Shunt and battery pack

Abstract

The invention discloses a shunt and a battery pack. The shunt comprises a detection resistor, a circuit board assembly, a first temperature sensor, a second temperature sensor and a third temperature sensor. The detection resistor and the circuit board assembly are oppositely arranged. The first temperature sensor and the second temperature sensor are arranged on the two sides of the detection resistor respectively. The first temperature sensor and the second temperature sensor are both connected with the circuit board assembly, and the third temperature sensor is arranged on the circuit board assembly. The first temperature sensor is used for measuring the first temperature of the anode of the shunt, the second temperature sensor is used for measuring the second temperature of the cathode of the shunt, and the third temperature sensor is used for measuring the third temperature of the detection resistor. The circuit board assembly is used for correcting the detection current of the shunt according to the first temperature, the second temperature and the third temperature. Therefore, the influence of the Seebeck effect and the temperature change of the detection resistor on the detection current can be corrected, and the current detection precision of the shunt is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of current detection, and in particular to a shunt and a battery pack. Background Art

[0002] The shunt has a simple structure and strong anti-interference ability, and is widely used in current detection in power battery packs. At present, the shunt is composed of copper and manganese-copper alloy. During operation, the temperature difference between the positive and negative electrodes will generate electromotive force. This phenomenon is called the Seebeck effect (the first thermoelectric effect). The measurement voltage of the shunt is very small, and the thermoelectric electromotive force at the μV level can seriously affect the current detection result. How to correct the influence of the Seebeck effect on current detection is an urgent problem to be solved. Summary of the invention

[0003] The embodiments of the present application provide a shunt and a battery pack to solve at least one of the above-mentioned technical problems.

[0004] A shunt according to an embodiment of the present application includes: a detection resistor, a circuit board assembly, a first temperature sensor, a second temperature sensor, and a third temperature sensor, wherein the detection resistor is arranged opposite to the circuit board assembly, the first temperature sensor and the second temperature sensor are arranged on both sides of the detection resistor, respectively, the first temperature sensor and the second temperature sensor are both connected to the circuit board assembly, and the third temperature sensor is arranged on the circuit board assembly;

[0005] The first temperature sensor is used to measure the first temperature of the positive electrode of the shunt, the second temperature sensor is used to measure the second temperature of the negative electrode of the shunt, the third temperature sensor is used to measure the third temperature of the detection resistor, and the circuit board assembly is used to correct the detection current of the shunt according to the first temperature, the second temperature and the third temperature.

[0006] In some embodiments, the shunt further includes a first fixing plate, a second fixing plate, a first voltage sensor and a second voltage sensor, the first fixing plate and the second fixing plate are respectively arranged on both sides of the detection resistor, the first voltage sensor is arranged at one end of the first fixing plate close to the detection resistor, the second voltage sensor is arranged at one end of the second fixing plate close to the detection resistor, and the first voltage sensor and the second voltage sensor are both connected to the circuit board assembly;

[0007] The circuit board assembly is used to collect the voltage difference between two sides of the detection resistor through the first voltage sensor and the second voltage sensor, so as to determine the detection current based on the voltage difference.

[0008] In certain embodiments, the circuit board assembly includes a temperature compensation circuit;

[0009] A circuit input end of the temperature compensation circuit is connected to the first temperature sensor, the second temperature sensor and the third temperature sensor;

[0010] The circuit output end of the temperature compensation circuit is used to respectively output a compensation voltage which is linearly related to the inverse of the temperature measured by each temperature sensor.

[0011] In certain embodiments, the temperature compensation circuit includes a first triode, a second triode, a first operational amplifier, and a second operational amplifier;

[0012] The base and collector of the first transistor are both connected to the circuit input end, the emitter of the first transistor is connected to the emitter of the second transistor, the base and collector of the second transistor are both connected to the non-inverting input end of the second operational amplifier, the inverting input end of the first operational amplifier is connected to the circuit input end, the non-inverting input end of the first operational amplifier is grounded, the output end of the first operational amplifier is connected between the emitter of the first transistor and the emitter of the second transistor, the inverting input end of the second operational amplifier is grounded, and the output end of the second operational amplifier is connected to the circuit output end.

[0013] In some embodiments, the circuit board assembly further includes a selection circuit connected to the first temperature sensor, the second temperature sensor, and the third temperature sensor;

[0014] The selection circuit is used to select the branch where the first temperature sensor, the second temperature sensor or the third temperature sensor is located to be turned on, so that the circuit output end of the temperature compensation circuit outputs the corresponding compensation voltage.

[0015] In certain embodiments, the circuit board assembly further comprises a zeroing circuit;

[0016] The zero adjustment circuit is connected to the circuit output end of the temperature compensation circuit and is used to perform zero point adjustment on the compensation voltage to obtain a corresponding first output voltage.

[0017] In certain embodiments, the circuit board assembly further includes a divider circuit;

[0018] The division circuit is connected to the zero adjustment circuit, and is used for performing a division operation on the first output voltage to obtain a corresponding second output voltage.

[0019] In certain embodiments, the circuit board assembly further includes a limiting circuit;

[0020] The amplitude limiting circuit is connected to the dividing circuit, and the amplitude limiting circuit is used to limit the amplitude of the second output voltage to obtain a corresponding third output voltage.

[0021] In some embodiments, the circuit board assembly also includes a processor, which is connected to the limiting circuit and is used to determine the first temperature based on the third output voltage corresponding to the first temperature sensor, determine the second temperature based on the third output voltage corresponding to the second temperature sensor, and determine the third temperature based on the third output voltage corresponding to the third temperature sensor, so as to determine a first correction coefficient and a second correction coefficient based on the first temperature, the second temperature and the third temperature to correct the detection current.

[0022] A battery pack according to an embodiment of the present application comprises a shunt according to any of the above embodiments; and

[0023] The shunt is used to detect the current of the battery cell.

[0024] In the shunt and battery pack of the embodiment of the present application, a first temperature sensor and a second temperature sensor are arranged on both sides of the detection resistor, respectively used to detect the first temperature of the positive electrode of the shunt and the second temperature of the negative electrode of the shunt, and a third temperature sensor is arranged on the circuit board assembly to measure the third temperature of the detection resistor itself, and the circuit board assembly corrects the detection current of the shunt according to the first temperature, the second temperature and the third temperature. In this way, the influence of the Seebeck effect and the temperature change of the detection resistor itself on the detection current can be corrected, and the current detection accuracy of the shunt can be effectively improved.

[0025] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. Among them:

[0027] Figure 1 is a schematic side view of the structure of a flow divider in certain embodiments of the present application;

[0028] Figure 2 is a schematic diagram of a top view of a partial structure of a flow divider in certain embodiments of the present application;

[0029] Figure 3is a schematic diagram of the Seebeck effect of certain embodiments of the present application;

[0030] Figure 4 is a schematic diagram of a module for connecting a temperature sensor and a circuit board assembly in certain embodiments of the present application;

[0031] Figure 5 It is a schematic diagram of a structure in which a selection circuit, a temperature sensor and a temperature compensation circuit are connected in sequence in certain embodiments of the present application;

[0032] Figure 6 It is a structural schematic diagram of a zero adjustment circuit, a division circuit and a limiter circuit connected in sequence in certain embodiments of the present application;

[0033] Figure 7 is a schematic diagram of the structure of a four-quadrant analog multiplier in certain embodiments of the present application;

[0034] Figure 8 It is a module schematic diagram of a battery pack of certain embodiments of the present application.

[0035] Description of reference numerals:

[0036] The shunt 100, the detection resistor 10, the circuit board assembly 20, the temperature compensation circuit 21, the first transistor Q1, the second transistor Q2, the first operational amplifier U1, the second operational amplifier U2, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the selection circuit 22, the first field effect transistor M1, the second field effect transistor M2, the third field effect transistor M3, the zero adjustment circuit 23, the third operational amplifier U3, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the division circuit 24, the fourth operational amplifier U4, the analog multiplier U6, the first The twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the limiting circuit 25, the fifth operational amplifier U5, the sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18, the nineteenth resistor R19, the twentieth resistor R20, the twenty-first resistor R21, the processor 26, the power supply unit 27, the first temperature sensor 30, the second temperature sensor 40, the third temperature sensor 50, the first fixing plate 61, the first fixing hole 611, the second fixing plate 62, the second fixing hole 621, the first voltage sensor 71, the second voltage sensor 72, the first soldering pad 73, the second soldering pad 74, the battery pack 200, and the battery cell 210. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0038] See also Figure 1 and Figure 2 , an embodiment of the present application provides a shunt 100. The shunt 100 includes a detection resistor 10, a circuit board assembly 20, a first temperature sensor 30, a second temperature sensor 40 and a third temperature sensor 50. The detection resistor 10 is arranged opposite to the circuit board assembly 20. The first temperature sensor 30 and the second temperature sensor 40 are respectively arranged on both sides of the detection resistor 10. The first temperature sensor 30 and the second temperature sensor 40 are both connected to the circuit board assembly 20, and the third temperature sensor 50 is arranged on the circuit board assembly 20. The first temperature sensor 30 is used to measure the first temperature of the positive electrode of the shunt 100, the second temperature sensor 40 is used to measure the second temperature of the negative electrode of the shunt 100, and the third temperature sensor 50 is used to measure the third temperature of the detection resistor 10. The circuit board assembly 20 is used to correct the detection current of the shunt 100 according to the first temperature, the second temperature and the third temperature.

[0039] In the shunt 100 of the embodiment of the present application, a first temperature sensor 30 and a second temperature sensor 40 are arranged on both sides of the detection resistor 10, respectively used to detect the first temperature of the positive electrode of the shunt 100 and the second temperature of the negative electrode of the shunt 100, and a third temperature sensor 50 is arranged on the circuit board assembly 20, used to measure the third temperature of the detection resistor 10 itself, and the circuit board assembly 20 corrects the detection current of the shunt 100 according to the first temperature, the second temperature and the third temperature. In this way, the influence of the Seebeck effect and the temperature change of the detection resistor 10 itself on the detection current can be corrected, and the current detection accuracy of the shunt 100 can be effectively improved.

[0040] Specifically, the detection resistor 10 can adopt a resistance of μΩ level. The first temperature sensor 30, the second temperature sensor 40 and the third temperature sensor 50 can adopt a negative temperature coefficient (NTC) thermistor, and the resistance of the NTC thermistor decreases with the increase of temperature. When the resistance of the NTC thermistor changes with temperature, the current or voltage across the NTC thermistor changes. By measuring the current or voltage across the NTC thermistor, the resistance of the NTC thermistor can be determined, thereby determining the corresponding temperature.

[0041] The first temperature sensor 30 and the second temperature sensor 40 are respectively arranged on both sides of the detection resistor 10, and are symmetrical along the center of the detection resistor 10. When current flows through the detection resistor 10, a voltage drop of mV level is generated on both sides of the detection resistor 10, and the detection current can be calculated by measuring this voltage drop. Along the direction of the current flowing through the detection resistor 10, one side of the detection resistor 10 is the positive electrode of the shunt 100, and the other side is the negative electrode of the shunt 100. The first temperature sensor 30 is used to measure the first temperature of the positive electrode of the shunt 100, and the second temperature sensor 40 is used to measure the second temperature of the negative electrode of the shunt 100.

[0042] The detection resistor 10 is arranged opposite to the circuit board assembly 20, and the third temperature sensor 50 is arranged on a side of the circuit board assembly 20 opposite to the detection resistor 10, and the third temperature sensor 50 is used to measure the third temperature of the detection resistor 10. The circuit board assembly 20 is also connected to the first temperature sensor 30 and the second temperature sensor 40. After the circuit board assembly 20 obtains the first temperature, the second temperature and the third temperature, the detection current of the shunt 100 can be corrected according to the first temperature, the second temperature and the third temperature.

[0043] It can be understood that during the operation of the shunt 100, the current flows through the detection resistor 10, causing the temperature of the detection resistor 10 to change, resulting in fluctuations in the resistance of the detection resistor 10. The detection current is determined by the voltage drop on both sides of the detection resistor 10 and the resistance of the detection resistor 10. The fluctuation of the resistance of the detection resistor 10 will cause errors in the detection current. Therefore, a third temperature sensor 50 is provided in the circuit board assembly 20 to measure the third temperature of the detection resistor 10 itself, so that the circuit board assembly 20 can correct the detection current according to the third temperature. In this way, the influence of the temperature change of the detection resistor 10 itself on the detection current can be corrected, and the current detection accuracy of the shunt 100 can be improved.

[0044] In the related technology, the shunt is composed of copper and manganese-copper alloy. During operation, there will be a temperature difference between the positive and negative electrodes of the shunt, resulting in the generation of thermoelectric potential. This phenomenon is called the Seebeck effect. Figure 3 As shown in Figure 1, the direction of the generated thermoelectric emf depends on the direction of the temperature gradient. Since the measured voltage of the shunt is very small, the thermoelectric emf of μV level can seriously affect the current detection result of the shunt.

[0045] In the embodiment of the present application, a first temperature sensor 30 and a second temperature sensor 40 are arranged on both sides of the detection resistor 10, which are respectively used to detect the first temperature of the positive electrode of the shunt 100 and the second temperature of the negative electrode of the shunt 100. After the circuit board assembly 20 obtains the first temperature and the second temperature, the temperature difference between the positive electrode of the shunt 100 and the negative electrode of the shunt 100 can be determined according to the first temperature and the second temperature, so as to correct the detection current according to the temperature difference. In this way, the influence of the Seebeck effect on the detection current can be corrected, and the current detection accuracy of the shunt 100 can be further improved.

[0046] See also Figure 1 and Figure 2 In some embodiments, the shunt 100 further includes a first fixing plate 61, a second fixing plate 62, a first voltage sensor 71, and a second voltage sensor 72. The first fixing plate 61 and the second fixing plate 62 are respectively disposed on both sides of the detection resistor 10. The first voltage sensor 71 is disposed at one end of the first fixing plate 61 close to the detection resistor 10, and the second voltage sensor 72 is disposed at one end of the second fixing plate 62 close to the detection resistor 10. The first voltage sensor 71 and the second voltage sensor 72 are both connected to the circuit board assembly 20. The circuit board assembly 20 is used to collect the voltage difference between the two sides of the detection resistor 10 through the first voltage sensor 71 and the second voltage sensor 72 to determine the detection current based on the voltage difference.

[0047] Specifically, the first fixing plate 61 and the second fixing plate 62 can be made of metal. The first fixing plate 61 and the second fixing plate 62 are respectively arranged on both sides of the detection resistor 10, the first temperature sensor 30 can be fixedly arranged on the first fixing plate 61 by bolts, and the second temperature sensor 40 can be fixedly arranged on the second fixing plate 62 by bolts. The detection resistor 10 is located between the first fixing plate 61 and the second fixing plate 62. The height of the detection resistor 10 is less than the height of the first fixing plate 61 and the second fixing plate 62, the height of the first fixing plate 61 and the second fixing plate 62 are consistent, the bottom surface of the detection resistor 10 is flush with the bottom surface of the first fixing plate 61 and the bottom surface of the second fixing plate 62, so that there is a gap between the circuit board and the detection resistor 10, and the third temperature sensor 50 is arranged at a position corresponding to the gap between the circuit board and the gap.

[0048] A first fixing hole 611 is provided at one end of the first fixing plate 61 away from the detection resistor 10, and a second fixing hole 621 is provided at one end of the second fixing plate 62 away from the detection resistor 10. The first fixing hole 611 and the second fixing hole 621 are symmetrically arranged along both sides of the detection resistor 10. The first fixing hole 611 and the second fixing hole 621 can be matched with bolts to fix the shunt 100 to a device that needs to perform current detection. For example, the first fixing hole 611 is connected to the positive pole of the device, and the second fixing hole 621 is connected to the negative pole of the device, so that the current flows out from the positive pole of the device, flows to the detection resistor 10 through the first fixing plate 61, and then flows back to the negative pole of the device through the second fixing plate 62.

[0049] The first voltage sensor 71 is disposed at one end of the first fixing plate 61 close to the detection resistor 10, and the second voltage sensor 72 is disposed at one end of the second fixing plate 62 close to the detection resistor 10. The first voltage sensor 71 and the second voltage sensor 72 are symmetrically disposed along both sides of the detection resistor 10. On one side of the circuit board assembly 20 opposite to the detection resistor 10, a first solder pad 73 is disposed at a position corresponding to the first voltage sensor 71, and a second solder pad 74 is disposed at a position corresponding to the second voltage sensor 72.

[0050] The first voltage sensor 71 and the second voltage sensor 72 can be conductive wires. One end of the first voltage sensor 71 is connected to one side of the detection resistor 10, and the other end of the first voltage sensor 71 is connected to the first pad 73, so that the circuit board assembly 20 can obtain the voltage on one side of the detection resistor 10 through the first voltage sensor 71. One end of the second voltage sensor 72 is connected to the other side of the detection resistor 10, and the other end of the second voltage sensor 72 is connected to the second pad 74, so that the circuit board assembly 20 can obtain the voltage on the other side of the detection resistor 10 through the second voltage sensor 72. Further, the circuit board assembly 20 can obtain the voltage drop generated by the current flowing through the two sides of the detection resistor 10, that is, the voltage difference. After obtaining the voltage difference, the ratio of the voltage difference to the resistance value of the detection resistor 10 is calculated to obtain the detection current.

[0051] See also Figure 1 , Figure 4 and Figure 5 In some embodiments, the circuit board assembly 20 includes a temperature compensation circuit 21. The circuit input end of the temperature compensation circuit 21 is connected to the first temperature sensor 30, the second temperature sensor 40, and the third temperature sensor 50. The circuit output end of the temperature compensation circuit 21 is used to output a compensation voltage that is linearly related to the inverse of the temperature measured by each temperature sensor.

[0052] Specifically, the circuit input end of the temperature compensation circuit 21 is connected to the first temperature sensor 30 , the second temperature sensor 40 and the third temperature sensor 50 , and the temperature compensation circuit 21 is used to compensate for the nonlinear relationship between the resistance value and temperature of the temperature sensor.

[0053] When the branch where the first temperature sensor 30 is located is turned on, if the temperature of the positive electrode of the shunt 100 changes, the resistance of the first temperature sensor 30 changes with the temperature, and thus the voltage across the first temperature sensor 30 also changes; the temperature compensation circuit 21 processes the received voltage and outputs a first compensation voltage that is linearly related to the inverse of the temperature measured by the first temperature sensor 30, thereby compensating for the nonlinear relationship between the resistance of the first temperature sensor 30 and the first temperature.

[0054] When the branch where the second temperature sensor 40 is located is turned on, if the temperature of the negative electrode of the shunt 100 changes, the resistance of the second temperature sensor 40 changes with the temperature, and thus the voltage across the second temperature sensor 40 also changes; the temperature compensation circuit 21 processes the received voltage and outputs a second compensation voltage that is linearly related to the inverse of the temperature measured by the second temperature sensor 40, thereby compensating for the nonlinear relationship between the resistance of the second temperature sensor 40 and the second temperature.

[0055] When the branch where the third temperature sensor 50 is located is turned on, if the temperature of the detection resistor 10 changes, the resistance of the third temperature sensor 50 changes with the temperature, and thus the voltage across the third temperature sensor 50 also changes; the temperature compensation circuit 21 processes the received voltage and outputs a third compensation voltage that is linearly related to the inverse of the temperature measured by the third temperature sensor 50, thereby compensating for the nonlinear relationship between the resistance of the third temperature sensor 50 and the third temperature.

[0056] See also Figure 4 In some embodiments, the circuit board assembly 20 further includes a power supply unit 27 , which is connected to the temperature compensation circuit 21 , and is used to supply power to the temperature compensation circuit 21 .

[0057] See also Figure 5In some embodiments, the temperature compensation circuit 21 includes a first transistor Q1, a second transistor Q2, a first operational amplifier U1, and a second operational amplifier U2. The base and collector of the first transistor Q1 are both connected to the circuit input terminal, and the emitter of the first transistor Q1 is connected to the emitter of the second transistor Q2. The base and collector of the second transistor Q2 are both connected to the non-inverting input terminal of the second operational amplifier U2. The inverting input terminal of the first operational amplifier U1 is connected to the circuit input terminal, the non-inverting input terminal of the first operational amplifier U1 is grounded, and the output terminal of the first operational amplifier U1 is connected between the emitter of the first transistor Q1 and the emitter of the second transistor Q2. The inverting input terminal of the second operational amplifier U2 is grounded, and the output terminal of the second operational amplifier U2 is connected to the circuit output terminal.

[0058] Specifically, the first transistor Q1 and the second transistor Q2 have the same characteristics, and an integrated common emitter NPN pair can be used, which can eliminate the influence of the PN junction reverse saturation current on the circuit operation relationship. The temperature compensation circuit 21 also includes multiple resistors. In one example, the multiple resistors include a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4.

[0059] The base and collector of the first transistor Q1 are both connected to the circuit input terminal, and the emitter of the first transistor Q1 is connected to the emitter of the second transistor Q2. The base and collector of the second transistor Q2 are both connected to the non-inverting input terminal of the second operational amplifier U2, and the base and collector of the second transistor Q2 are also connected to one end of the first resistor R1, and the other end of the first resistor R1 is used to access the reference voltage. The inverting input terminal of the first operational amplifier U1 is connected to the circuit input terminal, the non-inverting input terminal of the first operational amplifier U1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, and the output terminal of the first operational amplifier U1 is connected between the emitter of the first transistor Q1 and the emitter of the second transistor Q2. The inverting input terminal of the second operational amplifier U2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is grounded, and the output terminal of the second operational amplifier U2 is connected to the circuit output terminal. One end of the fourth resistor R4 is connected to the inverting input terminal of the second operational amplifier U2, and the other end is connected to the output terminal of the second operational amplifier U2.

[0060] The compensation principle of the temperature compensation circuit 21 is described in detail below.

[0061] According to the current distribution relationship of the transistor, we can get:

[0062]

[0063] Among them, I 11 , I CT and I E1are the currents of the base, collector and emitter of the first transistor Q1, I B2 , I C2 and I E2 are the currents of the base, collector and emitter of the second transistor Q2 respectively; R T is the resistance of the temperature sensor; U REF is a reference voltage, which may be provided by the power supply unit 27 .

[0064] The relationship between the voltage and current at the PN junction is as follows:

[0065]

[0066] Among them, I S is the reverse saturation current; U BE is the voltage between the base and collector of the transistor; U T =kT / q is the temperature voltage equivalent, k is the Boltzmann constant, and q is the charge of the electron.

[0067] When the PN junction is forward biased, the terminal voltage and current can be approximated as:

[0068]

[0069] Among them, U BE >>U T .

[0070] Substituting formula (2) and formula (3) into formula (4) respectively, the transformed form can be obtained:

[0071]

[0072] Among them, the second operational amplifier U2 is a common-phase amplifier. BE1 and U BE2 The voltage value can be used to calculate the output voltage U of the temperature compensation circuit 21 O :

[0073]

[0074] The empirical formula for RT of NTC thermistor is: Substituting the RT empirical formula into formula (7), we can obtain:

[0075]

[0076] Where R0 is the nominal resistance of the NTC thermistor at temperature T0, B is the material constant of the NTC thermistor, let For the determined temperature compensation circuit 21 and NTC thermistor, the quantities in the formula are all known, so:

[0077]

[0078] From formula (9), we can see that U O and Into a linear relationship.

[0079] See also Figure 1 , Figure 4 and Figure 5 In some embodiments, the circuit board assembly 20 further includes a selection circuit 22. The selection circuit 22 is connected to the first temperature sensor 30, the second temperature sensor 40, and the third temperature sensor 50. The selection circuit 22 is used to select the branch where the first temperature sensor 30, the second temperature sensor 40, or the third temperature sensor 50 is located to be turned on, so that the circuit output end of the temperature compensation circuit 21 outputs a corresponding compensation voltage.

[0080] Specifically, the selection circuit 22 may include multiple field effect transistors, and the number of field effect transistors is the same as the number of temperature sensors. For example, the selection circuit 22 includes a first field effect transistor M1, a second field effect transistor M2 and a third field effect transistor M3. The first field effect transistor M1 is connected to the first temperature sensor 30, the second field effect transistor M2 is connected to the second temperature sensor 40, and the third field effect transistor M3 is connected to the third temperature sensor 50.

[0081] When the first field effect transistor M1 is turned on, the branch where the first temperature sensor 30 is located is turned on, and at this time, the circuit output end of the temperature compensation circuit 21 is used to output the first compensation voltage. When the second field effect transistor M2 is turned on, the branch where the second temperature sensor 40 is located is turned on, and at this time, the circuit output end of the temperature compensation circuit 21 is used to output the second compensation voltage. When the third field effect transistor M3 is turned on, the branch where the third temperature sensor 50 is located is turned on, and at this time, the circuit output end of the temperature compensation circuit 21 is used to output the third compensation voltage.

[0082] See also Figure 1 , Figure 4 and Figure 6 In some embodiments, the circuit board assembly 20 further includes a zero adjustment circuit 23. The zero adjustment circuit 23 is connected to the circuit output end of the temperature compensation circuit 21 and is used to perform zero point adjustment on the compensation voltage to obtain a corresponding first output voltage.

[0083] Specifically, the zero adjustment circuit 23 is also connected to the power supply unit 27, and the power supply unit 27 is used to supply power to the zero adjustment circuit 23. The zero adjustment circuit 23 includes a third operational amplifier U3 and a plurality of resistors. The third operational amplifier U3 is used for in-phase summing. In an example, the plurality of resistors include a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and an eleventh resistor R11. One end of the fifth resistor R5 is connected to a 5V voltage, and the other end is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the inverting input terminal of the third operational amplifier U3, one end of the sixth resistor R6 is connected between the fifth resistor R5 and the seventh resistor R7, and the other end is grounded. One end of the eighth resistor R8 is connected to the circuit output terminal of the temperature compensation circuit 21, and the other end is connected to the in-phase input terminal of the third operational amplifier U3, and one end of the ninth resistor R9 is connected to the in-phase input terminal of the third operational amplifier U3, and the other end is grounded. One end of the eleventh resistor R11 is connected to the inverting input terminal of the third operational amplifier U3, and the other end is grounded. One end of the tenth resistor R10 is connected to the inverting input terminal of the third operational amplifier U3, and the other end is connected to the output terminal of the third operational amplifier U3. The output terminal of the third operational amplifier U3 is used to output the first output voltage.

[0084] Zero point adjustment refers to adjusting the compensation voltage output by the temperature compensation circuit 21 so that within the temperature measurement range of the temperature sensor, the output compensation voltage is always positive, that is, the first output voltage output by the zero adjustment circuit 23 is always greater than zero. It can be understood that if different types of NTC thermistors are used as temperature sensors, the temperature sensors will have different temperature measurement ranges. Before practical application, the zero adjustment circuit 23 needs to be debugged according to the actual temperature measurement range of the temperature sensor so that the zero adjustment circuit 23 can achieve the effect of zero point adjustment. The debugging of the zero adjustment circuit 23 is achieved by adjusting the resistance value of the sixth resistor R6. During the debugging process, a variable resistance box can be used to equalize the resistance value of the NTC thermistor at different temperatures.

[0085] Take the NTC thermistor with a temperature measurement range of -40℃~125℃ as the temperature sensor as an example. If the first output voltage at -40℃ is E1, the first output voltage at 42.5℃ is E2, and the first output voltage at 125℃ is E3, it is necessary to select the sixth resistor R6 with a suitable resistance value so that the first output voltage is greater than zero and the first output voltage meets the condition:

[0086] |E2-E1|=|E3-E2| (10)

[0087] The relationship between the resistance of the sixth resistor R6 and the first output voltage is as follows:

[0088]

[0089] Among them, E X is the first output voltage; R P is the equivalent resistance of the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9; U IN =U O .

[0090] After the debugging of the zero adjustment circuit 23 is completed, in practical applications, the zero adjustment circuit 23 can be directly used to adjust the zero point of the compensation voltage to obtain the corresponding first output voltage.

[0091] See also Figure 1 , Figure 4 and Figure 6 In some embodiments, the circuit board assembly 20 further includes a dividing circuit 24. The dividing circuit 24 is connected to the zeroing circuit 23, and the dividing circuit 24 is used to perform a division operation on the first output voltage to obtain a corresponding second output voltage.

[0092] Specifically, the division circuit 24 is also connected to a power supply unit 27, and the power supply unit 27 is used to supply power to the division circuit 24. The division circuit 24 includes a fourth operational amplifier U4, an analog multiplier U6, and a plurality of resistors. In one example, the plurality of resistors include a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifteenth resistor R15. The analog multiplier U6 can be a four-quadrant analog multiplier. The relationship between the input signal and the output signal of the four-quadrant analog multiplier is as follows: Figure 7 As shown, the output signal at the W output terminal is In the dividing circuit 24 , the analog multiplier U6 is disposed in the non-feedback channel of the fourth operational amplifier U4 .

[0093] The X1 input terminal of the analog multiplier U6 is connected to the zero adjustment circuit 23, and specifically can be connected to the output terminal of the third operational amplifier U3, so as to convert the first output voltage E X Input to the analog multiplier U6, the X2 input terminal, the Y2 input terminal and the Z input terminal of the analog multiplier U6 are all grounded, that is, the input voltage is 0. The VS+ terminal of the analog multiplier U6 is used to access the positive voltage and is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is grounded, and the VS- terminal of the analog multiplier U6 is used to access the negative voltage and is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is grounded. The W output terminal of the analog multiplier U6 is connected to one end of the fifteenth resistor R15, and the other end of the fifteenth resistor R15 is connected to the inverting input terminal of the fourth operational amplifier U4.

[0094] One end of the twelfth resistor R12 is connected to a 5V voltage, and the other end is respectively connected to one end of the thirteenth resistor R13 and one end of the fourteenth resistor R14. The other end of the thirteenth resistor R13 is connected to the non-inverting input end of the fourth operational amplifier U4, and the non-inverting input end of the fourth operational amplifier U4 is also grounded. The other end of the fourteenth resistor R14 is connected to the inverting input end of the fourth operational amplifier U4. The output end of the fourth operational amplifier U4 is connected to the Y1 input end of the analog multiplier U6 and is used to output a second output voltage.

[0095] The first input voltage E X After the division operation in analog multiplier U6, the output voltage at the W output terminal is:

[0096]

[0097] The fourth operational amplifier U4 is virtually disconnected, then:

[0098] E / R 14 =-W / R 15 (13)

[0099] Wherein, E is the voltage between the twelfth resistor R12 and the fourteenth resistor R14, R 14 =R 15 =10KΩ. Substituting formula (13) into formula (12), we can get:

[0100]

[0101] Wherein, W′ is the second output voltage.

[0102] Before actual application, the division circuit 24 needs to be debugged. During the debugging process, a variable resistance box can be used to equalize the resistance of the NTC thermistor at different temperatures. By adjusting the resistance of the twelfth resistor R12 and the thirteenth resistor R13, so that E = 0.1V, the second output voltage W' is equal to the first input voltage E X The inverse of the first input voltage E is linearly related to X With compensation voltage U O (That is, U IN ) is linearly related, the compensation voltage U O The second output voltage W′ is linearly related to the inverse of the temperature. Therefore, the second output voltage W′ is linearly related to the temperature. At this time, the nonlinear relationship between the resistance value of the NTC thermistor and the temperature is compensated.

[0103] See also Figure 1 , Figure 4 and Figure 6In some embodiments, the circuit board assembly 20 further includes a limiter circuit 25. The limiter circuit 25 is connected to the divider circuit 24, and the limiter circuit 25 is used to limit the amplitude of the second output voltage to obtain a corresponding third output voltage.

[0104] Specifically, the amplitude limiting circuit 25 is also connected to the power supply unit 27, and the power supply unit 27 is used to supply power to the amplitude limiting circuit 25. The amplitude limiting circuit 25 includes a fifth operational amplifier U5 and a plurality of resistors, and the fifth operational amplifier U5 is used for inverting and summing. The plurality of resistors may include a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, and a twenty-first resistor R21. One end of the eighteenth resistor R18 is connected to the dividing resistor, and specifically can be connected to the output end of the fourth operational amplifier U4, and the other end of the eighteenth resistor R18 is connected to the inverting input end of the fifth operational amplifier U5. One end of the sixteenth resistor R16 is connected to a 5V voltage, and the other end is respectively connected to one end of the seventeenth resistor R17 and one end of the nineteenth resistor R19, the other end of the nineteenth resistor R19 is connected to the inverting input end of the fifth operational amplifier U5, and the other end of the seventeenth resistor R17 is grounded. The non-inverting input terminal of the fifth operational amplifier U5 is connected to one end of the twentieth resistor R20, the other end of the twentieth resistor R20 is grounded, and the output terminal of the fifth operational amplifier U5 is used to output the third output voltage. One end of the twenty-first resistor R21 is connected to the output terminal of the fifth operational amplifier U5, and the other end is connected to the inverting output terminal of the fifth operational amplifier U5.

[0105] The amplitude limiting circuit 25 is used to limit the amplitude of the second output voltage W' to obtain a third output voltage. After obtaining the third output voltage, the third output voltage will be input to the processor 26 (which will be described in detail later) to determine the temperature detected by the temperature sensor based on the third output voltage. The processor 26 has a certain voltage receiving range, so it is necessary to limit the amplitude of the second output voltage W' to prevent the third output voltage from exceeding the receiving range of the processor 26 and affecting the current detection result.

[0106] In one example, the voltage receiving range of the processor 26 is 0V-5V, so the amplitude of the second output voltage W' can be limited to 0.1V~4.9V by the limiting circuit 25. Before actual application, the limiting circuit 25 needs to be debugged. During the debugging process, a variable resistance box can be used to equal the resistance of the NTC thermistor at different temperatures. By adjusting the resistance of the seventeenth resistor R17, the third output voltage is equal to 0.1V at -40°C, and then adjusting the twenty-first resistor R21, the third output voltage is equal to 4.9V at 125°C. The relationship between the resistance of the seventeenth resistor R17 and the twenty-first resistor R21 and the third output voltage is as follows:

[0107]

[0108] Among them, U OUT is the third output voltage.

[0109] Substituting formula (9), formula (11) and formula (14) into formula (15), we can get the relationship between temperature T and the third output voltage U OUT The linear relationship is as follows:

[0110] U OUT =αT+μ (16)

[0111] The coefficients α and μ are constants and are related to the resistance values ​​of the above-mentioned multiple resistors.

[0112] In one example, the temperature T and the third output voltage U OUT The theoretical calculation relationship is:

[0113] U OUT =0.0291T+1.264 (17)

[0114] Among them, α=0.0291, μ=1.264, that is, the output voltage changes by 29.1 mV when the temperature changes by 1° C. In the entire temperature test range, the temperature voltage resolution of the temperature sensor remains at 29.1 mV, which is higher than the recommended voltage resolution of the processor 26 .

[0115] In the related art, in order to simplify the design of the temperature sampling circuit, only one voltage divider resistor is used. The nonlinear compensation temperature range of the thermistor is generally less than 100°C, and the nonlinear error is 0.5%, resulting in poor measurement accuracy of the thermistor in high temperature areas. When the temperature exceeds 100°C, the sampling error of the thermistor reaches ±1.5°C. However, the current extreme operating temperature of the shunt exceeds 120°C, and the temperature sampling circuit cannot meet the detection accuracy requirements. For example, in a temperature sampling circuit, only a 10KΩ voltage divider resistor is used. After the temperature exceeds 70°C, the temperature voltage resolution of the thermistor is less than 20mV.

[0116] In the embodiment of the present application, a temperature compensation circuit 21, a zero adjustment circuit 23, a division circuit 24 and a limiter circuit 25 connected in sequence are designed to form a temperature sampling circuit. The temperature compensation circuit 21 can compensate for the nonlinear relationship between the resistance value and the temperature of the temperature sensor and output a compensation voltage. The zero adjustment circuit 23 is used to adjust the compensation voltage to zero point and output a first output voltage, and the first output voltage is always positive within the temperature measurement range of the temperature sensor. The division circuit 24 is used to divide the first output voltage by the voltage to obtain a second output voltage, so that the temperature is linearly related to the second output voltage. The limiter circuit 25 is used to limit the amplitude of the second output voltage to obtain a third output voltage, so that the amplitude of the third output voltage can meet the voltage receiving range of the processor 26. In this way, the temperature sensor can achieve wide temperature range and high-precision temperature measurement, and the temperature voltage resolution of the temperature sensor is high, which can ensure the current detection accuracy of the shunt 100.

[0117] See also Figure 1 and Figure 4 In some embodiments, the circuit board assembly 20 also includes a processor 26, which is connected to the limiting circuit 25 and is used to determine the first temperature according to the third output voltage corresponding to the first temperature sensor 30, determine the second temperature according to the third output voltage corresponding to the second temperature sensor 40, and determine the third temperature according to the third output voltage corresponding to the third temperature sensor 50, so as to determine the first correction coefficient and the second correction coefficient based on the first temperature, the second temperature and the third temperature, and correct the detection current.

[0118] Specifically, the processor 26 is connected to the limiter circuit 25, and the processor 26 includes a general purpose input output (GPIO) interface, and the GPIO interface is used to receive the third output voltage output by the limiter circuit 25. The processor 26 is also connected to the power supply unit 27, and the power supply unit 27 is used to supply power to the processor 26.

[0119] It can be understood that based on the selection circuit 22, when the branch where the first temperature sensor 30 is located is turned on, the circuit output end of the temperature compensation circuit 21 outputs a first compensation voltage. At this time, the limiting circuit 25 outputs a third output voltage corresponding to the first temperature sensor 30, and the processor 26 can determine the first temperature detected by the first temperature sensor 30 based on the third output voltage.

[0120] When the branch where the second temperature sensor 40 is located is turned on, the circuit output end of the temperature compensation circuit 21 outputs a second compensation voltage. At this time, the limiting circuit 25 outputs a third output voltage corresponding to the second temperature sensor 40, and the processor 26 can determine the second temperature detected by the second temperature sensor 40 based on the third output voltage.

[0121] When the branch where the third temperature sensor 50 is located is turned on, the circuit output end of the temperature compensation circuit 21 outputs a third compensation voltage. At this time, the limiting circuit 25 outputs a third output voltage corresponding to the third temperature sensor 50, and the processor 26 can determine the third temperature detected by the third temperature sensor 50 based on the third output voltage.

[0122] After the processor 26 obtains the first temperature and the second temperature, it calculates the temperature difference between the first temperature and the second temperature, and the temperature difference represents the temperature difference between the positive and negative electrodes of the diverter 100. According to the temperature difference between the first temperature and the second temperature, based on the relationship table between the temperature difference and the first correction coefficient, the first correction coefficient corresponding to the temperature difference can be determined. The first correction coefficient is a coefficient related to the Seebeck effect and is used to correct the Seebeck effect. The relationship table between the temperature difference and the first correction coefficient can be obtained in advance by calibrating the relationship between the temperature difference and the first correction coefficient.

[0123] After the processor 26 obtains the third temperature, based on the relationship table between the temperature and the second correction coefficient, the second correction coefficient corresponding to the third temperature can be determined. The second correction coefficient is a coefficient related to the resistance value of the detection resistor 10 and is used to correct the resistance value of the detection resistor 10. The correction process is as follows:

[0124] The thermoelectric electromotive force generated by the temperature difference between the positive and negative electrodes of the shunt 100 is calculated as:

[0125] ΔU EMF =S EMF ΔT (18)

[0126] Among them, ΔU EMF is the thermal electromotive force, S EMF is the Seebeck coefficient, i.e. the first correction coefficient. ΔT is the temperature difference between the positive and negative electrodes of the shunt 100 .

[0127] According to the thermoelectric potential ΔU EMF Calculate the Seebeck correction as follows:

[0128] Offset EMF =ΔU EMF / R Shunt =S EMF ΔT / R Shunt (19)

[0129] Among them, Offset EMF is the Seebeck correction, R Shunt is the resistance value of the detection resistor 10. Based on the second correction coefficient, the resistance value R of the detection resistor 10 can be Shunt Make corrections.

[0130] In addition, the processor 26 can obtain the voltage on one side of the detection resistor 10 through the first voltage sensor 71, and obtain the voltage on the other side of the detection resistor 10 through the second voltage sensor 72, and then obtain the voltage drop generated by the current flowing through the two sides of the detection resistor 10, that is, the voltage difference. After obtaining the voltage difference, the ratio of the voltage difference to the resistance value of the corrected detection resistor 10 is calculated to obtain the detection current. Based on the detection current and the Seebeck correction amount, the final current detection result can be determined. In this way, the influence of the Seebeck effect and the temperature change of the detection resistor 10 itself on the detection current can be corrected, and the current detection accuracy of the shunt 100 can be effectively improved.

[0131] See also Figure 1 and Figure 8 The embodiment of the present application further provides a battery pack 200 . The battery pack 200 includes the shunt 100 and a battery cell 210 according to any of the above embodiments, and the shunt 100 is used to detect the current of the battery cell 210 .

[0132] Specifically, the first fixing plate 61 of the shunt 100 is provided with a first fixing hole 611, and the second fixing plate 62 is provided with a second fixing hole 621. The first fixing hole 611 and the second fixing hole 621 can be matched with bolts to fix the shunt 100 to the battery cell 210. For example, the first fixing hole 611 is connected to the positive electrode of the battery cell 210, and the second fixing hole 621 is connected to the negative electrode of the battery cell 210, so that the current flows out from the positive electrode of the battery cell 210, flows to the detection resistor 10 through the first fixing plate 61, and then flows back to the negative electrode of the battery cell 210 through the second fixing plate 62, so that the current of the battery cell 210 can be detected.

[0133] In the shunt 100 and the battery pack 200 of the embodiment of the present application, a first temperature sensor 30 and a second temperature sensor 40 are arranged on both sides of the detection resistor 10, respectively used to detect the first temperature of the positive electrode of the shunt 100 and the second temperature of the negative electrode of the shunt 100, and a third temperature sensor 50 is arranged on the circuit board assembly 20, used to measure the third temperature of the detection resistor 10 itself, and the circuit board assembly 20 corrects the detection current of the shunt 100 according to the first temperature, the second temperature and the third temperature. In this way, the influence of the Seebeck effect and the temperature change of the detection resistor 10 itself on the detection current can be corrected, and the current detection accuracy of the shunt 100 can be effectively improved.

[0134] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0135] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0136] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0137] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides various specific processes and examples of materials, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0138] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "example", "specific example", "some examples", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0139] Although the embodiments of the present application have been shown and described above, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A flow divider (100), characterized in that: include: A detection resistor (10), a circuit board assembly (20), a first temperature sensor (30), a second temperature sensor (40) and a third temperature sensor (50), wherein the detection resistor (10) and the circuit board assembly (20) are arranged opposite to each other, the first temperature sensor (30) and the second temperature sensor (40) are arranged on both sides of the detection resistor (10), the first temperature sensor (30) and the second temperature sensor (40) are both connected to the circuit board assembly (20), and the third temperature sensor (50) is arranged on the circuit board assembly (20); The first temperature sensor (30) is used to measure a first temperature of the positive electrode of the shunt (100), the second temperature sensor (40) is used to measure a second temperature of the negative electrode of the shunt (100), the third temperature sensor (50) is used to measure a third temperature of the detection resistor (10), and the circuit board assembly (20) is used to correct the detection current of the shunt (100) according to the first temperature, the second temperature and the third temperature.

2. The flow divider (100) according to claim 1, characterized in that: The shunt (100) further comprises a first fixing plate (61), a second fixing plate (62), a first voltage sensor (71) and a second voltage sensor (72); the first fixing plate (61) and the second fixing plate (62) are respectively arranged on both sides of the detection resistor (10); the first voltage sensor (71) is arranged at one end of the first fixing plate (61) close to the detection resistor (10); the second voltage sensor (72) is arranged at one end of the second fixing plate (62) close to the detection resistor (10); and the first voltage sensor (71) and the second voltage sensor (72) are both connected to the circuit board assembly (20); The circuit board assembly (20) is used to collect the voltage difference between two sides of the detection resistor (10) through the first voltage sensor (71) and the second voltage sensor (72), so as to determine the detection current based on the voltage difference.

3. The flow divider (100) according to claim 1, characterized in that: The circuit board assembly (20) comprises a temperature compensation circuit (21); A circuit input end of the temperature compensation circuit (21) is connected to the first temperature sensor (30), the second temperature sensor (40) and the third temperature sensor (50); The circuit output end of the temperature compensation circuit (21) is used to respectively output a compensation voltage which is linearly related to the inverse of the temperature measured by each temperature sensor.

4. The flow divider (100) according to claim 3, characterized in that: The temperature compensation circuit (21) comprises a first transistor (Q1), a second transistor (Q2), a first operational amplifier (U1) and a second operational amplifier (U2); The base and collector of the first transistor (Q1) are both connected to the circuit input end, the emitter of the first transistor (Q1) is connected to the emitter of the second transistor (Q2), the base and collector of the second transistor (Q2) are both connected to the non-inverting input end of the second operational amplifier (U2), the inverting input end of the first operational amplifier (U1) is connected to the circuit input end, the non-inverting input end of the first operational amplifier (U1) is grounded, the output end of the first operational amplifier (U1) is connected between the emitter of the first transistor (Q1) and the emitter of the second transistor (Q2), the inverting input end of the second operational amplifier (U2) is grounded, and the output end of the second operational amplifier (U2) is connected to the circuit output end.

5. The flow divider (100) according to claim 3, characterized in that: The circuit board assembly (20) further comprises a selection circuit (22), wherein the selection circuit (22) is connected to the first temperature sensor (30), the second temperature sensor (40) and the third temperature sensor (50); The selection circuit (22) is used to select the branch where the first temperature sensor (30), the second temperature sensor (40) or the third temperature sensor (50) is located to be turned on, so that the circuit output end of the temperature compensation circuit (21) outputs the corresponding compensation voltage.

6. The flow divider (100) according to claim 3, characterized in that: The circuit board assembly (20) further includes a zero adjustment circuit (23); The zero adjustment circuit (23) is connected to the circuit output end of the temperature compensation circuit (21) and is used to perform zero point adjustment on the compensation voltage to obtain a corresponding first output voltage.

7. The flow divider (100) according to claim 6, characterized in that: The circuit board assembly (20) further includes a divider circuit (24); The dividing circuit (24) is connected to the zero adjustment circuit (23), and the dividing circuit (24) is used to perform a division operation on the first output voltage to obtain a corresponding second output voltage.

8. The flow divider (100) according to claim 7, characterized in that: The circuit board assembly (20) further includes a limiting circuit (25); The amplitude limiting circuit (25) is connected to the dividing circuit (24), and the amplitude limiting circuit (25) is used to limit the amplitude of the second output voltage to obtain a corresponding third output voltage.

9. The flow divider (100) according to claim 8, characterized in that: The circuit board assembly (20) further includes a processor (26), which is connected to the limiting circuit (25) and is used to determine the first temperature according to the third output voltage corresponding to the first temperature sensor (30), determine the second temperature according to the third output voltage corresponding to the second temperature sensor (40), and determine the third temperature according to the third output voltage corresponding to the third temperature sensor (50), so as to determine a first correction coefficient and a second correction coefficient based on the first temperature, the second temperature and the third temperature, and correct the detection current.

10. A battery pack (200), characterized in that: include: The flow divider (100) according to any one of claims 1 to 9; and A battery cell (210), wherein the shunt (100) is used to detect current on the battery cell (210).

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