power control terminal device.

The battery pack constant power control terminal device can be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The battery pack constant power control terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above examples are merely examples of the battery pack constant power control terminal device and do not constitute a limitation on the battery pack constant power control terminal device. The battery pack constant power control terminal device may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the battery pack constant power control terminal device may also include input and output devices, network access devices, buses, etc.

The processor may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the battery pack constant power control terminal device, and uses various interfaces and lines to connect the various parts of the battery pack constant power control terminal device.

The memory can be used to store the computer program and/or module, and the processor realizes various functions of the battery pack constant power control terminal device by running or executing the computer program and/or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

The module/unit integrated in the battery pack constant power control terminal device, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal and software distribution medium, etc.

The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A battery pack constant power control circuit, the resistance group includes M batteries, its characterized in that: the system comprises a main control circuit and M abnormal control circuits, wherein two ends of each battery are connected with one abnormal control circuit in parallel, the main control circuit is connected with each battery and each abnormal control circuit and is used for detecting voltages at two ends of each battery, judging whether each battery generates an abnormality according to voltage, current, charging state, voltage drop condition during discharging state and internal resistance of each battery, when determining that a certain battery is abnormal, the main control circuit discharges the abnormal battery, and after the discharging is completed, the abnormal control circuit connected with the abnormal battery in parallel is controlled to be conducted, the abnormal battery is bypassed, so that the whole battery pack is normally powered.

2. The battery pack constant power control circuit according to claim 1, wherein: the abnormal control circuit comprises a first switch circuit which is turned on or turned off according to an abnormal control signal of the main control circuit.

3. The battery pack constant power control circuit according to claim 2, wherein: the first switch circuit comprises two butted power tubes, a control electrode of the first power tube is connected with a control electrode of the second power tube and is connected with an abnormal signal output end of the main control circuit, an input end of the first power tube is connected to a positive end of the battery, an output end of the first power tube is connected to an output end of the second power tube, and an input end of the second power tube is connected with a negative end of the battery.

4. A battery pack constant power control circuit, the resistance group includes M batteries, its characterized in that: the battery charging control device comprises a main control circuit and M equalizing circuits, wherein two ends of each battery are connected with one equalizing circuit in parallel, the main control circuit is connected with each battery and each equalizing circuit and is used for detecting voltages at two ends of each battery, judging whether the voltages of the batteries are higher than the voltages of other batteries according to the voltages of the batteries, and when the voltages of certain batteries are determined to be higher, the equalizing circuits control the high-voltage batteries to charge the low-voltage batteries in the group.

5. The battery pack constant power control circuit according to claim 4, wherein: the equalization circuit comprises a second switch circuit which is turned on or off according to the equalization signal of the main control circuit and transmits the electric quantity of the high-voltage battery to the next connected low-voltage battery.

6. The battery pack constant power control circuit according to claim 4, wherein: the second switch circuit comprises a third power tube and a current-limiting resistor, wherein the input end of the third power tube is connected to the positive end of the battery through the current-limiting resistor, the output end of the third power tube is connected to the negative end of the battery, and the control end of the third power tube is connected with the balanced signal output end of the main control circuit through the resistor.

7. A battery pack constant power control circuit, the resistance group includes M batteries, its characterized in that: the battery pack charging and discharging control device comprises a main control circuit, M abnormal control circuits, M equalizing circuits and a battery pack abnormal control circuit, wherein the abnormal control circuit and the equalizing circuits are connected in parallel at two ends of a battery, the negative end of the battery pack is connected with one end of the battery pack abnormal control circuit, the other end of the battery pack abnormal control circuit is connected to the negative end of a first battery in the battery pack, the control end of the battery pack abnormal control circuit is connected to the main control circuit, and when the main control circuit detects that the battery pack charging and discharging are abnormal, the current flow direction of the battery pack is controlled.

8. A battery pack constant power control method is characterized in that: the control circuit detects the voltage, the charging state and the discharging state of the two ends of each battery, compares the voltages of the batteries, and controls the duty ratio of a power tube control signal in the equalization circuit according to the voltage difference of the upper battery and the lower battery if the voltage of one battery is higher than that of the other batteries, so as to control the magnitude of the equalization current, and transfer the electric quantity of the high-voltage battery to the low-voltage battery to realize equalization; if the voltage of a certain battery is lower than that of the rest batteries in the battery pack, the battery is charged or discharged, and when the battery abnormality is detected, an abnormality control circuit for controlling the battery is opened, the battery is short-circuited, and the abnormal battery is bypassed.

9. A battery pack constant power control circuit terminal comprising a memory, a processor, and a computer program stored in the memory and operable on the processor, characterized by: the processor, when executing the computer program, implements the method of claim 8.

10. A computer readable storage medium storing a computer program, which when executed by a processor performs the method of claim 8.