A multi-cell intelligent power supply monitoring device

Abstract

The application provides a multi-cell intelligent power supply monitoring device, and relates to the field of lithium battery management; the device comprises a main control chip, an auxiliary chip connected with the main control chip, the main control chip, a lithium battery connected with an electric vehicle, which is used for receiving temperature data and current data and transmitting the temperature data and the current data to the auxiliary chip; the auxiliary chip is connected with a host computer of the electric vehicle, which is used for receiving temperature data and current data, receiving voltage data and discharge data, and transmitting the temperature data, the current data, the voltage data and the discharge data to the host computer; the host computer and the auxiliary chip communicate with each other, the state information and the state data of the lithium battery monitored and received by the auxiliary chip are displayed on the host computer in real time, and the protection parameters of the lithium battery, such as the voltage protection threshold, the current protection threshold and the temperature protection threshold, can be modified on the host computer software due to the communication between the host computer and the auxiliary chip, so that the lithium battery can be better managed and protected.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of lithium battery management, in particular to a multi-cell intelligent power supply monitoring device. BACKGROUND

[0002] With the rapid development and popularization of electric vehicles, the battery management system (BMS) becomes more and more important, and the BMS is one of the key components of electric vehicles, which is responsible for monitoring the state of the battery and implementing the management of the battery, and the BMS can improve the performance and life of the battery, while ensuring the safety of the battery, and the reliability, power consumption and integration difficulty of the battery management system (BMS) need to be improved. SUMMARY

[0003] The purpose of the present application is to provide a multi-cell intelligent power supply monitoring device to solve the problems in the background art.

[0004] The embodiments of the present application are implemented as follows:

[0005] The embodiments of the present application provide a multi-cell intelligent power supply monitoring device applied to lithium battery management of electric vehicles, which comprises a main control chip and an auxiliary chip connected with the main control chip, and further comprises a temperature acquisition circuit and a current acquisition circuit connected with the main control chip, and a voltage acquisition circuit and a discharge monitoring circuit connected with the auxiliary chip.

[0006] The main control chip is used for connecting the lithium battery of the electric vehicle, receiving the temperature data of the lithium battery acquired by the temperature acquisition circuit, and receiving the current data of the lithium battery acquired by the current acquisition circuit, and transmitting the temperature data and the current data to the auxiliary chip.

[0007] The auxiliary chip is used for connecting the host computer of the electric vehicle, receiving the temperature data and the current data, receiving the voltage data of the lithium battery acquired by the voltage acquisition circuit and the discharge data of the lithium battery acquired by the discharge monitoring circuit, and transmitting the temperature data, the current data, the voltage data and the discharge data to the host computer.

[0008] The beneficial effects of this invention are as follows: The main control chip is an integrated circuit (IC) for battery protection; temperature and current data are acquired through temperature and current acquisition circuits; the auxiliary chip can conveniently and quickly obtain battery status information by reading and writing registers in the main control chip. In actual use, the auxiliary chip needs to modify the configuration information in the corresponding registers to achieve communication with the main control chip, thus achieving better battery protection. Simultaneously, the host computer of the electric vehicle or other lithium battery-powered device communicates with the auxiliary chip via RS485. The lithium battery status information monitored by the auxiliary chip and the received battery status data are displayed on the host computer in real time. Furthermore, due to the communication between the host computer and the auxiliary chip, the corresponding battery protection parameters, such as voltage protection threshold, current protection threshold, and temperature protection threshold, can be modified in the host computer software, achieving better management and protection of the lithium battery.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, the aforementioned multi-cell intelligent power monitoring device also includes a cell balancing circuit, through which the main control chip is connected to the lithium battery of the electric vehicle.

[0011] The cell balancing circuit includes multiple single-cell circuits, each of which includes resistors R1, R2, R3, and R4, transistor S12, and MOSFET Q4.

[0012] The gate of MOSFET Q4 is connected to one end of resistor R2, the other end of resistor R2 is connected to one end of resistor R1, the other end of resistor R1 is connected to the collector of transistor S12, the base of transistor S12 and the drain of MOSFET Q4 are connected to the two ends of resistor R3 respectively, the base of transistor S12 is also connected to one end of capacitor C6, the drain of MOSFET Q4 is also connected to one end of resistor R4, the other ends of capacitor C6 and resistor R4 are both connected to the emitter of transistor S12, the emitter of transistor S12 is connected to one end of one of the single cells, and the common connection point of resistors R1 and R2 is connected to the other end of the single cell.

[0013] The beneficial effect of the further scheme is that the battery equalization circuit adopts a passive equalization mode, two battery voltage equalization methods are designed according to the equalization efficiency, one is to adopt the equalization mode in the internal control chip, and the charging current of the selected multiple single batteries is limited by adding a load, so that the voltage of multiple single batteries can be balanced at the same time; the other is to adopt an external battery equalization circuit, when the difference between the single battery voltage at both ends of the single battery and the voltage of the smallest single battery in the lithium battery reaches the set threshold value or the maximum single battery voltage of the single battery reaches the set threshold value, the control chip forms a discharge circuit by controlling the conduction of the triode, and the excess power of the single battery with high voltage is discharged, which has the advantages of good heat dissipation effect and high equalization efficiency.

[0014] Further, the current collection circuit includes a capacitor C1, a capacitor C2, a capacitor C3, a resistor R5, a resistor R6, and a resistor RSENS.

[0015] The two ends of the capacitor C3 are connected to the ISP pin and the ISN pin of the main control chip, one end of the capacitor C1 is connected to one end of the capacitor C2, the other end of the capacitor C1 is connected to the ISP pin of the main control chip, and the other end of the capacitor C2 is connected to the ISP pin of the main control chip; one end of the resistor R5 is connected to the ISP pin of the main control chip, one end of the resistor R6 is connected to the ISN pin of the main control chip, and the other end of the resistor R5 and the other end of the resistor R6 are respectively connected to the two ends of the resistor RSENS.

[0016] Further, the current collection circuit further includes a detection chip, a resistor R7, and a resistor R8.

[0017] The IN- pin of the detection chip is connected to the ISP pin of the main control chip, the IN+ pin of the detection chip is connected to the ISN pin of the main control chip, the out pin of the detection chip is connected to the PA1 pin of the auxiliary chip, the REF pin of the detection chip is respectively connected to one end of the resistor R7 and one end of the resistor R8, the other end of the resistor R8 is connected to the VREF pin of the auxiliary chip, and the other end of the resistor R7 is grounded.

[0018] The beneficial effect of the further scheme is that the current collection is divided into two ways, one way is to connect the two ends of the sampling resistor through the RC filter network and the ISP and ISN pins of the OZ7716, the OZ7716 obtains current data by monitoring the current between the ISP pin and the ISN pin and simultaneously judges the state of the lithium battery, and the detected current is positive and greater than the set charging detection threshold value, which is regarded as charging, otherwise it is regarded as an idle state; the other way is to connect the voltage at the two ends of the sampling resistor SENSE to the PA1 pin of the auxiliary chip after amplification by the detection chip, and the current value is read by the auxiliary chip, and the output current of the lithium battery is collected by the two ways to obtain more accurate circuit information of the lithium battery.

[0019] Further, the discharge monitoring circuit comprises a MOS tube Q1, a MOS tube Q2 and a transistor S1;

[0020] The gate of the MOS tube Q1 is connected to one end of a resistor R14 and one end of a resistor R15, the other end of the resistor R15 is connected to the source of the MOS tube Q1, and the other end of the resistor R14 is connected to the source of the MOS tube Q2; the drain of the MOS tube Q1 is connected to one end of a resistor R10, the other end of the resistor R10 is connected to one end of a resistor R9 and one end of a resistor R13, the other end of the resistor R9 is connected to the drain of the MOS tube Q2, and the other end of the resistor R13 is connected to the base of the transistor S1; the drain of the MOS tube Q2 and the source of the MOS tube Q1 are connected to the cell balancing circuit;

[0021] The gate of the MOS tube Q2 is connected to one end of a resistor R12 and one end of a resistor R16, and the other end of the resistor R2 is connected to the drain of the MOS tube Q2;

[0022] The base of the transistor S1 is also connected to one end of a resistor R11, the other end of the resistor R11 is grounded, the collector of the transistor S1 is connected to one end of a resistor R18 and one end of a resistor R17, the other end of the resistor R18 is connected to the DSGD pin of the auxiliary chip, and the emitter of the transistor S1 is grounded.

[0023] Further, the cell intelligent power supply monitoring device further comprises a charging and discharging protection circuit, the charging and discharging protection circuit is connected to the main control chip and the auxiliary chip, and the charging and discharging protection circuit comprises a charging monitoring circuit, and the charging monitoring circuit comprises a transistor S2 and a transistor S3;

[0024] The base of the transistor S2 is connected to one end of a capacitor C4, one end of a resistor R19 and one end of a resistor R20, the other end of the capacitor C4 is connected to the base of the transistor S2, the other end of the resistor R20 is connected to the emitter of the transistor S3, and the other end of the resistor R19 is grounded;

[0025] The base of the transistor S3 is connected to one end of a resistor R21 and one end of a resistor R22, the other end of the resistor R21 is connected to the collector of the transistor S2; the collector of the transistor S3 is connected to one end of a resistor R23 and one end of a resistor R24, the other end of the resistor R23 and the other end of the resistor R24 are connected to both ends of a capacitor C5, the other end of the resistor R24 is also connected to the CHGD pin of the auxiliary chip, and the other end of the resistor R23 is grounded.

[0026] Further, the charging and discharging protection circuit further comprises an anti-reverse connection circuit and a charging and discharging driving circuit;

[0027] The reverse connection prevention circuit comprises an optical coupler and a diode D1, an output terminal of the diode D1 is connected to one end of a resistor R25, the other end of the resistor R25 is connected to the optical coupler, the optical coupler is further connected to one end of a resistor R26 and one end of a resistor R27, the other end of the resistor R26 is grounded, and the other end of the resistor R27 is connected to a PD1 pin of the auxiliary chip.

[0028] Further, the charging and discharging driving circuit comprises a triode S4, a triode S5, a triode S6, a triode S7, a triode S8 and a triode S9.

[0029] The base of the triode S4 is connected to one end of a resistor R29 and one end of a resistor R30, the collector of the triode S4 is connected to one end of a resistor R28 and one end of a resistor R31 respectively, the other end of the resistor R28 and the other end of the resistor R29 are connected to the auxiliary chip respectively, and the other end of the resistor R30 is connected to the other end of the resistor R31.

[0030] The base of the triode S5 is connected to one end of a resistor R32 and one end of a resistor R33 respectively, the emitter of the triode S5 is connected to the other end of the resistor R33, and the collector of the triode S5 is connected to the base of the triode S6.

[0031] The emitter of the triode S6 is connected to the emitter of the triode S5, the collector of the triode S6 is connected to one end of a resistor R37, and the other end of the resistor R37 is connected to the triode S7.

[0032] The base of the triode S7 is further connected to one end of a resistor R35, the other end of the resistor R35 is connected to the emitter of the triode S7, the collector of the triode S7 is connected to one end of a resistor R36, the base of the triode S9, the collector of the triode S8 and one end of the resistor R37 respectively, the other end of the resistor R36 is connected to the emitter of the triode S9, and the other end of the resistor R37 is connected to the emitter of the triode S8.

[0033] The base of the triode S8 is connected to the collector of the triode S9, and the emitter of the triode S8 and the collector of the triode S7 are connected to two ends of a resistor R38 respectively.

[0034] Further, the charging and discharging protection circuit further comprises a pre-charge circuit, the pre-charge circuit comprises a triode S10, a triode S11 and a MOS tube Q3.

[0035] The base of the triode S10 is connected to one end of a resistor R39 and one end of a resistor R40 respectively, the other end of the resistor R39 is connected to the auxiliary chip, the other end of the resistor R40 is connected to the emitter of the triode S10, the collector of the triode S10 is connected to one end of a resistor R41, and the other end of the resistor R41 is connected to the base of the triode S11.

[0036] The base of the triode S11 is also connected to one end of the resistor R42, the other end of the resistor R42 is connected to the emitter of the triode S11, the collector of the triode S11 is connected to the input end of the diode D2, the output end of the diode D2 is connected to one end of the resistor R43 and one end of the resistor R44 respectively, the other end of the resistor R43 is connected to the source of the MOS tube Q3, the other end of the resistor R44 is connected to the gate of the MOS tube Q3, and the drain of the MOS tube Q3 is connected with the resistor R45.

[0037] The beneficial effect of the above further scheme is that the pre-charge circuit can reduce current impact, protect circuit components and prolong the service life of the lithium battery, the MOS tube Q3 in the pre-charge circuit limits the charging current and realizes the function of slowly increasing the charging current, thereby reducing the load pressure and heat of the equipment in an instant. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of the drawings.

[0039] Figure 1 The structure block diagram of the power supply monitoring device in the embodiment of the present application;

[0040] Figure 2 The circuit principle diagram of the cell equalization circuit in the embodiment of the present application;

[0041] Figure 3 The circuit principle diagram of the current collection circuit in the embodiment of the present application;

[0042] Figure 4 The circuit principle diagram of the discharge monitoring circuit in the embodiment of the present application;

[0043] Figure 5 The circuit principle diagram of the charging monitoring circuit in the embodiment of the present application;

[0044] Figure 6 The circuit principle diagram of the anti-reverse connection circuit and the charge-discharge driving circuit in the embodiment of the present application;

[0045] Figure 7 The circuit principle diagram of the pre-charge circuit in the embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0048] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0049] Embodiments

[0050] The present embodiment provides a multi-cell intelligent power supply monitoring device, which is applied to lithium battery management of an electric vehicle, and includes a main control chip, an auxiliary chip connected with the main control chip, a temperature acquisition circuit and a current acquisition circuit connected with the main control chip, and a voltage acquisition circuit and a discharge monitoring circuit connected with the auxiliary chip.

[0051] The main control chip is used for connecting the lithium battery of the electric vehicle, receiving temperature data of the lithium battery acquired by the temperature acquisition circuit and current data of the lithium battery acquired by the current acquisition circuit, and transmitting the temperature data and the current data to the auxiliary chip.

[0052] Specifically, the model of the main control chip can be OZ7716, and the model of the auxiliary chip can be GD32F103VCT6; specifically, see Figure 1 , Figure 1 The connection schematic diagram of the power supply management device is shown in FIG. 1, Figure 1 The auxiliary chip in FIG. 1 is connected with an upper computer, and is also connected with an LCD display screen of the electric vehicle, a buzzer alarm circuit, an RTC circuit and an EEPROM (Electrically Erasable Programmable Read-Only Memory, a storage chip that can save data when power off), so as to display the collected data of the power supply management device on the LCD display screen.

[0053] Optionally, the multi-cell intelligent power supply monitoring device further includes a cell balancing circuit, and the main control chip is connected with the lithium battery of the electric vehicle through the cell balancing circuit.

[0054] As shown in FIG. 2, Figure 2As shown, the battery cell equalization circuit includes a plurality of single cell circuits, each of which includes resistors R1, R2, R3, R4, a transistor S12, and a MOS tube Q4.

[0055] The gate of the MOS tube Q4 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the transistor S12, the base of the transistor S12 and the drain of the MOS tube Q4 are respectively connected to two ends of the resistor R3, the base of the transistor S12 is also connected to one end of the capacitor C6, the drain of the MOS tube Q4 is also connected to one end of the resistor R4, the other end of the capacitor C6 and the other end of the resistor R4 are both connected to the emitter of the transistor S12, and the emitter of the transistor S12 is connected to one end of one of the single cells, and the common connection point of the resistor R1 and the resistor R2 is connected to the other end of the single cell.

[0056] Since the lithium battery is composed of a plurality of single cells, the battery cell equalization circuit is used to equalize the output end voltage of the plurality of single cells, so that the electric vehicle obtains a stable power supply voltage. Specifically, referring to Figure 2 , the lithium battery can be composed of 16 single cells of lithium iron phosphate, and the 16 single cells of lithium iron phosphate are connected to the electrical nodes of BAT1-BAT16 of OZ7716, so that the voltage of the single cell can be measured, and the transistor in the equalization circuit is controlled by OZ7716 to be turned on and off, so as to realize the functions of turning on and off the battery cell voltage equalization; the positive and negative ends of the lithium battery output are connected to the PA0 pin and the WKUP pin of the GD32F103VCT6, which are used as the voltage sampling input of the lithium battery and the wake-up from the sleep low-power mode.

[0057] Specifically, the battery cell equalization circuit adopts a passive equalization mode, and two battery cell voltage equalization methods are designed according to different equalization efficiencies: one is to use the equalization mode in the internal control chip (OZ7716), which limits the charging current of the selected plurality of single cells by adding a load, and the remaining single cells are charged with current, and after a period of time, the voltage of the remaining single cells will catch up with the voltage of the selected single cells. The voltage of the plurality of single cells can be balanced at the same time; the other is to use an external battery cell equalization circuit, and when the difference between the single cell voltage at both ends of the single cell and the voltage of the smallest single cell in the lithium battery reaches a set threshold value or the maximum single cell voltage of the single cell reaches a set threshold value, the battery cell equalization function is started. The control chip (OZ7716) controls the conduction of the transistor to form a discharge loop, and the excess energy of the single cell with high voltage is discharged, and the voltage of the external single cell is used to dissipate heat, which can more efficiently realize the battery cell voltage balance.

[0058] Optionally, the current collection circuit includes capacitors C1, C2, C3, resistors R5, R6, and RSENS.

[0059] The two ends of the capacitor C3 are connected with the ISP pin and the ISN pin of the main control chip respectively, one end of the capacitor C1 is connected with one end of the capacitor C2, the other end of the capacitor C1 is connected with the ISP pin of the main control chip, the other end of the capacitor C2 is connected with the ISP pin of the main control chip; one end of the resistor R5 is connected with the ISP pin of the main control chip, one end of the resistor R6 is connected with the ISN pin of the main control chip, the other end of the resistor R5 and the other end of the resistor R6 are connected with the two ends of the resistor RSENS respectively.

[0060] Specifically, the connection diagram of the current collection circuit is shown in the following figure Figure 3 , wherein the current collection is divided into two paths; one path is to connect the two ends of the sampling resistor through the RC filter network and the ISP and ISN pins of the OZ7716, and the OZ7716 judges the state information of the current battery pack by monitoring the voltage drop formed by the current flowing through the sampling resistor between the ISP pin and the ISN pin, the charging is positive, the discharging is negative, when the detected current is negative and the absolute value is greater than the set discharging detection threshold, it is considered as discharging, when the detected current is positive and greater than the set charging detection threshold, it is considered as charging, otherwise it is considered as idle state.

[0061] Optionally, the current collection circuit further comprises a detection chip, a resistor R7 and a resistor R8.

[0062] The IN- pin of the detection chip is connected with the ISP pin of the main control chip, the IN+ pin of the detection chip is connected with the ISN pin of the main control chip, the out pin of the detection chip is connected with the PA1 pin of the auxiliary chip, the REF pin of the detection chip is connected with one end of the resistor R7 and one end of the resistor R8 respectively, the other end of the resistor R8 is connected with the VREF pin of the auxiliary chip, and the other end of the resistor R7 is grounded.

[0063] Specifically, another way of current measurement is to connect the voltage across the SENSE sampling resistor to the PA1 pin of the auxiliary chip (GD32F103VCT6) after amplification by the detection chip (INA181A2IDBVT), and read the current value by the auxiliary chip, INA181A2IDBVT has a bidirectional current monitoring function, the IN+ pin and the IN- pin are connected to the two ends of the sampling resistor SENSE, and the REF pin of the detection chip inputs a reference voltage, according to the formula V OUT =(I LOAD ×R SENSE ×GAIN)+V REF , the bidirectional current detection mode is realized by applying a voltage to the REF pin, when the output current is positive, the output voltage is greater than the reference voltage, when the output voltage is less than the reference voltage, it represents that the output current is negative.

[0064] Optionally, the discharge monitoring circuit comprises MOS Q1, MOS Q2 and transistor S1;

[0065] The gate of MOS Q1 is connected to one end of resistor R14 and one end of resistor R15, the other end of resistor R15 is connected to the source of MOS Q1, and the other end of resistor R14 is connected to the source of MOS Q2; the drain of MOS Q1 is connected to one end of resistor R10, the other end of resistor R10 is connected to one end of resistor R9 and one end of resistor R13, the other end of resistor R9 is connected to the drain of MOS Q2, and the other end of resistor R13 is connected to the base of transistor S1; the drain of MOS Q2 and the source of MOS Q1 are connected to the cell balancing circuit;

[0066] The gate of MOS Q2 is connected to one end of resistor R12 and one end of resistor R16, and the other end of resistor R2 is connected to the drain of MOS Q2;

[0067] The base of transistor S1 is also connected to one end of resistor R11, the other end of resistor R11 is grounded, the collector of transistor S1 is connected to one end of resistor R18 and one end of resistor R17, the other end of resistor R18 is connected to the DSGD pin of the auxiliary chip, and the emitter of transistor S1 is grounded.

[0068] Specifically, the connection diagram of the discharge monitoring circuit is shown in Figure 4 The discharge detection method is divided into two paths, one is the load detection circuit integrated in the main control chip, and the auxiliary chip reads the register state of the main control chip through IIC communication mode to determine whether the load is released; the other discharge detection circuit is to detect the high and low level of the DSGD pin to detect discharge, when discharging, the MOS is turned on, and the voltage across the discharge MOS tends to 0, Figure 4 The MOS Q1 in the MOS Q1 is closed, the transistor S1 is closed, and the DSGD pin outputs high level; when the discharge MOS Q1 is closed, the MOS Q2 is N-channel MOS, which is always in the on state, the MOS Q1 is P-channel MOS, and when the S terminal voltage of the MOS Q1 is greater than the G terminal voltage, the MOS Q1 is turned on, the MOS Q2 is opened, and the voltage of the DSGD pin is pulled down to realize the discharge monitoring function.

[0069] The auxiliary chip is used to connect the host computer of the electric vehicle, receive temperature data and current data, receive voltage data of the lithium battery obtained by the voltage acquisition circuit and discharge data of the lithium battery obtained by the discharge monitoring circuit, and transmit the temperature data, current data, voltage data and discharge data to the host computer.

[0070] Among them, as Figure 1As shown, by connecting the auxiliary chip with each device (host computer, LCD display screen, etc.) in the electric vehicle, the communication between the auxiliary chip and the central control system of the electric vehicle is realized. In the system of the electric vehicle, the state data of the lithium battery collected by the power management device can be displayed and viewed. Specifically, the state data includes the charging monitoring state of the lithium battery (current size, charging time length, etc.), the discharging state (output voltage size, etc.), the temperature of the lithium battery, and the like.

[0071] Optionally, the above-mentioned intelligent power monitoring device of the battery cell further comprises a charging and discharging protection circuit, the charging and discharging protection circuit is connected with the main control chip and the auxiliary chip, and the charging and discharging protection circuit comprises a charging monitoring circuit, the charging monitoring circuit comprises a transistor S2 and a transistor S3.

[0072] The base of the transistor S2 is connected with one end of a capacitor C4, one end of a resistor R19 and one end of a resistor R20, respectively; the other end of the capacitor C4 is connected with the base of the transistor S2; the other end of the resistor R20 is connected with the emitter of the transistor S3; and the other end of the resistor R19 is grounded.

[0073] The base of the transistor S3 is connected with one end of a resistor R21 and one end of a resistor R22, respectively; the other end of the resistor R21 is connected with the collector of the transistor S2; the collector of the transistor S3 is connected with one end of a resistor R23 and one end of a resistor R24, respectively; the other end of the resistor R23 and the other end of the resistor R24 are connected with two ends of a capacitor C5, respectively; the other end of the resistor R24 is further connected with a CHGD pin of the auxiliary chip; and the other end of the resistor R23 is grounded.

[0074] Specifically, the connection diagram of the charging monitoring circuit is shown in Figure 5 The charging monitoring circuit is divided into two paths. One path is a charging detection circuit integrated in the main control chip, and the auxiliary chip GD32F103VCT6 reads the state register of the OZ7716 through the IIC communication mode to determine whether the lithium battery is charging. The other path is to detect the high and low levels of the CHGD pin through the auxiliary chip to detect charging. When the charging MOS tube is in the closed state, the charging end C- is pulled high, the NPN type transistor S2 is in the closed state, and the PNP type transistor S3 is in the closed state. When the charging MOS tube is in the open state, the charging end C- is pulled low, the transistor S2 is turned on, the transistor S3 is turned on, and the CHGD pin is pulled high.

[0075] Optionally, the above-mentioned charging and discharging protection circuit further comprises an anti-reverse connection circuit and a charging and discharging driving circuit.

[0076] The anti-reverse connection circuit comprises an optical coupling isolator and a diode D1, an output end of the diode D1 is connected to one end of a resistor R25, the other end of the resistor R25 is connected to the optical coupling isolator, the optical coupling isolator is further connected to one end of a resistor R26 and one end of a resistor R27, the other end of the resistor R26 is grounded, and the other end of the resistor R27 is connected to a PD1 pin of the auxiliary chip.

[0077] Optionally, the charging and discharging driving circuit comprises a triode S4, a triode S5, a triode S6, a triode S7, a triode S8 and a triode S9.

[0078] The base of the triode S4 is connected to one end of a resistor R29 and one end of a resistor R30, the collector of the triode S4 is connected to one end of a resistor R28 and one end of a resistor R31 respectively, the other end of the resistor R28 and the other end of the resistor R29 are connected to the auxiliary chip respectively, and the other end of the resistor R30 is connected to the other end of the resistor R31.

[0079] The base of the triode S5 is connected to one end of a resistor R32 and one end of a resistor R33 respectively, the emitter of the triode S5 is connected to the other end of the resistor R33, and the collector of the triode S5 is connected to the base of the triode S6.

[0080] The emitter of the triode S6 is connected to the emitter of the triode S5, the collector of the triode S6 is connected to one end of a resistor R37, and the other end of the resistor R37 is connected to the triode S7.

[0081] The base of the triode S7 is further connected to one end of a resistor R35, the other end of the resistor R35 is connected to the emitter of the triode S7, the collector of the triode S7 is connected to one end of a resistor R36, the base of the triode S9, the collector of the triode S8 and one end of the resistor R37 respectively, the other end of the resistor R36 is connected to the emitter of the triode S9, and the other end of the resistor R37 is connected to the emitter of the triode S8.

[0082] The base of the triode S8 is connected to the collector of the triode S9, and the emitter of the triode S8 and the collector of the triode S7 are connected to two ends of a resistor R38 respectively.

[0083] Specifically, the connection schematic diagram of the anti-reverse connection circuit and the charging and discharging driving circuit is shown in Figure 6 In the anti-reverse connection circuit, the optical coupling isolator is used to isolate the electrical signal, the PD1 pin level of the main control chip is pulled high when the charging head is reversely connected, and the auxiliary chip detects the PD1 pin level to determine whether the charging head is reversely connected; at the same time of the reverse connection, the network at the RC end is also pulled high. In the charging and discharging driving circuit, the triode S5 is opened, the triode S6, the triode S7 and the triode S9 are closed, the CHG end is a low-level signal, and the charging MOS tube is closed; the circuit composed of the triode S8 and the triode S9, i.e. the common-emitter-collector amplification circuit, plays a role of amplifying the signal and enhancing the driving capability of the MOS tube.

[0084] Optionally, the charge and discharge protection circuit further comprises a pre-charge circuit, the pre-charge circuit comprising a transistor S10, a transistor S11 and a MOS Q3;

[0085] The base of the transistor S10 is connected to one end of a resistor R39 and one end of a resistor R40, the other end of the resistor R39 is connected to an auxiliary chip, the other end of the resistor R40 is connected to the emitter of the transistor S10, the collector of the transistor S10 is connected to one end of a resistor R41, the other end of the resistor R41 is connected to the base of the transistor S11;

[0086] The base of the transistor S11 is also connected to one end of a resistor R42, the other end of the resistor R42 is connected to the emitter of the transistor S11, the collector of the transistor S11 is connected to the input of a diode D2, the output of the diode D2 is connected to one end of a resistor R43 and one end of a resistor R44, the other end of the resistor R43 is connected to the source of the MOS Q3, the other end of the resistor R44 is connected to the gate of the MOS Q3, and the drain of the MOS Q3 is connected to a resistor R45.

[0087] Specifically, the connection diagram of the pre-charge circuit is shown in Figure 7 In order to reduce the current impact on the service life of the protection circuit components and the lithium battery, the MOS Q3 in the pre-charge circuit is used to limit the charging current and achieve the function of slowly increasing the charging current, thereby reducing the instantaneous load pressure and heat of the device; the PCHGC end is connected to the PE4 pin of the auxiliary chip, the signal of the PCHGC end is pulled high to turn on the pre-charge circuit, and R7 is a current limiting resistor.

[0088] Specifically, the power management device of the electric vehicle of the present application can be suitable for large current application scenarios, and adopts a battery protection IC (Integrated Circuit) OZ7716 (main control chip). The main control chip is built-in 16-bit ADC to collect the voltage, current and temperature of the lithium battery, and the collected data is stable, and the zero offset is small. The GD32F103VCT6 (auxiliary chip) can conveniently and quickly obtain the state information of the battery by reading and writing the registers in the OZ7716 (main control chip), and the hardware protection function of the OZ7716 (main control chip) also has the battery protection function. In actual use, the GD32F103VCT6 (auxiliary chip) only needs to modify the configuration information in the corresponding register to realize the communication between the main control chip, and can achieve good battery protection effect. Among them, the host computer of the electric vehicle or other equipment powered by lithium battery communicates with the auxiliary chip through RS485, and the GD32F103VCT6 (auxiliary chip) displays the monitored state information of the battery and the received battery state data on the host computer in real time. At the same time, the corresponding protection parameters of the battery, such as voltage protection threshold, current protection threshold and temperature protection threshold, and the control of the charge-discharge MOS tube can also be modified on the host computer software, which is convenient and fast to operate, improves the universality of the power management device in the present application, and is convenient for management and maintenance and suitable for battery protection under multiple nominal voltages. The power management device in the present application has the characteristics of high reliability, low power consumption and easy integration, and can be widely applied to various types of electric vehicles and energy storage systems.

[0089] It is apparent for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, but can be implemented in other concrete forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all aspects as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and range of equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be considered as limiting the claims involved.

Claims

1. A multi-cell intelligent power monitoring device applied to lithium battery monitoring of an electric vehicle, characterized in that, The application relates to a multi-cell intelligent power supply monitoring device, which comprises a main control chip and an auxiliary chip connected with the main control chip, a temperature acquisition circuit and a current acquisition circuit connected with the main control chip, a voltage acquisition circuit and a discharge monitoring circuit connected with the auxiliary chip. The main control chip is used for connecting a lithium battery of an electric vehicle, receiving temperature data of the lithium battery acquired by the temperature acquisition circuit and current data of the lithium battery acquired by the current acquisition circuit, and transmitting the temperature data and the current data to the auxiliary chip. The auxiliary chip is used for connecting a host computer of the electric vehicle, receiving the temperature data and the current data, receiving voltage data of the lithium battery acquired by the voltage acquisition circuit and discharge data of the lithium battery acquired by the discharge monitoring circuit, and transmitting the temperature data, the current data, the voltage data and the discharge data to the host computer. The multi-cell intelligent power supply monitoring device further comprises a cell equalization circuit, the main control chip is connected with the lithium battery of the electric vehicle through the cell equalization circuit, and the lithium battery is composed of multiple single batteries. The cell equalization circuit comprises multiple single battery circuits, each single battery circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a triode S12 and a MOS tube Q4. The gate of the MOS tube Q4 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with one end of the resistor R1, the other end of the resistor R1 is connected with the collector of the triode S12, the base of the triode S12 and the drain of the MOS tube Q4 are respectively connected with two ends of the resistor R3, the base of the triode S12 is also connected with one end of a capacitor C6, the drain of the MOS tube Q4 is also connected with one end of the resistor R4, the other end of the capacitor C6 and the other end of the resistor R4 are both connected with the emitter of the triode S12, and the emitter of the triode S12 is connected with one end of one single battery of the multiple single batteries, and the common connection point of the resistor R1 and the resistor R2 is connected with the other end of the single battery. The current acquisition circuit comprises a capacitor C1, a capacitor C2, a capacitor C3, a resistor R5, a resistor R6 and a resistor RSENS. Two ends of the capacitor C3 are respectively connected with an ISP pin and an ISN pin of the main control chip, one end of the capacitor C1 is connected with one end of the capacitor C2, the other end of the capacitor C1 is connected with the ISP pin of the main control chip, and the other end of the capacitor C2 is connected with the ISP pin of the main control chip; one end of the resistor R5 is connected with the ISP pin of the main control chip, one end of the resistor R6 is connected with the ISN pin of the main control chip, and the other end of the resistor R5 and the other end of the resistor R6 are respectively connected with two ends of the resistor RSENS. The current acquisition circuit further comprises a detection chip, a resistor R7 and a resistor R8. The IN-pin of the detection chip is connected with the ISP pin of the main control chip, the IN+ pin of the detection chip is connected with the ISN pin of the main control chip, the out pin of the detection chip is connected with the PA1 pin of the auxiliary chip, the REF pin of the detection chip is connected with one end of the resistor R7 and one end of the resistor R8 respectively, the other end of the resistor R8 is connected with the VREF pin of the auxiliary chip, and the other end of the resistor R7 is grounded.

2. A multi-cell intelligent power monitoring device according to claim 1, wherein, The discharge monitoring circuit comprises a MOS tube Q1, a MOS tube Q2 and a triode S1. The gate of the MOS tube Q1 is connected with one end of a resistor R14 and one end of a resistor R15 respectively, the other end of the resistor R15 is connected with the source of the MOS tube Q1, and the other end of the resistor R14 is connected with the source of the MOS tube Q2; the drain of the MOS tube Q1 is connected with one end of a resistor R10, the other end of the resistor R10 is connected with one end of a resistor R9 and one end of a resistor R13 respectively, the other end of the resistor R9 is connected with the drain of the MOS tube Q2, and the other end of the resistor R13 is connected with the base of the triode S1; the drain of the MOS tube Q2 and the source of the MOS tube Q1 are connected with the battery equalization circuit. The gate of the MOS tube Q2 is connected with one end of a resistor R12 and one end of a resistor R16 respectively, and the other end of the resistor R2 is connected with the drain of the MOS tube Q2. The base of the triode S1 is also connected with one end of a resistor R11, the other end of the resistor R11 is grounded, the collector of the triode S1 is connected with one end of a resistor R18 and one end of a resistor R17 respectively, the other end of the resistor R18 is connected with the DSGD pin of the auxiliary chip, and the emitter of the triode S1 is grounded.

3. A multi-cell intelligent power monitoring device according to any one of claims 1-2, characterized in that, The battery intelligent power supply monitoring device further comprises a charging and discharging protection circuit, the charging and discharging protection circuit is connected with the main control chip and the auxiliary chip, and the charging and discharging protection circuit comprises a charging monitoring circuit. The base of the triode S2 is connected with one end of a capacitor C4, one end of a resistor R19 and one end of a resistor R20 respectively, the other end of the capacitor C4 is connected with the base of the triode S2, the other end of the resistor R20 is connected with the emitter of the triode S3, and the other end of the resistor R19 is grounded. The base of the triode S3 is connected with one end of a resistor R21 and one end of a resistor R22 respectively, the other end of the resistor R21 is connected with the collector of the triode S2; the collector of the triode S3 is connected with one end of a resistor R23 and one end of a resistor R24 respectively, the other end of the resistor R23 and the other end of the resistor R24 are connected with two ends of a capacitor C5 respectively, the other end of the resistor R24 is also connected with the CHGD pin of the auxiliary chip, and the other end of the resistor R23 is grounded.

4. The multi-cell intelligent power monitoring device of claim 3, wherein, The charging and discharging protection circuit further comprises an anti-reverse connection circuit and a charging and discharging driving circuit. The reverse connection prevention circuit comprises an optical coupling isolator and a diode D1, an output end of the diode D1 is connected with one end of a resistor R25, the other end of the resistor R25 is connected with the optical coupling isolator, the optical coupling isolator is further connected with one end of a resistor R26 and one end of a resistor R27, the other end of the resistor R26 is grounded, and the other end of the resistor R27 is connected with a PD1 pin of the auxiliary chip.

5. A multi-cell intelligent power monitoring device according to claim 4, wherein, The charge and discharge driving circuit comprises a triode S4, a triode S5, a triode S6, a triode S7, a triode S8 and a triode S9. One end of a resistor R29 and one end of a resistor R30 are connected with the base of the triode S4, one end of a resistor R28 and one end of a resistor R31 are connected with the collector of the triode S4, the other end of the resistor R28 and the other end of the resistor R29 are connected with the auxiliary chip respectively, and the other end of the resistor R30 is connected with the other end of the resistor R31. One end of a resistor R32 and one end of a resistor R33 are connected with the base of the triode S5 respectively, the other end of the resistor R33 is connected with the emitter of the triode S5, and the collector of the triode S5 is connected with the base of the triode S6. The emitter of the triode S6 is connected with the emitter of the triode S5, the collector of the triode S6 is connected with one end of a resistor R37, and the other end of the resistor R37 is connected with the triode S7. The base of the triode S7 is further connected with one end of a resistor R35, the other end of the resistor R35 is connected with the emitter of the triode S7, the collector of the triode S7 is connected with one end of a resistor R36, the base of the triode S9, the collector of the triode S8 and one end of the resistor R37 respectively, the other end of the resistor R36 is connected with the emitter of the triode S9, and the other end of the resistor R37 is connected with the emitter of the triode S8. The base of the triode S8 is connected with the collector of the triode S9, and the emitter of the triode S8 and the collector of the triode S7 are connected with both ends of a resistor R38 respectively.

6. A multi-cell intelligent power monitoring device according to claim 5, wherein, The charge and discharge protection circuit further comprises a pre-charge circuit, the pre-charge circuit comprises a triode S10, a triode S11 and a MOS tube Q3. One end of a resistor R39 and one end of a resistor R40 are connected with the base of the triode S10 respectively, the other end of the resistor R39 is connected with the auxiliary chip, the other end of the resistor R40 is connected with the emitter of the triode S10, the collector of the triode S10 is connected with one end of a resistor R41, and the other end of the resistor R41 is connected with the base of the triode S11. The base of the triode S11 is further connected with one end of a resistor R42, the other end of the resistor R42 is connected with the emitter of the triode S11, the collector of the triode S11 is connected with an input end of a diode D2, one end of a resistor R43 and one end of a resistor R44 are connected with an output end of the diode D2 respectively, the other end of the resistor R43 is connected with the source of the MOS tube Q3, the other end of the resistor R44 is connected with the gate of the MOS tube Q3, and the drain of the MOS tube Q3 is connected with a resistor R45.

Images