A power management circuit for micro-energy harvesting
By using micro-energy harvesting circuits and precise power management circuits, the problems of energy loss and inaccurate energy release caused by leakage current are solved, achieving efficient energy storage and release and meeting the stable power supply requirements of battery-free IoT devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG JOHAR TECH CO LTD
- Filing Date
- 2025-07-25
- Publication Date
- 2026-06-30
AI Technical Summary
Existing micro-energy harvesting systems suffer from excessive leakage current, leading to severe energy loss. Furthermore, existing power management solutions cannot accurately control energy release, resulting in low energy utilization and difficulty in meeting the stable power supply requirements of battery-free IoT devices.
Employing a micro-energy harvesting circuit, a linear voltage regulator circuit, and a switching management circuit, energy is harvested through the low leakage current of the energy storage capacitor and charged and discharged within a certain voltage range. Combined with voltage detection and dual diode protection, precise energy management is achieved.
It improves the energy utilization rate of energy storage capacitors, shortens the charging cycle, improves the efficiency of micro-energy harvesting, ensures stable power supply for equipment, and reduces energy waste.
Smart Images
Figure CN224438574U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of energy storage system technology, and in particular to a power management circuit for micro-energy harvesting. Background Technology
[0002] With the widespread application of IoT technology in remote monitoring, agricultural sensing, and other scenarios, the issue of device power supply is becoming increasingly prominent. Traditional battery-powered methods have significant limitations in long-term deployment: limited battery life and frequent replacements not only significantly increase maintenance costs, but discarded batteries also cause continuous pollution to the field environment, posing an environmentally unfriendly problem. Although micro-energy harvesting technologies (such as light and vibration energy harvesting) have made battery-free power supply possible, existing power management solutions still face many technical obstacles.
[0003] Current micro-energy harvesting systems commonly suffer from excessively high leakage current in their energy storage components, leading to significant energy loss during storage. While commonly used supercapacitors offer high charge-discharge efficiency, their operating voltage range is incompatible with the requirements of low-power devices, making them unsuitable for direct application in low-voltage applications.
[0004] In terms of energy management and control, most existing solutions employ a simple single-threshold voltage control strategy. This control method has significant drawbacks in actual operation: when the start-up voltage is set too high, the energy storage element requires an excessively long charging cycle, and the equipment remains in a dormant state for extended periods; when the shutdown voltage is set too low, a considerable amount of energy in the energy storage element remains unused before being forced into dormancy. This crude energy management results in the overall system energy utilization rate remaining at a low level for a long time, failing to meet the stringent requirements of continuous monitoring equipment for stable power supply.
[0005] Current technologies have not effectively resolved the contradiction between static losses and control precision of energy storage components, making it difficult for micro-energy harvesting systems to achieve the expected results in practical deployments. Especially in environments with extremely low energy harvesting density (such as indoor light energy or weak vibration energy), how to achieve efficient energy storage and precise release remains a core technological bottleneck restricting the large-scale application of battery-free IoT devices. Utility Model Content
[0006] To address the aforementioned problems, this invention provides a power management circuit for micro-energy harvesting. Energy is harvested through a micro-energy harvesting storage capacitor. Because the leakage current of the storage capacitor is very small, it can store the harvested micro-energy more efficiently. A switching management circuit allows the storage capacitor to charge and discharge within a certain voltage range, improving the effective utilization rate of the stored energy and increasing the efficiency of micro-energy harvesting.
[0007] To achieve the above objectives, this utility model provides a power management circuit for micro-energy harvesting, comprising: a micro-energy harvesting circuit, a linear voltage regulator circuit, a switching management circuit, and a power management circuit;
[0008] The micro-energy harvesting circuit includes a micro-energy input port and an energy storage capacitor, and the linear voltage regulation circuit includes a linear voltage regulator.
[0009] The micro-energy input port is connected to the energy harvesting circuit, the micro-energy input port is connected to the energy storage capacitor, and the energy storage capacitor is connected to the linear regulator;
[0010] The energy storage capacitor and the linear regulator are respectively connected to the switch management circuit, and the enable terminal of the switch management circuit is connected to the enable terminal of the linear regulator.
[0011] The linear regulator is also connected to the power management circuit, the output of which is connected to the input of the load.
[0012] In the above technical solution, preferably, the micro-energy harvesting circuit further includes a diode, the micro-energy input port is connected to the positive terminal of the diode, the negative terminal of the diode is connected to the positive terminal of the energy storage capacitor, the positive terminal of the energy storage capacitor is connected to the input terminal of the linear regulator and the input terminal of the switch management circuit respectively, and the negative terminal of the energy storage capacitor is grounded.
[0013] In the above technical solution, preferably, the input terminal of the linear regulator is grounded through a first capacitor, the output terminal is grounded through a second capacitor, and the grounding terminal of the linear regulator is grounded.
[0014] In the above technical solution, preferably, the switch management circuit adopts a dual diode switch circuit, the first input terminal of the switch management circuit is connected to the positive terminal of the energy storage capacitor, and the second input terminal is connected to the output terminal of the linear regulator.
[0015] In the above technical solution, preferably, the output terminal of the linear regulator is connected to the input terminal of the power management circuit, and the output voltage of the linear regulator is used as the BUCK / BOOST input, and the BUCK / BOOST output is used as the load input.
[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: energy is collected by a micro-energy harvesting storage capacitor. Since the leakage current of the storage capacitor is very small, the collected micro-energy can be stored more efficiently. The energy storage capacitor is charged and discharged within a certain voltage range by a switching management circuit, which improves the effective utilization rate of the energy stored by the storage capacitor and improves the efficiency of micro-energy harvesting. Attached Figure Description
[0017] Figure 1 This is a schematic block diagram illustrating the working principle of a power management circuit for micro-energy harvesting disclosed in one embodiment of the present invention.
[0018] Figure 2 This is a circuit diagram of a micro-energy harvesting circuit disclosed in one embodiment of the present invention;
[0019] Figure 3 This is a circuit diagram of a linear voltage regulator circuit disclosed in one embodiment of the present invention;
[0020] Figure 4 This is a circuit diagram of a switch management circuit disclosed in one embodiment of the present invention;
[0021] Figure 5 This is a circuit diagram of a power management circuit disclosed in one embodiment of the present invention. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0023] The present invention will now be described in further detail with reference to the accompanying drawings:
[0024] like Figure 1 As shown, a power management circuit for micro-energy harvesting provided by this utility model includes: a micro-energy harvesting circuit, a linear voltage regulator circuit, a switching management circuit, and a power management circuit.
[0025] The micro-energy harvesting circuit includes a micro-energy input port and an energy storage capacitor, and the linear voltage regulator circuit includes a linear voltage regulator;
[0026] The micro-energy input port is connected to the energy harvesting circuit, the micro-energy input port is connected to the energy storage capacitor, and the energy storage capacitor is connected to the linear regulator.
[0027] The energy storage capacitor and the linear regulator are respectively connected to the switching management circuit, and the enable terminal of the switching management circuit is connected to the enable terminal of the linear regulator.
[0028] The linear regulator is also connected to a power management circuit, the output of which is connected to the input of the load.
[0029] In this embodiment, energy is collected by a micro-energy harvesting storage capacitor. Since the leakage current of the storage capacitor is very small, the collected micro-energy can be stored more efficiently. The storage capacitor is charged and discharged within a certain voltage range by a switching management circuit, which improves the effective utilization rate of the stored energy and the efficiency of micro-energy harvesting.
[0030] Specifically, the micro-energy is harvested by connecting the micro-energy input port P1 to the energy storage capacitor C1. The energy harvested by the energy storage capacitor C1 is used to provide a discharge start threshold through a voltage detection circuit and a discharge cutoff threshold through the minimum operating voltage parameter of the linear regulator LDO. The output of the voltage detection circuit provides a start-up enable to the linear regulator U1 through the first diode of the dual-diode circuit, and the output of the linear regulator U1 provides a continuous discharge enable to the linear regulator U1 through the second diode of the dual-diode circuit. Through the above process, the energy storage capacitor C1 has charge / discharge start and cutoff thresholds, thereby improving the effective utilization efficiency of micro-energy harvesting and shortening the charging interval between multiple charges.
[0031] During implementation, the energy collected by the energy storage capacitor C1 simultaneously powers the linear regulator U1 and the switching management circuit U2. Once the energy collected by the energy storage capacitor C1 reaches the set value Vin, the switching management circuit outputs a high-level EN signal, activating the linear regulator. After the linear regulator U1 starts operating, the energy in the energy storage capacitor C1 decreases, and the amplitude of Vin decreases. When it drops to a certain threshold, the switching management circuit outputs EN to turn off the voltage. The energy storage capacitor C1 continues to charge based on the decreased voltage threshold, accelerating the charging of the energy storage capacitor C1 under non-cold start conditions, thus improving the efficiency of micro-energy collection and utilization.
[0032] like Figure 2As shown, in the above embodiment, preferably, the micro-energy harvesting circuit further includes a diode. The micro-energy input port is connected to the anode of the diode, the cathode of the diode is connected to the anode of the energy storage capacitor, the anode of the energy storage capacitor is connected to the input terminal of the linear regulator and the input terminal of the switching management circuit, and the cathode of the energy storage capacitor is grounded. The diode D1 plays a crucial role in unidirectional conduction and energy protection in the micro-energy harvesting circuit. When the output voltage of the micro-energy input port P1 is lower than the voltage of C1 (e.g., when the energy source operates intermittently or stops), the diode D1 is reverse-biased and cut off, completely blocking the energy stored in C1 from flowing back to P1, thus avoiding energy waste. The cut-off state of D1 forms physical isolation, ensuring that the microjoule-level energy stored in C1 will not leak through the internal impedance of P1 or the reverse electromotive force. When a transient high voltage (such as mechanical shock from a piezoelectric element) or a negative voltage (such as a sudden temperature change in a thermopile) is generated at the P1 terminal, the semiconductor junction characteristics of D1 can quickly clamp the abnormal voltage, preventing C1 and the subsequent voltage regulator circuit (U1) from being broken down, and avoiding electrode corrosion or performance degradation of the energy source caused by current backflow.
[0033] like Figure 3 As shown, in the above embodiment, preferably, the input terminal of the linear regulator is grounded through a first capacitor, the output terminal is grounded through a second capacitor, and the grounding terminal of the linear regulator is grounded.
[0034] In this embodiment, the positive terminal of the energy storage capacitor C1 is connected to one end of the first capacitor C2 and then to pin 1 of the linear regulator U1. The other end of the first capacitor C2 is connected to GND. Pin 5 of the linear regulator U1 is connected to one end of the second capacitor C3, and the other end of the second capacitor C3 is connected to GND. Pin 2 of the linear regulator U1 is connected to GND, and pin 3 (enable pin EN) of the linear regulator is connected to the enable output EN of the switch management circuit. Both the first capacitor C2 and the second capacitor C3 are surface-mount ceramic capacitors.
[0035] like Figure 4 As shown, in the above embodiment, preferably, the switch management circuit adopts a dual diode switch circuit, the first input terminal of the switch management circuit is connected to the positive terminal of the energy storage capacitor, and the second input terminal is connected to the output terminal of the linear regulator.
[0036] like Figure 5 As shown, in the above embodiment, preferably, the output terminal of the linear regulator LDO is connected to the input terminal of the power management circuit. The output voltage of the linear regulator LDO serves as the BUCK / BOOST input, and the BUCK / BOOST output serves as the load input. When the discharge voltage threshold of the energy storage capacitor C1 is lower than the minimum input threshold of the LDO, the discharge terminates, and the energy storage capacitor C1 begins to charge.
[0037] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A power management circuit for micro-energy harvesting, characterized in that, include: Micro-energy harvesting circuit, linear voltage regulator circuit, switching management circuit, and power management circuit; The micro-energy harvesting circuit includes a micro-energy input port and an energy storage capacitor, and the linear voltage regulation circuit includes a linear voltage regulator. The micro-energy input port is connected to the energy harvesting circuit, the micro-energy input port is connected to the energy storage capacitor, and the energy storage capacitor is connected to the linear regulator; The energy storage capacitor and the linear regulator are respectively connected to the switch management circuit, and the enable terminal of the switch management circuit is connected to the enable terminal of the linear regulator. The linear regulator is also connected to the power management circuit, the output of which is connected to the input of the load.
2. The power management circuit for micro-energy harvesting according to claim 1, characterized in that, The micro-energy harvesting circuit also includes a diode. The micro-energy input port is connected to the positive terminal of the diode, the negative terminal of the diode is connected to the positive terminal of the energy storage capacitor, the positive terminal of the energy storage capacitor is connected to the input terminal of the linear regulator and the input terminal of the switching management circuit, and the negative terminal of the energy storage capacitor is grounded.
3. The power management circuit for micro-energy harvesting according to claim 1, characterized in that, The input terminal of the linear regulator is grounded through a first capacitor, the output terminal is grounded through a second capacitor, and the grounding terminal of the linear regulator is grounded.
4. The power management circuit for micro-energy harvesting according to claim 1, characterized in that, The switch management circuit adopts a dual diode switch circuit. The first input terminal of the switch management circuit is connected to the positive terminal of the energy storage capacitor, and the second input terminal is connected to the output terminal of the linear regulator.
5. The power management circuit for micro-energy harvesting according to claim 1, characterized in that, The output terminal of the linear regulator is connected to the input terminal of the power management circuit. The output voltage of the linear regulator serves as the BUCK / BOOST input, and the BUCK / BOOST output serves as the load input.