A battery module charge-discharge voltage acquisition system and method

Abstract

The application provides a battery module charging and discharging voltage acquisition system and method in the technical field of battery module testing, which comprises a probe crimping tool, a voltage photoelectric isolation filtering module, a voltage acquisition board card, a case, an industrial computer, a temperature sensor and a memory; the input end of the voltage photoelectric isolation filtering module is connected with the output end of the probe crimping tool, and the output end is connected with the input end of the voltage acquisition board card; one end of the case is connected with the voltage acquisition board card, and the other end is connected with the industrial computer; the temperature sensor and the memory are both connected with the industrial computer; and the temperature sensor is arranged in the voltage photoelectric isolation filtering module. The application has the advantage that the voltage acquisition precision is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery module testing, and particularly refers to a battery module charging and discharging voltage acquisition system and method. BACKGROUND

[0002] Before being assembled, the battery module (PACK package) for an automobile needs to be verified for qualification, one of which is to directly acquire the voltage of each battery cell in the battery module, which needs to be compared with the voltage information read by the BMS to assess whether the battery cell voltage tested by the BMS is accurate, and the precision requirement reaches ±1 millivolt.

[0003] To achieve the accuracy and reliability of voltage comparison, the battery module needs to be alternately charged and discharged at 400 amperes, and each charging and discharging cycle is performed for 30 seconds. The real-time voltage acquisition and comparison are performed during the charging and discharging process. If the deviation between the actually acquired voltage value and the voltage value read by the BMS is greater than ±1 millivolt at any time period, it is judged as unqualified. Because the voltage reading rate of the BMS is about 500 Hz on average, the voltage acquisition system also needs to have a 500 Hz acquisition rate to compare the voltage data acquired by the BMS. Because the charging and discharging equipment is a high-power AC-to-DC equipment, there is a high-power electromagnetic transformer inside the charging and discharging equipment, which will cause strong magnetic interference to the surrounding electronic equipment. The traditional voltage acquisition system has poor anti-interference ability, which directly affects the voltage acquisition precision.

[0004] Therefore, how to provide a battery module charging and discharging voltage acquisition system and method to improve the voltage acquisition precision has become a technical problem to be solved. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a battery module charging and discharging voltage acquisition system and method to improve the voltage acquisition precision.

[0006] In a first aspect, the present application provides a battery module charging and discharging voltage acquisition system, which comprises a probe crimping tool, a voltage opto-isolating filtering module, a voltage acquisition board card, a case, an industrial computer, a temperature sensor and a memory.

[0007] The input end of the voltage opto-isolating filtering module is connected with the output end of the probe crimping tool, and the output end is connected with the input end of the voltage acquisition board card. One end of the case is connected with the voltage acquisition board card, and the other end is connected with the industrial computer. The temperature sensor and the memory are both connected with the industrial computer. The temperature sensor is arranged in the voltage opto-isolating filtering module.

[0008] Further, the voltage photoelectric isolation filter module comprises a voltage dividing and attenuating circuit, a gain common mode rejection circuit, an amplifying circuit, a photoelectric coupling isolation circuit, an amplifying and gain compensation circuit, an input reference bias circuit and an output reference bias circuit.

[0009] The input end of the voltage dividing and attenuating circuit is connected with the output end of the probe crimping tool, and the output end is connected with the input end of the gain common mode rejection circuit; the input end of the amplifying circuit is connected with the output end of the gain common mode rejection circuit, and the output end is connected with the input end of the photoelectric coupling isolation circuit; the input end of the amplifying and gain compensation circuit is connected with the output end of the photoelectric coupling isolation circuit, and the output end is connected with the voltage acquisition board card.

[0010] The output end of the input reference bias circuit is connected with the gain common mode rejection circuit; and the output end of the output reference bias circuit is connected with the amplifying and gain compensation circuit.

[0011] Further, the voltage dividing and attenuating circuit comprises a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23, a diode D2 and a switching diode D5.

[0012] One end of the resistor R7 is connected with the probe crimping tool, and the other end is connected with the resistor R8; one end of the resistor R11 is connected with the probe crimping tool, and the other end is connected with the resistor R12.

[0013] One end of the resistor R9 is connected with the resistor R8, the capacitor C19, the capacitor C20, the capacitor C21, the output end of the diode D2, one end of the switching diode D5 and the gain common mode rejection circuit, and the other end is connected with the resistor R10, the capacitor C19, the capacitor C20, the capacitor C22 and the capacitor C23 and grounded;

[0014] The resistor R12 is connected with the resistor R10, the capacitor C22, the capacitor C23, the capacitor C21, the input end of the diode D2, the other end of the switching diode D5 and the gain common mode rejection circuit.

[0015] Further, the gain common mode rejection circuit comprises an operational amplifier U8, a resistor R5, a resistor R6, a resistor R13, a resistor R14, an inductor L5, an inductor L6, a capacitor C24, a capacitor C25 and a capacitor C26.

[0016] The resistance R5 and the resistance R6 are connected in parallel, one end of which is connected with the pin 2 of the operational amplifier U8, and the other end of which is connected with the pin 3 of the operational amplifier U8; the pins 1 and 4 of the operational amplifier U8 are connected with a voltage dividing and attenuating circuit, the pin 5 is connected with an inductor L6 and a capacitor C24, the pin 6 is connected with a resistance R14, a capacitor C26 and a resistance R13, the pin 7 is connected with an amplifying circuit, and the pin 8 is connected with an inductor L5 and a capacitor C25; the capacitor C24 is connected with the capacitor C25, the resistance R14 and the capacitor C26; and the resistance R13 is connected with an input reference bias circuit.

[0017] Further, the amplifying circuit comprises an operational amplifier U9A, a resistance R15, a resistance R16, a resistance R17, a resistance R18, a resistance R23, a resistance R31, a resistance R34, an inductor L7, an inductor L9, a capacitor C27, a capacitor C30, a capacitor C33 and a capacitor C34.

[0018] One end of the resistance R15 is connected with a gain common mode rejection circuit, and the other end of the resistance R15 is connected with the resistance R16, the resistance R23 and the capacitor C30; the pin 1 of the operational amplifier U9A is connected with the resistance R17 and the resistance R31, the pin 2 is connected with the resistance R34 and the resistance R31, the pin 3 is connected with the resistance R16, the pin 4 is connected with the inductor L9 and the capacitor C34, and the pin 8 is connected with the inductor L7 and the capacitor C27;

[0019] The resistance R34 is connected with the resistance R23 and the capacitor C30 and grounded; one end of the resistance R18 is connected with the resistance R17 and the capacitor C33, and the other end of the resistance R18 is connected with an opto-coupler isolation circuit.

[0020] Further, the opto-coupler isolation circuit comprises an opto-coupler U11, an operational amplifier U9B, a diode D3, a resistance R19, a resistance R24, a resistance R28, a capacitor C29, a capacitor C31, a capacitor C32, a capacitor C35 and a capacitor C35.

[0021] The pin 1 of the opto-coupler U11 is connected with the output end of the diode D3, the pin 2 is connected with the resistance R19 and the input end of the diode D3, the pin 3 is connected with the capacitor C32, the pin 4 is connected with the resistance R24, the capacitor C31 and the pin 6 of the operational amplifier U9B, the pin 5 is connected with the resistance R28, the capacitor C36, the capacitor C35 and an amplifying and gain compensation circuit, and the pin 6 is connected with the capacitor C29;

[0022] The pin 5 of the operational amplifier U9B is connected with the amplifying circuit, and the pin 7 is connected with the capacitor C31 and the resistance R19; the resistance R28 is connected with the capacitor C36 and the capacitor C35 and grounded.

[0023] Further, the amplification and gain compensation circuit comprises an operational amplifier U10A, an operational amplifier U10B, a resistor R20, a resistor R21, a resistor R22, a resistor R25, a resistor R26, a resistor R27, a resistor R29, a resistor R30, an inductor L8, an inductor L10, a capacitor C28, a capacitor C37, a capacitor C38 and a capacitor C39;

[0024] Pin 1 of the operational amplifier U10A is connected with the resistor R26 and the capacitor R30, pin 2 is connected with the resistor R30, pin 3 is connected with the photoelectric coupling isolation circuit, pin 4 is connected with the capacitor C39 and the inductor L10, and pin 8 is connected with the capacitor C28 and the inductor L8;

[0025] Pin 5 of the operational amplifier U10B is connected with the resistor R26, the resistor R29 and the capacitor C38, pin 6 is connected with the resistor R20, the resistor R21 and the resistor R22, and pin 7 is connected with the resistor R21, the resistor R25 and the resistor R27;

[0026] The capacitor C28 is connected with the resistor R20, the resistor R22 is connected with the output reference bias circuit, the resistor R29 is connected with the capacitor C38 and grounded, one end of the capacitor C37 is connected with the resistor R25 and the voltage acquisition board card, and the other end is connected with the resistor R27 and grounded.

[0027] Further, the input reference bias circuit and the output reference bias circuit each comprises a voltage reference chip U13, an inductor L13, a capacitor C45, a capacitor C47 and a capacitor C48;

[0028] Pin 2 of the voltage reference chip U13 is connected with the inductor L13, the capacitor C45 and the capacitor C47, pin 4 is connected with the capacitor C45, the capacitor C47 and the capacitor C48 and grounded, and pin 6 is connected with the capacitor C48, the gain common mode rejection circuit and the amplification and gain compensation circuit.

[0029] In a second aspect, the application provides a battery module charging and discharging voltage acquisition method, comprising the following steps:

[0030] In step S10, the industrial computer acquires actual voltage values y1, y2, y3 of the battery module under standard voltages x1, x2, x3 through the case, the voltage acquisition board card, the voltage photoelectric isolation filter module and the probe compression tool in sequence, and based on the x1, x2, x3, y1, y2, y3, the normal equation is used to calculate the normal numbers a, b, c.

[0031] Step S20, set a temperature T1 and a temperature T2, respectively measure the voltage V1 and the voltage V2 of the battery module at the temperature T1 and the temperature T2, correct the voltage V1 and the voltage V2 based on the correction parameters a, b and c to obtain the voltage V3 and the voltage V4; the temperature T1 is less than the temperature T2;

[0032] Step S30, calculate the temperature coefficient TCV based on the temperature T1, the temperature T2, the voltage V3 and the voltage V4;

[0033] Step S40, the industrial computer collects the pre-calibration voltage Ya of the battery module through the voltage acquisition board card, and collects the temperature t1 and the current temperature t2 when the voltage is calibrated through the temperature sensor;

[0034] Step S50, the industrial computer outputs the calibration voltage Yb based on the pre-calibration voltage Ya, the temperature t1, the temperature t2 and the temperature coefficient TCV.

[0035] Further, in the step S10, the correction parameters a, b and c are calculated by using a quadratic equation based on the x1, x2, x3, y1, y2 and y3, and the specific calculation formula is as follows:

[0036] y1=a*x1 2 +b*x1+c;

[0037] y2=a*x2 2 +b*x2+c;

[0038] y3=a*x3 2 +b*x3+c;

[0039] In the step S20, the calculation formula of the voltage V3 and the voltage V4 is as follows:

[0040] V3=a*V1 2 +b*V1+c;

[0041] V4=a*V2 2 +b*V2+c;

[0042] In the step S30, the calculation formula of the temperature coefficient TCV is as follows:

[0043] TCV=(V4-V3) / (V3*(T2-T1));

[0044] In the step S50, the calculation formula of the calibration voltage Yb is as follows:

[0045] Yb=Ya*(1-TCV*(t2-t1))。

[0046] The advantages of the present application are as follows:

[0047] The voltage photoelectric isolation filtering module including a voltage division attenuation circuit, a gain common mode rejection circuit, an amplification circuit, a photoelectric coupling isolation circuit, an amplification and gain compensation circuit, an input reference bias circuit and an output reference bias circuit is arranged to filter and electrically isolate the voltage signal collected by the probe crimping tool, so that the voltage signal is not distorted and delayed during transmission, the anti-interference capability is improved, the temperature sensor is arranged to collect the temperature of the voltage photoelectric isolation filtering module, and the collected temperature is used to calibrate the voltage collected by the voltage collection board card, so that the voltage collection accuracy is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0048] The application will be further described below with reference to the embodiments and the accompanying drawings.

[0049] Figure 1 is a circuit principle block diagram of a battery module charging and discharging voltage collection system of the application.

[0050] Figure 2 is a circuit principle block diagram of a voltage photoelectric isolation filtering module of the application.

[0051] Figure 3 is a circuit diagram of a voltage division attenuation circuit of the application.

[0052] Figure 4 is a circuit diagram of a gain common mode rejection circuit of the application.

[0053] Figure 5 is a circuit diagram of an amplification circuit of the application.

[0054] Figure 6 is a circuit diagram of a photoelectric coupling isolation circuit of the application.

[0055] Figure 7 is a circuit diagram of an amplification and gain compensation circuit of the application.

[0056] Figure 8 is a circuit diagram of an input reference bias circuit and an output reference bias circuit of the application.

[0057] Figure 9 is a flow chart of a battery module charging and discharging voltage collection method of the application. DETAILED DESCRIPTION

[0058] The technical solution in the embodiments of the application has the following general idea: a voltage photoelectric isolation filtering module is arranged to filter and electrically isolate the voltage signal collected by the probe crimping tool, so that the voltage signal is not distorted and delayed during transmission, the anti-interference capability is improved, a temperature sensor is arranged to collect the temperature of the voltage photoelectric isolation filtering module, and the collected temperature is used to calibrate the voltage collected by the voltage collection board card, so that the voltage collection accuracy is improved.

[0059] Referring to Figures 1 to 9 The preferred embodiment of the battery module charging and discharging voltage acquisition system of the present application comprises a probe crimping tool, a voltage optoelectronic isolation filtering module, a voltage acquisition board card, a cabinet, an industrial computer, a temperature sensor and a memory.

[0060] The probe crimping tool supports access to more than 20 channels of battery modules, and adopts gold-plated probes to ensure small contact resistance and no wear after multiple contacts; the model of the voltage acquisition board card is preferably NI-PX16289; the model of the cabinet is preferably NI-1062Q, which is used to transmit the voltage signals collected by the voltage acquisition board card to the industrial computer in the form of digital signals; NI-PXI6289 and NI-1062Q are the most precise multi-channel parallel voltage acquisition board cards on the market, with 32 two-wire test channels, and each test channel is a supply ground, so the supply ground channel acquisition loop is not applicable when collecting battery module string voltage, therefore the front-end voltage optoelectronic isolation filtering module also has the function of channel isolation; the voltage optoelectronic isolation filtering module is used for filtering interference harmonics and electric signal isolation; the industrial computer is used to control the operation of the voltage acquisition system; the temperature sensor is used to collect the temperature of the voltage optoelectronic isolation filtering module for voltage calibration; the memory is used to store relevant test data and calculation data.

[0061] The input end of the voltage optoelectronic isolation filtering module is connected with the output end of the probe crimping tool, and the output end is connected with the input end of the voltage acquisition board card; one end of the cabinet is connected with the voltage acquisition board card, and the other end is connected with the industrial computer; the temperature sensor and the memory are both connected with the industrial computer; the temperature sensor is arranged in the voltage optoelectronic isolation filtering module.

[0062] The voltage optoelectronic isolation filtering module comprises a voltage dividing and attenuating circuit, a gain common mode rejection circuit, an amplifying circuit, an optoelectronic coupling isolation circuit, an amplifying and gain compensation circuit, an input reference bias circuit and an output reference bias circuit.

[0063] The input end of the voltage dividing and attenuating circuit is connected with the output end of the probe crimping tool, and the output end is connected with the input end of the gain common mode rejection circuit; the input end of the amplifying circuit is connected with the output end of the gain common mode rejection circuit, and the output end is connected with the input end of the optoelectronic coupling isolation circuit; the input end of the amplifying and gain compensation circuit is connected with the output end of the optoelectronic coupling isolation circuit, and the output end is connected with the voltage acquisition board card.

[0064] The output end of the input reference bias circuit is connected with the gain common mode rejection circuit; the output end of the output reference bias circuit is connected with the amplifying and gain compensation circuit.

[0065] The voltage division attenuation circuit comprises a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23, a diode D2 and a switching diode D5; the model of the switching diode D5 is preferably BAV199;

[0066] One end of the resistor R7 is connected with the probe crimping tool, and the other end is connected with the resistor R8; one end of the resistor R11 is connected with the probe crimping tool, and the other end is connected with the resistor R12;

[0067] One end of the resistor R9 is connected with the resistor R8, the capacitor C19, the capacitor C20, the capacitor C21, the output end of the diode D2, one end of the switching diode D5 and the gain common mode rejection circuit, and the other end is connected with the resistor R10, the capacitor C19, the capacitor C20, the capacitor C22 and the capacitor C23 and grounded;

[0068] The resistor R12 is connected with the resistor R10, the capacitor C22, the capacitor C23, the capacitor C21, the input end of the diode D2, the other end of the switching diode D5 and the gain common mode rejection circuit.

[0069] The gain common mode rejection circuit comprises an operational amplifier U8, a resistor R5, a resistor R6, a resistor R13, a resistor R14, an inductor L5, an inductor L6, a capacitor C24, a capacitor C25 and a capacitor C26; the model of the operational amplifier U8 is preferably AD8221BRZ;

[0070] The resistor R5 and the resistor R6 are connected in parallel, one end of which is connected with pin 2 of the operational amplifier U8, and the other end is connected with pin 3 of the operational amplifier U8; pin 1 and pin 4 of the operational amplifier U8 are connected with the voltage division attenuation circuit, pin 5 is connected with the inductor L6 and the capacitor C24, pin 6 is connected with the resistor R14, the capacitor C26 and the resistor R13, pin 7 is connected with the amplification circuit, and pin 8 is connected with the inductor L5 and the capacitor C25; the capacitor C24 is connected with the capacitor C25, the resistor R14 and the capacitor C26; the resistor R13 is connected with the input reference bias circuit.

[0071] The amplification circuit comprises an operational amplifier U9A, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R23, a resistor R31, a resistor R34, an inductor L7, an inductor L9, a capacitor C27, a capacitor C30, a capacitor C33 and a capacitor C34; the model of the operational amplifier U9A is preferably ADA4522-2;

[0072] One end of the resistor R15 is connected with the gain common mode rejection circuit, the other end is connected with the resistor R16, the resistor R23 and the capacitor C30; the pin 1 of the operational amplifier U9A is connected with the resistor R17 and the resistor R31, the pin 2 is connected with the resistor R34 and the resistor R31, the pin 3 is connected with the resistor R16, the pin 4 is connected with the inductor L9 and the capacitor C34, the pin 8 is connected with the inductor L7 and the capacitor C27;

[0073] The resistor R34 is connected with the resistor R23 and the capacitor C30 and grounded; one end of the resistor R18 is connected with the resistor R17 and the capacitor C33, the other end is connected with the photoelectric coupling isolation circuit.

[0074] The photoelectric coupling isolation circuit comprises a photo-coupler U11, an operational amplifier U9B, a diode D3, a resistor R19, a resistor R24, a resistor R28, a capacitor C29, a capacitor C31, a capacitor C32, a capacitor C35 and a capacitor C35; the model number of the photo-coupler U11 is preferably HCRN201; the model number of the operational amplifier U9B is preferably ADA4522-2;

[0075] The pin 1 of the photo-coupler U11 is connected with the output end of the diode D3, the pin 2 is connected with the resistor R19 and the input end of the diode D3, the pin 3 is connected with the capacitor C32, the pin 4 is connected with the resistor R24, the capacitor C31 and the pin 6 of the operational amplifier U9B, the pin 5 is connected with the resistor R28, the capacitor C36, the capacitor C35 and the amplification and gain compensation circuit, the pin 6 is connected with the capacitor C29;

[0076] The pin 5 of the operational amplifier U9B is connected with the amplification circuit, the pin 7 is connected with the capacitor C31 and the resistor R19; the resistor R28 is connected with the capacitor C36 and the capacitor C35 and grounded.

[0077] The amplification and gain compensation circuit comprises an operational amplifier U10A, an operational amplifier U10B, a resistor R20, a resistor R21, a resistor R22, a resistor R25, a resistor R26, a resistor R27, a resistor R29, a resistor R30, an inductor L8, an inductor L10, a capacitor C28, a capacitor C37, a capacitor C38 and a capacitor C39; the model number of the operational amplifier U10A and the operational amplifier U10B is preferably ADA4522-2;

[0078] The pin 1 of the operational amplifier U10A is connected with the resistor R26 and the capacitor R30, the pin 2 is connected with the resistor R30, the pin 3 is connected with the photoelectric coupling isolation circuit, the pin 4 is connected with the capacitor C39 and the inductor L10, the pin 8 is connected with the capacitor C28 and the inductor L8;

[0079] Pin 5 of the operational amplifier U10B is connected to resistors R26, R29 and capacitor C38, pin 6 is connected to resistors R20, R21 and R22, and pin 7 is connected to resistors R21, R25 and R27.

[0080] The capacitor C28 is connected to the resistor R20; the resistor R22 is connected to the output reference bias circuit; the resistor R29 is connected to the capacitor C38 and grounded; one end of the capacitor C37 is connected to the resistor R25 and the voltage acquisition board, and the other end is connected to the resistor R27 and grounded.

[0081] The input reference bias circuit and the output reference bias circuit each include a voltage reference chip U13, an inductor L13, a capacitor C45, a capacitor C47, and a capacitor C48; the preferred model of the voltage reference chip U13 is ADR431B.

[0082] Pin 2 of the voltage reference chip U13 is connected to inductor L13, capacitor C45 and capacitor C47, pin 4 is connected to capacitor C45, capacitor C47 and capacitor C48 and grounded, and pin 6 is connected to capacitor C48, gain common-mode rejection circuit and amplification and gain compensation circuit.

[0083] A preferred embodiment of the battery module charging and discharging voltage acquisition method of the present invention includes the following steps:

[0084] Step S10: The industrial control computer sequentially passes through the chassis, voltage acquisition board, voltage opto-isolation filter module, and probe crimping fixture to acquire the actual voltage values ​​y1, y2, and y3 of the battery module under standard voltages x1, x2, and x3. Based on x1, x2, x3, y1, y2, and y3, the correction constants a, b, and c are calculated using a quadratic equation.

[0085] Step S20: Set a temperature T1 and a temperature T2, and measure the voltage V1 and voltage V2 of the battery module at the temperature T1 and temperature T2 respectively. Correct the voltage V1 and voltage V2 based on the correction normals a, b, and c to obtain voltage V3 and voltage V4; the temperature T1 is lower than the temperature T2.

[0086] Step S30: Calculate the temperature coefficient TCV based on the temperature T1, temperature T2, voltage V3, and voltage V4;

[0087] Step S40: The industrial control computer collects the pre-calibration voltage Ya of the battery module through the voltage acquisition board, and collects the temperature t1 during voltage calibration and the current temperature t2 through the temperature sensor.

[0088] Step S50, the industrial computer outputs the calibration voltage Yb based on the pre-calibration voltage Ya, the temperature t1, the temperature t2 and the temperature coefficient TCV.

[0089] In the step S10, the normal constants a, b and c are calculated by using a quadratic equation based on the x1, x2, x3, y1, y2 and y3, and the calculation is specifically as follows:

[0090] y1=a*x1 2 +b*x1+c;

[0091] y2=a*x2 2 +b*x2+c;

[0092] y3=a*x3 2 +b*x3+c;

[0093] In the step S20, the calculation formulae of the voltage V3 and the voltage V4 are as follows:

[0094] V3=a*V1 2 +b*V1+c;

[0095] V4=a*V2 2 +b*V2+c;

[0096] In the step S30, the calculation formula of the temperature coefficient TCV is as follows:

[0097] TCV=(V4-V3) / (V3*(T2-T1));

[0098] In the step S50, the calculation formula of the calibration voltage Yb is as follows:

[0099] Yb=Ya*(1-TCV*(t2-t1))。

[0100] In summary, the present application has the following advantages:

[0101] The voltage photoelectric isolation filtering module including a voltage division attenuation circuit, a gain common-mode rejection circuit, an amplification circuit, a photoelectric coupling isolation circuit, an amplification and gain compensation circuit, an input reference bias circuit and an output reference bias circuit is arranged to filter and electrically isolate the voltage signal collected by the probe crimping tool, so that the voltage signal is not distorted and delayed during transmission, the anti-interference capability is improved, the temperature of the voltage photoelectric isolation filtering module is collected by the temperature sensor, the collected temperature is used to calibrate the voltage collected by the voltage collection board card, and the voltage collection precision is greatly improved.

[0102] While the foregoing description has described specific embodiments of the application, one ordinary skill in the art will appreciate that various modifications and changes can be made thereto without departing from the spirit and scope of the application, as set forth in the appended claims.

Claims

1. A battery module charge-discharge voltage acquisition system, characterized in that: The probe compression tool, the voltage photoelectric isolation filter module, the voltage acquisition board, the cabinet, the industrial computer, the temperature sensor and the memory are connected in series. The input end of the voltage photoelectric isolation filter module is connected with the output end of the probe compression tool, and the output end is connected with the input end of the voltage acquisition board. The voltage photoelectric isolation filter module comprises a voltage division and attenuation circuit, a gain common mode rejection circuit, an amplification circuit, a photoelectric coupling isolation circuit, an amplification and gain compensation circuit, an input reference bias circuit and an output reference bias circuit. The input end of the voltage division and attenuation circuit is connected with the output end of the probe compression tool, and the output end is connected with the input end of the gain common mode rejection circuit. The output end of the input reference bias circuit is connected with the gain common mode rejection circuit, and the output end of the output reference bias circuit is connected with the amplification and gain compensation circuit. The amplification and gain compensation circuit comprises an operational amplifier U10A, an operational amplifier U10B, a resistor R20, a resistor R21, a resistor R22, a resistor R25, a resistor R26, a resistor R27, a resistor R29, a resistor R30, an inductor L8, an inductor L10, a capacitor C28, a capacitor C37, a capacitor C38 and a capacitor C39. The pin 1 of the operational amplifier U10A is connected with the resistor R26 and the capacitor R30, the pin 2 is connected with the resistor R30, the pin 3 is connected with the photoelectric coupling isolation circuit, the pin 4 is connected with the capacitor C39 and the inductor L10, and the pin 8 is connected with the capacitor C28 and the inductor L8. The pin 5 of the operational amplifier U10B is connected with the resistor R26, the resistor R29 and the capacitor C38, the pin 6 is connected with the resistor R20, the resistor R21 and the resistor R22, and the pin 7 is connected with the resistor R21, the resistor R25 and the resistor R27. The capacitor C28 is connected with the resistor R20, the resistor R22 is connected with the output reference bias circuit, the resistor R29 is connected with the capacitor C38 and grounded, and one end of the capacitor C37 is connected with the resistor R25 and the voltage acquisition board, and the other end is connected with the resistor R27 and grounded.

2. The battery module charge-discharge voltage acquisition system of claim 1, wherein: The voltage division and attenuation circuit comprises a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23, a diode D2 and a switching diode D5. One end of the resistor R7 is connected with the probe compression tool, and the other end is connected with the resistor R8, and one end of the resistor R11 is connected with the probe compression tool, and the other end is connected with the resistor R12. One end of the resistor R9 is connected with the resistor R8, the capacitor C19, the capacitor C20, the capacitor C21, the output end of the diode D2, one end of the switching diode D5 and the gain common mode rejection circuit, and the other end is connected with the resistor R10, the capacitor C19, the capacitor C20, the capacitor C22 and the capacitor C23 and grounded; The resistor R12 is connected with the resistor R10, the capacitor C22, the capacitor C23, the capacitor C21, the input end of the diode D2, the other end of the switching diode D5 and the gain common mode rejection circuit.

3. The battery module charge-discharge voltage acquisition system of claim 1, wherein: The gain common mode rejection circuit comprises an operational amplifier U8, a resistor R5, a resistor R6, a resistor R13, a resistor R14, an inductor L5, an inductor L6, a capacitor C24, a capacitor C25 and a capacitor C26; One end of the resistor R5 and the resistor R6 is connected with the pin 2 of the operational amplifier U8, and the other end is connected with the pin 3 of the operational amplifier U8; the pins 1 and 4 of the operational amplifier U8 are connected with the voltage dividing and attenuating circuit, the pin 5 is connected with the inductor L6 and the capacitor C24, the pin 6 is connected with the resistor R14, the capacitor C26 and the resistor R13, the pin 7 is connected with the amplifying circuit, and the pin 8 is connected with the inductor L5 and the capacitor C25; the capacitor C24 is connected with the capacitor C25, the resistor R14 and the capacitor C26; the resistor R13 is connected with the input reference bias circuit.

4. The battery module charge-discharge voltage acquisition system of claim 1, wherein: The amplifying circuit comprises an operational amplifier U9A, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R23, a resistor R31, a resistor R34, an inductor L7, an inductor L9, a capacitor C27, a capacitor C30, a capacitor C33 and a capacitor C34; One end of the resistor R15 is connected with the gain common mode rejection circuit, and the other end is connected with the resistor R16, the resistor R23 and the capacitor C30; the pin 1 of the operational amplifier U9A is connected with the resistor R17 and the resistor R31, the pin 2 is connected with the resistor R34 and the resistor R31, the pin 3 is connected with the resistor R16, the pin 4 is connected with the inductor L9 and the capacitor C34, and the pin 8 is connected with the inductor L7 and the capacitor C27; The resistor R34 is connected with the resistor R23 and the capacitor C30 and grounded; one end of the resistor R18 is connected with the resistor R17 and the capacitor C33, and the other end is connected with the opto-coupler isolation circuit.

5. The battery module charge and discharge voltage acquisition system of claim 1, wherein: The opto-coupler isolation circuit comprises an opto-coupler U11, an operational amplifier U9B, a diode D3, a resistor R19, a resistor R24, a resistor R28, a capacitor C29, a capacitor C31, a capacitor C32, a capacitor C35 and a capacitor C35; The pin 1 of the opto-coupler U11 is connected with the output end of the diode D3, the pin 2 is connected with the resistor R19 and the input end of the diode D3, the pin 3 is connected with the capacitor C32, the pin 4 is connected with the resistor R24, the capacitor C31 and the pin 6 of the operational amplifier U9B, the pin 5 is connected with the resistor R28, the capacitor C36, the capacitor C35 and the amplifying and gain compensation circuit, and the pin 6 is connected with the capacitor C29; The pin 5 of the operational amplifier U9B is connected with the amplification circuit, the pin 7 is connected with the capacitor C31 and the resistor R19; the resistor R28 is connected with the capacitor C36 and the capacitor C35 and grounded.

6. The battery module charge and discharge voltage acquisition system of claim 1, wherein: The input reference bias circuit and the output reference bias circuit both comprise a voltage reference chip U13, an inductor L13, a capacitor C45, a capacitor C47 and a capacitor C48; The pin 2 of the voltage reference chip U13 is connected with the inductor L13, the capacitor C45 and the capacitor C47, the pin 4 is connected with the capacitor C45, the capacitor C47 and the capacitor C48 and grounded, the pin 6 is connected with the capacitor C48, the gain common mode rejection circuit and the amplification and gain compensation circuit.

7. A battery module charge-discharge voltage acquisition method, characterized in that: The method needs to use the voltage acquisition system as claimed in any one of claims 1 to 6, comprising the following steps: In step S10, the industrial computer collects the actual voltage values y1, y2, y3 of the battery module under the standard voltages x1, x2, x3 through the case, the voltage acquisition board card, the voltage optoelectronic isolation filter module and the probe compression tooling in sequence, and calculates the correction parameters a, b, c by using a quadratic equation based on the x1, x2, x3, y1, y2, y3. In step S20, a temperature T1 and a temperature T2 are set, the voltage V1 and the voltage V2 of the battery module at the temperature T1 and the temperature T2 are measured respectively, and the voltage V3 and the voltage V4 are obtained by correcting the voltage V1 and the voltage V2 based on the correction parameters a, b, c; the temperature T1 is less than the temperature T2. In step S30, the temperature coefficient TCV is calculated based on the temperature T1, the temperature T2, the voltage V3 and the voltage V4. In step S40, the industrial computer collects the pre-calibration voltage Ya of the battery module through the voltage acquisition board card, and collects the temperature t1 and the current temperature t2 at the voltage calibration time through the temperature sensor. In step S50, the industrial computer outputs the calibration voltage Yb based on the pre-calibration voltage Ya, the temperature t1, the temperature t2 and the temperature coefficient TCV.

8. The method of claim 7, wherein the method further comprises: determining whether the voltage of the battery module is within a predetermined range; and if the voltage of the battery module is not within the predetermined range, then adjusting the voltage of the battery module to be within the predetermined range. In step S10, the correction parameters a, b, c are calculated by using a quadratic equation based on the x1, x2, x3, y1, y2, y3. y1 = a * x1 2 + b * x1 + c; y2 = a * x2 2 + b * x2 + c; y3 = a * x3 2 + b * x3 + c; In step S20, the calculation formula of the voltage V3 and the voltage V4 is as follows: V3 = a*V1 2 + b*V1 + c; V4 = a*V2 2 + b*V2 + c; In step S30, the calculation formula of the temperature coefficient TCV is as follows: TCV= (V4-V3) / (V3*(T2-T1)); In step S50, the calculation formula of the calibration voltage Yb is as follows: Yb= Ya*(1-TCV*(t2-t1)).

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