A detection channel expansion device for AC internal resistance detection equipment

Abstract

The present invention provides a detection channel expansion device for an AC internal resistance detection device in the field of lithium battery detection technology, comprising a control signal expansion module, a sampling channel expansion switching module and a sampling line capacitor charge discharge module; the control signal expansion module is respectively connected to the sampling channel expansion switching module and the sampling line capacitor charge discharge module; the sampling channel expansion switching module is connected to the sampling line capacitor charge discharge module. The advantages of the present invention are: greatly improving the flexibility of the detection channel configuration of the AC internal resistance detection device.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery detection, and in particular to a detection channel expansion device for AC internal resistance detection equipment. Background Art

[0002] The effective utilization rate of lithium battery energy is an important parameter. The AC internal resistance of lithium battery directly determines the energy loss of lithium battery itself during energy release process, so the AC internal resistance detection of lithium battery is a very important test in the lithium battery inspection stage; and the aging and poor manufacturing of lithium battery will lead to the decline of battery performance and irreversible changes in battery chemical composition. The AC internal resistance of lithium battery increases linearly with the decrease of capacity. The increase of AC internal resistance can determine the battery capacity and whether the lithium battery needs to be replaced, thereby reducing the maintenance cost of lithium battery.

[0003] As the demand for lithium batteries continues to rise, there are more and more scenarios where lithium batteries are used, and the types of lithium battery modules composed of different series and parallel combinations of lithium batteries are also increasing. During the testing of lithium battery modules, users need to test not only the total AC internal resistance of the lithium battery module, but also the AC internal resistance of each lithium battery in the lithium battery module to ensure that each lithium battery in the lithium battery module meets the requirements.

[0004] Traditionally, when performing AC internal resistance testing on a lithium battery module composed of multiple lithium batteries connected in series and parallel, it is necessary to manually switch the position where the detection fixture line of the AC internal resistance testing equipment is connected, and then perform the test after the switch is completed, which results in a long detection time and the risk of operational errors during the switching of the detection line. If multiple AC internal resistance testing devices are used for simultaneous testing, on the one hand, the testing cost will increase, and on the other hand, the space occupied by the AC internal resistance testing equipment will increase.

[0005] Therefore, how to provide a detection channel expansion device for an AC internal resistance detection device to improve the flexibility of the detection channel configuration of the AC internal resistance detection device has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a detection channel expansion device for an AC internal resistance detection device, so as to improve the flexibility of the detection channel configuration of the AC internal resistance detection device.

[0007] The present invention is implemented as follows: a detection channel expansion device for an AC internal resistance detection device comprises a control signal expansion module, a sampling channel expansion switching module and a sampling line capacitor charge discharge module; the control signal expansion module is connected to the sampling channel expansion switching module and the sampling line capacitor charge discharge module respectively; the sampling channel expansion switching module is connected to the sampling line capacitor charge discharge module;

[0008] The control signal expansion module includes a shift register U5, a shift register U6, a resistor R61, a resistor R62, a resistor R63, a resistor R64, a resistor R65, a resistor R66, a resistor R67, a resistor R68, a resistor R69, a resistor R70, a resistor R71, a resistor R72, a resistor R73, a resistor R74, a resistor R75, a resistor R76, a resistor R94, a resistor R95, a resistor R96, a resistor R97, a resistor R98, a resistor R99, a resistor R100, a resistor R101, a resistor R102, a resistor R103 and a resistor R104;

[0009] Pins 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, and 15 of the shift register U5 are respectively connected to resistors R72, R74, R75, R76, R94, R95, R96, R65, R64, R63, R62, R61, and R73; the resistor R72 is connected to resistors R74, R75, R76, R94, R95, R96, and a sampling channel expansion switching module; the resistor R63 is connected to resistors R64 and R65; the resistor R73 is connected to resistor R61;

[0010] Pins 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, and 15 of the shift register U6 are respectively connected to resistors R97, R99, R100, R101, R102, R103, R104, R71, R70, R69, R68, R67, R66, and R98; the resistor R97 is connected to resistors R99, R100, R101, R102, R103, and R104; the resistor R68 is connected to resistors R69 and R70; the resistor R98 is connected to resistor R66;

[0011] Pins 10, 11, 12, 14 of the shift register U5 are connected to pins 10, 11, 12, 14 of the shift register U6 respectively; pin 10 of the shift register U5 and pin 10 of the shift register U6 are both connected to the sampling line capacitor charge discharge module.

[0012] Further, the sampling channel expansion switching module includes a single-channel analog multiplexer U1, a single-channel analog multiplexer U2, a single-channel analog multiplexer U3, a single-channel analog multiplexer U4, a relay K1, a relay K2, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a diode D1, a diode D3, a diode D4, a diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a connector J5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a resistor R32, a resistor R33, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R 39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53, a resistor R54, a resistor R55, a resistor R56, a resistor R57, a resistor R58, a resistor R59 and a resistor R60;

[0013] Pins 1, 2, 5, and 6 of the relay K1 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D4, capacitor C5, and resistor R72, and pin 4 is connected to the input end of the diode D4 and the D pole of the MOS tube Q3; the G pole of the MOS tube Q3 is connected to the resistor R57, the resistor R58, the capacitor C3, and the input end of the diode D1, and the S pole is connected to the resistor R58 and the capacitor C3 and grounded; the output end of the diode D1 is connected to the resistor R57, the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, and the resistor R8. Resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17, resistor R18, resistor R20, resistor R21, resistor R23, resistor R24, resistor R25, resistor R26, resistor R27, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U1, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U2 are connected;

[0014] Pins 1, 2, 5, and 6 of the relay K2 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D5, the capacitor C6, and the resistor R97, and pin 4 is connected to the input end of the diode D5 and the D pole of the MOS tube Q4; the G pole of the MOS tube Q4 is connected to the resistor R59, the resistor R60, the capacitor C4, and the input end of the diode D3, and the S pole is connected to the resistor R60 and the capacitor C4 and grounded; the output end of the diode D3 is connected to the resistor R59, the resistor R29, the resistor R30, the resistor R31, the resistor R32, the resistor R33, the resistor R34, and the resistor R35 , resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, resistor R41, resistor R42, resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, resistor R55, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U3, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U4 are connected;

[0015] After the resistor R28 is connected in parallel with the capacitor C1, one end is connected to the resistor R22 and the G pole of the MOS tube Q1, and the other end is connected to the S pole of the MOS tube Q1 and grounded; the resistor R22 is connected to the pin 17 of the single-channel analog multiplexer U1; the pin 15 of the single-channel analog multiplexer U2 is connected to the resistor R19 and the D pole of the MOS tube Q1;

[0016] After the resistor R56 is connected in parallel with the capacitor C2, one end is connected to the resistor R50 and the G pole of the MOS tube Q2, and the other end is connected to the S pole of the MOS tube Q2 and grounded; the resistor R50 is connected to the pin 17 of the single-channel analog multiplexer U3; the pin 15 of the single-channel analog multiplexer U4 is connected to the resistor R47 and the D pole of the MOS tube Q2;

[0017] The resistor R1 is connected to the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, the resistor R11, the resistor R12, and the resistor R13 and is grounded; the resistor R14 is connected to the resistor R15, the resistor R16, the resistor R17, the resistor R18, the resistor R20, the resistor R21, the resistor R23, the resistor R24, the resistor R25, the resistor R26, and the resistor R27 and is grounded; R29 is connected to resistor R30, resistor R31, resistor R32, resistor R33, resistor R34, resistor R35, resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, and resistor R41 and grounded; the resistor R42 is connected to resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, and resistor R55 and grounded;

[0018] The connector J5 is connected to the pins 1, 2, 5, 6 of the relay K1 and the pins 1, 2, 5, 6 of the relay K2.

[0019] Further, the sampling line capacitor charge discharge module includes a relay K3, a relay K4, a connector J4, a MOS tube Q5, a MOS tube Q6, a diode D6, a diode D7, a capacitor C9, a capacitor C10, a capacitor C15, a capacitor C16, a resistor R78, a resistor R79, a resistor R80, a resistor R81, a resistor R82, a resistor R83, a resistor R84, a resistor R85, a resistor R86, a resistor R87, a resistor R88, a resistor R89, a resistor R90, a resistor R91, a resistor R92 and a resistor R93;

[0020] Pin 1 of the relay K3 is connected to pin 3 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 4 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D6 and the D pole of the MOS tube Q5, pin 4 is connected to the input end of the diode D6, pin 5 is connected to the resistor R79, the resistor R83, and the resistor R87, and pin 6 is connected to the resistor R78, the resistor R82, and the resistor R86; the resistor R78 is connected to the resistor R82, the resistor R86, the resistor R79, the resistor R83, and the resistor R87; after the resistor R93 is connected in parallel with the capacitor C9, one end is connected to the resistor R92 and the G pole of the MOS tube Q5, and the other end is connected to the capacitor C15 and the S pole of the MOS tube Q5; the resistor R92 is connected to pin 10 of the shift register U5;

[0021] Pin 1 of the relay K4 is connected to pin 1 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 2 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D7 and the D pole of the MOS tube Q6, pin 4 is connected to the input end of the diode D7, pin 5 is connected to the resistor R81, the resistor R85, and the resistor R89, and pin 6 is connected to the resistor R80, the resistor R84, and the resistor R88; the resistor R80 is connected to the resistor R84, the resistor R88, the resistor R81, the resistor R85, and the resistor R89; after the resistor R91 is connected in parallel with the capacitor C10, one end is connected to the resistor R90 and the G pole of the MOS tube Q6, and the other end is connected to the capacitor C16 and the S pole of the MOS tube Q6; the resistor R90 is connected to pin 10 of the shift register U6.

[0022] The advantages of the present invention are:

[0023] 1. By setting the control signal expansion module, the sampling channel expansion switching module and the sampling line capacitor charge discharge module, the detection channel of the AC internal resistance detection equipment is expanded, which greatly improves the flexibility of the detection channel configuration of the AC internal resistance detection equipment. The entire detection channel switching process takes a short time, which greatly improves the efficiency of AC internal resistance detection.

[0024] 2. The user only needs to perform simple configuration and connect the detection signal line to the detection object in the initial state of the detection to realize the expansion of the single-channel detection line to the multi-channel detection line, which enhances the safety and reliability of the detection process and avoids operational errors caused by multiple manual switching operations during the detection process; before each new detection starts, the residual charge of the capacitor used to isolate the DC component in the AC internal resistance detection equipment is discharged through the sampling line capacitor charge discharge module, ensuring that the previous detection object will not affect the next detection object.

[0025] 3. Use a combination of shift registers to expand the control signal, effectively reducing the number of previous control signal lines required.

[0026] 4. When setting up the sampling channel expansion switching module, use a single-channel analog multiplexer for the expansion relay to ensure that only one set of relays is turned on at a time, to avoid the risk of malfunction caused by multiple sets of relays being turned on at the same time due to erroneous control, which may cause the detection points of multiple detection ends to be short-circuited by the expansion module.

[0027] 5. The lowest bit Y0 of the single-channel analog multiplexer in the sampling channel expansion switching module remains in a floating state, and the SRCLR control signal of the control shift register is used to control the sampling line capacitor charge discharge module at the same time, so as to ensure that when SRCLR is pulled low, the channel expansion switching relay in the sampling channel expansion switching module is controlled to be in a disconnected state, and the relay in the sampling line capacitor charge discharge module is in a closed state and controlled as a charge discharge working state. When the SRCLR signal line is set high, the relay in the sampling line capacitor charge discharge module is in a disconnected state, and the sampling channel expansion switching module can work normally according to the signal of the control signal line, avoiding the phenomenon that the sampling line capacitor charge discharge module and the relay in the sampling channel expansion switching module work at the same time.

[0028] 6. The enabling of the high-bit controlled single-channel analog multiplexer U2 and the single-channel analog multiplexer U4 are respectively controlled by Y14 of the low-bit controlled single-channel analog multiplexer U1 and the single-channel analog multiplexer U3, thereby avoiding the possibility of detection failure caused by the simultaneous operation of the high-bit and low-bit controlled single-channel analog multiplexers due to control errors.

[0029] 7. The driving of the extended relay in the sampling channel extended switching module is achieved by using a relay slow opening and fast closing circuit composed of a resistor, a capacitor, a diode, and an NPN MOS tube; the charge discharge switching relay of the sampling line capacitor charge discharge module is designed by using a relay switch delay combined with a resistor, a capacitor, and a PNP MOS tube, further ensuring that there is a switching interval between the relay in the sampling channel extended switching module and the relay in the sampling line capacitor charge discharge module, avoiding the risk of the relays in the two modules being turned on at the same time at the switching moment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0031] Figure 1 The invention discloses a circuit principle block diagram of a detection channel expansion device for an AC internal resistance detection device.

[0032] Figure 2It is a circuit diagram of the control signal expansion module of the present invention.

[0033] Figure 3 It is a circuit diagram of the sampling channel expansion switching module of the present invention.

[0034] Figure 4 It is a circuit diagram of the sampling line capacitor charge discharge module of the present invention. DETAILED DESCRIPTION

[0035] Please refer to Figures 1 to 4 As shown, a preferred embodiment of a detection channel expansion device for an AC internal resistance detection device of the present invention comprises a control signal expansion module, a sampling channel expansion switching module and a sampling line capacitor charge discharge module; the control signal expansion module is connected to the sampling channel expansion switching module and the sampling line capacitor charge discharge module respectively; the sampling channel expansion switching module is connected to the sampling line capacitor charge discharge module;

[0036] The control signal expansion module is used to expand the number of control signals, reduce the number of detection fixture lines used, transmit the expanded control signals to the sampling channel expansion switching module and the sampling line capacitor charge discharge module, and perform corresponding switching control according to the instructions issued by the user;

[0037] The sampling channel expansion switching module is used to expand the single-channel sampling line connected to the AC internal resistance detection device according to the control signal transmitted by the control signal expansion module, and then connect it to different signal lines of the output interface according to the configuration information of the control signal, and at the same time connect the single-channel sampling line of the AC internal resistance detection device to the sampling line capacitor charge discharge module;

[0038] The sampling line capacitor charge discharge module is used to connect the single-channel sampling line connected to the lithium battery AC internal resistance in the sampling channel expansion switching module to the corresponding load resistor according to the control signal transmitted by the control signal expansion module; before performing a new detection after the previous detection in each round is completed, the signal SRCLR signal is pulled down through the signal configuration of the control signal expansion module, and the output ends of the shift register are all set low. Since the Y0 output end of the single-channel analog multiplexer is in a floating state, the sampling will be turned off at this time, and all the channel expansion selection relays in the sampling channel expansion switching module will be selected. At the same time, the SRCLR signal will be pulled down to turn on relays K3 and K4, and the capacitor used to isolate the DC voltage of the lithium battery itself in the AC internal resistance detection device will be discharged after the previous round of detection. After the discharge is completed, the signal SRCLR signal is pulled up, and after closing relays K3 and K4, a new round of detection channel switching configuration is performed to avoid the previous detection from affecting the next detection.

[0039] The control signal expansion module includes a shift register U5, a shift register U6, a resistor R61, a resistor R62, a resistor R63, a resistor R64, a resistor R65, a resistor R66, a resistor R67, a resistor R68, a resistor R69, a resistor R70, a resistor R71, a resistor R72, a resistor R73, a resistor R74, a resistor R75, a resistor R76, a resistor R94, a resistor R95, a resistor R96, a resistor R97, a resistor R98, a resistor R99, a resistor R100, a resistor R101, a resistor R102, a resistor R103 and a resistor R104; the model of the shift register U5 and the shift register U6 can be selected as SN74LV595;

[0040] Pins 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, and 15 of the shift register U5 are respectively connected to resistors R72, R74, R75, R76, R94, R95, R96, R65, R64, R63, R62, R61, and R73; the resistor R72 is connected to resistors R74, R75, R76, R94, R95, R96, and a sampling channel expansion switching module; the resistor R63 is connected to resistors R64 and R65; the resistor R73 is connected to resistor R61;

[0041] Pins 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, and 15 of the shift register U6 are respectively connected to resistors R97, R99, R100, R101, R102, R103, R104, R71, R70, R69, R68, R67, R66, and R98; the resistor R97 is connected to resistors R99, R100, R101, R102, R103, and R104; the resistor R68 is connected to resistors R69 and R70; the resistor R98 is connected to resistor R66;

[0042] Pins 10, 11, 12, 14 of the shift register U5 are connected to pins 10, 11, 12, 14 of the shift register U6 respectively; pin 10 of the shift register U5 and pin 10 of the shift register U6 are both connected to the sampling line capacitor charge discharge module.

[0043] The sampling channel expansion switching module includes a single-channel analog multiplexer U1, a single-channel analog multiplexer U2, a single-channel analog multiplexer U3, a single-channel analog multiplexer U4, a relay K1, a relay K2, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a diode D1, a diode D3, a diode D4, a diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C 4. A capacitor C5, a capacitor C6, a connector J5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a resistor R32, a resistor R33, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53, a resistor R54, a resistor R55, a resistor R56, a resistor R57, a resistor R58, a resistor R59 and a resistor R60; the model of the single-channel analog multiplexer U1, the single-channel analog multiplexer U2, the single-channel analog multiplexer U3 and the single-channel analog multiplexer U4 can be selected as 74HC4067;

[0044] Pins 1, 2, 5, and 6 of the relay K1 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D4, capacitor C5, and resistor R72, and pin 4 is connected to the input end of the diode D4 and the D pole of the MOS tube Q3; the G pole of the MOS tube Q3 is connected to the resistor R57, the resistor R58, the capacitor C3, and the input end of the diode D1, and the S pole is connected to the resistor R58 and the capacitor C3 and grounded; the output end of the diode D1 is connected to the resistor R57, the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, and the resistor R8. Resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17, resistor R18, resistor R20, resistor R21, resistor R23, resistor R24, resistor R25, resistor R26, resistor R27, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U1, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U2 are connected;

[0045] Pins 1, 2, 5, and 6 of the relay K2 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D5, the capacitor C6, and the resistor R97, and pin 4 is connected to the input end of the diode D5 and the D pole of the MOS tube Q4; the G pole of the MOS tube Q4 is connected to the resistor R59, the resistor R60, the capacitor C4, and the input end of the diode D3, and the S pole is connected to the resistor R60 and the capacitor C4 and grounded; the output end of the diode D3 is connected to the resistor R59, the resistor R29, the resistor R30, the resistor R31, the resistor R32, the resistor R33, the resistor R34, and the resistor R35 , resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, resistor R41, resistor R42, resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, resistor R55, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U3, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U4 are connected;

[0046] After the resistor R28 is connected in parallel with the capacitor C1, one end is connected to the resistor R22 and the G pole of the MOS tube Q1, and the other end is connected to the S pole of the MOS tube Q1 and grounded; the resistor R22 is connected to the pin 17 of the single-channel analog multiplexer U1; the pin 15 of the single-channel analog multiplexer U2 is connected to the resistor R19 and the D pole of the MOS tube Q1;

[0047] After the resistor R56 is connected in parallel with the capacitor C2, one end is connected to the resistor R50 and the G pole of the MOS tube Q2, and the other end is connected to the S pole of the MOS tube Q2 and grounded; the resistor R50 is connected to the pin 17 of the single-channel analog multiplexer U3; the pin 15 of the single-channel analog multiplexer U4 is connected to the resistor R47 and the D pole of the MOS tube Q2;

[0048] The resistor R1 is connected to the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, the resistor R11, the resistor R12, and the resistor R13 and is grounded; the resistor R14 is connected to the resistor R15, the resistor R16, the resistor R17, the resistor R18, the resistor R20, the resistor R21, the resistor R23, the resistor R24, the resistor R25, the resistor R26, and the resistor R27 and is grounded; R29 is connected to resistor R30, resistor R31, resistor R32, resistor R33, resistor R34, resistor R35, resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, and resistor R41 and grounded; the resistor R42 is connected to resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, and resistor R55 and grounded;

[0049] The connector J5 is connected to the pins 1, 2, 5, 6 of the relay K1 and the pins 1, 2, 5, 6 of the relay K2.

[0050] The sampling line capacitor charge discharge module includes a relay K3, a relay K4, a connector J4, a MOS tube Q5, a MOS tube Q6, a diode D6, a diode D7, a capacitor C9, a capacitor C10, a capacitor C15, a capacitor C16, a resistor R78, a resistor R79, a resistor R80, a resistor R81, a resistor R82, a resistor R83, a resistor R84, a resistor R85, a resistor R86, a resistor R87, a resistor R88, a resistor R89, a resistor R90, a resistor R91, a resistor R92 and a resistor R93;

[0051] Pin 1 of the relay K3 is connected to pin 3 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 4 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D6 and the D pole of the MOS tube Q5, pin 4 is connected to the input end of the diode D6, pin 5 is connected to the resistor R79, the resistor R83, and the resistor R87, and pin 6 is connected to the resistor R78, the resistor R82, and the resistor R86; the resistor R78 is connected to the resistor R82, the resistor R86, the resistor R79, the resistor R83, and the resistor R87; after the resistor R93 is connected in parallel with the capacitor C9, one end is connected to the resistor R92 and the G pole of the MOS tube Q5, and the other end is connected to the capacitor C15 and the S pole of the MOS tube Q5; the resistor R92 is connected to pin 10 of the shift register U5;

[0052] Pin 1 of the relay K4 is connected to pin 1 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 2 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D7 and the D pole of the MOS tube Q6, pin 4 is connected to the input end of the diode D7, pin 5 is connected to the resistor R81, the resistor R85, and the resistor R89, and pin 6 is connected to the resistor R80, the resistor R84, and the resistor R88; the resistor R80 is connected to the resistor R84, the resistor R88, the resistor R81, the resistor R85, and the resistor R89; after the resistor R91 is connected in parallel with the capacitor C10, one end is connected to the resistor R90 and the G pole of the MOS tube Q6, and the other end is connected to the capacitor C16 and the S pole of the MOS tube Q6; the resistor R90 is connected to pin 10 of the shift register U6.

[0053] Working principle of the present invention:

[0054] The detection of the AC internal resistance of the lithium battery adopts a four-wire system. The sampling lines of the AC internal resistance detection device (two excitation current signal lines SOURCE and two response voltage sampling lines SENSE) are respectively connected to the connector J4 of the sampling channel expansion module, and four control signal lines are connected to the control signal expansion module. The four control signal lines are pre-coded with corresponding programs. According to the user's configuration of the number of lithium battery strings to be tested in the lithium battery module and the sampling line group to be used, the single-channel sampling line of the AC internal resistance detection device is connected to the connector J5 after the extended detection channel according to the configuration. The user connects the corresponding pins of the connector J5 to the corresponding detection points of the object to be tested in advance. During the detection process, there is no need to manually change the contact position of the sampling line frequently, and a single AC internal resistance detection device can be directly used for multi-point detection.

[0055] In summary, the advantages of the present invention are:

[0056] 1. By setting the control signal expansion module, the sampling channel expansion switching module and the sampling line capacitor charge discharge module, the detection channel of the AC internal resistance detection equipment is expanded, which greatly improves the flexibility of the detection channel configuration of the AC internal resistance detection equipment. The entire detection channel switching process takes a short time, which greatly improves the efficiency of AC internal resistance detection.

[0057] 2. The user only needs to perform simple configuration and connect the detection signal line to the detection object in the initial state of the detection to realize the expansion of the single-channel detection line to the multi-channel detection line, which enhances the safety and reliability of the detection process and avoids operational errors caused by multiple manual switching operations during the detection process; before each new detection starts, the residual charge of the capacitor used to isolate the DC component in the AC internal resistance detection equipment is discharged through the sampling line capacitor charge discharge module, ensuring that the previous detection object will not affect the next detection object.

[0058] 3. Use a combination of shift registers to expand the control signal, effectively reducing the number of previous control signal lines required.

[0059] 4. When setting up the sampling channel expansion switching module, use a single-channel analog multiplexer for the expansion relay to ensure that only one set of relays is turned on at a time, to avoid the risk of malfunction caused by multiple sets of relays being turned on at the same time due to erroneous control, which may cause the detection points of multiple detection ends to be short-circuited by the expansion module.

[0060] 5. The lowest bit Y0 of the single-channel analog multiplexer in the sampling channel expansion switching module remains in a floating state, and the SRCLR control signal of the control shift register is used to control the sampling line capacitor charge discharge module at the same time, so as to ensure that when SRCLR is pulled low, the channel expansion switching relay in the sampling channel expansion switching module is controlled to be in a disconnected state, and the relay in the sampling line capacitor charge discharge module is in a closed state and controlled as a charge discharge working state. When the SRCLR signal line is set high, the relay in the sampling line capacitor charge discharge module is in a disconnected state, and the sampling channel expansion switching module can work normally according to the signal of the control signal line, avoiding the phenomenon that the sampling line capacitor charge discharge module and the relay in the sampling channel expansion switching module work at the same time.

[0061] 6. The enabling of the high-bit controlled single-channel analog multiplexer U2 and the single-channel analog multiplexer U4 are respectively controlled by Y14 of the low-bit controlled single-channel analog multiplexer U1 and the single-channel analog multiplexer U3, thereby avoiding the possibility of detection failure caused by the simultaneous operation of the high-bit and low-bit controlled single-channel analog multiplexers due to control errors.

[0062] 7. The driving of the extended relay in the sampling channel extended switching module is achieved by using a relay slow opening and fast closing circuit composed of a resistor, a capacitor, a diode, and an NPN MOS tube; the charge discharge switching relay of the sampling line capacitor charge discharge module is designed by using a relay switch delay combined with a resistor, a capacitor, and a PNP MOS tube, further ensuring that there is a switching interval between the relay in the sampling channel extended switching module and the relay in the sampling line capacitor charge discharge module, avoiding the risk of the relays in the two modules being turned on at the same time at the switching moment.

[0063] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A detection channel expansion device for an AC internal resistance detection device, characterized in that: It includes a control signal expansion module, a sampling channel expansion switching module and a sampling line capacitor charge discharge module; the control signal expansion module is connected to the sampling channel expansion switching module and the sampling line capacitor charge discharge module respectively; the sampling channel expansion switching module is connected to the sampling line capacitor charge discharge module; The control signal expansion module includes a shift register U5, a shift register U6, a resistor R61, a resistor R62, a resistor R63, a resistor R64, a resistor R65, a resistor R66, a resistor R67, a resistor R68, a resistor R69, a resistor R70, a resistor R71, a resistor R72, a resistor R73, a resistor R74, a resistor R75, a resistor R76, a resistor R94, a resistor R95, a resistor R96, a resistor R97, a resistor R98, a resistor R99, a resistor R100, a resistor R101, a resistor R102, a resistor R103 and a resistor R104; Pins 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, and 15 of the shift register U5 are respectively connected to resistors R72, R74, R75, R76, R94, R95, R96, R65, R64, R63, R62, R61, and R73; the resistor R72 is connected to resistors R74, R75, R76, R94, R95, R96, and a sampling channel expansion switching module; the resistor R63 is connected to resistors R64 and R65; the resistor R73 is connected to resistor R61; Pins 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, and 15 of the shift register U6 are respectively connected to resistors R97, R99, R100, R101, R102, R103, R104, R71, R70, R69, R68, R67, R66, and R98; the resistor R97 is connected to resistors R99, R100, R101, R102, R103, and R104; the resistor R68 is connected to resistors R69 and R70; the resistor R98 is connected to resistor R66; Pins 10, 11, 12, 14 of the shift register U5 are connected to pins 10, 11, 12, 14 of the shift register U6 respectively; pin 10 of the shift register U5 and pin 10 of the shift register U6 are both connected to the sampling line capacitor charge discharge module.

2. A detection channel expansion device for an AC internal resistance detection device as claimed in claim 1, characterized in that: The sampling channel expansion switching module includes a single-channel analog multiplexer U1, a single-channel analog multiplexer U2, a single-channel analog multiplexer U3, a single-channel analog multiplexer U4, a relay K1, a relay K2, a MOS tube Q1, a MOS tube Q2, a MOS tube Q3, a MOS tube Q4, a diode D1, a diode D3, a diode D4, a diode D5, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a connector J5, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a resistor R32, a resistor R33, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R39, a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R49, a resistor R50, a resistor R51 a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a resistor R27, a resistor R28, a resistor R29, a resistor R30, a resistor R31, a resistor R32, a resistor R33, a resistor R34, a resistor R35, a resistor R36, a resistor R37, a resistor R38, a resistor R3 9. a resistor R40, a resistor R41, a resistor R42, a resistor R43, a resistor R44, a resistor R45, a resistor R46, a resistor R47, a resistor R48, a resistor R49, a resistor R50, a resistor R51, a resistor R52, a resistor R53, a resistor R54, a resistor R55, a resistor R56, a resistor R57, a resistor R58, a resistor R59 and a resistor R60; Pins 1, 2, 5, and 6 of the relay K1 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D4, capacitor C5, and resistor R72, and pin 4 is connected to the input end of the diode D4 and the D pole of the MOS tube Q3; the G pole of the MOS tube Q3 is connected to the resistor R57, the resistor R58, the capacitor C3, and the input end of the diode D1, and the S pole is connected to the resistor R58 and the capacitor C3 and grounded; the output end of the diode D1 is connected to the resistor R57, the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, and the resistor R8. Resistor R8, resistor R9, resistor R10, resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17, resistor R18, resistor R20, resistor R21, resistor R23, resistor R24, resistor R25, resistor R26, resistor R27, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U1, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U2 are connected; Pins 1, 2, 5, and 6 of the relay K2 are connected to the sampling line capacitor charge discharge module, pin 3 is connected to the output end of the diode D5, the capacitor C6, and the resistor R97, and pin 4 is connected to the input end of the diode D5 and the D pole of the MOS tube Q4; the G pole of the MOS tube Q4 is connected to the resistor R59, the resistor R60, the capacitor C4, and the input end of the diode D3, and the S pole is connected to the resistor R60 and the capacitor C4 and grounded; the output end of the diode D3 is connected to the resistor R59, the resistor R29, the resistor R30, the resistor R31, the resistor R32, the resistor R33, the resistor R34, and the resistor R35 , resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, resistor R41, resistor R42, resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, resistor R55, pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U3, and pins 8, 7, 6, 5, 4, 3, 2, 23, 22, 21, 20, 19, 18 of the single-channel analog multiplexer U4 are connected; After the resistor R28 is connected in parallel with the capacitor C1, one end is connected to the resistor R22 and the G pole of the MOS tube Q1, and the other end is connected to the S pole of the MOS tube Q1 and grounded; the resistor R22 is connected to the pin 17 of the single-channel analog multiplexer U1; the pin 15 of the single-channel analog multiplexer U2 is connected to the resistor R19 and the D pole of the MOS tube Q1; After the resistor R56 is connected in parallel with the capacitor C2, one end is connected to the resistor R50 and the G pole of the MOS tube Q2, and the other end is connected to the S pole of the MOS tube Q2 and grounded; the resistor R50 is connected to the pin 17 of the single-channel analog multiplexer U3; the pin 15 of the single-channel analog multiplexer U4 is connected to the resistor R47 and the D pole of the MOS tube Q2; The resistor R1 is connected to the resistor R2, the resistor R3, the resistor R4, the resistor R5, the resistor R6, the resistor R7, the resistor R8, the resistor R9, the resistor R10, the resistor R11, the resistor R12, and the resistor R13 and is grounded; the resistor R14 is connected to the resistor R15, the resistor R16, the resistor R17, the resistor R18, the resistor R20, the resistor R21, the resistor R23, the resistor R24, the resistor R25, the resistor R26, and the resistor R27 and is grounded; R29 is connected to resistor R30, resistor R31, resistor R32, resistor R33, resistor R34, resistor R35, resistor R36, resistor R37, resistor R38, resistor R39, resistor R40, and resistor R41 and grounded; the resistor R42 is connected to resistor R43, resistor R44, resistor R45, resistor R46, resistor R48, resistor R49, resistor R51, resistor R52, resistor R53, resistor R54, and resistor R55 and grounded; The connector J5 is connected to the pins 1, 2, 5, 6 of the relay K1 and the pins 1, 2, 5, 6 of the relay K2.

3. A detection channel expansion device for an AC internal resistance detection device as claimed in claim 1, characterized in that: The sampling line capacitor charge discharge module includes a relay K3, a relay K4, a connector J4, a MOS tube Q5, a MOS tube Q6, a diode D6, a diode D7, a capacitor C9, a capacitor C10, a capacitor C15, a capacitor C16, a resistor R78, a resistor R79, a resistor R80, a resistor R81, a resistor R82, a resistor R83, a resistor R84, a resistor R85, a resistor R86, a resistor R87, a resistor R88, a resistor R89, a resistor R90, a resistor R91, a resistor R92 and a resistor R93; Pin 1 of the relay K3 is connected to pin 3 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 4 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D6 and the D pole of the MOS tube Q5, pin 4 is connected to the input end of the diode D6, pin 5 is connected to the resistor R79, the resistor R83, and the resistor R87, and pin 6 is connected to the resistor R78, the resistor R82, and the resistor R86; the resistor R78 is connected to the resistor R82, the resistor R86, the resistor R79, the resistor R83, and the resistor R87; after the resistor R93 is connected in parallel with the capacitor C9, one end is connected to the resistor R92 and the G pole of the MOS tube Q5, and the other end is connected to the capacitor C15 and the S pole of the MOS tube Q5; the resistor R92 is connected to pin 10 of the shift register U5; Pin 1 of the relay K4 is connected to pin 1 of the connector J4 and the sampling channel expansion switching module, pin 2 is connected to pin 2 of the connector J4 and the sampling channel expansion switching module, pin 3 is connected to the output end of the diode D7 and the D pole of the MOS tube Q6, pin 4 is connected to the input end of the diode D7, pin 5 is connected to the resistor R81, the resistor R85, and the resistor R89, and pin 6 is connected to the resistor R80, the resistor R84, and the resistor R88; the resistor R80 is connected to the resistor R84, the resistor R88, the resistor R81, the resistor R85, and the resistor R89; after the resistor R91 is connected in parallel with the capacitor C10, one end is connected to the resistor R90 and the G pole of the MOS tube Q6, and the other end is connected to the capacitor C16 and the S pole of the MOS tube Q6; the resistor R90 is connected to pin 10 of the shift register U6.

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