Battery internal resistance detection device

Abstract

The utility model relates to a battery internal resistance detection device. The battery internal resistance detection device comprises a master control single-chip microcomputer, a signal conversion circuit, an AC voltage acquisition module and an IEC61850 protocol conversion module. The output end of the master control single-chip microcomputer is electrically connected with the input end of the signal conversion circuit so as to transmit sine AC voltage signals. A first output end of the signal conversion circuit is electrically connected with positive and negative power supply ends of the battery pack; the second output end of the signal conversion circuit is electrically connected with the master control single-chip microcomputer. The input end of the alternating-current voltage acquisition module is suitable for being electrically connected with the positive and negative power supply ends of each single battery and is suitable for acquiring a voltage signal in a channel alternating-current loop of each single battery; the output end of the AC voltage acquisition module is electrically connected with the high-speed ADC module of the master control single-chip microcomputer. And the main control single chip microcomputer is electrically connected with the IEC61850 protocol conversion module.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery power supply, and in particular to a battery internal resistance detection device. BACKGROUND

[0002] In recent years, with the vigorous development of the power system construction in China, the automation level is higher and higher, and the power supply reliability is higher and higher. More and more backup battery groups are added in power control devices to enable the devices to work normally in a power failure state.

[0003] Since the power system devices are mostly in a normal inaction state, only when a power failure occurs, the main power supply is powered off and the switch needs to be actuated. At this time, it is necessary to ensure that the backup battery group works normally under such abnormal conditions. Therefore, the backup battery group needs to be monitored in daily situations to ensure that the battery group is in a healthy state, so that the backup battery group can work normally when needed.

[0004] The condition of the battery group is mainly caused by the large internal resistance of the battery, which leads to insufficient power storage. Therefore, regular detection of the internal resistance of the battery is an important link for monitoring the state of the battery group. The application provides a battery internal resistance detection device for detecting the internal resistance of the battery. SUMMARY

[0005] Therefore, the application provides a battery internal resistance detection device.

[0006] According to an aspect of the application, a battery internal resistance detection device is provided, which comprises a master control single-chip microcomputer, a signal conversion circuit, an alternating current voltage acquisition module and an IEC61850 protocol conversion module.

[0007] The battery group comprises two or more single batteries connected in series.

[0008] The output end of the master control single-chip microcomputer is electrically connected to the input end of the signal conversion circuit to transmit a sinusoidal alternating current voltage signal. The first output end of the signal conversion circuit is adapted to be electrically connected to the positive and negative power supply ends of the battery group to convert the sinusoidal alternating current voltage signal into a constant current signal and output the constant current signal to the positive and negative power supply ends of each single battery. The second output end of the signal conversion circuit is electrically connected to the high-speed ADC module of the master control single-chip microcomputer.

[0009] The input end of the alternating current voltage acquisition module is adapted to be electrically connected to the positive and negative power supply ends of each single battery, and is adapted to acquire the voltage signal in the channel alternating current loop of each single battery. The output end of the alternating current voltage acquisition module is electrically connected to the high-speed ADC module of the master control single-chip microcomputer, and is adapted to transmit the voltage signals in the channel alternating current loops of the two or more single batteries to the high-speed ADC module.

[0010] The master single-chip microcomputer is electrically connected with the IEC61850 protocol conversion module.

[0011] In a possible implementation, the signal conversion circuit comprises: a direct-current isolation circuit and a power amplification chip.

[0012] The high-speed DAC module of the master single-chip microcomputer is electrically connected with the input end of the power amplification chip to transmit a sinusoidal alternating voltage signal; the power amplification chip is electrically connected with the positive and negative power supply ends of the battery pack through the direct-current isolation circuit to output a constant current signal to the positive and negative power supply ends of each single battery; and the direct-current isolation circuit is electrically connected with the input end of the high-speed ADC module.

[0013] In a possible implementation, the power amplification chip is of the type NS4203.

[0014] In a possible implementation, the alternating voltage acquisition module comprises: a second instrument amplifier N5.

[0015] The input end of the second instrument amplifier N5 is electrically connected with the positive and negative power supply ends of each single battery and is suitable for acquiring the voltage signal of each single battery; and the output end of the second instrument amplifier N5 is electrically connected with the high-speed ADC module.

[0016] In a possible implementation, the direct-current voltage acquisition module comprises: a first instrument amplifier N4.

[0017] The input end of the direct-current voltage acquisition module is electrically connected with the positive and negative power supply ends of each single battery to acquire the direct-current voltage of each single battery; and the output end of the direct-current voltage acquisition module is electrically connected with the input end of the master single-chip microcomputer.

[0018] In a possible implementation, the temperature sensor is suitable for being connected with the terminal head of each single battery to acquire the temperature of the terminal head of each single battery; and the output end of the temperature sensor is electrically connected with the high-speed ADC module of the master single-chip microcomputer.

[0019] In a possible implementation, the master single-chip microcomputer is of the type GD32F303RC.

[0020] Beneficial effects: the signal conversion circuit is suitable for converting a sine wave signal into an alternating constant current; the power amplifier chip of the signal conversion circuit is electrically connected with the battery pack and is suitable for transmitting the alternating constant current to each single battery as a detection power supply voltage; the sampling voltage signal is uploaded to the main control single chip on the direct current isolation circuit of the signal conversion circuit, and the main control single chip obtains the current value of the alternating constant current after calculation; the alternating voltage acquisition module is suitable for acquiring the voltage data of each single battery and uploading the voltage data to the high-speed ADC module of the main control single chip; the main control single chip performs division operation on the voltage value of each single battery and the current value of the alternating constant current to obtain the battery internal resistance of the single battery, adds all the single battery internal resistance values to obtain the total resistance value of the battery pack, and the main control single chip compares and judges the total resistance value signal, and if the total resistance value of the battery pack is not within the qualified range, it indicates that the performance of the battery pack is poor.

[0021] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and serve to explain the principles of the present application.

[0023] Figure 1 A structure connection diagram of a battery internal resistance detection device of an embodiment of the present application is shown;

[0024] Figure 2 A circuit diagram of a main control single chip of an embodiment of the present application is shown;

[0025] Figure 3 A circuit diagram of a signal conversion circuit of an embodiment of the present application is shown;

[0026] Figure 4 A partial circuit diagram of a battery internal resistance detection device of an embodiment of the present application is shown;

[0027] Figure 5 A circuit diagram of a first instrument amplifier N4 and a second instrument amplifier N5 of an embodiment of the present application is shown;

[0028] Figure 6 A circuit diagram of a direct current voltage acquisition module of an embodiment of the present application is shown;

[0029] Figure 7 A signal transmission circuit diagram of a temperature sensor of an embodiment of the present application is shown;

[0030] Figure 8 A decoder circuit diagram of an embodiment of the present application is shown;

[0031] Figure 9A partial circuit diagram of a battery internal resistance detection device according to an embodiment of the present application is shown.

[0032] Figure 10 A circuit diagram of an RS-485 transceiver according to an embodiment of the present application is shown.

[0033] Figure 11 A partial circuit diagram of a battery internal resistance detection device according to an embodiment of the present application is shown.

[0034] Figure 12 A partial circuit diagram of a battery internal resistance detection device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] Various exemplary embodiments, features, and aspects of the present application will be described herein below with reference to the accompanying drawings. The same reference numbers in different drawings represent the same or similar elements. Although various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0036] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application or simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0037] In addition, the terms "first", "second", etc. are only 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 with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0038] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0039] In addition, in order to better illustrate the present application, a large number of specific details are given in the specific embodiments below. Those skilled in the art should understand that the present application can also be implemented without certain specific details. In some examples, methods, means, elements and circuits well known to those skilled in the art are not described in detail in order to highlight the main idea of the present application.

[0040] Figure 1 The structure connection diagram of the battery internal resistance detection device according to an embodiment of the present application is shown. As shown in the drawing, the battery internal resistance detection device comprises a master control single-chip microcomputer 100, a signal conversion circuit 200, and an alternating current voltage acquisition module 300. Figure 1 The battery pack comprises two or more single batteries connected in series. The output end (high-speed DAC module 900) of the master control single-chip microcomputer 100 is electrically connected with the input end of the signal conversion circuit 200. The first output end of the signal conversion circuit 200 is electrically connected with the positive and negative power supply ends of the battery pack, and is suitable for outputting an alternating constant current signal to the positive and negative power supply ends of each single battery. The second output end of the signal conversion circuit 200 is electrically connected with the high-speed ADC module 400 of the master control single-chip microcomputer 100, and is suitable for feeding back the sampling voltage of the alternating constant current signal to the high-speed ADC module 400. The input end of the alternating current voltage acquisition module 300 is electrically connected with the positive and negative power supply ends of each single battery, and the alternating current voltage acquisition module 300 is suitable for acquiring the voltage signal in the channel alternating current loop of each single battery. The output end of the alternating current voltage acquisition module 300 is electrically connected with the high-speed ADC module 400, and is suitable for feeding the voltage signal in the channel alternating current loop of two or more single batteries to the high-speed ADC module 400. The master control single-chip microcomputer 100 is electrically connected with the IEC61850 protocol conversion module 700.

[0041] Here, it should be noted that the signal conversion circuit 200 is suitable for converting the sine wave signal output from the output end (high-speed DAC module 900) of the master control single-chip microcomputer 100 into an alternating constant current signal. The power amplification chip N2 of the signal conversion circuit 200 is electrically connected with the battery pack, and is suitable for transmitting the alternating constant current signal to each single battery as a detection power supply voltage. The direct current isolation circuit of the signal conversion circuit 200 is electrically connected with the high-speed ADC module 400 of the master control single-chip microcomputer 100, and is suitable for uploading the sampling voltage of the alternating constant current signal to the master control single-chip microcomputer 100. The master control single-chip microcomputer 100 can calculate the current value of the alternating constant current signal according to the sampling voltage. The alternating current voltage acquisition module 300 is suitable for acquiring the voltage data of each single battery and uploading it to the high-speed ADC module 400 of the master control single-chip microcomputer 100. The master control single-chip microcomputer 100 performs division operation on the voltage value of each single battery acquired and the current value of the alternating constant current signal calculated, to obtain the battery internal resistance of the single battery. The total internal resistance value of the battery pack can be obtained by adding all the single battery internal resistance values. The master control single-chip microcomputer 100 compares and judges the total internal resistance value. If the total resistance value of the battery pack is not within the qualified range, it indicates that the performance of the battery pack is poor.

[0042] In a possible implementation, the signal conversion circuit 200 comprises: a direct-current isolation circuit and a power amplification chip N2; an output end (a high-speed DAC module 900) of the master control single-chip microcomputer 100 is electrically connected to an input end of the power amplification chip N2 to transmit a sinusoidal alternating voltage signal, and an output end of the power amplification chip N2 is electrically connected to positive and negative power supply ends of the battery pack through the direct-current isolation circuit to output a constant current signal to the positive and negative power supply ends of each single battery; further, the power amplification chip N2 is of a model of NS4203.

[0043] As shown in Figure 1 and Figure 3 , a 21st pin of the master control single-chip microcomputer 100 is electrically connected to a 10th pin (an RIN end) of the power amplification chip N2 through a resistor R2 and a capacitor C13 to output a standard sinusoidal alternating signal DAC to the power amplification chip N2; a 16th pin (an ROUT+ end) of the power amplification chip N2 is electrically connected to the direct-current isolation circuit to transmit a differential alternating signal ACOUT1, and a 14th pin (an ROUT- end) of the power amplification chip N2 is electrically connected to the direct-current isolation circuit to transmit a differential alternating signal ACOUT2; a 6th pin, a 12th pin, a 13th pin and a 9th pin of the power amplification chip N2 are connected to a +5V working voltage; a 11th pin, a 15th pin, a 2nd pin, a 4th pin, a 7th pin and an 8th pin of the power amplification chip N2 are grounded. The direct-current isolation circuit comprises: capacitors C19, C18, C17, C16 and C15 connected in parallel, one end of the capacitor C15 is electrically connected to the 16th pin (the ROUT+ end) of the power amplification chip N2 through a resistor R5 and a resistor R3 to connect to the differential alternating signal ACOUT1; the direct-current isolation circuit further comprises: capacitors C20, C21, C22, C23 and C24 connected in parallel, one end of the capacitor C24 is electrically connected to the 14th pin (the ROUT- end) of the power amplification chip N2 through a resistor R8 and a resistor R7 to connect to the differential alternating signal ACOUT2; the capacitor C24 and the capacitor C15 are electrically connected through a TVS diode V3. One end of the capacitor C17 outputs an alternating signal IO1, and one end of the capacitor C22 outputs an alternating signal IO2; the alternating signal IO1 and the alternating signal IO2 are connected to a stake head of the battery pack.

[0044] Further, as shown in Figure 3 , the signal conversion circuit further comprises: a power conversion chip N3; an input end of the power conversion chip N3 is adapted to connect to a +5V voltage; and an output end of the power conversion chip N3 is adapted to output a -5V voltage. The power conversion chip N3 is adapted to convert the +5V into a -5V signal to supply power to the system.

[0045] Further, as shown in Figure 5As shown, the signal conversion circuit further comprises: a first instrument amplifier N4; the direct current isolation circuit is electrically connected with the high-speed ADC module 400 through the first instrument amplifier N4. The input end of the first instrument amplifier N4 is electrically connected with the direct current isolation circuit to collect the sampling voltage of the alternating constant current signal (i.e. the voltage of the current sampling resistor R5 on the direct current isolation circuit); the output end of the first instrument amplifier N4 is electrically connected with the high-speed ADC module 400 to feed back the voltage signal of the current sampling resistor R5. Further, the model of the first instrument amplifier N4 is SGM621; the second pin (VIN- end) of the first instrument amplifier N4 is electrically connected with one end of the current sampling resistor R5 of the direct current isolation circuit to access the I1 signal; the third pin (VIN+ end) of the first instrument amplifier N4 is electrically connected with the other end of the current sampling resistor R5 of the direct current isolation circuit to access the I2 signal; the first pin (RG end) of the first instrument amplifier N4 is electrically connected with the eighth pin (RG end) through the resistor R13; the fourth pin (V- end) of the first instrument amplifier N4 accesses the -5V working voltage, and the seventh pin (V+ end) of the first instrument amplifier N4 accesses the +5V working voltage; the sixth pin (VO end) of the first instrument amplifier N4 is electrically connected with the main control single-chip microcomputer 100 in sequence through the inductor L4, the resistor R14 and the TVS diode V5, which is suitable for feeding back the ADC1 signal (the voltage signal of the current sampling resistor R5 corresponding to the collection signal of the constant current channel) to the high-speed ADC module 400 of the main control single-chip microcomputer 100, and the main control single-chip microcomputer 100 can calculate the current value of the alternating constant current signal according to the voltage signal of the current sampling resistor R5; the fifth pin (REF end) of the first instrument amplifier N4 accesses the VREF signal.

[0046] In a possible implementation, as shown in Figure 4 As shown, the alternating signal IO1 output by the direct current isolation circuit is connected to the positive power end of the battery pack (i.e. the positive power end BAT4+ of the battery BAT4) through the relay JI; the alternating signal IO2 output by the direct current isolation circuit is connected to the negative power end of the battery pack (i.e. the negative power end BAT1- of the battery BAT1). It should be noted that the direct current isolation circuit is suitable for isolating direct current signals or direct current voltages, and only allows alternating current signals to be superimposed on the direct current voltage of the battery pack. Since the internal equivalent of the battery pack is a series connection of a direct current power supply and an internal resistance, the direct current voltage signal can be eliminated by alternating current signal conversion, so as to collect the internal resistance signal.

[0047] Further, as shown in Figure 1 and Figure 4As shown, the single battery is provided with four; BAT4+ is the positive power supply end of the battery BAT4 (i.e. the positive power supply end of the battery pack), BAT4- is the negative power supply end of the battery BAT4 and is directly connected with BAT4+, connecting the battery BAT3 to the negative power supply end BAT4- of the battery BAT4; BAT3- is the negative power supply end of the battery BAT3, directly connected with the positive power supply end BAT2+ of the battery BAT2, connecting the battery BAT2 into the circuit; BAT2- is the negative power supply end of the battery BAT2, directly connected with the positive power supply end BAT1+ of the battery BAT1, connecting the battery BAT1 into the circuit; BAT1- is the negative power supply end of the battery BAT1 (i.e. the negative power supply end of the battery pack).

[0048] In a possible implementation, the positive and negative power supply ends of each single battery are respectively connected with the input end of the AC voltage acquisition module 300 through relays; further, as shown in Figure 1 As shown, the BAT1- end outputs the signal IO1_1 to the AC voltage acquisition module 300; the BAT2- end outputs the signal IO2_1 to the AC voltage acquisition module 300; the BAT3- end outputs the signal IO3_1 to the AC voltage acquisition module 300; the BAT4- end outputs the signal IO4_1 to the AC voltage acquisition module 300; the BAT4+ terminal outputs the signal IO4_2 to the AC voltage acquisition module 300; the battery internal resistance is acquired through 4-wire system, for eliminating the influence of lead resistance. As shown in Figure 4 As shown, since the single battery is four, and the constant current circuit is only one, and because the change of the battery internal resistance is a slow process and will not mutate, the battery internal resistance acquisition does not need to be acquired at all times, but can be acquired once a week, so the relays J1, J2, J3, J4 and J5 are used to switch the signal channel of the acquisition circuit signal, and the single battery internal resistance is acquired through time-sharing switching.

[0049] In a possible implementation, as shown in Figure 5 As shown, the AC voltage acquisition module comprises: a second instrument amplifier N5; the input end of the second instrument amplifier N5 is electrically connected with the positive and negative power supply ends of each single battery, and is suitable for acquiring the voltage signal of each single battery; the output end of the second instrument amplifier N5 is electrically connected with the high-speed ADC module 400 of the master control single chip 100. It should be noted that the first instrument amplifier N4 and the second instrument amplifier N5 are both small signal amplification circuits, which can amplify the acquired small signal to an ADC acquisition signal with an amplitude of 0-3.3V, and the full amplitude is applied to the 0-3.3V acquisition range of the ADC, so as to improve the acquisition accuracy.

[0050] Further, the model of the second instrument amplifier N5 is SGM621; as shown in Figure 5 As shown, the 2nd pin (VIN- end) of the second instrument amplifier N5 is connected with the input end of the AC voltage acquisition module 300 through the inductor L1 and the capacitor C29. Figure 4All BAT2 signals in the VIN+ terminal of the 3rd pin of the second instrumentation amplifier N5 are connected through the inductor L2 and the capacitor C30 Figure 4 All BAT1 signals in the VO terminal of the 6th pin of the second instrumentation amplifier N5 are connected through the resistor R37, the capacitor C37, the resistor R38, the resistor R22, the TVS diode V5 and the main control single-chip microcomputer 100 in sequence.

[0051] In summary, it needs to be noted that the main control single-chip microcomputer 100 Figure 2 has 16 channels of the high-speed ADC module 400, as shown in Figure 2 the VO terminal of the 6th pin of the second instrumentation amplifier N5 is connected to the 17th pin of the main control single-chip microcomputer 100, which is suitable for transmitting the ADC2 signal to the main control single-chip microcomputer 100; and the VO terminal of the 6th pin of the first instrumentation amplifier N4 is connected to the 27th pin of the main control single-chip microcomputer 100, which is suitable for transmitting the ADC1 signal to the main control single-chip microcomputer 100. The main control single-chip microcomputer 100 performs division operation on the collected voltage value of each monomer battery and the alternating constant current value, and thus the battery internal resistance data of each monomer battery can be obtained. The model of the main control single-chip microcomputer 100 is GD32F303RC.

[0052] In a possible implementation, the application further includes a direct-current voltage acquisition module 500; the input end of the direct-current voltage acquisition module 500 is connected to the positive and negative power supply ends of each monomer battery, so as to acquire the direct-current voltage of each monomer battery; and the output end of the direct-current voltage acquisition module 500 is connected to the high-speed ADC module 400 of the main control single-chip microcomputer 100. It needs to be noted that the direct-current voltage acquisition module 500 can acquire the direct-current voltage signal of each monomer battery and the total voltage signal of the battery pack, amplify the signals and send the signals to the high-speed ADC module 400 of the main control single-chip microcomputer 100.

[0053] As shown in Figure 6As shown, the direct current voltage acquisition module 500 comprises an amplifier N108, an amplifier N107 and an amplifier N9; wherein the non-inverting input end of the amplifier N108 is connected to the VinN signal through a resistor R168, the inverting input end of the amplifier N108 is electrically connected with the output end of the amplifier N108, and the output end of the amplifier N108 is electrically connected with the 15th pin of the main control single-chip microcomputer 100 through a resistor R170 and is suitable for transmitting the Ibat signal; it should be noted that the amplifier N108 uses a small resistance and a large current sampling resistor R166 and a resistor R168 connected with GND and the VinN signal respectively, and converts the charging current signal of the battery into the Ibat signal which can be collected by the high-speed ADC module 400 through a differential circuit, and sends the Ibat signal into the high-speed ADC module 400 for signal acquisition to obtain the battery charging current signal.

[0054] The non-inverting input end of the amplifier N107 is electrically connected with each single battery through a resistor R163 to access all BAT2 signals in the Figure 4 The inverting input end of the amplifier N107 is electrically connected with each single battery through a resistor R161 to access all BAT1 signals in the Figure 4 The inverting input end of the amplifier N107 is electrically connected with the output end of the amplifier N107, and the output end of the amplifier N107 is electrically connected with the 14th pin of the main control single-chip microcomputer 100 through a resistor R165 and is suitable for transmitting the Vbat signal; it should be noted that the amplifier N107 is used to collect the section voltage of each single battery, uses relays J1B, J1C, J2B, J2C, J3B, J3C, J4B and J4C to switch the signal channel of the acquisition circuit signal, collects the single battery voltage through time-sharing switching, collects the voltage of the single battery through the amplifier N107 and converts the voltage into the Vbat signal which can be collected by the high-speed ADC module 400, sends the Vbat signal into the high-speed ADC module 400 for signal acquisition, and thus collects the section voltage of the four single batteries BAT1, BAT2, BAT3 and BAT4.

[0055] The non-inverting input end of the amplifier N9 is electrically connected with the negative power supply end of the BAT1 battery through a resistor R63, the inverting input end of the amplifier N9 is electrically connected with the positive power supply end of the BAT1 battery through a resistor R61 and is electrically connected with the output end of the amplifier N9, and the output end of the amplifier N9 is electrically connected with the 16th pin of the main control single-chip microcomputer 100 through a resistor R65 and is suitable for transmitting the Vbat_48V signal; it should be noted that the amplifier N9 is used to collect the total voltage of the four single batteries, collects the total voltage of the four single batteries (battery pack) through a differential circuit and converts the total voltage into the Vbat_48V signal which can be collected by the high-speed ADC module 400, sends the Vbat_48V signal into the high-speed ADC module 400 for signal acquisition, and thus obtains the battery pack voltage.

[0056] In a possible implementation, the temperature sensor 600 is further included; the detection end of each temperature sensor 600 is connected with the lug head of each single battery respectively to collect the temperature of the lug head of each single battery; and the output end of the temperature sensor 600 is electrically connected with the input end of the main control single chip 100. It should be noted that the temperature sensor 600 is internally provided with a 103AT NTC thermistor, and each single battery is equipped with a temperature sensor 600 externally connected to collect the temperature of the single battery. The temperature signal can be converted into TEMP1, TEMP2, TEMP3 and TEMP4 signals collected by the high-speed ADC module 400 through resistance voltage division, and since the main control single chip 100 has 16 ADC channels, four ADC signals can be directly collected, and the four temperature collection circuits can be directly collected.

[0057] Further, as shown in Figure 7 , the TEMP1 signal output by the temperature sensor 600 is transmitted to the 8th pin of the main control single chip 100, the TEMP2 signal is transmitted to the 9th pin of the main control single chip, the TEMP3 signal is transmitted to the 10th pin of the main control single chip, and the TEMP4 signal is transmitted to the 11th pin of the main control single chip. Through the conversion of the high-speed ADC module 400, the analog signal measured by the temperature sensor 600 is converted into a digital signal, and the main control single chip 100 determines whether the temperature of the single battery is within the normal temperature range according to the collected temperature signal, so as to determine whether the single battery has a bad heating phenomenon.

[0058] In a possible implementation, the main control single chip 100 uses its Ethernet interface to upload the collected data to the remote host 800 through the IEC61850 protocol conversion module 700, uses the Ethernet interface to receive the control signal and data sent by the remote host 800 through the IEC61850 protocol conversion module 700, realizes data remote transmission and device remote measurement, so that the staff can obtain the relevant detection data in time in the remote host 800. Further, as shown in Figure 2 , the 29th pin of the main control single chip is electrically connected with the input end of the IEC61850 protocol conversion module 700 to transmit the T_RXD2 signal, and the 30th pin of the main control single chip is electrically connected with the input end of the IEC61850 protocol conversion module 700 to transmit the T_TXD2 signal.

[0059] In a possible implementation, as shown in Figure 8As shown, it also includes: decoder D0; pin 15 of decoder D0 is electrically connected to relay J2 through transistor V10 to transmit the DO2 signal; pin 14 of decoder D0 is electrically connected to relay J3 through transistor V12 to transmit the DO3 signal; pin 13 of decoder D0 is electrically connected to relay J4 through transistor V14 to transmit the DO4 signal; and pin 12 of decoder D0 is electrically connected to relay J5 through transistor V16 to transmit the DO3 signal. Output DO5 signal; pin 1 of decoder D0 is electrically connected to pin 43 of the main control microcontroller 100; pin 2 of decoder D0 is electrically connected to pin 42 of the main control microcontroller 100; pin 5 of decoder D0 is electrically connected to pin 41 of the main control microcontroller 100; pin 6 of decoder D0 is electrically connected to pin 40 of the main control microcontroller 100; pins 3 and 8 of decoder D0 are grounded; pin 16 of decoder D0 is connected to a +5V operating voltage. It should be noted that, if... Figure 8 and Figure 4 As shown, DO1 is the constant current circuit output enable signal. Only when DO1 = 1 is relay J1 connected to the circuit, superimposing the AC constant current onto the battery circuit to collect the internal resistance. DO2, DO3, DO4, and DO5 are digital output control signals, which are selected by decoder D0 (model: 74HC138) to switch the contacts of relays J2, J3, J4, and J5 to collect the internal resistance and voltage of the four individual batteries. The diodes (V9, V11, V13, V15, V17) act as reverse freewheeling diodes, freewheeling the reverse electromotive force of the relay drive coil during switching to eliminate its influence on the entire circuit. The transistors (V8, V10, V12, V14, V16) are driver transistors, used to amplify the voltage signal output by the chip into a large current line that can drive the relay coil to drive the relay.

[0060] In one possible implementation, such as Figure 9As shown, the input signal protection is carried out by the voltage division of the input resistor and the TVS voltage protection chip V602, V603, and the switch quantity input signal protection is prevented to obtain DI1, DI2, DI3, DI4 signals. The 24th pin of the main control single-chip is electrically connected to the TVS voltage protection chip V602 through the resistor R601 to input the DI_in1 signal; the 23rd pin of the main control single-chip is electrically connected to the TVS voltage protection chip V602 through the resistor R603 to input the DI_in2 signal; the 22nd pin of the main control single-chip is electrically connected to the TVS voltage protection chip V603 through the resistor R605 to input the DI_in3 signal; the 61st pin of the main control single-chip is electrically connected to the TVS voltage protection chip V603 through the resistor R607 to input the DI_in4 signal; DI_in1, DI_in2, DI_in3, DI_in4 are four switch quantity input signals, DI_in1 represents the first power supply normal / loss of power, DI_in2 represents the second power supply normal / loss of power, DI_in3 represents the standby signal, and DI_in4 represents the internal resistance measurement start signal. The first power supply normal / loss of power, the second power supply normal / loss of power, the standby, and the internal resistance measurement start signal are collected.

[0061] In a possible implementation manner, as shown in Figure 10 As shown, further comprising: an RS-485 transceiver U501; the 1st pin (RXD end) of the RS-485 transceiver U501 is electrically connected to the 54th pin of the main control single-chip 100 through the TVS diode V500; the 2nd pin (TXD end) of the RS-485 transceiver U501 is electrically connected to the 53rd pin of the main control single-chip 100 through the TVS diode V500; the 3rd pin of the RS-485 transceiver U501 is grounded; the 4th pin (VCC end) of the RS-485 transceiver U501 is connected to the +3.3V working voltage through the capacitor C502; the 7th pin (B end) of the RS-485 transceiver U501 is electrically connected to the RS485 communication through the resistor RT501; the 6th pin (A end) of the RS-485 transceiver U501 is electrically connected to the RS485 communication through the resistor RT502. The RS-485 transceiver U501 is used to convert the TTL serial port signal into the 485 level signal for 485 communication.

[0062] In a possible implementation manner, as shown in Figure 11 As shown, further comprising: a circuit charging loop chip N301 (model: XL7035); the 1st pin (IN end) of the circuit charging loop chip N301 is connected to the power switch POWER to input the VinP signal and the VinN signal; the 3rd pin and the 5th pin of the circuit charging loop chip N301 are grounded; the 2nd pin (SW end) of the circuit charging loop chip N301 is electrically connected to the positive power supply end of the battery BAT4 through the inductor L301.

[0063] In one possible implementation, such as Figure 11 As shown, it also includes: a step-down circuit chip N302 (model: XL7035); pin 1 of the step-down circuit chip N302 is connected to the power switch POWER to receive VinP and VinN signals; pins 3 and 5 of the step-down circuit chip N302 are grounded; pin 2 (SW terminal) of the step-down circuit chip N302 outputs +5V voltage through inductor L302; pin 4 (FB terminal) of the step-down circuit chip N302 outputs +5V voltage through capacitor C310 to obtain the 5V power supply for the system.

[0064] In one possible implementation, it also includes: a voltage conversion chip N1 (model: AMS1117-3.3); pin 1 (IN terminal) of the voltage conversion chip N1 is electrically connected to the circuit step-down circuit chip N302 through inductor L5 to receive +5V voltage; pins 2 and 4 of the voltage conversion chip N1 output +3.3V voltage through capacitors C63 and C3; used to convert 5V power supply into 3.3V power supply signal, thereby providing 3.3V operating voltage for the system.

[0065] The working process for this application is as follows:

[0066] a) Enable the high-speed DAC module 900 of the main control microcontroller 100 to generate a sinusoidal AC voltage signal and transmit it to the signal conversion circuit 200;

[0067] b) The sinusoidal AC voltage signal is converted into a constant AC current by the signal conversion circuit 200 and output to the battery pack;

[0068] c) The second instrumentation amplifier N5 of the AC voltage acquisition module 300 acquires the voltage data of each individual cell and uploads it to the high-speed main control microcontroller 100.

[0069] ADC module 400; at the same time, the first instrumentation amplifier N4 of the signal conversion circuit 200 collects the voltage data of the current sampling resistor R5 and uploads it to the high-speed ADC module 400 of the main control microcontroller 100. The main control microcontroller 100 calculates the current value of the AC constant current signal (according to Ohm's law, the current value of the AC constant current signal is equal to the voltage value of the current sampling resistor R5 divided by the resistance value of the current sampling resistor R5).

[0070] d) The main control microcontroller 100 divides the voltage value of each individual battery cell by the current value of the AC constant current to obtain the internal resistance of each individual battery cell. The internal resistances of each individual battery cell are added together to obtain the total internal resistance value of the battery pack.

[0071] e) using screw fixing hole to install temperature sensor to the stud head of each monomer battery, collecting the stud head temperature of each monomer battery for judging the battery health state and system health state;

[0072] f) judging the health state of the battery pack by the master single-chip microcomputer 100 comparing the original signal with the current signal and whether the current data collected exceeds the alarm threshold, and performing data interaction through the IEC61850 protocol conversion module 700.

[0073] g) using the IEC61850 protocol conversion module 700 to perform data interaction with the digital substation master station 800.

[0074] 800 (remote host). The control command of the digital substation master station 800 can be transmitted to the master single-chip microcomputer 100, and the corresponding operation is performed.

[0075] Compared with the prior art, the present application has the following advantages: both the internal resistance value of the battery pack and the voltage value of the battery pack can be measured; the battery internal resistance is collected using the alternating current constant current method, and through the use of the FFT algorithm, the alternating current effective value calculation can be directly performed, and through the calculation result, the waveform distortion judgment can be performed, which is used to prevent the measurement error caused by excessive waveform distortion.

[0076] It has manual participation setting port, only manual participation can set the initial value, through software communication mode, the initial value cannot be set and adjusted for the device, ensuring that the basic data (device initial value) calculated by the whole system is unique and unchangeable, which is used to eliminate the data change caused by software communication misoperation, hacker intrusion and other ways, leading to system misjudgment and misoperation.

[0077] The above has described the embodiments of the present application, the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical application or improvement of the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A battery internal resistance detection device characterized by comprising: The application relates to a battery pack and a battery management system. The battery pack comprises: two or more single batteries connected in series. An output end of the main control single-chip microcomputer is electrically connected with an input end of the signal conversion circuit to transmit a sinusoidal alternating voltage signal; a first output end of the signal conversion circuit is adapted to be electrically connected with positive and negative power supply ends of the battery pack to convert the sinusoidal alternating voltage signal into a constant current signal and output the constant current signal to the positive and negative power supply ends of each single battery; and a second output end of the signal conversion circuit is electrically connected with a high-speed ADC module of the main control single-chip microcomputer. An input end of the alternating voltage acquisition module is adapted to be electrically connected with the positive and negative power supply ends of each single battery and is adapted to acquire a voltage signal in a channel alternating current loop of each single battery; and an output end of the alternating voltage acquisition module is electrically connected with the high-speed ADC module of the main control single-chip microcomputer and is adapted to transmit the voltage signals in the channel alternating current loops of the two or more single batteries to the high-speed ADC module. The main control single-chip microcomputer is electrically connected with the IEC61850 protocol conversion module. The signal conversion circuit comprises: a direct-current isolation circuit and a power amplification chip.

2. The battery internal resistance detection device according to claim 1, characterized by A high-speed DAC module of the main control single-chip microcomputer is electrically connected with an input end of the power amplification chip to transmit a sinusoidal alternating voltage signal; an output end of the power amplification chip is electrically connected with the positive and negative power supply ends of the battery pack through the direct-current isolation circuit to output a constant current signal to the positive and negative power supply ends of each single battery; and the direct-current isolation circuit is electrically connected with the high-speed ADC module. The model of the power amplification chip is NS4203.

3. The battery internal resistance detection device according to claim 2, characterized by The signal conversion circuit further comprises: a first instrument amplifier.

4. The battery internal resistance detection device according to claim 2, characterized by The direct-current isolation circuit is electrically connected with the high-speed ADC module through the first instrument amplifier. The alternating voltage acquisition module comprises: a second instrument amplifier.

5. The battery internal resistance detection device according to claim 2, wherein An input end of the second instrument amplifier is electrically connected with the positive and negative power supply ends of each single battery and is adapted to acquire a voltage signal of each single battery; and an output end of the second instrument amplifier is electrically connected with the high-speed ADC module. The application further comprises:

6. The battery internal resistance detection device according to claim 1, wherein A direct-current voltage acquisition module. An input end of the direct-current voltage acquisition module is adapted to be electrically connected with the positive and negative power supply ends of each single battery to acquire a direct-current voltage of each single battery; and an output end of the direct-current voltage acquisition module is electrically connected with an input end of the main control single-chip microcomputer. The application further comprises:

7. The battery internal resistance detection device according to claim 1, wherein A temperature sensor; a detection end of the temperature sensor is adapted to be connected with a terminal stud of each single battery to acquire a temperature of the terminal stud of each single battery; and an output end of the temperature sensor is electrically connected with the high-speed ADC module of the main control single-chip microcomputer. The model of the main control single-chip microcomputer is GD32F303RC.

8. The battery internal resistance detection device according to claim 1, wherein ​

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