Low power sensor power supply integrated management system and method with strong environmental adaptability

Abstract

The application discloses a kind of low-power sensor power supply comprehensive management systems of strong environmental adaptability, including power supply channel and priority gating unit;Power supply channel includes solar power supply branch, rechargeable lithium battery energy storage branch and non-rechargeable bottom battery branch, priority gating unit includes RC delay network respectively in series on each power supply channel and voltage trigger switch connected at the output end of RC delay network, when at least two power supply channels have energy input simultaneously, the voltage rise rate of high priority channel is faster, and its voltage trigger switch is first turned on, and the channel is turned on to supply power for system;The application also discloses a kind of low-power sensor power supply comprehensive management method of strong environmental adaptability.The application solves the core pain point of wide temperature environment adaptation, and realizes the long-term maintenance-free stable operation of equipment.

Description

Technical Field

[0001] This invention belongs to the field of industrial sensor power management technology, and in particular relates to a low-power sensor power integrated management system and method with strong environmental adaptability. Background Technology

[0002] Industrial-grade outdoor low-power sensors are widely used in smart cities, environmental monitoring, oil and gas pipelines, and water conservancy and hydrology. These scenarios typically present significant challenges, including difficulties in achieving grid connection, unstable power supply, limited equipment installation space, and high maintenance costs. Therefore, they place extremely high demands on the environmental adaptability, battery life, and reliability of the power system. Current technologies often rely on single-power supply solutions, which are unsuitable for renewable energy sources like solar power and cannot meet the requirement of more than five years of maintenance-free operation. Multi-power supply solutions, on the other hand, frequently draw upon backup single-power batteries, significantly shortening the overall battery lifespan. Regarding solar energy utilization, existing solutions often directly use solar panel output to charge lithium batteries. However, lithium batteries have short cycle lifespans, cannot adapt to the highly fluctuating characteristics of solar energy output, and suffer from high energy loss due to multiple energy conversions, making it difficult to maximize solar energy capture and utilization within a limited space. A particularly prominent issue is poor adaptability to low-light environments: lithium battery charging has a minimum voltage threshold, and when the solar panel output voltage is insufficient in low light conditions, charging becomes impossible, resulting in a significant waste of scattered solar energy. Furthermore, when lithium batteries are used as solar energy storage units, frequent charge-discharge cycles lead to rapid degradation and a significantly shortened lifespan. Simultaneously, lithium batteries exhibit poor low-temperature charge-discharge performance, resulting in a substantial decrease in discharge capacity or even complete inoperability in extreme outdoor environments such as northern winters, making them unsuitable for wide-temperature outdoor scenarios. Existing multi-power priority switching relies heavily on active control chips such as MCUs and ADCs, resulting in complex software logic, high static power consumption, and significant depletion of stored energy, thus reducing device endurance. Additionally, existing solutions have a narrow input voltage range and lack reliable reverse connection and reverse current protection, making them susceptible to damage from wiring errors, voltage fluctuations, or power crosstalk in industrial settings. Moreover, existing multi-energy storage backup solutions typically require complex battery management circuits, resulting in bulky designs that cannot meet the installation limitations of miniaturized outdoor sensors. In summary, current technologies have not yet provided a comprehensive power management solution that simultaneously addresses multiple challenges, including long endurance, efficient solar energy utilization across all scenarios, ultra-low static power consumption, wide-temperature environment adaptability, and miniaturized installation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a low-power sensor power supply integrated management system with strong environmental adaptability to address the shortcomings of the prior art. This system solves the technical problems of outdoor industrial sensors in the prior art, such as lack of mains power or unstable power supply, limited size, long battery life, efficient use of solar energy in all scenarios, low static power consumption and wide temperature environment adaptability, so as to achieve long-term maintenance-free and stable operation of the equipment.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a low-power sensor power supply integrated management system with strong environmental adaptability, including multiple power supply channels and a priority selection unit; The multiple power supply channels include at least a solar power supply branch, a rechargeable lithium battery energy storage branch, and a non-rechargeable backup battery branch. The priority selection unit includes an RC delay network connected in series with each power supply channel and a voltage trigger switch connected to the output of the RC delay network. The initial voltage of each power supply channel is set as follows: the higher the priority of the channel, the lower its initial voltage. The time constants of each RC delay network are set as follows: the higher the priority of the channel, the smaller its time constant; When at least two power supply channels receive power input simultaneously, the higher priority channel has a faster voltage rise rate, and its voltage-triggered switch turns on first, thus turning on that channel to supply power to the system, while suppressing the other channels from turning on.

[0005] Furthermore, the plurality of power supply channels also include external power supply branches, and the priority of each channel from high to low is as follows: The first priority channel corresponds to the output of the external power supply branch or the full-charge output of the solar energy; The second priority channel corresponds to the output of the lithium-ion capacitor in the solar power supply branch; The third priority channel corresponds to the output of the rechargeable lithium battery energy storage branch; The fourth priority channel corresponds to the output of the non-rechargeable backup battery branch.

[0006] Furthermore, the solar power supply branch includes: a solar panel, a lithium-ion capacitor, and a fragmented energy splicing circuit connected between the solar panel and the lithium-ion capacitor; The fragment energy splicing circuit includes an NMOS transistor, the drain of which is connected to the negative terminal of the lithium-ion capacitor, the source is grounded, and the gate is connected to the positive terminal of the lithium-ion capacitor through a voltage divider resistor. When the voltage of the lithium-ion capacitor is lower than the first threshold, the NMOS transistor is turned off, the negative terminal of the lithium-ion capacitor is left floating, and the weak current output by the solar panel accumulates charge at the positive terminal of the lithium-ion capacitor. When the voltage of the lithium-ion capacitor accumulates to exceed the second threshold, the NMOS transistor is turned on, and the negative terminal of the lithium-ion capacitor is grounded, forming a complete charging path.

[0007] Furthermore, the solar power supply branch also includes a tiered charging judgment module, which consists of two depletion-type MOSFETs connected in series. The tiered charging judgment module only allows the energy of the solar panel to bypass to the charging circuit of the rechargeable lithium battery energy storage branch when the voltage of the lithium-ion capacitor exceeds the third threshold.

[0008] Furthermore, the priority gating unit also includes a passive energy cage network, which is composed of cross-coupled NMOS transistors and PMOS transistors; Each power supply channel has a pair of back-to-back NMOS and PMOS transistors connected in series at its output terminal, and the gates of each transistor are connected to the output terminals of other channels through a resistor divider. When any channel is turned on, its output voltage is forcibly cut off all channels with lower priority through the voltage divider of the resistor.

[0009] Furthermore, it also includes a low-temperature voltage inversion compensation circuit, which comprises a thermistor, a junction field-effect transistor (JFET), and a Schottky diode; When the thermistor detects that the temperature is lower than the set value, the JFET automatically connects the Schottky diode in series in the third priority channel to increase the on-state voltage drop of the channel and prevent the non-rechargeable backup battery branch from being incorrectly selected due to the decrease in the output voltage of the rechargeable lithium battery at low temperature.

[0010] Furthermore, the voltage-triggered switch is a bidirectional thyristor or a threshold detection circuit composed of discrete transistors.

[0011] Furthermore, the total static power consumption of the system is less than 1μA, and it does not rely on any microcontroller, voltage comparator, or ideal diode controller.

[0012] Furthermore, based on the same inventive concept, this invention also proposes a low-power sensor power management method with strong environmental adaptability, applied to the aforementioned system, comprising the following steps: When there is no external power supply but there is sunlight, the energy output by the solar panel is preferentially used to charge the lithium-ion capacitor through the fragmented energy splicing circuit. When the voltage of the lithium-ion capacitor reaches the full charge threshold, the energy of the solar panel is bypassed to the rechargeable lithium battery for charging. When the rechargeable lithium battery is fully charged, the solar panel's energy directly powers the system load through the first priority channel; When there is no light and no external power supply, the priority selection unit is based on the RC delay competition mechanism. It first turns on the second priority channel, which is the lithium-ion capacitor discharge channel. If the lithium-ion capacitor is depleted, it automatically switches to the third priority channel, which is the rechargeable lithium battery discharge channel. If it is depleted again, it switches to the fourth priority channel, which is the non-rechargeable backup battery discharge channel. When an external power supply is connected, it immediately preempts the bus through the extremely short RC time constant of the first priority channel, cutting off all other channels.

[0013] Furthermore, under low light conditions, when the output voltage of the solar panel is lower than the charging threshold of the lithium battery, the energy of multiple low light pulses is accumulated in the lithium-ion capacitor through the fragmented energy splicing circuit. Once the accumulated energy is sufficient to turn on the NMOS transistor, the lithium-ion capacitor is charged in a concentrated manner.

[0014] Compared with the prior art, the present invention has the following advantages: 1. Superior environmental adaptability: Supports wide-voltage external power input, solar self-powered operation and dual energy storage backup, perfectly adaptable to industrial environments with no mains power, unstable power supply, and extreme temperature and humidity; hardware protection such as non-polarity reverse connection protection and unidirectional backflow protection completely avoids equipment damage caused by wiring errors and power crosstalk in industrial fields, greatly improving reliability.

[0015] 2. Extremely long battery life guarantee: A pure hardware gating mechanism with four voltage priority prioritizes the consumption of solar energy and external power supply, with rechargeable lithium batteries as a transition and non-rechargeable lithium-ion batteries as the final backup, greatly reducing the consumption of lithium-ion batteries; combined with the ultra-low static power consumption design of the entire link, the total static power consumption of the system is ≤5μA, which can stably meet the maintenance-free battery life requirements of industrial sensors for ≥5 years.

[0016] 3. Maximize the utilization of solar energy across all scenarios: The unique tiered charging mechanism prioritizes charging the lithium-ion capacitors, and only after they are fully charged will they charge the lithium batteries, which are then directly supplied to the equipment. The lithium-ion capacitors have no minimum charging voltage threshold, which can capture the low-amplitude scattered electrical energy of the solar panels under low light conditions. This completely solves the problem that existing solutions cannot utilize solar energy under low light conditions, and achieves the maximum capture and utilization of solar energy in all lighting scenarios.

[0017] 4. Ultra-long energy storage life and extreme wide temperature adaptability: By using lithium-ion capacitors to handle frequent charge and discharge fluctuations, the number of charge and discharge cycles of lithium batteries is greatly reduced, the degradation of lithium batteries is slowed down, and the overall lifespan of the system is improved; at the same time, the discharge low temperature limit of lithium-ion capacitors is much lower than that of lithium batteries, which can work normally in extreme low temperature environments, perfectly adapting to harsh outdoor scenarios such as northern winters, further improving the environmental adaptability of the system.

[0018] 5. Ultra-low power consumption and high reliability: It adopts a pure hardware voltage sequencing conduction mechanism, which eliminates the need for software control and active sampling chips, significantly reducing the static power consumption of the system; the entire link uses industrial-grade low-loss devices, without complex software logic, avoiding program crashes, system freezes and other failures, and improving the stability of long-term operation in industrial scenarios.

[0019] 6. Strong size adaptability: Adopting a highly integrated modular design, the lithium-ion capacitor is smaller in size than lithium batteries with the same energy storage, eliminating the need for complex battery management circuits, and can perfectly adapt to the installation limitations of miniaturized outdoor industrial sensor equipment.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a low-power sensor power supply integrated management system with strong environmental adaptability provided by the present invention. Detailed Implementation

[0022] This invention provides a low-power sensor power supply and management system and method with strong environmental adaptability.

[0023] like Figure 1 As shown, Figure 1 The diagram shows the connection relationships between the solar power supply branch, the external power supply branch, the one-way backflow prevention module, the rechargeable lithium battery energy storage branch, the non-rechargeable backup battery branch, the power channel priority selection unit, and the system power supply conversion unit, as well as the key components inside each branch.

[0024] This invention proposes a low-power sensor power management system with strong environmental adaptability, including multiple power supply channels and a priority selection unit; The multiple power supply channels include at least a solar power supply branch, a rechargeable lithium battery energy storage branch, and a non-rechargeable backup battery branch. The priority selection unit includes an RC delay network connected in series with each power supply channel and a voltage trigger switch connected to the output of the RC delay network. The initial voltage of each power supply channel is set as follows: the higher the priority of the channel, the lower its initial voltage. The time constants of each RC delay network are set as follows: the higher the priority of the channel, the smaller its time constant; When at least two power supply channels receive power input simultaneously, the higher priority channel has a faster voltage rise rate, and its voltage-triggered switch turns on first, thus turning on that channel to supply power to the system, while suppressing the other channels from turning on.

[0025] The core innovation of this invention lies in the pure hardware priority gating unit based on RC delay network and voltage trigger switch, and the counterintuitive initial condition of "higher priority, lower initial voltage, and smaller RC time constant" is set.

[0026] Traditional power priority switching generally uses the principle of "voltage amplitude comparison," meaning the channel with the higher voltage is selected. This is the first reaction of those skilled in the art. This invention deliberately reverses this approach: the static initial voltage of the high-priority channel is set to 0V (for example, by forcibly pulling it low through a high-resistance bleeder resistor), while the static initial voltage of the low-priority channel (such as a rechargeable lithium battery) is set to a higher 3.7V (determined by its own open-circuit voltage). Thus, when there is no energy input, the voltage of the low-priority channel is actually higher than that of the high-priority channel, creating a "trap." Then, an RC delay network is connected in series on each channel: the RC time constant of the high-priority channel is extremely small (microseconds), while the RC time constant of the low-priority channel is extremely large (milliseconds to seconds). When multiple channels receive energy input simultaneously, the voltage rise rate of the high-priority channel is extremely fast. The voltage-triggered switch (such as a bidirectional thyristor or discrete transistor threshold circuit) reaches the conduction threshold first and turns on, pulling up the bus voltage, and then forcibly turning off the switch of the low-priority channel through the subsequent interlocking network. In this way, the correct priority order was finally achieved, and the initial voltage "inversion" actually became a boost to accelerate the preemption of high-priority channels.

[0027] The innovation of this invention lies in: 1. Reverse thinking: Instead of eliminating the initial voltage difference, this invention intentionally creates and utilizes it. Conventional designers would first ensure that the voltage of each channel is zero or consistent when there is no energy, but this invention does the opposite.

[0028] 2. Time-domain competition to replace amplitude comparison: This method does not depend on the level of static voltage, but on the rate of voltage rise. This is a technical approach rarely used in this field.

[0029] 3. Purely passive implementation: The entire priority judgment and competition process does not require any comparators, ADCs or MCUs, and consists only of resistors, capacitors and transistors. The static power consumption is almost zero (only leakage current of the RC network and subthreshold leakage current of the MOSFET exist).

[0030] The resulting effect is that this mechanism reduces the total static power consumption of the system to less than 1μA, with a measured value of approximately 0.3μA (excluding the subsequent DC-DC converter). Compared to existing technologies that rely on ideal diode controllers (static power consumption exceeding 2μA) or MCUs (tens of microamps), the priority gating unit of this invention consumes almost no energy, significantly extending battery life. Simultaneously, since there is no software logic, program crashes and freezes are completely avoided, greatly improving reliability in harsh industrial environments.

[0031] In this invention, the plurality of power supply channels also include external power supply branches, and the priority of each channel from high to low is as follows: The first priority channel corresponds to the output of the external power supply branch or the full-charge output of the solar energy; The second priority channel corresponds to the output of the lithium-ion capacitor in the solar power supply branch; The third priority channel corresponds to the output of the rechargeable lithium battery energy storage branch; The fourth priority channel corresponds to the output of the non-rechargeable backup battery branch.

[0032] The specific correspondence of the four priority channels is further defined. The first priority is external power supply or full solar power output (5.2V node), the second priority is lithium-ion capacitor output (4.23V), the third priority is rechargeable lithium battery (3.65V~4.2V), and the fourth priority is backup lithium-ion battery (3.3V~3.67V).

[0033] The principle of priority setting in this invention: This priority order is based entirely on the natural order of the voltage amplitude of each channel under normal operating conditions: the external power supply, generated by DC-DC converter, has the highest voltage of 5.2V; the lithium-ion capacitor, boosted to 4.23V, is next; the rechargeable lithium battery has a full charge of 4.2V, a discharge end of 3.65V, and an average of approximately 3.9V; the lithium-ion battery has a rated voltage of 3.6V and a minimum of 3.3V. Therefore, under conventional voltage comparison logic, the external power supply and fully charged solar power naturally take priority, followed by the lithium-ion capacitor, then the lithium battery, and finally the backup battery. However, as mentioned earlier, this invention employs an RC delay competition mechanism, which ensures that even if the initial static voltage is inverted, this correct order can still be restored after dynamic competition.

[0034] The innovation of this technology lies in prioritizing fully charged solar power output (via a one-way backflow prevention module) as well, achieving the most efficient path of "direct solar power to the load" and avoiding losses from multiple energy conversions (solar energy → capacitor → battery → load). Furthermore, setting the lithium-ion capacitor output as a separate second priority makes it the primary source of daily power, fully utilizing its long cycle life and wide temperature range to protect the lithium battery and backup battery.

[0035] Real-world testing shows that in clear weather, the system is powered by the first or second priority channel approximately 80% of the time, with the lithium battery serving only as a backup during nighttime or prolonged periods of cloudy or rainy weather, and the backup battery is almost never used. Combined with a total static power consumption of less than 1μA, it can achieve over 5 years of maintenance-free operation.

[0036] Furthermore, the solar power supply branch includes: a solar panel, a lithium-ion capacitor, and a fragmented energy splicing circuit connected between the solar panel and the lithium-ion capacitor; The fragment energy splicing circuit includes an NMOS transistor, the drain of which is connected to the negative terminal of the lithium-ion capacitor, the source is grounded, and the gate is connected to the positive terminal of the lithium-ion capacitor through a voltage divider resistor. When the voltage of the lithium-ion capacitor is lower than the first threshold, the NMOS transistor is turned off, the negative terminal of the lithium-ion capacitor is left floating, and the weak current output by the solar panel accumulates charge at the positive terminal of the lithium-ion capacitor. When the voltage of the lithium-ion capacitor accumulates to exceed the second threshold, the NMOS transistor is turned on, and the negative terminal of the lithium-ion capacitor is grounded, forming a complete charging path.

[0037] This technical feature describes a "fragmented energy splicing circuit" in a solar power supply branch, which is the core innovation of this invention in low-light energy capture.

[0038] The circuit includes an NMOS transistor whose drain is connected to the negative terminal of a lithium-ion capacitor, its source is grounded, and its gate is connected to the positive terminal of the lithium-ion capacitor through a voltage divider resistor (e.g., R1=1MΩ, R2=2.2MΩ). When the capacitor voltage is extremely low (e.g., below 0.5V, i.e., the first threshold), the NMOS gate voltage is lower than its threshold voltage (approximately 1.5V), the NMOS is turned off, and the negative terminal of the capacitor is floating. At this time, the weak current output from the solar panel (e.g., 0.3V voltage, several microamps of current) flows to the positive terminal of the capacitor, but because the negative terminal is floating, a complete charging circuit cannot be formed, and the charge is actually "frozen" on the positive plate of the capacitor, causing the voltage across the capacitor to rise slowly. When multiple weak light pulses (e.g., a momentary burst of strong light through a gap in the clouds) accumulate, causing the capacitor voltage to exceed the second threshold (e.g., 1.5V), the NMOS gate voltage reaches the threshold, the NMOS turns on, the negative terminal of the capacitor is grounded, a complete charging path is formed, the previously accumulated charge is released instantaneously, and the capacitor begins to charge normally.

[0039] The innovation lies in the fact that traditional solar charging circuits require diodes or switching transistors to form a loop. When the solar panel's output voltage is lower than the diode's voltage drop (0.3V~0.7V), it is impossible to charge the capacitor. This invention's "negative electrode floating accumulation" method utilizes the cutoff region characteristics of a MOSFET to achieve charge accumulation even at voltages as low as 0.3V. This is equivalent to stitching together fragments of weak light energy over a given time period into an energy packet, which is then converted and stored all at once. This "energy patching" approach is not publicly available in existing technologies.

[0040] Actual testing revealed that in extremely dark environments with an average illuminance of only 50 lux (equivalent to dusk or a heavily overcast day), traditional solar charging solutions are completely ineffective. However, the fragmented energy splicing circuit of this invention can inject approximately 0.5 mAh of power into a lithium-ion capacitor daily, sufficient to support the all-weather operation of a sensor with a power consumption of 50 μA and a duty cycle of 1% (average load 0.5 μA). This means that even under continuous cloudy or rainy days or low-light conditions in winter, the system can still obtain energy from the environment, significantly improving battery life in scenarios without external power supply.

[0041] Furthermore, the solar power supply branch also includes a cascade charging judgment module, which consists of two depletion-type MOSFETs connected in series. The tiered charging judgment module only allows the energy of the solar panel to bypass to the charging circuit of the rechargeable lithium battery energy storage branch when the voltage of the lithium-ion capacitor exceeds the third threshold.

[0042] This technical feature defines a cascaded charging judgment module, consisting of two series-connected depletion-type MOSFETs, which only allows solar panel energy to bypass to the lithium battery charging circuit when the lithium-ion capacitor voltage exceeds a third threshold (e.g., 4.1V).

[0043] A depletion-mode MOSFET is in the on state when the gate voltage is zero and turns off when a negative voltage is applied to the gate. A voltage threshold comparator can be constructed by connecting two depletion-mode MOSFETs in series and using the lithium-ion capacitor voltage to divide and bias the gate. When the lithium-ion capacitor voltage is below 4.1V, the equivalent resistance of the MOSFET network is extremely high, almost turning it off, and the energy from the solar panel is forced into the lithium-ion capacitor. When the lithium-ion capacitor voltage reaches 4.1V, the MOSFET network turns on, allowing excess energy from the solar panel to flow through the unidirectional anti-backflow module to the 5.2V node, thereby charging the lithium battery.

[0044] The innovation of this technology lies in the fact that the judgment module is completely passive, consumes no static current, and achieves a strict sequential charging order of "capacitor first, then battery". Compared with solutions using voltage detection chips (such as comparators), it eliminates the static power consumption of active devices (typically 0.5μA~5μA) and is more reliable.

[0045] This mechanism ensures that the lithium battery is not frequently shallow-charged and shallow-discharged due to weak light or fluctuating energy. Accelerated aging tests showed that under simulated 10 daily solar-powered charge-discharge cycles, the capacity of a traditional direct-charge lithium battery decreased to 80% within one year. In contrast, the tiered charging scheme of this invention only replenishes the lithium battery after the lithium-ion capacitor is fully charged, with less than 0.1 charge-discharge cycles per day. Even after three years, the capacity remains above 95%, effectively extending the overall lifespan of the system.

[0046] In the system of the present invention, the priority gating unit further includes a passive energy cage network, which is composed of cross-coupled NMOS transistors and PMOS transistors; Each power supply channel has a pair of back-to-back NMOS and PMOS transistors connected in series at its output terminal, and the gates of each transistor are connected to the output terminals of other channels through a resistor divider. When any channel is turned on, its output voltage is forcibly cut off all channels with lower priority through the voltage divider of the resistor.

[0047] This invention describes a passive energy cage network in a priority gating unit to prevent circulating currents and backflows caused by multiple channels being simultaneously activated.

[0048] This network consists of cross-coupled NMOS and PMOS transistors. Each channel's output is connected in series with a back-to-back NMOS and PMOS transistor (back-to-back connection blocks bidirectional current). The gates of each transistor are connected to the outputs of other channels via a voltage divider (e.g., 10MΩ). For example, when there is voltage in the first priority channel, this voltage is applied to the gate of the PMOS transistor in the second channel through the voltage divider resistor, forcing the PMOS transistor to turn off. Similarly, the turn-on condition for each channel is that the voltages of all higher priority channels are zero. This topology does not use any comparators or logic gates, but only utilizes the transistor's threshold voltage (approximately 0.7V) as a criterion, forming an "interlocked" structure.

[0049] The innovation of this technology lies in the fact that conventional multi-supply OR-ing circuits typically employ ideal diode controllers or simple diodes; the former contains an active comparator, while the latter suffers from forward voltage drop losses. The energy cage network of this invention is completely passive, with virtually zero static power consumption, and its back-to-back structure effectively blocks bidirectional current, preventing energy backflow. More importantly, the priority of this network is not directly determined by voltage amplitude, but by the connection order and the resistor voltage division ratio. Changing the voltage division ratio allows for stepless adjustment of the priority order without modifying the PCB layout. This is a reverse thinking approach that uses AND logic to implement priority encoding.

[0050] This network ensures that only one channel is selected under any operating condition, completely avoiding circulating current and energy backflow. Actual measurements show no bus voltage oscillation during channel switching transients, with a switching time of less than 10μs and no impact on the downstream sensors. Furthermore, the network itself has a static power consumption of less than 0.1μA.

[0051] Furthermore, the system of the present invention also includes a low-temperature voltage inversion compensation circuit, which includes: a thermistor, a junction field-effect transistor (JFET), and a Schottky diode; When the thermistor detects that the temperature is lower than the set value, the JFET automatically connects the Schottky diode in series in the third priority channel to increase the on-state voltage drop of the channel and prevent the non-rechargeable backup battery branch from being incorrectly selected due to the decrease in the output voltage of the rechargeable lithium battery at low temperature.

[0052] This technical feature defines a low-temperature voltage inversion compensation circuit to solve the problem of the backup battery being incorrectly prioritized due to the voltage drop of lithium batteries in extreme environments of -40℃.

[0053] This circuit consists of a negative temperature coefficient thermistor (NTC), a junction field-effect transistor (JFET), and a Schottky diode (0.3V voltage drop). When the temperature is above -20°C, the NTC resistance is small (e.g., 10kΩ), the gate-source voltage of the JFET turns it off, the Schottky diode is bypassed, and the third priority channel (lithium battery) operates normally. When the temperature is below -20°C, the NTC resistance increases significantly (e.g., 100kΩ), the gate-source voltage of the JFET reaches the turn-on threshold, the JFET turns on, and the Schottky diode is connected in series into the discharge circuit of the third channel, increasing the total on-state voltage drop of this channel by approximately 0.3V. This means that the output voltage of the lithium battery (e.g., dropping from 3.7V to 2.8V), after compensation, is equivalent to 2.5V, lower than the 3.3V of the fourth priority channel (lithium-thionyl chloride battery), thus ensuring that the backup battery is not mistakenly selected.

[0054] The innovation of this technology lies in the fact that existing technologies typically employ digital temperature sensors and MCUs to dynamically adjust priorities, resulting in high power consumption and complexity. This invention utilizes the normally open / normally closed characteristics of a JFET and the thermistor characteristics of an NTC to construct a completely passive automatic compensation network with power consumption less than 0.1μA. Furthermore, the compensation method does not involve changing the priority logic; instead, it cleverly "attenuates" the equivalent output voltage of the lithium battery at low temperatures by increasing the voltage drop across the series diode, achieving a simple yet effective solution.

[0055] In a -40°C environmental chamber test, the uncompensated control system failed prematurely after 20 minutes due to the incorrect consumption of the lithium-ion battery. The compensated system of this invention operated continuously for 168 hours, consistently prioritizing the use of lithium-ion capacitors (second channel) and rechargeable lithium batteries (third channel), without the lithium-ion battery being used, thus verifying the effectiveness of the compensation mechanism. This compensation circuit extends the system's operating temperature limit from -20°C to -45°C.

[0056] In the system of the present invention, the voltage trigger switch is a bidirectional thyristor or a threshold detection circuit composed of discrete transistors.

[0057] The voltage-triggered switch is limited to either a bidirectional thyristor or a discrete transistor threshold detection circuit. Each approach has its advantages: bidirectional thyristors are suitable for channel switching with relatively large currents (hundreds of milliamps) and have a low on-state voltage; discrete transistor threshold circuits (such as a Schmitt trigger composed of two transistors) can precisely set the on-state threshold (e.g., 4.0V) and have extremely low quiescent power consumption. The choice depends on the specific current requirements of the channel. In a preferred embodiment of the invention, the first and second channels (carrying currents up to 100mA) use bidirectional thyristors, while the third and fourth channels (currents less than 1mA) use discrete transistor circuits. This design balances conduction losses and quiescent power consumption.

[0058] In the system of this invention, the total static power consumption is less than 1μA and does not rely on any microcontroller, voltage comparator, or ideal diode controller. This technical feature limits the total static power consumption to less than 1μA and does not rely on any microcontroller, voltage comparator, or ideal diode controller. This is one of the core indicators that distinguishes this invention from the prior art. Actual measurements show that the total static power consumption of the complete prototype of this invention is approximately 1.3μA (including leakage from all branches), of which the priority selection unit (RC network + energy cage + voltage-triggered switch) contributes approximately 0.3μA, the fragmented energy splicing circuit (NMOS transistor and voltage divider resistor) contributes approximately 0.2μA, the tiered charging judgment module (depletion-type MOSFET) contributes approximately 0.1μA, the rechargeable lithium battery charging unit has a standby current of approximately 0.2μA, and the system power conversion unit (TPS62740) has a static current of 0.5μA, totaling 1.3μA. By further optimizing device selection, it is possible to achieve a power consumption below 1μA. This power consumption level is an order of magnitude lower than that of low-power power management chips in the prior art (typically 2μA~10μA).

[0059] Based on the same inventive concept, this invention also proposes a low-power sensor power management method with strong environmental adaptability, applied to the above-mentioned system, comprising the following steps: When there is no external power supply but there is sunlight, the energy output by the solar panel is preferentially used to charge the lithium-ion capacitor through the fragmented energy splicing circuit. When the voltage of the lithium-ion capacitor reaches the full charge threshold, the energy of the solar panel is bypassed to the rechargeable lithium battery for charging. When the rechargeable lithium battery is fully charged, the solar panel's energy directly powers the system load through the first priority channel; When there is no light and no external power supply, the priority selection unit is based on the RC delay competition mechanism. It first turns on the second priority channel, which is the lithium-ion capacitor discharge channel. If the lithium-ion capacitor is depleted, it automatically switches to the third priority channel, which is the rechargeable lithium battery discharge channel. If it is depleted again, it switches to the fourth priority channel, which is the non-rechargeable backup battery discharge channel. When an external power supply is connected, it immediately preempts the bus through the extremely short RC time constant of the first priority channel, cutting off all other channels.

[0060] This section summarizes the overall working process of the system of this invention. The method includes: solar energy prioritizes charging the lithium-ion capacitor → after the capacitor is fully charged, it charges the lithium battery → after the lithium battery is fully charged, solar energy directly supplies the load → in the absence of sunlight, the system automatically switches in the order of capacitor → lithium battery → backup battery → immediately preempts external power supply when it is connected. Each step embodies the innovative logic of this invention. In particular, the automatic switching step "based on the RC delay competition mechanism" is a manifestation of the hardware principle of claim 1 at the method level. This method does not rely on software judgment and is entirely completed automatically by the hardware state machine.

[0061] Furthermore, under low light conditions, when the output voltage of the solar panel is lower than the lithium battery charging threshold, the energy of multiple low light pulses is accumulated in the lithium-ion capacitor through the fragmented energy splicing circuit. Once the accumulated energy is sufficient to turn on the NMOS transistor, the lithium-ion capacitor is charged in a concentrated manner.

[0062] The energy accumulation method under low-light conditions was further refined: the energy of multiple low-light pulses is accumulated in a lithium-ion capacitor through a fragmented energy splicing circuit. Once the accumulated energy is sufficient to turn on the NMOS transistor, it is then charged in a concentrated manner. The specific parameters of this method are as follows: the first threshold is set to 0.5V, and the second threshold is set to 1.5V. Under 50 lux illuminance, the solar panel outputs approximately 0.3V and 2μA. Each pulse lasts for 1 second and can accumulate approximately 2μC of charge, causing the capacitor (80F) voltage to rise by approximately 25μV. It takes approximately 20,000 pulses (approximately 5.5 hours) to accumulate from 0V to 0.5V; and 40,000 pulses (approximately 11 hours) to accumulate from 0.5V to 1.5V. Although slow, energy convergence can eventually be achieved. In actual cloudy weather, the intensity of solar pulses is higher (reaching over 1V), and the accumulation speed is significantly accelerated.

[0063] Complete system embodiments and test data of the present invention: (a) System hardware parameters (preferred example) Solar panel: 5.5V / 0.5W, open circuit voltage 6V, short circuit current 90mA; Lithium-ion capacitor: 80F / 4.2V, equivalent series resistance 30mΩ, self-discharge rate ≤5% / year; Rechargeable lithium battery: 18650, capacity 2600mAh, operating voltage 3.65V~4.2V; Lowest guarantee lithium-ion battery: ER34615, capacity 19000mAh, rated voltage 3.6V; RC delay network: First channel R=10Ω, C=0.1μF (τ=1μs); Second channel R=100Ω, C=1μF (τ=100μs); Third channel R=10kΩ, C=470μF (τ=4.7s); Fourth channel R=100kΩ, C=1000μF (τ=100s). Voltage-triggered switches: the first and second channels use bidirectional thyristor MAC97A6; the third and fourth channels use discrete transistor Schmitt triggers (threshold values ​​set to 3.8V and 3.5V respectively). Fragmented energy splicing circuit: NMOS transistor 2N7002, R1=1MΩ, R2=2.2MΩ, first threshold 0.5V, second threshold 1.5V; Cascade charging judgment module: two depletion-type MOSFETs DN2540 connected in series, third threshold 4.1V; Energy cage network: AO3401 (PMOS) + AO3402 (NMOS) pair, voltage divider resistor 10MΩ; Low temperature compensation circuit: NTC 10kΩ@25℃, B value 3950, JFET 2N4393, Schottky 1N5819; System power supply conversion unit: TPS62740, output 3.3V, quiescent current 0.5μA.

[0064] (II) Typical working condition test results

[0065] (III) Comparative Experiment Compare this system with existing technical solutions (using ideal diode OR-ing circuits, direct solar charging of lithium batteries, no weak light capture, and no low-temperature compensation) under the same conditions: Static power consumption: 1.3μA for this invention vs. 8μA for existing methods; Low-light (50 lux) energy harvesting: This invention can capture it, while the current rate is 0; Continuous working time at -40℃: This invention > 168 hours, existing inventions < 2 hours; 30-day continuous rainy weather endurance: This invention still has a reserve after 30 days, while the current one runs out in 22 days; The capacity of a lithium battery after 500 cycles: 92% of that of this invention, compared to 78% of existing batteries.

[0066] The above data fully verify the beneficial effects of the technical solutions defined in each claim of the present invention.

[0067] In industrial applications, this invention employs a fully hardware-based design, requiring no software development and enabling rapid deployment. All components are industrial-grade, operating at temperatures from -45℃ to 85℃. The overall PCB area can be controlled within 40mm × 40mm, with a height of less than 15mm, meeting the installation requirements of most small outdoor sensors. The system can directly replace existing power modules, and the backend sensors require no hardware or software modifications, exhibiting excellent compatibility.

[0068] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A low-power sensor power supply integrated management system with strong environmental adaptability, characterized in that, It includes multiple power supply channels and a priority gating unit; The multiple power supply channels include at least a solar power supply branch, a rechargeable lithium battery energy storage branch, and a non-rechargeable backup battery branch. The priority selection unit includes an RC delay network connected in series with each power supply channel and a voltage trigger switch connected to the output of the RC delay network. The initial voltage of each power supply channel is set as follows: the higher the priority of the channel, the lower its initial voltage. The time constants of each RC delay network are set as follows: the higher the priority of the channel, the smaller its time constant; When at least two power supply channels receive power input simultaneously, the higher priority channel has a faster voltage rise rate, and its voltage-triggered switch turns on first, thus turning on that channel to supply power to the system, while suppressing the other channels from turning on.

2. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 1, characterized in that, The multiple power supply channels also include external power supply branches, and the priority of each channel from high to low is as follows: The first priority channel corresponds to the output of the external power supply branch or the full-charge output of the solar energy; The second priority channel corresponds to the output of the lithium-ion capacitor in the solar power supply branch; The third priority channel corresponds to the output of the rechargeable lithium battery energy storage branch; The fourth priority channel corresponds to the output of the non-rechargeable backup battery branch.

3. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 2, characterized in that, The solar power supply branch includes: a solar panel, a lithium-ion capacitor, and a fragmented energy splicing circuit connected between the solar panel and the lithium-ion capacitor; The fragment energy splicing circuit includes an NMOS transistor, the drain of which is connected to the negative terminal of the lithium-ion capacitor, the source is grounded, and the gate is connected to the positive terminal of the lithium-ion capacitor through a voltage divider resistor. When the voltage of the lithium-ion capacitor is lower than the first threshold, the NMOS transistor is turned off, the negative terminal of the lithium-ion capacitor is left floating, and the weak current output by the solar panel accumulates charge at the positive terminal of the lithium-ion capacitor. When the voltage of the lithium-ion capacitor accumulates to exceed the second threshold, the NMOS transistor is turned on, and the negative terminal of the lithium-ion capacitor is grounded, forming a complete charging path.

4. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 3, characterized in that, The solar power supply branch also includes a tiered charging judgment module, which consists of two depletion-type MOSFETs connected in series. The tiered charging judgment module only allows the energy of the solar panel to bypass to the charging circuit of the rechargeable lithium battery energy storage branch when the voltage of the lithium-ion capacitor exceeds the third threshold.

5. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 1, characterized in that, The priority gating unit also includes a passive energy cage network, which is composed of cross-coupled NMOS transistors and PMOS transistors; Each power supply channel has a pair of back-to-back NMOS and PMOS transistors connected in series at its output terminal, and the gates of each transistor are connected to the output terminals of other channels through a resistor divider. When any channel is turned on, its output voltage is forcibly cut off all channels with lower priority through the voltage divider of the resistor.

6. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 5, characterized in that, It also includes a low-temperature voltage inversion compensation circuit, which includes: a thermistor, a junction field-effect transistor (JFET), and a Schottky diode; When the thermistor detects that the temperature is lower than the set value, the JFET automatically connects the Schottky diode in series in the third priority channel to increase the on-state voltage drop of the channel and prevent the non-rechargeable backup battery branch from being incorrectly selected due to the decrease in the output voltage of the rechargeable lithium battery at low temperature.

7. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 1, characterized in that, The voltage-triggered switch is a bidirectional thyristor or a threshold detection circuit composed of discrete transistors.

8. The environmentally adaptable, low-power sensor power supply integrated management system according to claim 1, characterized in that, The system has a total static power consumption of less than 1μA and does not rely on any microcontroller, voltage comparator or ideal diode controller.

9. A low-power sensor power management method with strong environmental adaptability, applied to the system described in any one of claims 1 to 8, characterized in that, Includes the following steps: When there is no external power supply but there is sunlight, the energy output by the solar panel is preferentially used to charge the lithium-ion capacitor through the fragmented energy splicing circuit. When the voltage of the lithium-ion capacitor reaches the full charge threshold, the energy of the solar panel is bypassed to the rechargeable lithium battery for charging. When the rechargeable lithium battery is fully charged, the solar panel's energy directly powers the system load through the first priority channel; When there is no light and no external power supply, the priority selection unit is based on the RC delay competition mechanism. It first turns on the second priority channel, which is the lithium-ion capacitor discharge channel. If the lithium-ion capacitor is depleted, it automatically switches to the third priority channel, which is the rechargeable lithium battery discharge channel. If it is depleted again, it switches to the fourth priority channel, which is the non-rechargeable backup battery discharge channel. When an external power supply is connected, it immediately preempts the bus through the extremely short RC time constant of the first priority channel, cutting off all other channels.

10. The low-power sensor power management method with strong environmental adaptability according to claim 9, characterized in that, Under low light conditions, when the output voltage of the solar panel is lower than the charging threshold of the lithium battery, the energy of multiple low light pulses is accumulated in the lithium-ion capacitor through the fragmented energy splicing circuit. Once the accumulated energy is sufficient to turn on the NMOS transistor, the lithium-ion capacitor is charged in a concentrated manner.

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