A kind of energy management circuit for decommissioned power battery

Abstract

This invention provides an energy management circuit for retired power batteries, comprising a main circuit area, a voltage detection area, a current detection area, a temperature detection area, an overvoltage and overcurrent protection area, a drive circuit area, a control and display area, and a power supply regulation area. The main circuit connects the battery module to the load. The drive area uses a MOSFET and a Schottky diode connected in series to form a power path structure. The outputs of each detection area are connected to the control area to achieve voltage, current, and temperature sampling and protection control, which are displayed through an LCD module. This invention can achieve efficient energy management and safety protection for retired power batteries, improve the stability and reliability of system operation, reduce voltage loss and reverse surge current, and extend battery life.

Description

Technical Field

[0001] This invention relates to the field of battery energy management technology, and more specifically, to an energy management circuit for retired power batteries. Background Technology

[0002] In the reuse of retired power batteries, energy management circuits are crucial for ensuring safe and efficient battery operation. Existing energy management circuits typically employ simple switching elements for charge and discharge control, but this design suffers from high reverse inrush current and significant voltage loss during charging and discharging. Furthermore, current technologies lack sufficient accuracy in detecting battery voltage, current, and temperature, failing to meet the refined management requirements of retired power batteries under complex operating conditions. Regarding hardware protection, existing overvoltage and overcurrent protection mechanisms have slow response times, failing to promptly disconnect the circuit to prevent battery damage. Retired power batteries exhibit complex internal resistance distributions, making them extremely sensitive to transient shocks. Traditional reconfiguration topologies primarily rely on the body diode of the MOSFET for reverse blocking. However, during high-frequency switching or reconfiguration, the charge storage effect of the body diode can trigger severe reverse recovery currents and inductive overvoltage spikes, seriously threatening the safety and lifespan of retired batteries.

[0003] In implementing the embodiments of the present invention, the prior art has at least the following problems or defects: it cannot effectively reduce reverse impact current, resulting in shortened battery life; the voltage loss is high, affecting energy utilization efficiency; the detection accuracy is insufficient, making it impossible to accurately monitor the battery status; the protection mechanism has a delayed response, making it difficult to ensure battery safety, and there is a lack of hardware transient impact suppression structure for the characteristics of retired batteries. Summary of the Invention

[0004] This invention provides an energy management circuit for retired power batteries, comprising: In the main circuit area, the main power lines connect the positive terminal of the battery module to the positive terminal of the load, and the busbars connect the negative terminal of the battery module to the negative terminal of the load. The driving circuit area is provided with a composite power path structure consisting of a MOSFET and a Schottky diode. The drain of the MOSFET is connected to the main power line, the source is connected to the cathode of the Schottky diode, and the anode of the Schottky diode is connected to the positive terminal of the load, forming a controlled unidirectional energy transmission path. The ultra-fast recovery characteristics of the Schottky diode are used to physically shield the charge storage effect of the MOSFET body diode, suppressing the reverse recovery current and inductive overvoltage spikes generated by switching transients. The voltage detection area, current detection area, and temperature detection area are used to sample the voltage, current, and temperature signals of the battery module, respectively, and output them to the control and display area. Overvoltage and overcurrent protection zones are used to receive voltage or current detection signals and output hardware protection signals when the voltage or current exceeds a preset threshold. The control and display area is used to receive various detection signals and protection signals, and output control signals to the drive circuit area to control the on / off state of the power path structure; The power supply regulation area is used to provide stable power to each functional area.

[0005] Furthermore, the overvoltage and overcurrent protection zone includes a comparator and an optocoupler isolator, and its output is divided into two paths: one path is connected to the protection input of the control and display area for software to identify the protection status; the other path directly or indirectly acts on the MOSFET gate of the drive circuit area for hardware to preferentially cut off the power path in abnormal conditions.

[0006] Furthermore, the driving circuit area also includes an optocoupler driving chip, whose input terminal is connected to the control and display area and whose output terminal is connected to the MOSFET gate; a gate resistor and a gate capacitor are connected in parallel between the MOSFET gate and the source to stabilize the switching characteristics.

[0007] Furthermore, the current detection area includes a Hall sensor, a first operational amplifier, and a second operational amplifier; the Hall sensor is routed through the main power trace, the positive output terminal of the Hall sensor is connected to the inverting input terminal of the first operational amplifier via a first gain resistor, and the negative output terminal is connected to the non-inverting input terminal of the first operational amplifier; the output terminal of the first operational amplifier is connected to the inverting input terminal of the second operational amplifier via a second gain resistor, the non-inverting input terminal of the second operational amplifier is connected to analog ground, and the output terminal of the second operational amplifier is connected to the ADC input terminal of the control and display area.

[0008] Furthermore, the temperature detection area includes a DS18B20 digital temperature sensor and a pull-up resistor; the VDD pin of the DS18B20 is connected to the positive terminal of the system power supply in the power supply regulation area, the DQ pin is connected to the GPIO pin in the control and display area, and the GND pin is connected to the analog ground; one end of the pull-up resistor is connected to the DQ pin of the DS18B20, and the other end is connected to the positive terminal of the system power supply.

[0009] Furthermore, the overvoltage and overcurrent protection zone includes an LM339 comparator and an optocoupler isolator; the non-inverting input of the LM339 is connected to the reference voltage divider network, and the inverting input is connected to the output of the TL074 voltage detection area or the output of the second operational amplifier in the current detection area. The open-drain output of the LM339 is connected to the cathode of the LED in the optocoupler isolator, and the anode of the LED is connected to the positive terminal of the system power supply via a current-limiting resistor. The emitter of the phototransistor in the optocoupler is connected to digital ground, and the collector is connected to the protection input pin of the control and display area and connected to the positive terminal of the system power supply via a pull-up resistor.

[0010] Furthermore, the power supply regulation area includes a REF02 reference source and a 7805 regulator; the input of REF02 is connected to the positive terminal of the external power supply, and the output of REF02 is connected to the positive terminal of the power supply of the TL074 voltage detection area; the input of 7805 is connected to the positive terminal of the external power supply, and the output of 7805 is connected to the positive terminal of the system power supply of the control and display area; decoupling capacitors are connected in parallel to ground at the input and output terminals of 7805 respectively.

[0011] Furthermore, the control and display area includes a microcontroller and a 12864 LCD module; the ADC input of the microcontroller is connected to the output of the TL074 voltage detection area and the output of the second operational amplifier in the current detection area, respectively; the GPIO pin is connected to the DQ pin of the DS18B20 temperature detection area; the protection input pin is connected to the collector of the phototransistor of the optocoupler isolator in the overvoltage and overcurrent protection area; and the drive output pin is connected to the positive input of the TLP250 in the drive circuit area. The RS pin of the 12864 LCD module is connected to the RC0 pin of the microcontroller, the RW pin is connected to the RC1 pin, the EN pin is connected to the RC2 pin, the data ports D0–D7 are connected to the PORTB0–PORTB7 of the microcontroller, the positive power supply terminal of the 12864 is connected to the positive power supply of the system, and the negative power supply terminal is connected to the digital ground.

[0012] Furthermore, the PCB adopts a double-sided board structure, with the copper thickness of the main power traces being greater than that of the signal traces. The main circuit area and the drive circuit area are equipped with heat dissipation copper foil and connected to the bottom copper foil through multiple vias. The analog ground of the voltage detection area, current detection area, temperature detection area, overvoltage and overcurrent protection area, control and display area, and power supply regulation area is connected to the bus copper foil of the main circuit area through a 0Ω resistor at a single point to form a star ground.

[0013] The embodiments of the present invention have at least the following beneficial effects: 1. A composite power path structure consisting of a MOSFET and a Schottky diode is used to replace the traditional switching element. By utilizing the ultrafast turn-off characteristics and low voltage drop characteristics of the Schottky diode, the charge storage effect of the MOSFET body diode is physically shielded, thus constructing a transient protection barrier. This structure effectively reduces reverse surge current, shortens the convergence time of surge current, reduces voltage loss during charging and discharging, improves energy conversion efficiency, extends the service life of retired power batteries, and enhances the stability and reliability of the system.

[0014] 2. The refined design of the voltage, current, and temperature detection zones, combined with high-precision operational amplifiers, Hall effect sensors, and digital temperature sensors, enables high-precision real-time sampling and detection of the voltage, current, and temperature of retired power batteries. This high-precision detection capability can accurately monitor battery status, providing a reliable basis for battery equalization management, safe operation, and fault early warning, thus solving the problem of insufficient detection accuracy in existing technologies.

[0015] 3. The overvoltage and overcurrent protection zone employs a combination of an LM339 comparator and an optocoupler isolator, enabling rapid response and circuit disconnection, effectively protecting the battery from damage caused by abnormal conditions such as overvoltage and overcurrent. This hardware protection mechanism improves system safety and reliability, solves the problem of delayed response in existing protection mechanisms, and ensures the safe operation of retired power batteries under complex operating conditions. Attached Figure Description

[0016] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the invention are illustrated in the drawings by way of example and not limitation, wherein: Figure 1 This is a schematic diagram of the structure of an energy management circuit for a retired power battery according to an embodiment of the present invention; Figure 2 This is a system overall topology diagram provided in an embodiment of the present invention; Figure 3 This is a circuit diagram of a retired battery single-row / array topology in a static state provided by an embodiment of the present invention; Figure 4 This is a schematic diagram of a single-row self-reconfiguration charging process for a retired battery according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a self-reconfigurable discharge process provided in an embodiment of the present invention; Figure 6 A constant 2A charging voltage versus time curve provided in an embodiment of the present invention; Figure 7 This is a constant current and voltage equalization charging curve diagram provided in the backup power mode according to an embodiment of the present invention; Figure 8 This is a constant current fault-tolerant voltage equalization charging effect diagram provided in an embodiment of the present invention; Figure 9 This is a constant current real-time voltage equalization charging curve provided in an embodiment of the present invention; Figure 10 This is a constant current fault-tolerant real-time voltage equalization charging curve provided in an embodiment of the present invention. Detailed Implementation

[0017] The principles and spirit of the invention will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are provided merely to enable those skilled in the art to better understand and implement the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided to make the invention more thorough and complete, and to fully convey the scope of the invention to those skilled in the art.

[0018] Those skilled in the art will recognize that embodiments of the present invention can be implemented as a system, apparatus, device, method, or computer program product. Therefore, the present invention can be specifically implemented in the following forms: entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0019] It should be noted that the number of any elements in the accompanying drawings is for illustrative purposes only and not as a limitation, and any naming is for distinction only and has no limiting meaning.

[0020] The following is for reference. Figure 1 , Figure 1 This is a schematic diagram of a structure for an energy management circuit for a retired power battery according to an embodiment of the present invention. Figure 1 As shown, an energy management circuit for retired power batteries includes: Main circuit area, voltage detection area, current detection area, temperature detection area, overvoltage and overcurrent protection area, drive circuit area, control and display area, and power supply regulation area; The main power traces in the main circuit area connect the positive terminal of the battery module to the positive terminal of the load, and the busbars connect the negative terminal of the battery module to the negative terminal of the load. The drive circuit area is equipped with a composite power path structure consisting of a MOSFET and a Schottky diode connected in series, forming a controlled unidirectional energy transfer path. The drain of the MOSFET is connected to the main power trace, the source is connected to the cathode of the Schottky diode, and the anode of the Schottky diode is connected to the positive terminal of the load. This structure utilizes the ultra-fast turn-off characteristics of the Schottky diode to physically suppress uncontrolled reverse discharge and transient current spikes caused by the charge storage effect of the MOSFET body diode between retired power battery modules. The input terminal of the voltage detection area is connected across the positive and negative terminals of the battery module, and the output terminal is connected to the control and display area. The current detection area is connected in series with the main power trace, and the output is connected to the control and display area. The signal terminal of the temperature detection area is connected to the control and display area, and the power supply terminal is connected to the power supply regulation area. The detection input terminal of the overvoltage and overcurrent protection zone is connected to the output terminal of the voltage detection zone or the current detection zone. Its protection output terminal is divided into two paths: one path is connected to the control and display zone for software identification of the protection status; the other path directly or indirectly acts on the MOSFET gate of the drive circuit zone to achieve hardware priority protection. The sampling input terminals of the control and display area are respectively connected to the voltage detection area, current detection area, and temperature detection area; the protection input terminal is connected to the first output of the overvoltage and overcurrent protection area; the drive output terminal is connected to the MOSFET gate of the drive circuit area; and the display interface is connected to the LCD module. The input terminal of the power supply regulation area is connected to an external power source, the reference output terminal is connected to the voltage detection area, and the system power output terminal supplies power to the control and display area and other functional areas.

[0021] The main circuit area of ​​this invention is responsible for transmitting electrical energy from the decommissioned power battery module to the load. Main power traces connect the positive terminal of the battery module to the positive terminal of the load, while busbars connect the negative terminal of the battery module to the negative terminal of the load, ensuring smooth current transmission between the battery and the load. Main power traces are the wires in the circuit used to carry the main current, while busbars are common wires used to connect multiple circuit nodes, typically for current distribution. This design ensures the stability and safety of the current during transmission, while providing a basic current path for other functional areas.

[0022] Specifically, the voltage detection area is used to monitor the voltage state of the battery module in real time. It reduces the high voltage signal from the battery module to a suitable detection range using a first and second voltage divider resistor, and then amplifies and processes the signal using a TL074 operational amplifier. The first and second voltage divider resistors are resistors connected in series in the circuit for voltage division; their values ​​depend on the voltage range of the battery module and the input requirements of the detection circuit. The TL074 operational amplifier is a high-precision amplification device used to further amplify the divided voltage signal for more accurate voltage change detection. The current detection area uses a Hall sensor for current sampling. A Hall sensor is a magnetoelectric conversion device based on the Hall effect that converts current signals into voltage signals, which are then processed by an operational amplifier. The temperature detection area uses a DS18B20 digital temperature sensor for temperature measurement. The DS18B20 is a high-precision digital temperature sensor that can directly output digital signals, facilitating communication with the microcontroller in the control and display area.

[0023] The overvoltage and overcurrent protection zone effectively prevents damage to the battery module under abnormal conditions. This zone uses an LM339 comparator to monitor the output signals of the voltage and current detection zones in real time. When the detected voltage or current exceeds a preset safety threshold, the LM339 comparator triggers an optocoupler. Its output is sent to the control and display area for status recording and display, and can also be directly or indirectly driven to the MOSFET gate for rapid hardware protection disconnection. This dual-channel protection mechanism, prioritizing hardware protection and supplementing it with software monitoring, significantly improves the system's safety and reliability in the event of control unit malfunctions. Furthermore, the gate resistor and gate capacitor connected in parallel between the MOSFET gate and source in the drive circuit area stabilize the MOSFET's switching characteristics, preventing malfunctions and further enhancing system reliability.

[0024] In some embodiments, the driving circuit area includes a TLP250 optocoupler driver, a MOSFET, and a Schottky diode; the positive input of the TLP250 is connected to the driving output terminal of the control and display area, the negative input is connected to digital ground, the positive output is connected to the gate of the MOSFET, and the negative output is connected to digital ground; the drain of the MOSFET is connected to the main power trace, the source is connected to the cathode of the Schottky diode, and the anode of the Schottky diode is connected to the positive terminal of the load.

[0025] The drive circuit area achieves unidirectional controllable current transmission through a controlled power path structure formed by a TLP250 optocoupler driver, a MOSFET, and a Schottky diode connected in series. The TLP250 optocoupler driver is an opto-isolating device that isolates the control signal from the main power circuit, ensuring system safety and reliability. The MOSFET, as a power path structure device, features low on-resistance and fast switching characteristics, enabling efficient control of current flow. The Schottky diode, with its low forward voltage drop and fast recovery characteristics, works in conjunction with the MOSFET to effectively block reverse current surges from the load or other modules during turn-off. This core structure, formed by the series connection of these two components, transforms the traditional bidirectional energy path into a controlled unidirectional path, fundamentally suppressing the uncontrolled energy backflow problem caused by battery module inconsistencies.

[0026] Specifically, the positive input of the TLP250 optocoupler driver is connected to the drive output of the control and display area to receive control signals from the microcontroller, and the negative input is connected to digital ground to provide a reference level. The positive output is connected to the MOSFET gate to control the MOSFET's switching state, and the negative output is connected to digital ground. The drain of the MOSFET is connected to the main power trace, the source is connected to the cathode of a Schottky diode, and the anode of the Schottky diode is connected to the positive terminal of the load. This connection method ensures that current flows smoothly to the load only when the MOSFET is on and in the positive direction, and reliably prevents reverse current when the MOSFET is off due to the unidirectional conductivity of the Schottky diode. The gate resistor and gate capacitor connected in parallel between the MOSFET gate and source are used to stabilize the switching characteristics of the MOSFET and prevent malfunctions caused by electromagnetic interference or signal jitter.

[0027] The gate resistor value can be adjusted according to the MOSFET's switching speed and the characteristics of the drive circuit, typically ranging from tens to hundreds of ohms, to ensure the MOSFET can switch states quickly and stably. The gate capacitor value is selected based on the MOSFET's gate drive voltage and switching frequency, generally ranging from hundreds of picofarads to several nanofarads, used to smooth the gate voltage and reduce voltage spikes during switching. Furthermore, the reverse recovery time of the Schottky diode should be as short as possible to minimize the impact of reverse current on the circuit. In practical applications, appropriate MOSFET and Schottky diode models can be selected based on the voltage level and current capacity of the retired power battery to ensure the drive circuit operates in a highly efficient and safe manner.

[0028] In some embodiments, the overvoltage and overcurrent protection zone includes a comparator and an optocoupler isolator, with its output divided into two paths: one path is connected to the protection input of the control and display area for software identification of the protection status; the other path directly or indirectly acts on the MOSFET gate of the drive circuit area for hardware priority to cut off the power path in abnormal conditions.

[0029] In this invention, the overvoltage and overcurrent protection zone employs a dual-channel decision mechanism combining hardware protection and software monitoring. The core comparator in this zone (such as the LM339) monitors signals from the voltage or current detection zone in real time. When the detected value exceeds a preset threshold, the comparator output changes. This changed signal is electrically isolated by an optocoupler and then processed through two independent channels. The first signal is sent to the GPIO pin of the microcontroller in the control and display area for the software program to identify and record the fault status and potentially trigger an alarm display. The crucial second protection signal is designed to act directly or indirectly, through a simple NOT gate or driver circuit, on the gate or enable terminal of the MOSFET in the driver circuit area. This design ensures that even in the event of software anomalies such as microcontroller program crashes, freezes, or communication failures, the hardware protection circuit can still independently and quickly cut off the main power path, prioritizing the protection of the battery module and greatly enhancing the system's robustness under extreme conditions.

[0030] In some embodiments, the VCC pin of the TLP250 is connected to the positive terminal of the system power supply in the power supply regulation area, and the GND pin is connected to the digital ground; a gate resistor and a gate capacitor are connected in parallel between the gate and source of the MOSFET, one end of the gate resistor is connected to the positive output of the TLP250, and the other end is connected to the gate of the MOSFET, and one end of the gate capacitor is connected to the gate of the MOSFET, and the other end is connected to the source of the MOSFET.

[0031] In this invention, the gate resistor and gate capacitor connected in parallel between the MOSFET gate and source in the drive circuit region are key components for optimizing MOSFET switching performance. The gate resistor limits the gate charging current, prevents gate voltage overshoot and oscillation, thereby protecting the MOSFET gate oxide layer from damage and suppressing high-frequency switching noise. The gate capacitor absorbs voltage spikes in the gate circuit, smooths the gate drive waveform, and improves the stability of the switching process. This design effectively improves the MOSFET's switching characteristics, reduces electromagnetic interference (EMI) during switching, and ensures reliable operation of the drive circuit region under frequent on / off conditions.

[0032] Specifically, one end of the gate resistor is connected to the positive output terminal of the TLP250 optocoupler driver, and the other end is connected to the gate of the MOSFET. Its resistance value is typically selected based on the MOSFET's gate charge, drive voltage, and desired switching speed. One end of the gate capacitor is connected to the MOSFET's gate, and the other end is connected to the MOSFET's source. Its capacitance value is adjusted based on parasitic inductance caused by circuit layout, switching frequency, and EMI requirements. The gate resistor value is generally between a few ohms and several hundred ohms, used to balance fast switching with oscillation suppression; the gate capacitor value is typically between several hundred picofarads and several nanofarads, used to filter high-frequency interference. These parameters need to be optimized based on specific circuit operating conditions, MOSFET model, and system reliability requirements to ensure that the power path structure responds quickly to control signals while operating stably and reliably.

[0033] In some embodiments, the voltage detection area includes a first voltage divider resistor, a second voltage divider resistor, and a TL074 operational amplifier; one end of the first voltage divider resistor is connected to the positive terminal of the battery module, and the other end is connected to one end of the second voltage divider resistor, and the other end of the second voltage divider resistor is connected to the negative terminal of the battery module; the connection point of the two voltage divider resistors is connected to the non-inverting input terminal of the TL074, the output terminal of the TL074 is connected to the ADC input terminal of the control and display area, the positive power supply terminal of the TL074 is connected to the reference output terminal of the power supply regulation area, and the negative power supply terminal is connected to analog ground.

[0034] The voltage detection area is a crucial component for real-time monitoring of the voltage status of retired power battery modules. It achieves high-precision voltage sampling and signal conditioning through a voltage divider circuit and an operational amplifier. Specifically, the first and second voltage divider resistors form a voltage divider network, reducing the high voltage signal from the battery module to a suitable detection range. The TL074 operational amplifier further amplifies and processes the divided voltage signal, ensuring accurate acquisition by the microcontroller in the control and display area.

[0035] Specifically, one end of the first voltage divider resistor is connected to the positive terminal of the battery module, and the other end is connected to one end of the second voltage divider resistor. The other end of the second voltage divider resistor is connected to the negative terminal of the battery module. The connection point of the two voltage divider resistors serves as the sampling point and is connected to the non-inverting input of the TL074 operational amplifier. The output of the TL074 is connected to the ADC input of the control and display area to transmit the processed voltage signal to the microcontroller for further processing. The positive power supply terminal of the TL074 is connected to the reference output of the power supply regulation area to provide a stable power supply voltage, while the negative power supply terminal is connected to analog ground to provide a stable reference level. The resistance value of the voltage divider resistor needs to be calculated based on the voltage range of the battery module and the input requirements of the operational amplifier to ensure that the voltage signal after voltage division is within the input range of the operational amplifier. For example, if the voltage of the battery module is 12V and the input range of the operational amplifier is 0-5V, then a suitable resistance value of the voltage divider resistor needs to be selected through calculation so that the voltage after voltage division is below 5V.

[0036] In some embodiments, the current detection area includes a Hall sensor, a first operational amplifier, and a second operational amplifier; the Hall sensor is routed through the main power trace, the positive output terminal of the Hall sensor is connected to the inverting input terminal of the first operational amplifier via a first gain resistor, and the negative output terminal is connected to the non-inverting input terminal of the first operational amplifier; the output terminal of the first operational amplifier is connected to the inverting input terminal of the second operational amplifier via a second gain resistor, the non-inverting input terminal of the second operational amplifier is connected to analog ground, and the output terminal of the second operational amplifier is connected to the ADC input terminal of the control and display area.

[0037] The current detection area is a crucial component for real-time monitoring of the current state of retired power battery modules. It utilizes a Hall sensor and a two-stage operational amplifier to achieve high-precision current sampling and signal conditioning. The Hall sensor is a magnetoelectric conversion device based on the Hall effect, capable of converting current signals into voltage signals. The two-stage operational amplifier amplifies and processes the weak signal output from the Hall sensor, ensuring accurate acquisition by the microcontroller in the control and display area. This design effectively improves the accuracy and stability of current detection, providing a reliable basis for assessing the battery's health status.

[0038] Specifically, the Hall sensor is routed through the main power trace and senses current by detecting changes in the magnetic field around the trace. The positive output of the Hall sensor is connected to the inverting input of the first operational amplifier via a first gain resistor, and the negative output is connected to the non-inverting input of the first operational amplifier. The output of the first operational amplifier is connected to the inverting input of the second operational amplifier via a second gain resistor. The non-inverting input of the second operational amplifier is connected to analog ground, and finally, the output of the second operational amplifier is connected to the ADC input of the control and display area. The first and second gain resistors are used to set the gain of the operational amplifier, ensuring that the weak signal output from the Hall sensor can be effectively amplified to a range suitable for ADC acquisition. For example, if the output voltage range of the Hall sensor is 0-100mV, while the input range of the ADC is 0-5V, then a suitable gain resistor value needs to be calculated and selected so that the amplified signal is within the ADC's input range.

[0039] In some embodiments, the temperature detection area includes a DS18B20 digital temperature sensor and a pull-up resistor; the VDD pin of the DS18B20 is connected to the positive terminal of the system power supply in the power supply regulation area, the DQ pin is connected to the GPIO pin in the control and display area, and the GND pin is connected to the analog ground; one end of the pull-up resistor is connected to the DQ pin of the DS18B20, and the other end is connected to the positive terminal of the system power supply.

[0040] The temperature detection area utilizes the DS18B20 digital temperature sensor for high-precision temperature measurement. The DS18B20 is a single-bus digital temperature sensor capable of directly outputting digital temperature signals, communicating with the microcontroller in the control and display area to achieve real-time temperature data acquisition and processing. This design effectively improves the accuracy and stability of temperature detection, providing a reliable basis for battery health status assessment. Furthermore, temperature monitoring helps prevent safety issues caused by battery overheating.

[0041] The VDD pin of the DS18B20 is connected to the positive terminal of the system power supply in the power regulation area, providing a stable power voltage. The DQ pin is connected to the GPIO pin in the control and display area for data communication with the microcontroller. The GND pin is connected to analog ground, providing a reference level. One end of the pull-up resistor is connected to the DQ pin of the DS18B20, and the other end is connected to the positive terminal of the system power supply to ensure stable signal transmission. The DS18B20 communicates with the microcontroller via a single-bus protocol. The microcontroller sends temperature read commands to the DS18B20 through GPIO pins, and the DS18B20 returns the measured temperature data to the microcontroller in the form of a digital signal. The DS18B20's measurement range is typically -55℃ to +125℃, with an accuracy of ±0.5℃, which meets the requirements for temperature monitoring of retired power batteries.

[0042] In some embodiments, the overvoltage and overcurrent protection zone includes an LM339 comparator and an optocoupler isolator; the non-inverting input of the LM339 is connected to a reference voltage divider network, and the inverting input is connected to the output of the TL074 voltage detection area or the output of the second operational amplifier in the current detection area; the open-drain output of the LM339 is connected to the cathode of the LED in the optocoupler isolator, the anode of the LED is connected to the positive terminal of the system power supply via a current-limiting resistor, the emitter of the phototransistor in the optocoupler is connected to digital ground, and the collector is connected to the protection input pin of the control and display area and is connected to the positive terminal of the system power supply via a pull-up resistor.

[0043] The overvoltage and overcurrent protection zone utilizes an LM339 comparator and an optocoupler to rapidly detect and protect against abnormal voltage and current conditions. The LM339 comparator monitors the output signal of the voltage or current detection zone in real time and compares it with a preset reference voltage. When the detected signal exceeds a safety threshold, it quickly triggers the optocoupler to cut off the drive circuit, thereby protecting the battery module from overvoltage or overcurrent damage. This design effectively improves the system's safety and reliability, ensuring timely circuit disconnection in abnormal situations to prevent battery damage or safety accidents.

[0044] The non-inverting input of the LM339 comparator is connected to a reference voltage divider network. This network generates a stable reference voltage through resistor division, used to set overvoltage or overcurrent thresholds. The inverting input is connected to the output of the TL074 in the voltage detection section or the output of the second operational amplifier in the current detection section, used to receive real-time voltage or current detection signals. The output of the LM339 uses an open-drain connection and is connected to the cathode of the LED in the optocoupler isolator. The anode of the LED is connected to the positive terminal of the system power supply via a current-limiting resistor to limit the LED current and protect its normal operation. The emitter of the phototransistor in the optocoupler is connected to digital ground, and the collector is connected to the protection input pin of the control and display section, and then connected to the positive terminal of the system power supply via a pull-up resistor, used to convert the optical signal into an electrical signal and transmit it to the microcontroller.

[0045] To further optimize the performance of the overvoltage and overcurrent protection zones, the parameters of the reference voltage divider network can be precisely set. For example, based on the maximum allowable voltage and current of the battery module, a suitable combination of resistor values ​​can be determined experimentally or by calculation to generate an accurate reference voltage. Simultaneously, to improve the response speed of the protection mechanism, a fast-response optocoupler can be selected, and its circuit parameters can be optimized, such as choosing an appropriate current-limiting resistor value, to ensure rapid circuit disconnection under abnormal conditions.

[0046] The protection mechanism can be enhanced through software algorithms. For example, protection logic can be set in the microcontroller. When a protection signal is detected, not only is the drive circuit cut off, but fault information can also be recorded and displayed on the LCD module, providing maintenance personnel with detailed fault information for quick troubleshooting and problem handling. Through these optimization measures, the overvoltage and overcurrent protection zone can more effectively ensure the safe operation of the battery module and improve the reliability and safety of the entire energy management system.

[0047] In some embodiments, the power supply regulation area includes a REF02 reference source and a 7805 regulator; the input terminal of REF02 is connected to the positive terminal of an external power supply, and the output terminal of REF02 is connected to the positive terminal of the power supply of the voltage detection area TL074; the input terminal of 7805 is connected to the positive terminal of an external power supply, and the output terminal of 7805 is connected to the positive terminal of the system power supply of the control and display area; and decoupling capacitors are connected in parallel to ground at the input and output terminals of 7805, respectively.

[0048] The power supply regulation section uses the REF02 reference source and the 7805 regulator to regulate the input power supply, ensuring the stable operation of the entire circuit system. The REF02 reference source provides a high-precision voltage reference, providing a stable reference voltage for analog circuits such as the voltage detection area; the 7805 regulator converts the external power supply into a stable system power supply, providing a stable power supply for digital circuits such as the control and display areas.

[0049] Specifically, the input of the REF02 reference source is connected to the positive terminal of an external power supply, and its output is connected to the positive terminal of the power supply of the TL074 voltage detection area, providing a stable reference voltage for the voltage detection circuit. Similarly, the input of the 7805 regulator is connected to the positive terminal of an external power supply, and its output is connected to the positive terminal of the system power supply in the control and display area, providing a stable 5V power supply for microcontrollers and other digital circuits. To ensure voltage regulation, decoupling capacitors are connected in parallel to ground at both the input and output terminals of the 7805 regulator. These capacitors filter out high-frequency noise and ripple in the power supply, ensuring power purity. The selection of decoupling capacitors is usually determined based on the ripple characteristics of the power supply and the circuit's requirements for power quality. Generally, electrolytic or ceramic capacitors with low ESR (equivalent series resistance) are chosen, with a capacitance range between 10μF and 100μF, to achieve good filtering effects.

[0050] In some embodiments, the control and display area includes a microcontroller and a 12864 LCD module; the ADC input terminal of the microcontroller is connected to the output terminal of the TL074 voltage detection area and the output terminal of the second operational amplifier in the current detection area, respectively; the GPIO pin is connected to the DQ pin of the DS18B20 temperature detection area; the protection input pin is connected to the collector of the phototransistor of the optocoupler isolator in the overvoltage and overcurrent protection area; and the drive output pin is connected to the positive input terminal of the TLP250 in the drive circuit area. The RS pin of the 12864 LCD module is connected to the RC0 pin of the microcontroller, the RW pin is connected to the RC1 pin, the EN pin is connected to the RC2 pin, the data ports D0–D7 are connected to the PORTB0–PORTB7 of the microcontroller, the positive power terminal of the 12864 is connected to the positive power terminal of the system power supply, and the negative power terminal is connected to the digital ground.

[0051] The control and display area includes a microcontroller and a 12864 LCD module. The microcontroller, as the control core, acquires detection signals such as voltage, current, and temperature through its ADC input and communicates with the temperature sensor via GPIO pins. It also receives overvoltage and overcurrent protection signals and controls the switching actions of the drive circuit. The 12864 LCD module displays battery status, alarm information, etc., providing users with an intuitive operating interface. This design integrates detection, control, and display, improving the system's intelligence and user experience.

[0052] Specifically, the microcontroller's ADC input is connected to the output of the TL074 voltage detection area and the output of the second operational amplifier in the current detection area, respectively, to receive amplified and processed voltage and current signals. The GPIO pin is connected to the DQ pin of the DS18B20 temperature detection area to read temperature data. The protection input pin is connected to the collector of the phototransistor in the overvoltage and overcurrent protection optocoupler isolator, to receive protection signals and trigger corresponding protection actions. The drive output pin is connected to the positive input of the TLP250 in the drive circuit area to control the on / off state of the power path structure. The control pins RS, RW, and EN of the 12864 LCD module and the data ports D0-D7 are connected to the corresponding pins of the microcontroller to receive control and data signals for information display. The microcontroller processes and analyzes the collected data through its internal program to determine the status of the battery module and displays relevant information such as voltage, current, temperature, and fault alarms through the LCD module.

[0053] In some embodiments, the PCB adopts a double-sided board structure, with the copper thickness of the main power traces being greater than that of the signal traces. The main circuit area and the drive circuit area are provided with heat dissipation copper foil and connected to the bottom copper foil through multiple vias. The analog ground of the voltage detection area, current detection area, temperature detection area, overvoltage and overcurrent protection area, control and display area, and power supply regulation area is connected to the bus copper foil of the main circuit area through a 0Ω resistor at a single point to form a star ground.

[0054] It should be noted that the PCB design of this invention adopts a double-sided board structure, achieving high-density integration and functional isolation of multiple modules through reasonable layout and routing. This design not only improves the integration of the circuit, but also effectively enhances the performance and reliability of the circuit by optimizing the copper thickness, heat dissipation design, and grounding strategy of the main power and signal traces. The double-sided board structure, while ensuring functional partitioning, reduces costs and simplifies the manufacturing process, making it suitable for large-scale production applications.

[0055] Specifically, the copper thickness of the main power traces is greater than that of the signal traces. Typically, the copper thickness of the main power traces can be set to 35μm or more, while the copper thickness of the signal traces is around 18μm, to meet the requirements of high current transmission and signal integrity. Heat dissipation copper foil with an area ≥200 mm² is installed in both the main circuit area and the drive circuit area, and is connected to the underlying copper foil through multiple vias to enhance heat dissipation. Analog ground is connected to the main circuit area bus copper foil at a single point via a 0Ω resistor, forming a star ground. This grounding method effectively reduces the potential difference between ground wires and lowers electromagnetic interference.

[0056] Figure 2 This is a system overall topology diagram provided according to an embodiment of the present invention. Figure 2 As shown, multiple retired battery modules are connected through the composite power path structure described in this invention. Each module corresponds to a controlled unidirectional power branch consisting of a MOSFET and a Schottky diode connected in series. This topology provides an optimal hardware platform for upper-level control strategies (such as BPWM control strategies), enabling the system to flexibly reconfigure the connection method of the battery modules under different operating conditions.

[0057] Figure 3 (A) and Figure 3 (B) Circuit diagrams of the single-row and array topologies of retired batteries in the static state, respectively. When the system is in the static state, all MOSFETs are off. At this time, due to the forward conduction and reverse cutoff characteristics of Schottky diodes, a closed current loop cannot be formed between the retired battery modules. This physical characteristic fundamentally eliminates uncontrolled energy flow caused by voltage inconsistency between modules, that is, modules with higher voltage cannot discharge to modules with lower voltage, avoiding self-loss phenomena, and also effectively isolating short-circuit faults that may occur between adjacent or phase-to-phase modules.

[0058] Figure 4 (A) and Figure 4 (B) illustrates the self-reconfiguration charging process of a retired battery cell. For example... Figure 4 As shown in (A), when the system is connected to a constant current source and begins charging, the microcontroller in the control and display area has not yet issued a drive signal, and all MOSFETs are in the off state. Figure 4As shown in (B), under the control of a microcontroller, the system can dynamically adjust the switching sequence of the MOSFETs according to the voltage status of each module to achieve voltage balancing or eliminate faulty batteries. When the voltage of a certain module reaches its rated value, its corresponding MOSFET is turned off, and the module is automatically bypassed from the charging path through the reverse blocking characteristic of the Schottky diode, while the other modules continue to charge. This self-reconfigurable charging method effectively prevents the risk of overvoltage.

[0059] Figure 5 (A) and Figure 5 (B) illustrates the self-reconfiguration discharge process. For example... Figure 5 As shown in (A), all MOSFETs are off in the initial state of the system. When discharge is required, as... Figure 5 As shown in (B), the microcontroller sends a drive signal and simultaneously closes the MOSFET of the corresponding branch. The modules are connected in series or parallel to discharge the load (resistor R). During this process, the Schottky diode, due to its extremely low forward voltage drop, generates almost no additional power consumption, ensuring discharge efficiency.

[0060] To further verify the technical effect of the present invention, KAMCAP supercapacitor modules (capacity 16F, rated voltage 16V, maximum charging current 11A, equivalent series internal resistance 90mΩ) were selected for the experiment. The initial parameters of the three modules were set to 14.4F / 0V, 15F / 0.7V, and 17F / 0.1V, respectively, and charged with a constant current of 2A. Figure 6 Voltage versus time curves under constant 2A charging conditions. From Figure 6 As can be clearly seen, due to the initial capacity and voltage variations, the second module was fully charged to 16V at 117.89s, while the first and third modules had voltages of 15.94V and 13.60V respectively, not yet reaching their rated values. If the traditional charging method is used to continue charging, the second module will face the risk of overvoltage; if charging is stopped, the first and third modules will not be fully charged, resulting in low system utilization.

[0061] This invention proposes multiple working modes for the diverse application scenarios of retired batteries. Figure 7 The constant current voltage equalization charging curve in backup power mode is shown. In this mode, the system does not need to achieve real-time voltage equalization, but prioritizes ensuring that each module is safely and fully charged. Figure 7 As shown, after the second group of modules is fully charged at 117.89s, the system controls its corresponding MOSFET to turn off, physically isolating it from the charging circuit using the reverse blocking characteristic of the Schottky diode. The first and third groups of modules continue charging. Finally, at 137.00s, the voltage of all three groups of modules reaches the rated value of 16V. No overvoltage, undervoltage, or module abnormalities occurred during the entire charging process. This mode is suitable for scenarios such as energy storage power stations and backup power supplies where real-time balancing requirements are not high but full utilization of capacity is necessary.

[0062] Figure 8 The diagram illustrates the effect of constant current fault-tolerant voltage equalization charging. Assuming that at 85 seconds, the second module experiences an anomaly (such as an internal short circuit or voltage drop), the system quickly identifies the fault through its detection circuit and immediately shuts down the corresponding MOSFET, physically removing it using the reverse blocking characteristic of a Schottky diode. The remaining modules continue charging until they reach their rated voltage. The entire process does not affect the normal charging of other modules, achieving fault-tolerant voltage equalization charging.

[0063] Figure 9 The charging curve in real-time voltage balancing mode is shown. This mode is suitable for microgrids and other applications requiring frequent charging and discharging with high randomness. In each control cycle, the system detects the voltage of each module and pauses charging for the module with the highest voltage (i.e., shuts off its corresponding MOSFET). Figure 9 As shown, this method can quickly achieve voltage equalization in the early stages of charging. Although the total charging time (184.04s) is slightly longer than that of the non-real-time mode, it effectively prevents any module from overcharging and ensures the safe operation of the system under complex working conditions.

[0064] Figure 10 The constant current fault-tolerant real-time voltage equalization charging curve is shown, which combines real-time balancing with fault-tolerant control. Rapid voltage equalization is achieved in the early stages of charging; at 136.99s, the second module malfunctioned, and the system immediately removed it, while the remaining two modules continued charging, finally reaching the rated voltage at 200.40s. Figure 10 It can be observed that as the number of modules decreases, the charging slope decreases slightly, but the entire charging process remains stable and controllable.

[0065] To demonstrate the superiority of the composite power path structure of this invention from a mechanistic perspective, PSIM simulations were conducted under harsh operating conditions including a 50nH parasitic inductance. Three topologies were compared: Scheme 1, a diode and a Schottky diode in series (without active control); Scheme 2, a MOSFET and a Schottky diode in series according to this invention; and Scheme 3, a traditional single diode. Simulation results show that the traditional diode scheme (Scheme 3) generates a peak reverse surge current as high as -1.78A and a convergence time as long as 3.82 microseconds, exhibiting the most severe impact and easily damaging the device. While the diode and Schottky diode series scheme (Scheme 1) can suppress the reverse surge current to -0.45A and shorten the convergence time to 1.41 microseconds, demonstrating good suppression, this scheme lacks active control capability. In contrast, the MOSFET and Schottky diode series scheme of this invention (Scheme 2) retains the flexibility of active control while suppressing the peak reverse surge current to -0.60A, a reduction of over 66% compared to the traditional scheme, with a convergence time of only 2.04 microseconds. This data fully demonstrates that the composite power path structure proposed in this invention utilizes the ultrafast reverse recovery characteristics of Schottky diodes to effectively shield the charge storage effect of MOSFET body diodes at the physical level, achieving optimal suppression of transient inrush current and inductive overvoltage spikes. It is the optimal solution that balances safety and control flexibility.

[0066] In one specific embodiment of the present invention, the PCB layout was optimized. The PCB adopts a double-sided board structure, with the copper thickness of the main power traces being greater than that of the signal traces. The main circuit area and the drive circuit area are provided with heat dissipation copper foil and connected to the bottom copper foil through multiple vias. The analog ground of the voltage detection area, current detection area, temperature detection area, overvoltage and overcurrent protection area, control and display area, and power supply regulation area is connected to the bus copper foil of the main circuit area through a 0Ω resistor at a single point to form a star ground.

[0067] It should be noted that the PCB design of this invention adopts a double-sided board structure, achieving high-density integration and functional isolation of multiple modules through reasonable layout and routing. This design not only improves the integration of the circuit, but also effectively enhances the performance and reliability of the circuit by optimizing the copper thickness, heat dissipation design, and grounding strategy of the main power and signal traces. The double-sided board structure, while ensuring functional partitioning, reduces costs and simplifies the manufacturing process, making it suitable for large-scale production applications.

[0068] Specifically, the copper thickness of the main power traces is greater than that of the signal traces. Typically, the copper thickness of the main power traces can be set to 35μm or more, while the copper thickness of the signal traces is around 18μm, to meet the requirements of high current transmission and signal integrity. Heat dissipation copper foil with an area ≥200 mm² is installed in both the main circuit area and the drive circuit area, and is connected to the underlying copper foil through multiple vias to enhance heat dissipation. Analog ground is connected to the main circuit area bus copper foil at a single point via a 0Ω resistor, forming a star ground. This grounding method effectively reduces the potential difference between ground wires and lowers electromagnetic interference.

[0069] The above description is merely an explanation of some preferred embodiments of the present invention and the technical principles employed. Those skilled in the art should understand that the scope of the invention as described in the embodiments of the present invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of the present invention.

Claims

1. An energy management circuit for retired power batteries, characterized in that, include: In the main circuit area, the main power lines connect the positive terminal of the battery module to the positive terminal of the load, and the busbars connect the negative terminal of the battery module to the negative terminal of the load. The driving circuit area is provided with a composite power path structure consisting of a MOSFET and a Schottky diode. The drain of the MOSFET is connected to the main power line, the source is connected to the cathode of the Schottky diode, and the anode of the Schottky diode is connected to the positive terminal of the load, forming a controlled unidirectional energy transmission path. The ultra-fast recovery characteristics of the Schottky diode are used to physically shield the charge storage effect of the MOSFET body diode, suppressing the reverse recovery current and inductive overvoltage spikes generated by switching transients. The voltage detection area, current detection area, and temperature detection area are used to sample the voltage, current, and temperature signals of the battery module, respectively, and output them to the control and display area. Overvoltage and overcurrent protection zones are used to receive voltage or current detection signals and output hardware protection signals when the voltage or current exceeds a preset threshold. The control and display area is used to receive various detection signals and protection signals, and output control signals to the drive circuit area to control the on / off state of the power path structure; The power supply regulation area is used to provide stable power to each functional area.

2. The energy management circuit according to claim 1, characterized in that, The overvoltage and overcurrent protection zone includes a comparator and an optocoupler isolator. Its output is divided into two paths: one path is connected to the protection input of the control and display area for software to identify the protection status; the other path directly or indirectly acts on the MOSFET gate of the drive circuit area for hardware to preferentially cut off the power path in abnormal conditions.

3. The energy management circuit according to claim 2, characterized in that, The driving circuit area also includes an optocoupler driving chip, whose input terminal is connected to the control and display area and whose output terminal is connected to the MOSFET gate; a gate resistor and a gate capacitor are connected in parallel between the MOSFET gate and the source to stabilize the switching characteristics.

4. The energy management circuit according to claim 1, characterized in that, The voltage detection area includes a first voltage divider resistor, a second voltage divider resistor, and a TL074 operational amplifier. One end of the first voltage divider resistor is connected to the positive terminal of the battery module, and the other end is connected to one end of the second voltage divider resistor. The other end of the second voltage divider resistor is connected to the negative terminal of the battery module. The connection point of the two voltage divider resistors is connected to the non-inverting input terminal of the TL074. The output terminal of the TL074 is connected to the ADC input terminal of the control and display area. The positive power supply terminal of the TL074 is connected to the reference output terminal of the power supply regulation area, and the negative power supply terminal is connected to analog ground.

5. The energy management circuit according to claim 1, characterized in that, The current detection area includes a Hall sensor, a first operational amplifier, and a second operational amplifier. The Hall sensor is routed through the main power trace. The positive output terminal of the Hall sensor is connected to the inverting input terminal of the first operational amplifier via a first gain resistor, and the negative output terminal is connected to the non-inverting input terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the inverting input terminal of the second operational amplifier via a second gain resistor. The non-inverting input terminal of the second operational amplifier is connected to analog ground, and the output terminal of the second operational amplifier is connected to the ADC input terminal of the control and display area.

6. The energy management circuit according to claim 1, characterized in that, The temperature detection area includes a DS18B20 digital temperature sensor and a pull-up resistor; the VDD pin of the DS18B20 is connected to the positive terminal of the system power supply in the power supply regulation area, the DQ pin is connected to the GPIO pin in the control and display area, and the GND pin is connected to the analog ground; one end of the pull-up resistor is connected to the DQ pin of the DS18B20, and the other end is connected to the positive terminal of the system power supply.

7. The energy management circuit according to claim 1, characterized in that, The overvoltage and overcurrent protection zone includes an LM339 comparator and an optocoupler isolator. The non-inverting input of the LM339 is connected to the reference voltage divider network, and the inverting input is connected to the output of the TL074 voltage detection area or the output of the second operational amplifier in the current detection area. The open-drain output of the LM339 is connected to the cathode of the LED in the optocoupler isolator. The anode of the LED is connected to the positive terminal of the system power supply via a current-limiting resistor. The emitter of the phototransistor in the optocoupler is connected to digital ground, and the collector is connected to the protection input pin of the control and display area and connected to the positive terminal of the system power supply via a pull-up resistor.

8. The energy management circuit according to claim 1, characterized in that, The power supply regulation area includes the REF02 reference source and the 7805 regulator; the input of the REF02 is connected to the positive terminal of the external power supply, and the output of the REF02 is connected to the positive terminal of the power supply of the TL074 voltage detection area; the input of the 7805 is connected to the positive terminal of the external power supply, and the output of the 7805 is connected to the positive terminal of the system power supply of the control and display area. Decoupling capacitors are connected in parallel to ground at both the input and output terminals of the 7805.

9. The energy management circuit according to claim 1, characterized in that, The control and display area includes a microcontroller and a 12864 LCD module. The ADC input of the microcontroller is connected to the output of the TL074 voltage detection area and the output of the second operational amplifier in the current detection area, respectively. The GPIO pin is connected to the DQ pin of the DS18B20 temperature detection area. The protection input pin is connected to the collector of the phototransistor in the optocoupler of the overvoltage and overcurrent protection area. The drive output pin is connected to the positive input of the TLP250 in the drive circuit area. The RS pin of the 12864 LCD module is connected to the RC0 pin of the microcontroller, the RW pin is connected to the RC1 pin, the EN pin is connected to the RC2 pin, the data ports D0–D7 are connected to the PORTB0–PORTB7 of the microcontroller, the positive power supply terminal of the 12864 is connected to the positive power supply of the system, and the negative power supply terminal is connected to the digital ground.

10. The energy management circuit according to any one of claims 1 to 9, characterized in that, The PCB adopts a double-sided board structure, with the copper thickness of the main power traces being greater than that of the signal traces. The main circuit area and the drive circuit area are equipped with heat dissipation copper foil and connected to the bottom copper foil through multiple vias. The analog ground of the voltage detection area, current detection area, temperature detection area, overvoltage and overcurrent protection area, control and display area, and power supply regulation area is connected to the bus copper foil of the main circuit area through a 0Ω resistor at a single point to form a star ground.

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