BMS power supply voltage diagnosis circuit based on operational amplifier

Abstract

The utility model provides a BMS power supply voltage diagnosis circuit based on an operational amplifier, and belongs to the technical field of diagnosis circuits. The BMS power supply voltage diagnosis circuit based on the operational amplifier comprises an operational amplifier U8, a resistor R49, a resistor R52, a capacitor C52, a resistor R51, a resistor R54, a resistor R3, a capacitor C53 and a resistor R50. According to the utility model, impedance matching is carried out through the operational amplifier, the reliability of the circuit is improved, and the operational amplifier is respectively connected with the first voltage output end and the second voltage output end of the power supply module. The voltage output by the first voltage output end and the second voltage output end of the power supply module is collected by the follower circuit made of the operational amplifier, so that the accurate voltage value output by the power supply module can be diagnosed, the voltage abnormity can be found in time, a user can process the voltage abnormity in time, and the accuracy of temperature and current detection can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to diagnostic circuit technical field, concretely relates to a BMS power supply voltage diagnostic circuit based on operational amplifier. BACKGROUND

[0002] The function of energy storage BMS is responsible for voltage collection, current collection of battery cluster, summary of single battery voltage and temperature information, calculation of battery cluster SOC / SOH state, execution of balance strategy judgment and battery fault diagnosis function, and realization of battery cluster on-site protection and relay control according to battery fault information. In the energy storage BMS, the reference voltage provided by the main control power supply DCDC module is used for temperature and current collection, however, when the output voltage of the DCDC module fluctuates, incorrect temperature and current values are obtained, and then diagnosis cannot be made. SUMMARY

[0003] The utility model discloses a BMS power supply voltage diagnostic circuit based on operational amplifier.

[0004] The utility model discloses a BMS power supply voltage diagnostic circuit based on operational amplifier, including operational amplifier U8, resistance R49, resistance R52, electric capacity C52, resistance R51, resistance R54, resistance R3, electric capacity C53, resistance R50, the A_O pin of operational amplifier U8 is connected to one end of resistance R49, the other end of resistance R49 can be connected to the first voltage output end of power module, the A of operational amplifier U8 - pin is connected to the connecting point of resistance R49 and the A_O pin of operational amplifier U8 through resistance R52, electric capacity C52 is connected in parallel with resistance R52, the A of operational amplifier U8 + pin is connected to power 5V through resistance R51, the GND pin of operational amplifier U8 is grounded, the B_O pin of operational amplifier U8 is connected to one end of resistance R50, the other end of resistance R50 can be connected to the second voltage output end of power module, the B of operational amplifier U8 - pin is connected to the connecting point of resistance R50 and the B_O pin of operational amplifier U8 through resistance R53, electric capacity C53 is connected in parallel with resistance R53, the B of operational amplifier U8 + pin is connected to power 12V through resistance R54, the VCC pin of operational amplifier U8 is connected to power 5V.

[0005] Further, the operational amplifier U8 is MCP6002 operational amplifier, and the first voltage output end and the second voltage output end are respectively PWR_5V_DTCT and PWR_12V_DTCT output ends of the power module.

[0006] Further, it further includes capacitor C49, capacitor C54, resistor R55, one end of the resistor R49 far away from the operational amplifier U8 is grounded through the capacitor C49, the A+ pin of the operational amplifier U8 is grounded through the capacitor C54, one end of the resistor R55 is connected to the connecting point of the resistor R51 and the A+ pin of the operational amplifier U8, and the other end of the resistor R55 is grounded.

[0007] Further, it further includes capacitor C50, capacitor C55, resistor R56, capacitor C51, one end of the resistor R50 far away from the operational amplifier U8 is grounded through the capacitor C50, the connecting point of the B+ pin of the operational amplifier U8 and the resistor R54 is grounded through the capacitor C55, the connecting point of the B+ pin of the operational amplifier U8 and the resistor R54 is grounded through the resistor R56, and the connecting point of the VCC pin of the operational amplifier U8 and the power supply 5V is grounded through the capacitor C51.

[0008] Further, the resistor R49 is 95-105Ω, the capacitor C52 is 0.08-0.12uF, and the resistor R51 is 9-11KΩ.

[0009] Further, the resistor R54 is 19-21KΩ, the capacitor C53 is 0.08-0.12uF, and the resistor R50 is 95-105Ω.

[0010] Further, the resistor R52 is 9-11KΩ, the capacitor C49 is 0.08-0.12uF, the capacitor C54 is 0.08-0.12uF, and the resistor R55 is 9-11KΩ.

[0011] Further, the resistor R53 is 9-11KΩ, the capacitor C50 is 0.08-0.12uF, the capacitor C55 is 0.08-0.12uF, the resistor R56 is 4.9-5.2KΩ, and the capacitor C51 is 0.08-0.12uF.

[0012] Further, the accuracy of the resistor R51 is 1%, and the accuracy of the resistor R55 is 1%.

[0013] Further, the accuracy of the resistor R54 is 1%, and the accuracy of the resistor R56 is 1%.

[0014] The BMS power supply voltage diagnostic circuit based on the operational amplifier has the following beneficial effects:

[0015] The reliability of the circuit is improved by impedance matching through the operational amplifier, the first voltage output end and the second voltage output end of the power module are connected with the application respectively, the follower circuit made of the operational amplifier is used to collect the voltage output by the first voltage output end and the second voltage output end of the power module respectively, which is beneficial to diagnose the accurate voltage value output by the power module and find the voltage abnormality in time, convenient for the user to handle the voltage abnormality in time, and beneficial to improve the accuracy of temperature and current detection. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the application and, together with the description, serve to explain the principles of the application. In the drawings, like reference numerals are used to indicate like elements throughout the various figures. The drawings in the following description are of some embodiments of the application, and are not all the embodiments. Those ordinarily skilled in the art can obtain other drawings according to these drawings without creative effort.

[0017] Figure 1 A circuit diagram in a BMS power supply voltage diagnostic circuit based on an operational amplifier for the embodiments of the application. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those ordinarily skilled in the art without creative effort belong to the protection scope of the application. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other arbitrarily without conflict.

[0019] Please refer to Figure 1The utility model discloses a BMS power supply voltage diagnostic circuit based on operational amplifier, including operational amplifier U8, resistance R49, resistance R52, electric capacity C52, resistance R51, resistance R54, resistance R3, electric capacity C53, resistance R50, the one end of resistance R49 is connected to the A_O pin of operational amplifier U8, and the other end of resistance R49 can be connected to the first voltage output end of power module, and the A of operational amplifier U8 - pin is connected to the connecting point of resistance R49 and the A_O pin of operational amplifier U8 through resistance R52, and electric capacity C52 is connected in parallel with resistance R52, and the A of operational amplifier U8 + pin is connected to power 5V through resistance R51, and the GND pin of operational amplifier U8 is grounded, the one end of resistance R50 is connected to the B_O pin of operational amplifier U8, and the other end of resistance R50 can be connected to the second voltage output end of power module, and the B of operational amplifier U8 - pin is connected to the connecting point of resistance R50 and the B_O pin of operational amplifier U8 through resistance R53, and electric capacity C53 is connected in parallel with resistance R53, and the B of operational amplifier U8 + pin is connected to power 12V through resistance R54, and the VCC pin of operational amplifier U8 is connected to power 5V.

[0020] Here, the other end of resistance R49 in the application can be connected to the first voltage output end of the power module, which can detect the voltage output by the first voltage output end of the power module, and is conducive to diagnosing the accurate voltage value output by the first voltage output end. The other end of resistance R50 in the application can be connected to the second voltage output end of the power module, which can detect the voltage output by the second voltage output end of the power module, and is conducive to diagnosing the accurate voltage value output by the second voltage output end. By detecting the voltage output by the power module, voltage abnormalities can be detected in time, and the user can repair the power module when the voltage is abnormal, avoiding abnormal operation of the BMS device, which helps to detect and handle voltage abnormalities in time, and the user can recheck the temperature and current value.

[0021] Specifically, in the prior art, the BMS master either does not detect the output voltage of the power module or directly uses resistance voltage division to detect the supply voltage, and there is a lack of isolation and buffering between the front and rear stages. The follower made of the operational amplifier in the application can serve as an intermediate stage to "isolate" the influence between the front and rear stages. The follower made of the operational amplifier has the characteristics of high input impedance and low output impedance, with input impedance of several megohms and output impedance of several tens of ohms or lower. The follower scheme has higher reliability in industries with high electrical performance requirements, and the application does not affect the front and rear stages of the circuit, improves the reliability design of the hardware, and plays a buffering, isolating and load capacity improving role.

[0022] The operational amplifier U8 can be an MCP6002 operational amplifier, and the first voltage output end and the second voltage output end are respectively PWR_5V_DTCT and PWR_12V_DTCT output ends of the power module.

[0023] Specifically, the MCP6002 is a dual operational amplifier chip, commonly used in low-power, low-noise and high-precision applications, and has a wide power supply voltage range and working temperature range. The A_O pin and the B_O pin of the operational amplifier U8 can be output ends, the A+ pin and the B+ pin of the operational amplifier U8 can be non-inverting input ends, and the A- pin and the B- pin of the operational amplifier U8 can be inverting input ends. The A+ pin and the A- pin of the operational amplifier U8 are used to receive an input signal, and by adjusting the ratio of the feedback resistance and the input resistance, the amplification of the input signal can be realized.

[0024] Specifically, the PWR_5V_DTCT output end of the power module outputs a 5V voltage, so that the 5V voltage output by the power module can be detected. The PWR_12V_DTCT output end of the voltage module outputs a 12V voltage, so that the 12V voltage output by the power module can be detected. The application realizes 1:1 following through the operational amplifier, and the resistance voltage division is realized by the adc pin of the MCU. Whether the voltage is abnormal can be diagnosed by software. The application realizes impedance matching through the operational amplifier, improves the reliability of the circuit, and the impedance matching of the operational amplifier refers to adjusting the impedance of the input or output end to match the amplifier with the external circuit or device, and improve the transmission quality and stability of the signal. Compared with the power output voltage and the direct resistance voltage division selected in the prior art, the effect of the application is better. TP13, TP14, TP15 and TP16 are test points of the PCB, which are metal pad points on the physical circuit board. The voltage value can be obtained by measuring these test points with a multimeter pen.

[0025] Specifically, the A_O pin of the operational amplifier U8 can be the No. 1 pin of the operational amplifier U8, the A- pin of the operational amplifier U8 can be the No. 2 pin of the operational amplifier U8, the A+ pin of the operational amplifier U8 can be the No. 3 pin of the operational amplifier U8, and the GND pin of the operational amplifier U8 can be the No. 4 pin of the operational amplifier U8. The B+ pin of the operational amplifier U8 can be the No. 5 pin of the operational amplifier U8, the B- pin of the operational amplifier U8 can be the No. 6 pin of the operational amplifier U8, the B_O pin of the operational amplifier U8 can be the No. 7 pin of the operational amplifier U8, and the VCC pin of the operational amplifier U8 can be the No. 8 pin of the operational amplifier U8.

[0026] As one of the BMS power supply voltage diagnostic circuits based on operational amplifier in the embodiment, it further comprises capacitor C49, capacitor C54, resistor R55, one end of resistor R49 far away from operational amplifier U8 is grounded through capacitor C49, A+ pin of operational amplifier U8 is grounded through capacitor C54, one end of resistor R55 is connected to the connection point of resistor R51 and A+ pin of operational amplifier U8, and the other end of resistor R55 is grounded.

[0027] Specifically, resistor R52 is connected in parallel with capacitor C52 to form a negative feedback loop. A+ pin of operational amplifier U8 is grounded through capacitor C54 to filter out high-frequency noise. One end of resistor R49 far away from operational amplifier U8 is grounded through capacitor C49 to stabilize the voltage at the output end.

[0028] As one of the BMS power supply voltage diagnostic circuits based on operational amplifier in the embodiment, it further comprises capacitor C50, capacitor C55, resistor R56, capacitor C51, one end of resistor R50 far away from operational amplifier U8 is grounded through capacitor C50, the connection point of B+ pin of operational amplifier U8 and resistor R54 is grounded through capacitor C55, the connection point of B+ pin of operational amplifier U8 and resistor R54 is grounded through resistor R56, and the connection point of VCC pin of operational amplifier U8 and power supply 5V is grounded through capacitor C51.

[0029] Specifically, resistor R53 is connected in parallel with capacitor C53 to form a negative feedback loop. The connection point of B+ pin of operational amplifier U8 and resistor R54 is grounded through capacitor C55 to filter out high-frequency noise. One end of resistor R50 far away from operational amplifier U8 is grounded through capacitor C50 to stabilize the voltage at the output end. The connection point of VCC pin of operational amplifier U8 and power supply 5V is grounded through capacitor C51 to provide a stable working voltage.

[0030] Resistor R49 can be 95-105Ω, capacitor C52 can be 0.08-0.12uF, and resistor R51 can be 9-11KΩ.

[0031] Specifically, resistor R49 can be 100Ω, capacitor C52 can be 0.1uF, and resistor R51 can be 10KΩ.

[0032] Resistor R54 can be 19-21KΩ, capacitor C53 can be 0.08-0.12uF, and resistor R50 can be 95-105Ω.

[0033] Specifically, resistor R54 can be 20KΩ, capacitor C53 can be 0.1uF, and resistor R50 can be 100Ω.

[0034] The resistance R52 can be 9-11KΩ, the capacitance C49 can be 0.08-0.12uF, the capacitance C54 can be 0.08-0.12uF, and the resistance R55 can be 9-11KΩ.

[0035] Specifically, the resistance R52 can be 10KΩ, the capacitance C49 can be 0.1uF, the capacitance C54 can be 0.1uF, and the resistance R55 can be 10KΩ.

[0036] The resistance R53 can be 9-11KΩ, the capacitance C50 can be 0.08-0.12uF, the capacitance C55 can be 0.08-0.12uF, the resistance R56 can be 4.9-5.2KΩ, and the capacitance C51 can be 0.08-0.12uF.

[0037] Specifically, the resistance R53 can be 10KΩ, the capacitance C50 can be 0.1uF, the capacitance C55 can be 0.1uF, the resistance R56 can be 5.1KΩ, and the capacitance C51 can be 0.1uF.

[0038] The precision of the resistance R51 can be 1%, and the precision of the resistance R55 can be 1%.

[0039] The precision of the resistance R54 can be 1%, and the precision of the resistance R56 can be 1%.

[0040] The above-described content can be implemented alone or in various combinations, and these variants are within the protection scope of the present application.

[0041] It should be noted that in the description of the present application, the terms of the indicated orientation or positional relationship "upper end", "lower end", "bottom end" are based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device containing a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including one" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0042] It should be finally pointed out that: the above examples are only used to illustrate the technical solutions of the utility model, and not limit it. Although the utility model has been explained in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.

Claims

1. An operational amplifier-based BMS supply voltage diagnostic circuit, characterized by: The resistor R49, the resistor R52, the capacitor C52, the resistor R51, the resistor R54, the resistor R3, the capacitor C53, the resistor R50 are connected to the operational amplifier U8; the A_O pin of the operational amplifier U8 is connected to one end of the resistor R49, the other end of the resistor R49 can be connected to the first voltage output end of the power module, the A- pin of the operational amplifier U8 is connected to the connection point of the resistor R49 and the A_O pin of the operational amplifier U8 through the resistor R52, the capacitor C52 is connected to the resistor R52 in parallel, the A+ pin of the operational amplifier U8 is connected to the power supply 5V through the resistor R51, and the GND pin of the operational amplifier U8 is grounded; the B_O pin of the operational amplifier U8 is connected to one end of the resistor R50, the other end of the resistor R50 can be connected to the second voltage output end of the power module, the B- pin of the operational amplifier U8 is connected to the connection point of the resistor R50 and the B_O pin of the operational amplifier U8 through the resistor R53, the capacitor C53 is connected to the resistor R53 in parallel, the B+ pin of the operational amplifier U8 is connected to the power supply 12V through the resistor R54, and the VCC pin of the operational amplifier U8 is connected to the power supply 5V.

2. The BMS supply voltage diagnostic circuit based on an operational amplifier according to claim 1, characterized in that: The operational amplifier U8 is MCP6002 operational amplifier, and the first voltage output end and the second voltage output end are respectively PWR_5V_DTCT and PWR_12V_DTCT output ends of the power module.

3. The BMS supply voltage diagnostic circuit based on an operational amplifier according to claim 1 or 2, characterized in that: The capacitor C49, the capacitor C54 and the resistor R55 are further included, one end of the resistor R49 away from the operational amplifier U8 is grounded through the capacitor C49, the A+ pin of the operational amplifier U8 is grounded through the capacitor C54, and one end of the resistor R55 is connected to the connection point of the resistor R51 and the A+ pin of the operational amplifier U8, and the other end of the resistor R55 is grounded.

4. The BMS supply voltage diagnostic circuit based on an operational amplifier according to claim 1 or 2, characterized in that: The capacitor C50, the capacitor C55, the resistor R56 and the capacitor C51 are further included, one end of the resistor R50 away from the operational amplifier U8 is grounded through the capacitor C50, the connection point of the B+ pin of the operational amplifier U8 and the resistor R54 is grounded through the capacitor C55, the connection point of the B+ pin of the operational amplifier U8 and the resistor R54 is grounded through the resistor R56, and the connection point of the VCC pin of the operational amplifier U8 and the power supply 5V is grounded through the capacitor C51.

5. The operational amplifier based BMS supply voltage diagnostic circuit of claim 3, wherein: The resistor R49 is 95-105Ω, the capacitor C52 is 0.08-0.12uF, and the resistor R51 is 9-11KΩ.

6. The operational amplifier based BMS supply voltage diagnostic circuit of claim 4, wherein: The resistor R54 is 19-21KΩ, the capacitor C53 is 0.08-0.12uF, and the resistor R50 is 95-105Ω.

7. The operational amplifier based BMS supply voltage diagnostic circuit of claim 5, wherein: The resistor R52 is 9-11KΩ, the capacitor C49 is 0.08-0.12uF, the capacitor C54 is 0.08-0.12uF, and the resistor R55 is 9-11KΩ.

8. The operational amplifier based BMS supply voltage diagnostic circuit of claim 6, wherein: The resistance R53 is 9-11KΩ, the capacitance C50 is 0.08-0.12uF, the capacitance C55 is 0.08-0.12uF, the resistance R56 is 4.9-5.2KΩ, and the capacitance C51 is 0.08-0.12uF.

9. The operational amplifier based BMS supply voltage diagnostic circuit of claim 7, wherein: The resistance R51 has an accuracy of 1%, and the resistance R55 has an accuracy of 1%.

10. The operational amplifier based BMS supply voltage diagnostic circuit of claim 8, wherein: The resistance R54 has an accuracy of 1%, and the resistance R56 has an accuracy of 1%.

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