A large-current fast charging supercapacitor voltage equalization power supply system for Linux terminal

Abstract

The application relates to the technical field of backup power supply, in particular to a large-current rapid charging super capacitor voltage equalization power supply system for a Linux terminal. The system comprises a commercial power input module; a step-down constant-current charging module, an input end of which is connected with a first output end of the commercial power input module; a series super capacitor group, an input end of which is connected with an output end of the step-down constant-current charging module, and the series super capacitor group comprises N super capacitors connected in series; a power supply switching module, a first input end of which is connected with a second output end of the commercial power input module, a second input end of the power supply switching module is connected with an output end of the series super capacitor group, and an output end of the power supply switching module is connected with a Linux terminal load; and N single-body voltage equalization modules, one single-body voltage equalization module being connected in parallel with one corresponding super capacitor. The system can realize large-current rapid charging of large-capacity super capacitors, greatly shorten charging time, and realize accurate equalization of voltages of the single-body super capacitors.

Description

Technical Field

[0001] The embodiments in this specification mainly relate to the field of backup power technology, specifically a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals. Background Technology

[0002] Linux terminals, as the core carriers of industrial IoT, data acquisition, and industrial gateways, typically integrate multiple communication modules such as Ethernet, serial ports, 4G / 5G, and WiFi, resulting in high power consumption. In industrial sites and outdoor maintenance scenarios, power outages or voltage fluctuations can easily cause sudden power loss to the terminals, leading to data loss and business interruption. Therefore, it is urgent to equip them with highly reliable backup power systems.

[0003] Supercapacitors, with their advantages of fast charging and discharging speed, long cycle life, wide temperature adaptability, and high reliability, have become the preferred solution for short-term high-power backup power. In practical applications, multiple supercapacitors need to be connected in series to meet the terminal power supply voltage requirements. However, series-connected supercapacitors suffer from uneven voltage among individual cells. If effective voltage equalization is not performed, individual cells are prone to overcharging, premature aging, or even damage, seriously affecting the lifespan and operational safety of the backup power system.

[0004] The current mainstream voltage equalization solution in the industry is the TL431 + resistor passive voltage equalization circuit. It is connected in parallel across the two ends of the supercapacitor cell through the voltage regulation characteristics of the TL431. When the voltage of the cell exceeds the threshold, the TL431 conducts to discharge the excess energy.

[0005] However, this solution has obvious drawbacks: First, the current carrying capacity of TL431 is limited (usually only in the tens of milliamps range), which cannot meet the high-current fast charging requirements of large-capacity supercapacitors, resulting in a significant increase in charging time; Second, TL431 generates a lot of heat under high current conditions, increasing system energy consumption and heat dissipation pressure, and long-term high-load operation is prone to component damage, reducing system reliability; Third, passive voltage equalization cannot achieve dynamic and precise control, resulting in poor voltage equalization consistency and failing to meet high-precision power supply requirements.

[0006] Meanwhile, high-power Linux terminals need to continue running for a period of time after a power outage, which places extremely high demands on the load-carrying capacity and voltage stability of the backup power supply. Traditional voltage equalization circuits can no longer meet the needs of fast charging and the reliability of backup power supply. Therefore, a new type of supercapacitor voltage equalization charging solution is urgently needed to adapt to the application requirements of industrial-grade Linux terminals. Summary of the Invention

[0007] This specification addresses the problems existing in the prior art by proposing a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals. This system solves the problems of insufficient current carrying capacity, inability to perform high-current fast charging, poor voltage equalization accuracy, and severe heat generation in the existing TL431 voltage equalization circuit.

[0008] This specification provides an embodiment of a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals, comprising:

[0009] AC power input module;

[0010] A step-down constant current charging module, the input terminal of which is connected to the first output terminal of the AC power input module;

[0011] A series supercapacitor bank, the input of which is connected to the output of a buck constant current charging module, consists of N supercapacitors connected in series.

[0012] The power switching module has its first input terminal connected to the second output terminal of the mains input module, its second input terminal connected to the output terminal of the series supercapacitor bank, and its output terminal connected to the Linux terminal load.

[0013] There are N individual voltage equalization modules, with each individual voltage equalization module connected in parallel with a corresponding supercapacitor.

[0014] As a preferred embodiment of the present invention, the single-unit voltage equalization module includes:

[0015] The voltage detection chip has its VIN pin connected to the positive terminal of the capacitor, and its GND pin connected to the negative terminal of the capacitor, with the negative terminal of the capacitor grounded.

[0016] The first resistor has its first connection terminal connected to the positive terminal of the capacitor;

[0017] The drain of the MOSFET is connected to the second terminal of the first resistor, the source of the MOSFET is connected to the negative terminal of the capacitor, and the gate of the MOSFET is connected to the OUT pin of the voltage detection chip.

[0018] The second resistor has its first connection terminal connected to the VIN pin of the voltage detection chip, and its second connection terminal connected to the VSEN pin of the voltage detection chip.

[0019] The third resistor has its first connection terminal connected to the VSEN pin of the voltage detection chip, and its second connection terminal connected to the GND pin of the voltage detection chip.

[0020] As a preferred embodiment of the present invention, the MOS transistor is a low on-resistance N-channel MOS transistor.

[0021] In a preferred embodiment of the present invention, the voltage detection chip is provided with a voltage threshold; when the voltage detection chip detects that the voltage of a single capacitor is lower than the voltage threshold, the OUT pin of the voltage detection chip outputs a low level, the MOSFET is turned off, and the capacitor charges normally; when the voltage detection chip detects that the voltage of a single capacitor is greater than or equal to the voltage threshold, the OUT pin of the voltage detection chip outputs a high level, the MOSFET is turned on, and the capacitor stops charging.

[0022] As a preferred embodiment of the present invention, the mains input module is used to convert external 220V AC mains power into high-voltage DC power. The mains input module includes a rectifier unit and a filter unit. The rectifier unit adopts a bridge rectifier circuit, and the filter unit adopts a filter architecture combining electrolytic capacitors and ceramic capacitors.

[0023] As a preferred embodiment of the present invention, the step-down constant current charging module is used to convert high voltage DC power into constant current DC power adapted to the supercapacitor bank. The step-down constant current charging module includes a step-down constant current control chip, which can be configured with a charging current of 3A-10A.

[0024] As a preferred embodiment of the present invention, the step-down constant current control chip is equipped with a MOSFET, a sampling resistor, and an inductor.

[0025] As a preferred embodiment of the present invention, the series supercapacitor bank is composed of N supercapacitors of 2.7V / 3.0V specifications connected in series, and its total voltage is adapted to the power supply requirements of the Linux terminal load.

[0026] As a preferred embodiment of the present invention, the power switching module is used to switch between mains power supply and backup power supply. The power switching module includes a diode chip, which includes a first diode and a second diode. The positive terminal of the first diode is connected to the mains input module and the negative terminal is connected to the Linux terminal load. The positive terminal of the second diode is connected to the series supercapacitor group and the negative terminal is connected to the Linux terminal load.

[0027] As a preferred embodiment of the present invention, the Linux terminal load is a high-power embedded terminal equipped with at least one of the following communication interfaces: network port, serial port, 4G / 5G, and WiFi.

[0028] The beneficial effects of the technical solutions provided in some embodiments of this specification include at least the following:

[0029] 1. Adapted to high-current fast charging: MOSFETs are used instead of traditional TL431s as voltage equalization actuators. MOSFETs have strong current carrying capacity (up to 1A and above) and low on-resistance, solving the problem of insufficient current carrying capacity of TL431. This enables high-current fast charging of large-capacity supercapacitors and significantly shortens charging time.

[0030] 2. High voltage equalization accuracy and high reliability: The voltage detection chip has an acquisition accuracy of ≤±20mV. Combined with the dynamic on / off control of the MOSFET, it can achieve precise voltage equalization of each individual supercapacitor, avoid overcharging / over-discharging of a single cell, and extend the service life of the supercapacitor bank. The heat generation of the MOSFET is much lower than that of the TL431, which reduces system energy consumption and heat dissipation pressure and improves overall operational reliability.

[0031] 3. Seamless switching, adaptable to high-power terminals: The power switching module adopts an ideal diode chip to achieve seamless switching between mains power and backup power without voltage fluctuations; at the same time, the high power density of the series supercapacitor bank can meet the power outage endurance requirements of Linux terminals with multiple communication interfaces and high power consumption, ensuring that data is not lost and services are not interrupted.

[0032] 4. High scalability and wide applicability: The individual voltage equalization module can be flexibly configured according to the number of supercapacitors connected in series to adapt to the terminal requirements of different voltage levels; the overall system architecture is simple and has no complex redundant design, and can be widely used in backup power supply scenarios for various embedded devices such as industrial Linux gateways, edge computing terminals, data acquisition devices, and vehicle communication terminals. Attached Figure Description

[0033] Figure 1 System block diagram of a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals provided in the embodiments of this specification;

[0034] Figure 2 This is a schematic diagram of the single-unit voltage equalization module provided in the embodiments of this specification;

[0035] Figure 3 This is a schematic diagram of a power switching module provided in an embodiment of this specification. Detailed Implementation

[0036] Embodiments of this specification will now be described in more detail with reference to the accompanying drawings.

[0037] Example 1:

[0038] This invention provides a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals, such as... Figure 1 As shown, the system includes:

[0039] AC power input module;

[0040] A step-down constant current charging module, the input terminal of which is connected to the first output terminal of the AC power input module;

[0041] A series supercapacitor bank, the input of which is connected to the output of a step-down constant current charging module, comprises N supercapacitors C connected in series.

[0042] The power switching module has its first input terminal connected to the second output terminal of the mains input module, its second input terminal connected to the output terminal of the series supercapacitor bank, and its output terminal connected to the Linux terminal load.

[0043] There are N individual voltage equalization modules, and each individual voltage equalization module is connected in parallel with a corresponding supercapacitor C.

[0044] In this embodiment, the mains input module converts external 220V AC mains power into high-voltage DC power to provide input energy for the subsequent step-down constant current charging module. Specifically, it includes a rectifier unit and a filter unit. The rectifier unit uses a bridge rectifier circuit, and the filter unit uses a filter architecture combining electrolytic capacitors and ceramic capacitors to filter out AC ripple and interference signals. Specifically, the mains input module can use a bridge rectifier circuit (diode model LTM540), paired with a high-voltage isolated DC-DC power conversion chip (model 8239S). The output uses a 1000μF / 50V electrolytic capacitor and a 0.1μF ceramic capacitor to achieve 220V AC conversion and filtering with a ripple factor ≤5%.

[0045] In this embodiment, the step-down constant current charging module is connected to the output terminal of the mains input module to convert high-voltage DC power into constant current DC power suitable for the supercapacitor bank, achieving high-current fast charging. This module uses a DC / DC constant current control chip with built-in overcurrent and overvoltage protection functions. It can be configured with a charging current of 3A-10A to adapt to the fast charging requirements of supercapacitor banks of different capacities. The output voltage and current are matched in real-time to the rated parameters of the series-connected supercapacitor bank. Specifically, the step-down constant current charging module can use the LM3424 step-down constant current control chip, paired with a MOSFET (model IRF3205), a sampling resistor (0.01Ω), and an inductor (100μH), configured with a charging current of 5A and an output voltage range of 2.5V-15V. It supports switching between constant current fast charging and float charging modes and has built-in overcurrent, overvoltage, and overtemperature protection.

[0046] In this embodiment, the series supercapacitor bank consists of N 2.7V / 3.0V supercapacitors connected in series. The total voltage is adapted to the power supply requirements of the Linux terminal load (e.g., 12V or 24V levels). It serves as the energy carrier for backup power supply after a power outage, possessing high power density and long cycle life characteristics. Specifically, the series supercapacitor bank can use four 3.0V / 100F supercapacitors connected in series, with a total voltage of 12V, a rated capacity of 100F, and a peak discharge current ≥30A, suitable for the high power consumption load requirements of industrial gateways.

[0047] like Figure 2 As shown, the single-cell voltage equalization module in this embodiment includes:

[0048] The voltage detection chip has its VIN pin connected to the positive terminal of capacitor C, and its GND pin connected to the negative terminal of capacitor C, with the negative terminal of capacitor C grounded.

[0049] The first resistor R1 has its first connection terminal connected to the positive terminal of the capacitor C.

[0050] The drain of MOSFET Q is connected to the second terminal of the first resistor R1, the source of MOSFET Q is connected to the negative terminal of capacitor C, and the gate of MOSFET Q is connected to the OUT pin of the voltage detection chip; MOSFET Q is a low on-resistance N-channel MOSFET.

[0051] The second resistor R2 has its first connection terminal connected to the VIN pin of the voltage detection chip, and its second connection terminal connected to the VSEN pin of the voltage detection chip.

[0052] The third resistor R3 has its first connection terminal connected to the VSEN pin of the voltage detection chip, and its second connection terminal connected to the GND pin of the voltage detection chip.

[0053] The voltage detection chip has a voltage threshold. When the voltage detection chip detects that the voltage of a single capacitor C is lower than the voltage threshold, the OUT pin of the voltage detection chip outputs a low level, the MOSFET Q is turned off, and capacitor C charges normally. When the voltage detection chip detects that the voltage of a single capacitor C is greater than or equal to the voltage threshold, the OUT pin of the voltage detection chip outputs a high level, the MOSFET Q is turned on, and capacitor C stops charging. Specifically, when the voltage of a single supercapacitor is lower than the voltage threshold, the VSEN of the voltage detection chip is less than the turn-on threshold, at which time the OUT output is low and Q1 is off. The constant current and constant voltage charging current directly charges C1 with a large current. When the voltage is higher than the single-cell voltage threshold, the VSEN of the voltage detection chip is higher than the turn-on threshold, at which time the OUT output is high and Q1 is on. The current flows to ground through R1 and Q1 to prevent the supercapacitor from overcharging, while also satisfying the large current flow during fast charging. When the supercapacitor voltage is lower than the single-cell voltage threshold, the OUT output is low and Q1 is off. By continuously detecting the capacitor voltage value and continuously turning Q1 on and off, the voltage of the supercapacitor is stabilized.

[0054] In this embodiment, the individual voltage equalization module is configured in parallel with each individual supercapacitor in the series supercapacitor bank. Each voltage equalization module independently corresponds to one supercapacitor and its core consists of a voltage detection chip, a MOSFET, and a current-limiting resistor. The VDD and GND pins of the voltage detection chip are connected to the positive and negative terminals of the corresponding supercapacitor, respectively, for real-time acquisition of the individual cell voltage. The acquisition accuracy is ≤±20mV, and the chip has a preset voltage threshold (which can be adjusted according to the supercapacitor's rated parameters, such as 2.85V). The MOSFET is a low-on-resistance N-channel MOSFET, with its drain connected to the positive terminal of the supercapacitor, its source connected to the negative terminal of the supercapacitor through the current-limiting resistor, and its gate connected to the output terminal of the voltage detection chip. When the individual cell voltage is below the preset threshold, the voltage detection chip outputs a low level, the MOSFET is cut off, the voltage equalization module does not work, and all charging current is used for supercapacitor energy storage. When the individual cell voltage reaches or exceeds the preset threshold, the voltage detection chip outputs a high level, the MOSFET is turned on, and the individual supercapacitor forms a discharge circuit through the current-limiting resistor, balancing the voltage of each cell and preventing overcharging of any single cell. Specifically, each supercapacitor is equipped with a voltage equalization module. The voltage detection chip is an SGM809B (accuracy ±10mV, preset threshold 3V), the MOSFET is an LN2302BLT1G (N-channel, Rdson=0.08Ω), and the current limiting resistor is a 10Ω / 1W resistor. The chip's VIN and GND are connected to the positive and negative terminals of the supercapacitor, and OUT is connected to the gate of the MOSFET, realizing accurate voltage monitoring and dynamic voltage equalization.

[0055] The power switching module in this embodiment is used to switch between mains power supply and backup power supply, such as... Figure 3 As shown, the power switching module includes a diode chip, which includes a first diode D1 and a second diode D2. The positive terminal of the first diode D1 is connected to the mains input module and the negative terminal is connected to the Linux terminal load. The positive terminal of the second diode D2 is connected to the series supercapacitor group and the negative terminal is connected to the Linux terminal load.

[0056] The power switching module in this embodiment uses an ideal diode chip or a dual-channel power switching chip, featuring low voltage drop and fast response. When the mains power is normal, it switches to the mains power supply circuit, and the supercapacitor bank is in charging or energy storage state. When the mains power fails or the voltage is abnormal, it switches to the supercapacitor bank power supply circuit without delay or interruption, ensuring the continuous and stable operation of the Linux terminal load. Specifically, the power switching module can use an ideal diode chip (model SS34A) with a forward voltage drop of 500mV / 3A, competing with the mains power supply to ensure no delay in power supply when the mains power fails.

[0057] In this embodiment, the Linux terminal load is a high-power Linux embedded terminal equipped with multiple communication interfaces (Ethernet, serial, 4G / 5G, WiFi), including a CPU, memory, communication module, and peripheral circuits. It serves as the application carrier for this invention, and the backup power supply system must meet its load requirements for continuous operation for a period of time after a power outage. Specifically, the Linux terminal load is equipped with a 12V industrial gateway running Linux, integrating an Ethernet port, two RS485 serial ports, and a 4G module. The maximum power consumption of the entire unit under full load is 15W, and the measured power outage recovery time is ≥5 minutes.

[0058] Working principle:

[0059] During the normal mains charging phase: The mains input module converts 220V AC mains power into high-voltage DC power and supplies it to the step-down constant current charging module. The step-down constant current charging module charges the series supercapacitor bank in a high-current constant-current manner. At this time, the voltage detection chip of the individual voltage equalization module collects the voltage of each individual supercapacitor in real time. If the voltage of an individual is lower than the preset threshold, the MOSFET remains off, the voltage equalization module does not participate in the operation, and it does not affect the charging speed. When the voltage of a certain individual reaches the preset threshold, the voltage detection chip outputs a high level, driving the corresponding MOSFET to conduct. The individual then discharges excess energy through the current-limiting resistor, so that the voltage of each individual remains consistent and overcharging is avoided.

[0060] During the backup power supply phase after a mains power outage: The power switching module monitors the mains power status in real time. When a mains power outage or voltage abnormality is detected, it immediately and seamlessly switches to the power supply circuit of the series supercapacitor bank. The supercapacitor bank releases its stored energy to provide stable DC power to the Linux terminal load. At this time, the individual voltage equalization modules work synchronously to monitor the voltage of each individual cell and avoid over-discharge of individual cells during the discharge process, thus ensuring the stability and safety of the backup power supply.

[0061] Mains power restoration phase: When the power switching module detects that the mains power has been restored and the voltage is normal, it quickly switches back to the mains power supply circuit. The buck constant current charging module restarts high-current fast charging to replenish the supercapacitor bank and complete one cycle.

[0062] In this embodiment, the supercapacitor bank's 1A high-current fast charging time is ≤30 minutes, the voltage difference between each individual supercapacitor is ≤15mV, the switching response is uninterrupted after a mains power outage, the terminal operates stably for 5 minutes, the data is stored completely, and the system runs continuously for 1000 hours without failure.

[0063] Example 2:

[0064] This invention provides a high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals, which differs from Embodiment 1 in that:

[0065] Series supercapacitor bank: 8 3.0V / 100F supercapacitors are connected in series, with a total voltage of 24V and a total capacitance of 12.5F.

[0066] Buck constant current charging module: configured with a charging current of 1A, suitable for fast charging requirements of 100F supercapacitors.

[0067] Linux terminal load: 24V edge computing terminal, integrating network port, 1 RS232 serial port, WiFi / Bluetooth module, the maximum power consumption of the whole machine under full load is 20W, and the actual power failure recovery time is ≥5 minutes.

[0068] In this embodiment, the supercapacitor bank has a fast charging time of ≤30 minutes, a voltage difference of ≤20mV, and a stable backup power supply, meeting the daily backup needs of the edge computing terminal.

[0069] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A high-current fast-charging supercapacitor voltage equalization power supply system for Linux terminals, characterized in that, include: AC power input module; A step-down constant current charging module, the input terminal of which is connected to the first output terminal of the mains power input module; A series supercapacitor bank, the input terminal of which is connected to the output terminal of the step-down constant current charging module, the series supercapacitor bank comprising N supercapacitors (C) connected in series. The power switching module has its first input terminal connected to the second output terminal of the mains input module, its second input terminal connected to the output terminal of the series supercapacitor group, and its output terminal connected to the Linux terminal load. N individual voltage equalization modules, each of which is connected in parallel with a corresponding supercapacitor (C).

2. The system according to claim 1, characterized in that, The single-unit voltage equalization module includes: The voltage detection chip has its VIN pin connected to the positive terminal of the capacitor (C), and its GND pin connected to the negative terminal of the capacitor (C), with the negative terminal of the capacitor (C) grounded. The first resistor (R1) has its first connection terminal connected to the positive terminal of the capacitor (C); The drain of the MOS transistor (Q) is connected to the second terminal of the first resistor (R1), the source of the MOS transistor (Q) is connected to the negative terminal of the capacitor (C), and the gate of the MOS transistor (Q) is connected to the OUT pin of the voltage detection chip. The first connection terminal of the second resistor (R2) is connected to the VIN pin of the voltage detection chip, and the second connection terminal of the second resistor (R2) is connected to the VSEN pin of the voltage detection chip. The third resistor (R3) has its first connection terminal connected to the VSEN pin of the voltage detection chip, and its second connection terminal connected to the GND pin of the voltage detection chip.

3. The system according to claim 2, characterized in that, The MOSFET (Q) is a low on-resistance N-channel MOSFET.

4. The system according to claim 3, characterized in that, The voltage detection chip has a voltage threshold. When the voltage detection chip detects that the voltage of a single capacitor (C) is lower than the voltage threshold, the OUT pin of the voltage detection chip outputs a low level, the MOS transistor (Q) is turned off, and the capacitor (C) charges normally. When the voltage detection chip detects that the voltage of a single capacitor (C) is greater than or equal to the voltage threshold, the OUT pin of the voltage detection chip outputs a high level, the MOS transistor (Q) is turned on, and the capacitor (C) stops charging.

5. The system according to claim 1, characterized in that, The mains input module is used to convert external 220V AC mains power into high-voltage DC power. The mains input module includes a rectifier unit and a filter unit. The rectifier unit adopts a bridge rectifier circuit, and the filter unit adopts a filter architecture combining electrolytic capacitors and ceramic capacitors.

6. The system according to claim 1, characterized in that, The step-down constant current charging module is used to convert high-voltage DC power into constant current DC power adapted to the supercapacitor bank. The step-down constant current charging module includes a step-down constant current control chip, which can be configured with a charging current of 3A-10A.

7. The system according to claim 6, characterized in that, The step-down constant current control chip is equipped with a MOSFET, a sampling resistor, and an inductor.

8. The system according to claim 1, characterized in that, The series supercapacitor bank consists of N 2.7V / 3.0V supercapacitors connected in series, and its total voltage is adapted to the power supply requirements of the Linux terminal load.

9. The system according to claim 1, characterized in that, The power switching module is used to switch between mains power supply and backup power supply. The power switching module includes a diode chip, which includes a first diode (D1) and a second diode (D2). The positive terminal of the first diode (D1) is connected to the mains input module and the negative terminal is connected to the Linux terminal load. The positive terminal of the second diode (D2) is connected to a series supercapacitor bank and the negative terminal is connected to the Linux terminal load.

10. The system according to claim 1, characterized in that, The Linux terminal workload is a high-power embedded terminal equipped with at least one of the following communication interfaces: Ethernet, serial port, 4G / 5G, and WiFi.

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