CN205353210U - It is applicable in internal resistance of cell on -line monitoring device of multiple battery type - Google Patents

Abstract

The utility model discloses an it is applicable in internal resistance of cell on -line monitoring device of multiple battery type, including cell, await measuring battery terminal, accurate constant ohmic resistance and blocking capacitance C promptly by the external connecting terminal who exchanges constant current signal generating circuit, battery monomer or group battery and constitute the return circuit, sampling unit constitutes return circuit, the 2nd preamplification circuit, the 2nd filter circuit and the 2nd lock -in amplifier circuit component return circuit by a preamplification circuit, a filter circuit and a lock -in amplifier circuit, the control unit constitutes the return circuit by exchanging constant current signal generating circuit and pressure regulating circuit and a lock -in amplifier circuit, constitutes the return circuit by interchange constant current signal generating circuit and pressure regulating circuit and the 2nd lock -in amplifier circuit, calculates the internal resistance of cell that awaits measuring by the alternating voltage value and the alternating current resistance at single -chip microcomputer control system battery both ends that the measurement obtained according to the sampling output unit and accurate constant ohmic resistance both ends. The utility model discloses can be in the internal resistance of different batteries under the condition of not changing the circuit.

Description

A battery internal resistance online monitoring device applicable to various battery types

Technical field:

The utility model relates to a battery internal resistance monitoring device applicable to various types of batteries, which is used for on-line monitoring of changes in the battery internal resistance.

Background technique:

Currently, known battery internal resistance monitoring devices mainly include a DC discharge method and an AC injection method. The principle of the DC discharge method is to keep the battery in a static (or offline) state, discharge the external load with a large current, measure the voltage and discharge current of the battery, and obtain the internal resistance of the battery through the ratio of these two values. However, in practical applications, the measurement of the internal resistance of the battery is mainly used in the online monitoring of the battery and the evaluation of the state of the battery, that is, the battery to be tested cannot be taken out of the battery pack during the measurement. Therefore, in order to overcome the deficiency that the existing battery internal resistance monitoring device cannot monitor the internal resistance of the battery when the battery is in the working state, the AC injection method is used to measure the internal resistance of the battery, which can monitor the change of the internal resistance of the battery in the working state .

Utility model content:

The purpose of the utility model is to provide a battery internal resistance monitoring device applicable to various battery types.

In order to achieve the above object, the utility model adopts the following technical solutions to realize:

An on-line battery internal resistance monitoring device applicable to various battery types, comprising a battery unit, the battery unit is composed of an AC constant current signal generating circuit, an external terminal of a battery cell or a battery pack (that is, a battery terminal to be tested), a precision fixed The value resistor and the DC blocking capacitor C are connected in series to form a loop;

Sampling unit, the sampling unit includes two loops, one loop consists of the first preamplifier circuit, the first filter circuit and the first lock-in amplifier circuit in series to form a loop, and the other loop consists of the second preamplifier circuit, the first lock-in amplifier circuit The second filter circuit and the second lock-in amplifier circuit are sequentially connected in series to form a loop;

Control unit, the control unit includes two loops, one loop consists of an AC constant current signal generating circuit, a voltage regulating circuit and a first lock-in amplifier circuit in series to form a loop, and the other loop consists of an AC constant current signal generating circuit, a voltage regulating circuit The circuit and the second lock-in amplifier circuit are connected in series successively to form a loop, and the output terminals of the first lock-in amplifier circuit and the output terminals of the second lock-in amplifier circuit are all connected to the input terminals of the single-chip control system; the single-chip control system outputs according to the sampling The internal resistance of the battery to be tested is calculated from the AC voltage and AC resistance values at both ends of the battery and at both ends of the precision fixed value resistor measured by the unit.

The further improvement of the utility model is that: the AC constant current signal generating circuit includes a sinusoidal AC voltage generating circuit and a constant voltage variable constant current circuit; wherein,

The sinusoidal AC voltage generation circuit is composed of ICL8038 chip U ₁ , including resistors R ₁ , R ₂ , R ₃ , R ₄ and capacitor C ₇ ; among them, the 4 terminals of U ₁ are connected to the +12V power supply through R ₁ , and the terminals of U ₁ Terminal 5 is connected to +12V power supply through R ₂ , terminal 6 of U ₁ is connected to +12V power supply, terminal 7 of U ₁ is connected to terminal 8 of U ₁ , terminal 9 of U ₁ is connected to +12V power supply through R ₄ Terminal 10 of U ₁ is connected to -12V power supply through C ₇ , terminal 11 of U ₁ is connected to -12V power supply, terminal 12 of U ₁ is connected to terminal 1 of R ₃ , terminal 3 of R ₃ is connected to -12V power supply connected;

The constant voltage variable constant current circuit is composed of power amplifier _LM1578 chip U2 and amplifier OP07 chip _U3 , including resistors R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ and capacitors C ₁ and C ₂ ; among them, U ₂ Terminal 1 is connected to terminal 2 of U 1 via R ₈ , terminal ₁ of U ₂ is connected to terminal 2 and terminal 6 of U ₃ via R ₉ , terminal 2 of U ₂ is grounded via R ₇ , terminal 2 of U ₂ is connected to terminal 2 via R ₁₀ and R ₁₁ are connected to the anode of C ₁ , terminal 3 of U ₂ is connected to -12V power supply, terminal 4 of U ₂ is connected to terminal 2 of diode D ₁ and D ₂ , terminal 5 of U ₂ is connected to + The 12V power supply is connected, the 3 terminal of D ₁ is connected with the +12V power supply, the 3 terminal of D ₂ is connected with the -12V power supply, the 1 terminal of D ₁ and D ₂ is connected with the positive pole of C ₁ through R ₁₁ , U ₃ Terminal 4 of U3 is connected to -12V power supply, terminal 7 of _U3 is connected to +12V power supply, terminal 2 of _U3 is connected to the positive pole of _C1 , _C1 passes through the battery terminal to be tested, precision fixed value resistor and _C2 grounded.

The further improvement of the utility model is that the voltage regulation circuit includes MOSFET tube T1 and resistors R4, _R5 , R6 _; wherein, the ₂ fixed terminals of R5 are connected with the ₉ terminals _{of U1, and the 1 terminal of} R5 is fixed _The terminal terminal is grounded, the three terminals of _R5 are connected to the gate terminal g _of T1, the source terminal _s of T1 is grounded, and the drain terminal d _of T1 is connected to the +3.3V power supply through R6.

The further improvement of the utility model is that: the first preamplifier circuit includes capacitors C ₈ , C ₉ , resistors R ₁₂ , R ₁₃ , R ₁₄ and amplifier AD620 chip U ₄ ; wherein terminal 1 of U ₄ is connected to U 4 through R ₁₄ The 8 terminals of ₄ are connected, the 2 terminals of U ₄ are connected to the negative pole of the battery terminal to be tested through C ₈ , the 2 terminals of U ₄ are grounded through R ₁₂ , and the 3 terminals of U ₄ are connected to the positive pole of the battery terminal to be tested through C ₉ Terminal 3 of U ₄ is grounded through R ₁₃ , Terminal 4 of U ₄ is connected to -12V power supply, Terminal 7 of U ₄ is connected to +12V power supply, Terminal 5 of U ₄ is grounded.

The further improvement of the utility model is: the first filter circuit includes resistors R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , capacitors C ₁₀ , C ₁₁ , C ₁₂ , C ₁₃ and amplifier Lm353 chips U ₅ , U ₆ , U ₇ ; Terminal 5 of U ₅ is connected to terminal 6 of U ₄ via C ₁₁ and C ₁₀ , terminal 5 of U ₅ is connected to terminal 6 and terminal 7 of U ₅ via C ₁₁ and R ₁₅ , terminal 5 of U ₅ After R ₁₆ is grounded, terminal 4 of U ₅ is connected to -12V power supply, terminal 8 of U ₅ is connected to +12V power supply, terminal 3 of U ₆ is connected to terminal 7 of U ₅ , terminal 4 of U ₆ is connected to - The 12V power supply is connected, the 8 terminal of U ₆ is connected with the +12V power supply, the 2 terminal of U ₆ is connected with the 1 terminal of U ₆ through R ₁₇ , R ₁₈ and the 5 terminal of U ₇ , and the 5 terminal of U ₇ is connected through R _18. C ₁₃ is connected to terminals 6 and 7 of U ₇ , terminal 5 of U ₇ is grounded through C ₁₃ , terminal 4 of U ₇ is connected to -12V power supply, terminal 8 of U ₇ is connected to +12V power supply.

The further improvement of the utility model is that: the first lock-in amplifier circuit includes resistors R ₁₉ , R ₂₀ , R ₂₁ , R ₂₂ , R ₂₃ , R ₂₄ , R ₂₅ and lock-in amplifier AD630 chip U ₈ ; wherein, U ₈ Terminal 1 and 16 are connected to terminal 7 of U ₇ , terminal 3 of U ₈ is connected to -12V power supply through R ₁₉ , terminal 4 of U ₈ is connected to -12V power supply through R ₂₀ , terminal 5 of U ₈ is connected to R ₂₁ is connected to -12V power supply, terminal 6 of U ₈ is connected to -12V power supply through R ₂₂ , terminal 8 of U ₈ is connected to -12V power supply, terminal 9 of U ₈ is connected to drain terminal d of T ₁ Connection, terminal 10 of U ₈ is grounded, terminal 11 of U ₈ is connected to +12V power supply, terminal 14 of U ₈ is grounded through R ₂₅ , terminal 15 of U ₈ is connected to terminal 13 of U ₈ through R ₂₄ , U ₈ Terminal 15 of U8 is connected to Terminal ₁₆ of U8 through _R23 , and Terminal ₁₃ of U8 is connected to the A/D sampling output terminal of the ARM microcontroller.

The further improvement of the utility model is that: the second preamplifier circuit includes capacitors C ₁₄ , C ₁₅ , resistors R ₂₆ , R ₂₇ , R ₂₈ and amplifier AD620 chip U ₉ ; wherein terminal 1 of U ₉ passes through R ₂₈ and U The 8 terminals of U ₉ are connected to each other, the 2 terminals of U ₉ are connected to the 1 terminal of the precision fixed value resistor through C ₁₄ , the 2 terminals of U ₉ are grounded through R ₂₆ , the 3 terminals of U ₉ are connected to the precision fixed value resistor through C ₁₅ The 2 terminals are connected, the 3 terminal of U ₉ is grounded through R ₂₇ , the 4 terminal of U ₉ is connected to the -12V power supply, the 7 terminal of U ₉ is connected to the +12V power supply, and the 5 terminal of U ₉ is grounded.

The further improvement of the utility model is that: the second filter circuit includes resistors R ₂₉ , R ₃₀ , R ₃₁ , R ₃₂ , capacitors C ₁₆ , C ₁₇ , C ₁₈ , C ₁₉ and amplifier Lm353 chips U ₁₀ , U ₁₁ , U ₁₂ ; Terminal 5 of U ₁₀ is connected to terminal 6 of U ₉ via C ₁₇ and C ₁₆ , terminal 5 of U ₁₀ is connected to terminal 6 and terminal 7 of U ₁₀ via C ₁₇ and R ₂₉ , terminal 5 of U ₁₀ After R ₃₀ is grounded, terminal 4 of U ₁₀ is connected to -12V power supply, terminal 8 of U ₁₀ is connected to +12V power supply, terminal 3 of U ₁₁ is connected to terminal 7 of U ₁₀ , terminal 4 of U ₁₁ is connected to - The 12V power supply is connected, the 8 terminal of U ₁₁ is connected with the +12V power supply, the 2 terminal of U ₁₁ is connected with the 1 terminal of U ₁₁ through R ₃₁ , R ₃₂ is connected with the 5 terminal of U ₇ , and the 5 terminal of U ₁₂ is connected through R _32. C ₁₉ is connected to terminals 6 and 7 of U ₁₂ , terminal 5 of U ₁₂ is grounded through C ₁₉ , terminal 4 of U ₁₂ is connected to -12V power supply, terminal 8 of U ₁₂ is connected to +12V power supply.

The further improvement of the utility model is that: the second lock-in amplifier circuit includes resistors R ₃₃ , R ₃₄ , R ₃₅ , R ₃₆ , R ₃₇ , R ₃₈ , R ₃₉ and lock-in amplifier AD630 chip U ₁₃ ; wherein, the U ₁₃ Terminal 1 and 16 are connected to terminal 7 of U ₁₂ , terminal 3 of U ₁₃ is connected to -12V power supply through R ₃₃ , terminal 4 of U ₁₃ is connected to -12V power supply through R ₃₄ , terminal 5 of U ₁₃ is connected to R ₃₅ is connected to -12V power supply, terminal 6 of U ₁₃ is connected to -12V power supply through R ₃₆ , terminal 8 of U ₁₃ is connected to -12V power supply, terminal 9 of U ₁₃ is connected to drain terminal d of T ₁ Connection, terminal 10 of U ₁₃ is grounded, terminal 11 of U ₁₃ is connected to +12V power supply, terminal 14 of U ₁₃ is grounded through R ₃₉ , terminal 15 of U ₁₃ is connected to terminal 13 of U ₁₃ through R ₃₈ , U ₁₃ Terminal ₁₅ of U13 is connected to Terminal 16 of U13 through _R37 , and Terminal ₁₃ of U13 is connected to the A/D sampling output terminal of the ARM microcontroller.

Compared with the prior art, the beneficial effects of the utility model are:

The utility model adopts the AC injection method to measure the internal resistance of the battery, connects the battery in series with a precision fixed-value resistor, and simultaneously inputs the AC voltage signal values generated at both ends of the precision fixed-value resistor and the battery into two preamplifier circuits. After the circuit is processed, the sum of the AC voltage value generated at both ends of the battery and the AC current value flowing through the battery during measurement can be determined, thereby calculating the internal resistance of the battery. The measurement operation is simple, and the battery can be measured only by connecting the battery with a lead wire, and the internal resistance of various types of batteries can be measured without changing the circuit. During the measurement process, the AC voltage value at the standard resistance and the voltage value at the battery are measured at the same time, which can effectively avoid the influence of circuit interference on the measurement results.

In summary, the utility model measures the AC voltage value at the standard resistance and the voltage value at the battery at the same time during the measurement process, which can effectively avoid the influence of circuit interference on the measurement results. And the measurement operation is simple, the battery can be measured only by connecting the battery with a lead wire, and the internal resistance of the battery can be changed without changing the circuit.

Description of drawings:

Fig. 1 is a block diagram of the utility model;

Fig. 2 is the AC constant current source circuit and voltage regulating circuit diagram of the utility model;

Fig. 3 is a preamplifier circuit diagram of the present utility model;

Fig. 4 is low-pass, high-pass filter circuit diagram of the present utility model;

Fig. 5 is a lock-in amplification circuit diagram of the utility model;

detailed description:

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

It can be seen from Fig. 1 that the specific method of the present invention is to use the four-lead connection method to reduce the influence of the lead impedance on the measurement of the internal resistance of the battery, and to measure the internal resistance of the battery by using the AC injection method. Connect the AC constant current output terminal to the positive pole of _C1 , connect the negative pole of _C1 to the positive pole of the battery to be tested, connect the negative pole of the battery to be tested to terminal 1 of the precision fixed value resistor, and connect the terminal 2 of the precision fixed value resistor to C ₂ , the negative pole of C ₂ is connected to the ground terminal; the positive and negative poles of the battery are connected to the first preamplifier circuit, the first filter circuit, and the first lock-in amplifier circuit in turn through C ₃ and C ₄ , and the output terminal is connected with the A/D sampling input terminal of the ARM system; terminal 1 and terminal 2 of the resistor are connected to the second preamplifier circuit, the second filter circuit and the second lock-in amplifier circuit in turn through _C5 and _C6 , Connect the output terminal to the A/D sampling input terminal of the ARM system; calculate the two voltage values obtained by A/D sampling, and obtain the battery internal resistance value and upload it to the computer for display. The formula for calculating the internal resistance of the battery is as follows.

${\mathrm{<span\; class="notranslate">\; r</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; /</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; \&CenterDot;</span>\frac{{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$

In the formula, r ₀ is the measured internal resistance of the battery; R ₀ is the resistance of a known precision fixed value resistor; U _rce is the measured voltage difference between the two sides of the internal resistance of the battery, and U _rce0 is the two sides of the measured internal resistance of the battery. The calibration value of the side voltage difference is the voltage value measured when the battery connection terminal is short-circuited; U _R0 is the measured voltage difference between the two sides of the precision fixed value resistor; K ₀ and K ₁ are the precision fixed value resistor and the battery internal resistance on both sides The magnification of the voltage value. During the measurement process, the AC voltage value at the standard resistance and the voltage value at the battery are measured at the same time, so the current flowing through the internal resistance of the battery and the precision fixed value resistance at the measurement moment can be considered to be the same, avoiding the time sequence in the circuit measurement The problem of out-of-phase synchronization.

The design of AC constant current source circuit and voltage regulating circuit is shown in Figure 2. ICL8083 is mainly used to generate sinusoidal voltage signal, and its 2 terminals output sinusoidal signal. After passing through the amplifying circuit, it is input into a circuit composed of LM1875 power amplifier and OP07 amplifier, and outputs constant current. The effective value of the AC signal current is determined by the ratio of the input voltage U _i to the resistor R ₁₁ , and the frequency of the current is determined by the resistor R ₁ , the resistor R ₂ and the capacitor C ₇ . The voltage regulating circuit is composed of MOSFET tube T1, and the square wave voltage output by the ₉ terminals of the ICL8038 chip is stepped down to a 1V square wave signal as a reference signal and connected to the reference signal input end of the phase-locking and amplifying circuit; the constant voltage involved in the utility model The current source is a sinusoidal constant current source of 1kHz, and the effective value of its output current can be adjusted according to the actual measurement requirements. When R ₁₁ is constant, the output current can be kept constant and linearly adjustable by adjusting U _in . In order to generate a larger current value, an integrated power amplifier LM1875 is used, which has a small output distortion, works at ±12V, and can output a current of up to 2A. Using OP07 as a follower stage can effectively reduce the output impedance and increase the input impedance, which can reduce signal distortion. R ₁₀ is a current-limiting resistor. Generally, a high-power resistor is required. In order to reduce the loss of the circuit, the value should be as small as possible.

The amplifying circuit is composed of the AD620 chip. The circuit connection is shown in Figure 3. The magnification of the amplifying circuit is determined by an external resistor. The formula for calculating the magnification K of the AD620 is as follows. The magnification is determined by the size of the resistor R ₁₄ (or R ₂₈ ).

The signal transmission method is to connect the two ends of the battery negative pole and the positive pole of the battery in Figure 2 to the terminals 2 and 3 of _U4 in Figure 3 through C ₈ and C ₉ respectively, and connect the terminals 1 and 2 of the fixed value resistor in Figure 2 to The two sets of measurement signals can be amplified by connecting C ₁₄ and C ₁₅ with terminals 2 and 3 of U ₉ .

The filter circuit is mainly composed of LM353 chips. The circuit connection is shown in Figure 4. The collected signal needs to be filtered before use. The filter circuit is involved according to the frequency of the AC signal. The frequency of the constant current AC signal is 1k. According to this A low-pass filter plus a high-pass filter is involved, and the cutoff frequency is 500Hz-2kHz. The signal transmission method is to connect terminal 7 of U ₄ to terminal 5 of U ₅ through C ₁₀ and C ₁₁ in Figure 3, connect terminal 7 of U ₉ to terminal 5 of U ₁₀ through C ₁₆ and C ₁₇ , Filtering of two sets of measurement signals can be realized.

The phase-locking and amplifying circuit is composed of the AD630 chip, and its circuit connection is shown in Figure 5. The filtered signal can be extracted again through the phase-locking amplifying circuit, and the signal that is not 1kHz is removed to weaken the noise to the measurement. impact on the outcome. The signal transmission method is to connect the 7 terminal of U ₇ in Figure 4 with the 1 terminal and 16 terminal of U ₈ in Figure 5, and connect the drain terminal d of T ₁ in Figure 2 with the 9 terminal of U ₈ in Figure 5 Connect the 13 terminal of U ₈ in Figure 5 with the A/D sampling module in the ARM microcontroller; connect the 7 terminal of U ₁₂ with the 1 terminal and 16 terminal of U ₁₃ , and connect the T ₁ terminal in Figure 2 The drain terminal d of U13 is connected with terminal 9 of U13, and terminal ₁₃ of _U13 is connected with the A/D sampling module in the ARM microcontroller. Calculate the two voltage values obtained by A/D sampling according to the formula to obtain the internal resistance of the battery and upload it to the computer for display.

In summary, the utility model provides a battery internal resistance online monitoring device applicable to various battery types. The injection signal line of the AC signal is at the outer end of the measurement signal line; The AC voltage value generated across the resistance can be measured simultaneously.

Claims (9)

1. A battery internal resistance online monitoring device applicable to multiple battery types, characterized in that: it includes a battery unit, and the battery unit is composed of an AC constant current signal generating circuit (1), a battery cell or an external connection of a battery pack The terminal is the battery terminal (2) to be tested, the precision fixed value resistor (3) and the DC blocking capacitor C (4) are sequentially connected in series to form a circuit; Sampling unit, the sampling unit includes two loops, one loop is composed of the first preamplifier circuit (5), the first filter circuit (6) and the first lock-in amplifier circuit (7) in series to form a loop successively, and the other loop The second preamplifier circuit (8), the second filter circuit (9) and the second lock-in amplifier circuit (10) are sequentially connected in series to form a loop; A control unit, the control unit includes two loops, one loop is composed of an AC constant current signal generating circuit (1), a voltage regulating circuit (11) and a first lock-in amplifier circuit (7) in series to form a loop, and the other loop is composed of The AC constant current signal generating circuit (1), the voltage regulating circuit (11) and the second lock-in amplifier circuit (10) are sequentially connected in series to form a loop, and the output terminal of the first lock-in amplifier circuit (7) and the second lock-in amplifier circuit The output ends of the circuit (10) are all connected to the input ends of the single-chip microcomputer control system (12). 2. A battery internal resistance online monitoring device applicable to various battery types according to claim 1, characterized in that: the AC constant current signal generating circuit (1) includes a sinusoidal AC voltage generating circuit (13) and a constant Voltage variable constant current circuit (14); Wherein, The sinusoidal AC voltage generating circuit ( ₁₃ ) is composed _of ICL8038 chip U1, including resistors R1, R2, _R3 , R4 and capacitor _{C7 ;} wherein, the ₄ terminals _of U1 are connected to the ₊ 12V power supply through R1, Terminal 5 of U ₁ is connected to +12V power supply through R ₂ , terminal 6 of U ₁ is connected to +12V power supply, terminal 7 of U ₁ is connected to terminal 8 of U ₁ , terminal 9 of U ₁ is connected to terminal 8 of U 1 through R ₄ Connect to +12V power supply, terminal 10 of U ₁ is connected to -12V power supply through C ₇ , terminal 11 of U ₁ is connected to -12V power supply, terminal 12 of U ₁ is connected to terminal 1 of R ₃ , and terminal 1 of R ₃ is connected 3 terminals are connected to -12V power supply; The constant voltage variable constant current circuit ( ₁₄ ) is composed of power amplifier _LM1578 chip U2 and amplifier OP07 chip _U3 , including resistors _R7 , _R8 , _R9 , R10, _R11 and capacitors _C1 , _C2 ; where, Terminal 1 of U ₂ is connected to terminal 2 of U 1 through R ₈ , terminal ₁ of U ₂ is connected to terminal 2 and terminal 6 of U ₃ through R ₉ , terminal 2 of U ₂ is grounded through R ₇ , and terminal 2 of U ₂ is grounded through R 7 Terminal 2 is connected to the anode of C ₁ through R ₁₀ and R ₁₁ , terminal 3 of U ₂ is connected to -12V power supply, terminal 4 of U ₂ is connected to terminal 2 of diode D ₁ and D ₂ , terminal 5 of U ₂ The terminals are connected to the +12V power supply, the 3 terminals of D ₁ are connected to the +12V power supply, the 3 terminals of D ₂ are connected to the -12V power supply, and the 1 terminals of D ₁ and D ₂ are connected to the positive pole of C ₁ through R ₁₁ , Terminal 4 of U ₃ is connected to the -12V power supply, Terminal 7 of U ₃ is connected to the +12V power supply, Terminal 2 of U ₃ is connected to the positive pole of C ₁ , C ₁ passes through the terminal of the battery to be tested (2), precision Fixed value resistor ( ₃ ) and C2 to ground. 3. An online battery internal resistance monitoring device applicable to various battery types according to claim 2, characterized in that: the voltage regulating circuit (11) includes a MOSFET tube T ₁ and resistors R ₄ , R ₅ , R ₆ ; wherein, the 2 fixed terminal terminals of R ₅ are connected with the 9 terminal of U ₁ , the 1 fixed terminal terminal of R ₅ is grounded, the three terminals of R ₅ are connected with the grid terminal g of T ₁ , and the source terminal of T ₁ The terminal _s is grounded, and the drain terminal d of T1 is connected to the +3.3V power supply through _R6 . 4. An online battery internal resistance monitoring device applicable to various battery types according to claim 3, characterized in that: the first preamplifier circuit (5) includes capacitors C ₈ and C ₉ , and resistor R _{12 . _ _ _ _ _ _ _} Terminal 2 of U ₄ is grounded through R ₁₂ , Terminal 3 of U ₄ is connected to the positive pole of the battery terminal (2) to be tested through C ₉ , Terminal 3 of U ₄ is grounded through R ₁₃ , Terminal 4 of U ₄ is connected to The -12V power supply is connected, the 7 terminal of U ₄ is connected with the +12V power supply, and the 5 terminal of U ₄ is grounded. 5. An online battery internal resistance monitoring device applicable to various battery types according to claim 4, characterized in that: the first filter circuit (6) includes resistors R ₁₅ , R ₁₆ , R ₁₇ , R ₁₈ , capacitors C ₁₀ , C ₁₁ , C ₁₂ , C ₁₃ and amplifier Lm353 chips U ₅ , U ₆ , U ₇ ; where terminal 5 of U ₅ is connected to terminal 6 of U ₄ through C ₁₁ and C ₁₀ , and terminal 6 of U ₅ Terminal 5 is connected to terminal 6 and terminal 7 of U ₅ through C ₁₁ and R ₁₅ , terminal 5 of U ₅ is grounded through R ₁₆ , terminal 4 of U ₅ is connected to -12V power supply, terminal 8 of U ₅ is connected to +12V The power supply is connected, the 3 terminal of U ₆ is connected with the 7 terminal of U ₅ , the 4 terminal of U ₆ is connected with the -12V power supply, the 8 terminal of U ₆ is connected with the +12V power supply, the 2 terminal of U ₆ is connected with the U ₆ Terminal 1 of U 7 is connected to terminal 5 of U 7 through R ₁₇ and R ₁₈ , terminal 5 of U ₇ is connected to terminal 6 and terminal _{7 of U 7 through} R ₁₈ and C ₁₃ , terminal 5 of U ₇ is grounded through C ₁₃ , Terminal 4 of U ₇ is connected to -12V power supply, terminal 8 of U ₇ is connected to +12V power supply. 6. An online battery internal resistance monitoring device applicable to various battery types according to claim 5, characterized in that: the first lock-in amplifier circuit (7) includes resistors R ₁₉ , R ₂₀ , R ₂₁ , R ₂₂ , R ₂₃ , R ₂₄ , R ₂₅ and lock-in amplifier AD630 chip U ₈ ; among them, terminals 1 and 16 of U ₈ are connected to terminal 7 of U ₇ , and terminal 3 of U ₈ is connected to -12V through R ₁₉ Connected to the power supply, terminal 4 of U ₈ is connected to the -12V power supply through R ₂₀ , terminal 5 of U ₈ is connected to the -12V power supply through R ₂₁ , terminal 6 of U ₈ is connected to the -12V power supply through R ₂₂ , U Terminal ₈ of 8 is connected to -12V power supply, terminal 9 of U ₈ is connected to drain terminal d of T ₁ , terminal 10 of U ₈ is grounded, terminal 11 of U ₈ is connected to +12V power supply, terminal 14 of U ₈ The terminal is grounded through R ₂₅ , the 15 terminal of U ₈ is connected with the 13 terminal of U ₈ through R ₂₄ , the 15 terminal of U ₈ is connected with the 16 terminal of U ₈ through R ₂₃ , and the 13 terminal of U ₈ is connected with the ARM microcontroller (12 ) The A/D sampling output is connected. 7. An online battery internal resistance monitoring device applicable to various battery types according to claim 2, characterized in that: the second preamplifier circuit (8) includes capacitors C ₁₄ and C ₁₅ , and resistor R _{26 . _ _ _ _ _ _ _} Terminal 2 of U ₉ is grounded via R ₂₆ , Terminal 3 of U ₉ is connected to Terminal 2 of the precision fixed value resistor (3) via C ₁₅ , Terminal 3 of U ₉ is grounded via R ₂₇ , Terminal 4 of U ₉ is grounded via R 27 The terminal is connected to the -12V power supply, the 7 terminal of U ₉ is connected to the +12V power supply, and the 5 terminal of U ₉ is grounded. 8. An online battery internal resistance monitoring device applicable to various battery types according to claim 5, characterized in that: the second filter circuit (9) includes resistors R ₂₉ , R ₃₀ , R ₃₁ , R ₃₂ , capacitors C ₁₆ , C ₁₇ , C ₁₈ , C ₁₉ and amplifier Lm353 chips U ₁₀ , U ₁₁ , U ₁₂ ; where terminal 5 of U ₁₀ is connected to terminal 6 of U ₉ through C ₁₇ , C ₁₆ , and terminal 6 of U ₁₀ Terminal 5 is connected to terminal 6 and terminal 7 of U ₁₀ through C ₁₇ and R ₂₉ , terminal 5 of U ₁₀ is grounded through R ₃₀ , terminal 4 of U ₁₀ is connected to -12V power supply, terminal 8 of U ₁₀ is connected to +12V The power supply is connected, the 3 terminal of U ₁₁ is connected with the 7 terminal of U ₁₀ , the 4 terminal of U ₁₁ is connected with the -12V power supply, the 8 terminal of U ₁₁ is connected with the +12V power supply, the 2 terminal of U ₁₁ is connected with the U ₁₁ Terminal 1 of U12 is connected to terminal 5 of U ₇ through R ₃₁ and R ₃₂ , terminal 5 of U ₁₂ is connected to terminal 6 and terminal 7 of U ₁₂ through R ₃₂ and C ₁₉ , terminal 5 of U ₁₂ is grounded through C ₁₉ , Terminal 4 of U ₁₂ is connected to -12V power supply, terminal 8 of U ₁₂ is connected to +12V power supply. 9. An online battery internal resistance monitoring device applicable to various battery types according to claim 2, characterized in that: the second lock-in amplifier circuit (10) includes resistors R ₃₃ , R ₃₄ , R ₃₅ , R ₃₆ , R ₃₇ , R ₃₈ , R ₃₉ and lock-in amplifier AD630 chip U ₁₃ ; among them, terminals 1 and 16 of U ₁₃ are connected to terminal 7 of U ₁₂ , and terminal 3 of U ₁₃ is connected to -12V through R ₃₃ Connected to the power supply, terminal 4 of U ₁₃ is connected to the -12V power supply through R ₃₄ , terminal 5 of U ₁₃ is connected to the -12V power supply through R ₃₅ , terminal 6 of U ₁₃ is connected to the -12V power supply through R ₃₆ , U Terminal 8 of ₁₃ is connected to -12V power supply, terminal 9 of U ₁₃ is connected to drain terminal d of T ₁ , terminal 10 of U ₁₃ is grounded, terminal 11 of U ₁₃ is connected to +12V power supply, terminal 14 of U ₁₃ The terminal is grounded through R ₃₉ , the 15 terminal of U ₁₃ is connected with the 13 terminal of U ₁₃ through R ₃₈ , the 15 terminal of U ₁₃ is connected with the 16 terminal of U ₁₃ through R ₃₇ , the 13 terminal of U ₁₃ is connected with the ARM microcontroller (12 ) The A/D sampling output is connected.