Voltage balance control system and method suitable for multiple types of batteries

Abstract

The invention relates to the technical field of batteries, and discloses a voltage balance control system suitable for multiple types of batteries, which comprises a system module assembly, the system module assembly comprises a data acquisition module, a comparison module, a generation module and a BPWM control strategy, the data acquisition module acquires charging and discharging current and voltage data of the batteries in real time, and the comparison module is used for comparing the charging and discharging current and voltage data with the BPWM control strategy; the comparison module compares the characteristic curve of the battery with the triangular wave carrier signal, the comparison module is connected with the generation module, and the generation module generates a PWM signal adaptive to the characteristics of the battery. The method can adapt to various different types of energy storage equipment including a super capacitor, a lithium iron phosphate battery, a ternary lithium battery and the like, complex circuit transformation does not need to be carried out aiming at different battery types under a general voltage balancing topological structure, and the problem that a traditional voltage balancing method is poor in adaptability in application of various battery types is effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a voltage balancing control system and method applicable to multiple types of batteries. Background Art

[0002] With the increasing use of renewable energy, batteries and supercapacitors are playing an increasingly important role in energy storage systems. In these applications, efficiently managing and balancing the voltage of battery or supercapacitor modules is crucial to ensuring long-term, stable system operation. In particular, as battery modules undergo operational changes in charge and discharge characteristics, effective voltage balancing technology is essential to ensure that each cell's voltage remains within a reasonable range, thereby preventing overcharging and over-discharging, which could lead to system performance degradation or safety hazards.

[0003] Existing battery voltage balancing technologies mainly fall into two categories: passive balancing and active balancing. Passive balancing consumes excess energy (usually converted into heat) to gradually reduce the voltage difference between batteries. This method is simple to implement and low-cost, but energy efficiency is low, especially in large-capacity battery systems, where energy waste is significant. Active balancing, on the other hand, achieves efficient balancing by transferring excess energy from higher-voltage cells to lower-voltage cells through energy transfer. While active balancing can improve system energy utilization, its circuit design is complex, costly, and requires precise control algorithms and hardware support. Summary of the Invention

[0004] (1) Technical problems solved

[0005] To address the shortcomings of the existing technology, the present invention provides a voltage balancing control system and method applicable to multiple types of batteries. It utilizes the dynamic adjustment of pulse width modulation signals and combines them with the charge and discharge characteristic curves of batteries or supercapacitors to achieve efficient voltage balancing.

[0006] (2) Technical solution

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A voltage balancing control system suitable for multiple types of batteries includes a system module assembly, which includes a data acquisition module, a comparison module, a generation module, and a BPWM control strategy. The data acquisition module collects battery charge and discharge current and voltage data in real time, and the comparison module compares the battery's characteristic curve with a triangular wave carrier signal. The comparison module is connected to the generation module, which generates a PWM signal adapted to the battery characteristics. The BPWM control strategy includes a unified voltage balancing topology and hardware modules. The hardware modules include a voltage detection circuit, a current detection circuit, a temperature detection circuit, a drive circuit, a protection circuit, and a single-chip microcomputer minimum system.

[0009] Furthermore, the voltage detection circuit is implemented using a TL074 operational amplifier, and its specific working principle is as follows:

[0010] 1) Input connection: Input terminals C1+ and C1- are connected to the positive and negative terminals of the supercapacitor module respectively. The first-stage operational amplifier (U10.1) is mainly used to measure the voltage across the battery.

[0011] 2) Voltage Scaling: The voltage at the supercapacitor module terminal is scaled proportionally by the second-stage operational amplifier (U10.2) to achieve voltage regulation.

[0012] 3) Voltage follower: The third-stage operational amplifier (U10.3) implements the voltage follower function to increase the strength of the input signal and ensure that the signal is not lost when it is transmitted to the input port (RA0) of the microcontroller;

[0013] 4) Output signal: The output terminal Uout1 is the voltage signal of the first supercapacitor module, which is sent to the port (RA0) of the microcontroller for further processing;

[0014] 5) Protection design: In order to prevent the microcontroller port from being damaged by excessive voltage, diodes D11 and D12 are set in the circuit as a protection circuit to ensure that the voltage does not exceed the maximum tolerance range of the microcontroller input port.

[0015] On the basis of the above scheme, the current detection circuit is composed of a Hall current sensor, a current-to-voltage conversion circuit, an absolute value circuit and a voltage follower circuit.

[0016] As a further solution of the present invention, the temperature detection circuit uses a DS18B20 temperature sensor for temperature detection, and its specific working principle and connection method are as follows:

[0017] 1) Power connection: Pin 1 and pin 3 of the temperature sensor are connected to ground (GND) and +5V power supply respectively. Pin 2 is connected to the RA4 port of the microcontroller for data transmission.

[0018] Data transmission: Through the RA4 port, the microcontroller communicates with the DS18B20 sensor to read temperature data. The sensor uses a one-wire communication protocol, allowing multiple DS18B20 sensors to communicate with the microcontroller through the same bus, which is efficient and scalable. The microcontroller monitors and processes the temperature changes of the battery module in real time based on the data transmitted by the sensor.

[0019] Furthermore, the driving circuit adopts TLP250 optocoupler isolation driver chip to achieve efficient driving of MOSFET.

[0020] Based on the above solution, the protection circuit is divided into two parts: voltage protection and current protection.

[0021] Furthermore, the single-chip microcomputer minimum system uses a PIC16F877A chip. The minimum system includes a crystal oscillator circuit, a reset circuit, and a program download port. The key circuit includes four buttons, each used to control different functions of the system. The function of each button is as follows:

[0022] 1) Charging control button: used to start and stop the battery charging process;

[0023] 2) Discharge control button: used to start and stop the battery discharge process;

[0024] 3)Balance control button: used to start the battery voltage balancing process;

[0025] 4) Pause button: used to pause the current charging, discharging or equalization operation.

[0026] The present invention also proposes a voltage balancing control method applicable to multiple types of batteries, comprising the following steps:

[0027] 1) Real-time collection of battery charge and discharge current and voltage data;

[0028] 2) Compare the battery's characteristic curve with the triangular wave carrier signal;

[0029] 3) Generate a PWM signal adapted to the battery characteristics based on the comparison result;

[0030] 4) Control the battery charging and discharging process through PWM signal to achieve voltage balance.

[0031] The beneficial effects of the present invention are:

[0032] 1. The present invention can adapt to various types of energy storage devices, including supercapacitors, lithium iron phosphate batteries, and ternary lithium batteries. Under the universal voltage balancing topology, there is no need for complex circuit modifications for different battery types, effectively solving the problem of poor adaptability of traditional voltage balancing methods in applications with multiple battery types.

[0033] 2. The present invention significantly simplifies hardware design and reduces the need for dedicated circuit development, thereby effectively reducing the R&D and manufacturing costs of the equipment. This universal design also reduces the compatibility testing time for different battery types, greatly improving development efficiency.

[0034] 3. This invention monitors the voltage status of each battery cell in real time and dynamically adjusts the charge and discharge process of each battery cell to ensure that it always operates within a safe voltage range. This solution effectively avoids overcharging and over-discharging, not only improving the safety and reliability of system operation, but also extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the hardware topology of a voltage balancing control system suitable for multiple types of batteries proposed in the present invention.

[0036] Figure 2 This is a schematic diagram of the voltage detection circuit structure of a voltage balancing control system applicable to multiple types of batteries proposed by the present invention.

[0037] Figure 3 This is a schematic diagram of the driving circuit structure of a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0038] Figure 4 This is a schematic diagram of the voltage protection circuit structure of a voltage balancing control system applicable to multiple types of batteries proposed by the present invention.

[0039] Figure 5 This is a schematic diagram of the current protection circuit structure of a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0040] Figure 6 This is a schematic diagram of the minimum system structure of a single-chip microcomputer for a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0041] Figure 7 This is a schematic diagram of the comparison structure between the battery charging characteristic curve and the triangular wave carrier signal of a voltage balancing control system applicable to multiple types of batteries proposed by the present invention.

[0042] Figure 8 This is a schematic diagram of the structure of equal-amplitude and unequal-width pulse signals generated by BPWM in a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0043] Figure 9 This is a schematic diagram of the voltage balancing process structure of a voltage balancing control system applicable to multiple types of batteries proposed by the present invention.

[0044] Figure 10This is a schematic diagram of the BPWM simulation wave structure of a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0045] Figure 11 This is a schematic diagram of the voltage simulation structure of three groups of supercapacitor modules of a voltage balancing control system suitable for multiple types of batteries proposed by the present invention.

[0046] Figure 12 This is the voltage balancing simulation waveform of the parallel resistance method. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. It should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", and "set" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0048] Example 1

[0049] Reference Figure 1-12 A voltage balancing control system suitable for multiple types of batteries includes a system module assembly, which includes a data acquisition module, a comparison module, a generation module, and a BPWM control strategy, namely, a pulse width modulation control strategy. The data acquisition module collects the battery's charge and discharge current and voltage data in real time, and the comparison module compares the battery's characteristic curve with a triangular wave carrier signal. The comparison module is connected to the generation module, and the generation module generates a PWM signal adapted to the battery characteristics, namely, a pulse width modulation signal. The triangular wave carrier signal has good symmetry and can accurately match the battery characteristic curve. By generating this pulse width modulation signal, the battery's charge and discharge time can be accurately controlled, and the charge and discharge process can be dynamically adjusted to achieve efficient voltage balancing. This not only effectively avoids the problem of low balancing efficiency caused by signal errors, but also ensures the performance and stability of the battery pack and improves the balancing efficiency of the entire system. The BPWM control strategy includes a unified voltage balancing topology and hardware modules. The hardware modules include a voltage detection circuit, a current detection circuit, a temperature detection circuit, a drive circuit, a protection circuit, and a single-chip minimum system. The hardware topology of the present invention (see Figure 1 b) is in the traditional shunt method (see Figure 1 For battery modules that have been tested and confirmed to have no problems, they will be optimized and improved based on a). Figure 1b), each battery module is connected in series with a switch S, and a switch S is also provided on the far right. This switch S consists of a MOSFET and a parallel Schottky diode. To increase the battery pack voltage, this can be achieved by increasing the number of batteries in series; to increase capacity, the system capacity can be increased by connecting batteries in parallel. The MOSFET mainly acts as a switch, while the parallel Schottky diode effectively reduces the negative impact of the PN junction, significantly improving the reliability and efficiency of the circuit.

[0050] The voltage detection circuit is implemented using the TL074 operational amplifier. The specific working principle is as follows:

[0051] 1) Input connection: Input terminals C1+ and C1- are connected to the positive and negative terminals of the supercapacitor module respectively. The first stage operational amplifier (U10.1) is mainly used to measure the voltage across the battery;

[0052] 2) Voltage Scaling: Since the MCU's voltage detection port supports a maximum of 5V, while the supercapacitor module's voltage can reach 16V, the supercapacitor module's voltage needs to be scaled proportionally. This process is accomplished by the second-stage operational amplifier (U10.2), which is used to achieve voltage regulation.

[0053] 3) Voltage follower: To ensure that the signal can be correctly input to the microcontroller, the third-stage operational amplifier (U10.3) implements a voltage follower function to increase the strength of the input signal and ensure that the signal is not lost when it is transmitted to the input port (RA0) of the microcontroller;

[0054] 4) Output signal: The output terminal Uout1 is the voltage signal of the first supercapacitor module, which is sent to the port (RA0) of the microcontroller for further processing;

[0055] 5) Protection design: In order to prevent the voltage from being too high and damaging the port of the microcontroller, diodes D11 and D12 are set in the circuit as a protection circuit to ensure that the voltage does not exceed the maximum tolerance range of the microcontroller input port;

[0056] Since the principles of the voltage detection circuit of each supercapacitor module are exactly the same, the present invention will not repeat the voltage detection circuits of other supercapacitor modules.

[0057] The current detection circuit consists of a Hall current sensor, a current-to-voltage conversion circuit, an absolute value circuit, and a voltage follower circuit. The working principle is as follows:

[0058] 1) Hall Effect Current Sensor (CSM025AY): This Hall Effect Current Sensor is used to detect the battery's charge and discharge currents. Pins 1 and 5 are connected to the battery current input and output, respectively. Pins 2 and 8, 3 and 7, and 4 and 6 are connected. Pins 10 and 9 are connected to ±15V power supplies, providing the necessary voltage for the sensor. Pin 11 outputs the detected current value.

[0059] 2) Current signal conversion and filtering: The current signal (positive and negative values) output by the sensor is connected through pin 3 of U9.1 (TL074 chip). The signal is processed by components R9 and C8 to convert the current signal into a voltage signal and filter it to ensure signal stability.

[0060] 3) Voltage follower and absolute value circuit: Since the current direction changes during the battery charging and discharging process, the current signal output by the Hall sensor may be positive or negative. This circuit converts the current signal into a positive value through the absolute value circuit to ensure that the current value is positive regardless of whether the battery is charging or discharging, which is convenient for subsequent processing. The signal processed by the absolute value circuit is amplified by the voltage follower circuit to ensure that the signal is strong enough to be input into the microcontroller;

[0061] Signal input to the microcontroller: The current signal processed by the voltage follower circuit is input to the RA3 port of the microcontroller for further processing and reading by the microcontroller.

[0062] The temperature detection circuit uses the DS18B20 temperature sensor for temperature detection. Its specific working principle and connection method are as follows:

[0063] 1) Power connection: Pin 1 and pin 3 of the temperature sensor are connected to ground (GND) and +5V power supply respectively. Pin 2 is connected to the RA4 port of the microcontroller for data transmission.

[0064] Data transmission: Through the RA4 port, the microcontroller communicates with the DS18B20 sensor to read temperature data. The sensor uses a one-wire communication protocol, allowing multiple DS18B20 sensors to communicate with the microcontroller through the same bus, which is efficient and scalable. The microcontroller monitors and processes the temperature changes of the battery module in real time based on the data transmitted by the sensor to ensure system safety and operational stability.

[0065] The drive circuit uses the TLP250 optocoupler isolation driver chip to achieve efficient MOSFET driving. Since multiple MOSFETs need to be driven and the principles of each drive circuit are the same, only one drive circuit is used as an example for explanation.

[0066] 1) Pin connection: Pins 1, 4, and 7 of the TLP250 chip remain floating and unconnected; Pin 2 is connected to the RD0 port of the microcontroller to receive the PWM signal output by the microcontroller; Pin 3 is grounded (GND) and consistent with the ground of the microcontroller;

[0067] 2) Power connection: Pin 8 and pin 5 on the right side of the TLP250 chip are connected to the +15V power supply and GND ground respectively;

[0068] To achieve electrical isolation between the input and output sides of the driver chip, a Jinshengyang 15V / 15V isolated power module is used to provide independent power supplies for VSS and GND, effectively reducing electromagnetic interference and improving system stability and reliability.

[0069] 3) Signal Transmission and MOSFET Driving: Pin 6 of the TLP250 chip is connected to the gate (G) of the MOSFET through a 25KΩ resistor to control the MOSFET's switching operation. The gate of the MOSFET is also connected to pin 5 of the driver chip and to GND through a 4.7V voltage regulator to ensure the voltage stability of the drive signal. The PWM signal output by the microcontroller is processed by the TLP250 chip to precisely control the on and off of the MOSFET, achieving efficient regulation and control of the battery module's charging and discharging process.

[0070] Through the drive circuit design, the present invention can ensure the reliability and response speed of the MOSFET switch, while significantly reducing electromagnetic interference through the isolation design, thereby improving the working efficiency and safety of the system.

[0071] The protection circuit is divided into two parts: voltage protection and current protection. It is mainly used to monitor the working status of the battery in real time and provide necessary protection measures. Since the present invention needs to monitor the voltage of multiple batteries, a set of voltage protection circuits is used as an example here for explanation. The principle is applicable to other circuits.

[0072] Voltage protection circuit:

[0073] 1) Input Signal: The input signal for the voltage protection circuit comes from the output of the final operational amplifier (UA) in the voltage detection circuit. This signal is first connected to the voltage follower circuit via pin 5 of the operational amplifier LM353. After being filtered by resistors and capacitors, it is transmitted to pin 6 of the comparator LM339 via the current-limiting resistor R71 (10kΩ).

[0074] 2) Voltage Comparison: Pin 7 of the LM339 is connected to the power supply Vdd (+5V) to provide a reference voltage. The LM339's main function is to compare the voltage signal detected by UA with a set threshold (Vdd). When the battery voltage exceeds the set threshold, the comparator outputs a high-level signal, indicating an overvoltage condition.

[0075] 3) Signal processing: The overvoltage signal is transmitted from the output of LM339 to the microcontroller. After receiving it, the microcontroller displays the warning message "overvoltage" on the LCD screen and triggers corresponding protection measures to prevent battery overvoltage damage;

[0076] Current protection circuit:

[0077] 1) Input signal: The input signal (I) of the current protection circuit comes from the output of the absolute value circuit in the current detection circuit. After being amplified by the voltage follower circuit composed of the operational amplifier LM353, the signal is processed by the resistor and capacitor filtering circuit to eliminate noise interference and stabilize the signal.

[0078] 2) Current comparison: The processed signal is input to pin 6 of the LM339 comparator and compared with the reference voltage Vdd (+5V). When the current exceeds the set safety threshold, the comparator outputs a high-level signal, indicating an overcurrent condition.

[0079] 3) Signal processing: The overcurrent signal is transmitted to the MCU, which performs logical judgment and displays a warning message "overcurrent" on the LCD screen, prompting the user to take appropriate measures. At the same time, it triggers the system protection action to prevent current overload from damaging the circuit and battery;

[0080] Through the above circuit design, the protection circuit of the present invention realizes real-time monitoring and protection of the battery module voltage and current, and can respond quickly in the event of overvoltage or overcurrent, thereby effectively improving the safety of the battery module and the stability of the system.

[0081] The single-chip microcontroller minimum system uses the PIC16F877A chip. The minimum system includes a crystal oscillator circuit, a reset circuit, and a program download port. The key circuit contains four buttons, each used to control different functions of the system. The function of each button is as follows:

[0082] 1) Charging control button: used to start and stop the battery charging process;

[0083] 2) Discharge control button: used to start and stop the battery discharge process;

[0084] 3)Balance control button: used to start the battery voltage balancing process;

[0085] 4) Pause button: used to pause the current charging, discharging or equalization operation.

[0086] Example 2

[0087] This embodiment differs from the first embodiment in that a general control strategy, BPWM, is also proposed. By converting the battery's charge and discharge characteristic curve into a pulse width modulation (PWM) signal, the battery's charge and discharge process is precisely controlled. This strategy is particularly suitable for voltage balancing control of multiple series battery modules. Although different types of batteries have different charge and discharge characteristic curves, efficient charge and discharge management can be achieved by simply adapting and converting the BPWM signal according to the characteristic curve of the specific battery. A detailed analysis is conducted using a supercapacitor battery as an example. The analysis of the supercapacitor charging characteristic curve is as follows:

[0088] The charging characteristics of a supercapacitor can be expressed as a time function B(t), where the charging current I B(t) and charging voltage V B(t) Both change with time. During the charging process, as time increases, the voltage rises nonlinearly and the current gradually decreases. By analyzing the charging characteristic curve of the supercapacitor, its charging demand can be modeled to provide a theoretical basis for the generation of the BPWM signal. The charging characteristic curve B(t) of the supercapacitor can be expressed as:

[0089]

[0090] Where I0 is the current in the constant current stage, V0 is the voltage in the constant voltage stage, and t1 is the time node for the constant current and constant voltage conversion.

[0091] The BPWM signal generation principle: This invention generates a corresponding PWM signal by superimposing and comparing the battery's charge and discharge characteristic curve with the triangular wave signal in real time, thereby achieving precise control of the battery's charge and discharge. The specific generation principle is as follows:

[0092] a) Real-time comparison between the input battery voltage signal B(t) and the triangular wave signal C(t);

[0093] b) The comparison result is used to generate PWM signals of equal amplitude and unequal width through a comparator;

[0094] c) PWM signal is input to the MOSFET switch tube to control its on and off state in real time;

[0095] d) The on-off state of the MOSFET directly regulates the charge and discharge current of the battery to achieve voltage balance;

[0096] e) The principle of the discharge process is similar to that of the charge process. The difference lies in the adjustment of the target voltage direction, which will not be repeated here.

[0097] The triangle wave carrier signal can be expressed as:

[0098]

[0099] Among them, A is the amplitude of the triangular wave, T is the period, and in natural sampling, the supercapacitor charging characteristic curve B(t) is used as a reference signal and compared with the triangular wave C(t) in real time. Figure 7 The comparison process of the supercapacitor charging characteristic curve and the triangle wave carrier is shown.

[0100] In natural sampling, the supercapacitor charging characteristic curve B(t) is used as a reference signal and compared with the triangular wave carrier C(t) in real time. The intersection points are natural sampling points. A series of PWM signals with equal amplitude and unequal width are generated through these intersection points. When the charging curve B(t) is greater than the triangular wave carrier C(t), the output is high; when the charging curve B(t) is less than or equal to the triangular wave carrier C(t), the output is low. The duty cycle D(t) of the BPWM signal can be calculated by the following formula:

[0101]

[0102] Among them, C max and C min are the maximum and minimum values of the triangle wave respectively, and B(t) is the charging characteristic curve function of the supercapacitor. By controlling the driving circuit through the duty cycle D(t), the switching action of the MOSFET can be adjusted in real time to achieve precise control of the supercapacitor charging process. In the constant current stage, the duty cycle is small and the PWM pulse width is narrow; in the constant voltage stage, the duty cycle gradually increases and the PWM pulse width gradually widens, thereby adapting to the changing characteristics of the supercapacitor charging curve to ensure charging efficiency and balancing effect (see the specific process). Figure 8 ).

[0103] BPWM control strategy: During the supercapacitor series charging process ( Figure 9 A) Due to the dispersion of capacitance, the voltage of capacitors with smaller capacitance increases faster. In constant current charging mode, if effective control is not performed, the capacitor with the smallest capacitance may reach the rated voltage first, and the other capacitors may not be fully charged when charging stops. If charging continues, the capacitor with smaller capacitance may be overcharged, causing damage or even explosion and other safety hazards.

[0104] In order to solve the above problems, the present invention is based on Figure 9 The voltage balancing topology shown in the figure can precisely adjust the capacitor voltage growth rate by controlling the on-off state of the switch S, thereby achieving voltage balancing management. The specific method is: when the voltage of a supercapacitor reaches or approaches the rated voltage ( Figure 9 B) By closing the switch S connected in parallel with it, it is "eliminated" from the series charging supercapacitor to avoid overcharging, while buying charging time for other capacitors and achieving charging balance of the entire system.

[0105] This paper uses three supercapacitors for simulation analysis. Each capacitor has a rated voltage of 16V, and initial voltages of 0V, 0.7V, and 0.1V, respectively. The capacitances vary, at 14.4F, 15F, and 16F. These three supercapacitors are charged via a constant current source (30A) to verify the effectiveness of the BPWM strategy in voltage balancing control.

[0106] Figure 10 The simulation demonstrates the generation of the BPWM signal. The supercapacitor terminal voltage signal (Battery1) is compared in real time with the triangular carrier signal (Carrier) to generate the BPWM1 waveform. As the charging process progresses, the BPWM signal's duty cycle D(t) gradually increases, reflecting the dynamic changes in the capacitor voltage.

[0107] exist Figure 11 At approximately 43 seconds, the voltages of the three series-connected supercapacitor modules approached their rated voltage of 16V. At this point, the switch drive signals all transitioned to a high level, stopping charging in the three supercapacitor modules and achieving voltage balance across the series capacitors. This result demonstrates that the BPWM strategy can effectively control the voltage growth rate of series-connected supercapacitor modules, preventing overcharging and significantly improving the safety and efficiency of the charging process.

[0108] To further verify the performance advantages of the present invention, the following comparative experiment with the traditional parallel resistance method is used to illustrate the above. The experimental conditions are that the voltage of the supercapacitor module is balanced to 16V and the current is 30A. The results are shown in the following table:

[0109] Table 1 Comparison of two solutions

[0110]

[0111] The parallel resistance method takes 47 seconds to equalize, where U1, U2, and U3 represent the battery voltages of the three battery modules. Calculations show that the parallel resistance loss is as high as 479.97W, while the solution of the present invention only takes 43 seconds, with a power loss of 7.83W, significantly improving efficiency. For the simulation waveform of the parallel resistance method, see Figure 12 , showing that its voltage increases slowly.

[0112] The results show that the scheme of the present invention shortens the voltage balancing time by about 8.5% and reduces the power loss by about 98.4%, which is significantly better than the traditional parallel resistance method.

[0113] Application analysis of supercapacitors and lithium batteries: Supercapacitors and lithium batteries have significant differences in charge and discharge characteristics, but through the flexible regulation of BPWM strategy, they can be compatible with the charge and discharge requirements of different types of batteries.

[0114] 1) Supercapacitors: Supercapacitors have high power density and short charge-discharge cycles. During charging, the voltage changes rapidly, which, if not controlled, can lead to performance degradation or even damage. This invention uses a BPWM strategy to adjust the duty cycle and frequency of the PWM signal, precisely controlling the voltage change rate and ensuring an efficient and safe charging process.

[0115] 2) Lithium Batteries: Lithium batteries have a high energy density and a relatively smooth discharge process. The BPWM strategy optimizes the modulation parameters of the PWM signal to make the charging process of lithium batteries more stable, effectively utilizing the battery's energy storage capacity while avoiding excessive voltage fluctuations that affect battery life.

[0116] Example 3

[0117] Reference Figure 1-12 A voltage balancing control system suitable for multiple types of batteries includes a system module assembly, which includes a data acquisition module, a comparison module, a generation module and a BPWM control strategy.

[0118] The data acquisition module collects the battery's charge and discharge current and voltage data in real time, and extracts characteristic curves reflecting the battery status, such as the voltage-time curve, by analyzing and processing the collected data, providing a basis for subsequent signal comparison.

[0119] The comparison module compares the battery characteristic curve extracted by the data acquisition module with the preset triangular wave carrier signal in real time. Its specific comparison logic is: when the battery characteristic curve value is greater than the triangular wave carrier signal value, it outputs a high level; when the battery characteristic curve value is less than or equal to the triangular wave carrier signal value, it outputs a low level, thereby forming a digital signal sequence reflecting the battery status.

[0120] The generation module generates a PWM signal tailored to the battery's characteristics based on the comparison results from the comparison module. Specifically, by analyzing the duration and switching frequency of the high and low levels in the comparison results, it determines the duty cycle and period of the PWM signal, thereby dynamically adjusting the battery voltage balance.

[0121] The BPWM control strategy includes a unified voltage-balancing topology and hardware modules. The hardware modules consist of a voltage detection circuit, a current detection circuit, a temperature detection circuit, a drive circuit, a protection circuit, and a single-chip microcomputer minimum system to support data acquisition, signal processing, and control execution. Furthermore, the voltage detection circuit is implemented using a TL074 operational amplifier, and its specific operating principle is as follows:

[0122] 1) Input connection: Input terminals C1+ and C1- are connected to the positive and negative terminals of the supercapacitor module respectively. The first-stage operational amplifier (U10.1) is mainly used to measure the voltage across the battery.

[0123] 2) Voltage Scaling: The voltage at the supercapacitor module terminal is scaled proportionally by the second-stage operational amplifier (U10.2) to achieve voltage regulation.

[0124] 3) Voltage follower: The third-stage operational amplifier (U10.3) implements the voltage follower function to increase the strength of the input signal and ensure that the signal is not lost when it is transmitted to the input port (RA0) of the microcontroller;

[0125] 4) Output signal: The output terminal Uout1 is the voltage signal of the first supercapacitor module, which is sent to the port (RA0) of the microcontroller for further processing;

[0126] 5) Protection design: In order to prevent the microcontroller port from being damaged by excessive voltage, diodes D11 and D12 are set in the circuit as a protection circuit to ensure that the voltage does not exceed the maximum tolerance range of the microcontroller input port.

[0127] On the basis of the above scheme, the current detection circuit is composed of a Hall current sensor, a current-to-voltage conversion circuit, an absolute value circuit and a voltage follower circuit.

[0128] As a further solution of the present invention, the temperature detection circuit uses a DS18B20 temperature sensor for temperature detection, and its specific working principle and connection method are as follows:

[0129] 1) Power connection: Pin 1 and pin 3 of the temperature sensor are connected to ground (GND) and +5V power supply respectively. Pin 2 is connected to the RA4 port of the microcontroller for data transmission.

[0130] Data transmission: Through the RA4 port, the microcontroller communicates with the DS18B20 sensor to read temperature data. The sensor uses a one-wire communication protocol, allowing multiple DS18B20 sensors to communicate with the microcontroller through the same bus, which is efficient and scalable. The microcontroller monitors and processes the temperature changes of the battery module in real time based on the data transmitted by the sensor.

[0131] The drive circuit uses the TLP250 optocoupler isolation driver chip to achieve efficient MOSFET driving. The protection circuit is divided into two parts: voltage protection and current protection. The single-chip microcomputer minimum system uses the PIC16F877A chip. The minimum system includes a crystal oscillator circuit, a reset circuit, and a program download port. The key circuit contains 4 buttons, which are used to control different functions of the system. The function of each button is as follows:

[0132] 1) Charging control button: used to start and stop the battery charging process;

[0133] 2) Discharge control button: used to start and stop the battery discharge process;

[0134] 3)Balance control button: used to start the battery voltage balancing process;

[0135] 4) Pause button: used to pause the current charging, discharging or equalization operation.

[0136] The present invention also proposes a voltage balancing control method applicable to multiple types of batteries, comprising the following steps:

[0137] 1) Real-time collection of battery charge and discharge current and voltage data;

[0138] 2) Compare the battery's characteristic curve with the triangular wave carrier signal;

[0139] 3) Generate a PWM signal adapted to the battery characteristics based on the comparison result;

[0140] 4) Control the battery charging and discharging process through PWM signal to achieve voltage balance.

[0141] In summary, the BPWM control strategy proposed in this paper can flexibly adjust PWM signal parameters based on battery type, providing customized charge and discharge control solutions for different energy storage devices, such as supercapacitors and lithium batteries. This strategy improves charge and discharge efficiency while effectively ensuring battery safety, adapting to the needs of various energy storage devices in different application scenarios.

[0142] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A voltage balancing control system applicable to multiple types of batteries, comprising a system module assembly, characterized in that: The system module assembly includes a data acquisition module, a comparison module, a generation module, and a BPWM control strategy. The data acquisition module collects the battery's charge and discharge current and voltage data in real time, and the comparison module compares the battery's characteristic curve with a triangular wave carrier signal. The comparison module is connected to the generation module, and the generation module generates a PWM signal that adapts to the battery's characteristics. The BPWM control strategy includes a unified voltage balancing topology and a hardware module. The hardware module includes a voltage detection circuit, a current detection circuit, a temperature detection circuit, a drive circuit, a protection circuit, and a single-chip microcomputer minimum system.

2. A voltage balancing control system applicable to multiple types of batteries according to claim 1, characterized in that: The voltage detection circuit is implemented using the TL074 operational amplifier, and its specific working principle is as follows: 1) Input connection: Input terminals C1+ and C1- are connected to the positive and negative terminals of the supercapacitor module respectively. The first-stage operational amplifier (U10.1) is mainly used to measure the voltage across the battery. 2) Voltage Scaling: The voltage at the supercapacitor module terminal is scaled proportionally by the second-stage operational amplifier (U10.2) to achieve voltage regulation. 3) Voltage follower: The third-stage operational amplifier (U10.3) implements the voltage follower function to increase the strength of the input signal and ensure that the signal is not lost when it is transmitted to the input port (RA0) of the microcontroller; 4) Output signal: The output terminal Uout1 is the voltage signal of the first supercapacitor module, which is sent to the port (RA0) of the microcontroller for further processing; 5) Protection design: In order to prevent the microcontroller port from being damaged by excessive voltage, diodes D11 and D12 are set in the circuit as a protection circuit to ensure that the voltage does not exceed the maximum tolerance range of the microcontroller input port.

3. The voltage balancing control system applicable to multiple types of batteries according to claim 1, characterized in that: The current detection circuit consists of a Hall current sensor, a current-to-voltage conversion circuit, an absolute value circuit and a voltage follower circuit.

4. The voltage balancing control system applicable to multiple types of batteries according to claim 1, characterized in that: The temperature detection circuit uses the DS18B20 temperature sensor for temperature detection. Its specific working principle and connection method are as follows: 1) Power connection: Pin 1 and pin 3 of the temperature sensor are connected to ground (GND) and +5V power supply respectively. Pin 2 is connected to the RA4 port of the microcontroller for data transmission. Data transmission: Through the RA4 port, the microcontroller communicates with the DS18B20 sensor to read temperature data. The sensor uses a one-wire communication protocol, allowing multiple DS18B20 sensors to communicate with the microcontroller through the same bus, which is efficient and scalable. The microcontroller monitors and processes the temperature changes of the battery module in real time based on the data transmitted by the sensor.

5. The voltage balancing control system applicable to multiple types of batteries according to claim 1, characterized in that: The drive circuit uses the TLP250 optocoupler isolation driver chip to achieve efficient driving of the MOSFET.

6. The voltage balancing control system applicable to multiple types of batteries according to claim 5, characterized in that: The protection circuit is divided into two parts: voltage protection and current protection.

7. The voltage balancing control system applicable to multiple types of batteries according to claim 1, characterized in that: The single-chip microcomputer minimum system uses the PIC16F877A chip. The minimum system includes a crystal oscillator circuit, a reset circuit, and a program download port. The key circuit contains four buttons, each used to control different functions of the system. The function of each button is as follows: 1) Charging control button: used to start and stop the battery charging process; 2) Discharge control button: used to start and stop the battery discharge process; 3)Balance control button: used to start the battery voltage balancing process; 4) Pause button: used to pause the current charging, discharging or equalization operation.

8. A voltage balancing control method applicable to multiple types of batteries, characterized in that: The following steps are involved: 1) Real-time collection of battery charge and discharge current and voltage data; 2) Compare the battery's characteristic curve with the triangular wave carrier signal; 3) Generate a PWM signal adapted to the battery characteristics based on the comparison result; 4) Control the battery charging and discharging process through PWM signal to achieve voltage balance.

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