Multi-source energy collection system based on charging time difference

Abstract

The utility model discloses a multi-source energy collecting system based on charging time difference, which belongs to the technical field of electric power energy storage and comprises a plurality of energy collecting circuits, each energy collecting circuit is connected with a rectifying circuit, and output ends of the rectifying circuits are connected in parallel and electrically connected with an input end of the energy collecting circuit based on the charging time difference. The output end t of the energy collection circuit based on the charging time difference is electrically connected with a load through a controller. According to the multi-source energy collection system based on the charging time difference, multi-source energy is connected in parallel, direct-current energy is output, multiple paths of direct-current energy are parallel, and the current of the output end can be improved, so that the output complementary function of multiple energy sources is realized, the energy collection efficiency is improved, and the energy utilization rate is improved. Multi-source energy output complementation can still realize an energy collection function when all sources are relatively weak, so that the application scene is expanded, the energy collection circuit based on the charging time difference is utilized to replace a special energy collection chip, and the cost is also reduced.

Description

Technical Field

[0001] This utility model belongs to the field of passive energy storage technology, specifically a multi-source energy harvesting system based on charging time difference. Background Technology

[0002] The Internet of Things (IoT) brings convenience to human life; however, in most deployed IoT systems, batteries are still used as the power source for nodes. The use of large numbers of batteries and their periodic replacement not only place a huge burden on the operation of the IoT but also severely pollutes the ecosystem upon which we depend. If we could break free from the IoT's dependence on batteries and utilize ambient energy to power IoT nodes, the applications of the IoT would become much more widespread.

[0003] Nature offers a wealth of energy sources, including light, kinetic energy, mechanical energy, thermal energy, and ubiquitous electromagnetic energy. Light energy has the largest reserves and is the easiest to collect; mechanical energy is not limited by time; and energy derived from temperature differences is unaffected by time, location, or the state of motion of objects. With the rapid development of IoT applications, wireless passive products have received widespread attention.

[0004] Existing energy harvesting primarily uses radio frequency (RF) energy or solar energy. A rectifier circuit converts the RF or solar energy into direct current (DC), and then a dedicated energy harvesting chip collects the DC energy output from the rectifier circuit. The system architecture is as follows: Figure 1 As shown, the disadvantages are: existing energy harvesting uses a single energy source, which limits its application areas and results in low energy harvesting efficiency; using dedicated energy harvesting chips has problems such as complex design, high cost, and lack of control. Utility Model Content

[0005] The technical problem to be solved by this utility model is that the existing single energy harvesting technology has low efficiency, limited application scenarios and expensive energy harvesting chips. It proposes a multi-source energy harvesting system based on charging time difference, which does not require the use of energy harvesting chips and can achieve multi-source energy harvesting with only a small number of capacitors, resistors and MOSFETs.

[0006] To address the aforementioned technical problems, this utility model provides a multi-source energy harvesting system based on charging time difference, comprising several energy harvesting circuits. Each energy harvesting circuit is connected to a rectifier circuit, and the output terminals of the rectifier circuits are connected in parallel with the input terminal V of the energy harvesting circuit based on charging time difference. in Electrical connection, output terminal V of the energy harvesting circuit based on charging time difference. out The controller is electrically connected to the load.

[0007] The energy harvesting circuit based on charging time difference includes an energy storage circuit, a discharge control circuit, an inverter, and an energy-saving control circuit. The energy storage circuit is connected between the input terminal of the energy harvesting circuit based on charging time difference and the controller. The discharge control circuit is connected in parallel with the energy storage circuit between the input terminal of the energy harvesting circuit based on charging time difference and the controller. The inverter is electrically connected to the energy storage circuit, the discharge control circuit, the controller, and ground (GND) respectively. The energy-saving control circuit is electrically connected to the discharge control circuit, the controller, and ground (GND) respectively.

[0008] As a further description of the above technical solution, the energy harvesting circuit includes one or a combination of several of the following: electromagnetic energy harvesting circuit, light energy harvesting circuit, vibration energy harvesting circuit, or thermoelectric energy harvesting circuit; the electromagnetic energy harvesting circuit uses a radio frequency energy harvesting source to harvest radio frequency signals and convert the electromagnetic energy of the surrounding environment into electrical energy; the light energy harvesting circuit uses a solar panel to harvest light energy and convert it into electrical energy; the vibration energy harvesting circuit converts mechanical vibration energy into electrical energy through a piezoelectric transducer; and the thermoelectric energy harvesting circuit converts temperature gradients and heat flow into electrical energy through thermoelectric energy conversion.

[0009] As a further description of the above technical solution, a Zener diode is also connected in parallel at the output of the rectifier circuit, which can prevent the Zener diode from being broken down due to excessively high output voltage from certain sources.

[0010] As a further description of the above technical solution, the energy storage circuit includes a resistor R0, a diode D0, and a capacitor C0 connected in series.

[0011] As a further description of the above technical solution, the discharge control circuit includes a resistor R1, a diode D1, and a capacitor C1 connected in series.

[0012] As a further description of the above technical solution, the inverter includes a PMOS transistor P0, an NMOS transistor N0, and a PMOS switch P1. The gates of both the PMOS transistor P0 and the NMOS transistor N0 are connected to a discharge control circuit. The drain of the PMOS transistor P0 is connected to the drain of the NMOS transistor N0 and is connected to the gate of the PMOS switch P1. The sources of both the PMOS transistor P0 and the PMOS switch P1 are connected to an energy storage circuit. The source of the NMOS transistor N0 is connected to ground (GND), and the drain of the PMOS switch P1 is electrically connected to the controller.

[0013] As a further description of the above technical solution, a resistor R3 is connected in series between the source of the NMOS transistor N0 and ground GND.

[0014] As a further description of the above technical solution, the energy-saving control circuit includes an NMOS switch N1 and a resistor R2. The gate of the NMOS switch N1 is electrically connected to the controller, the drain of the NMOS switch N1 is connected to the discharge control circuit, and the source of the NMOS switch N1 is connected to the resistor R2 and then grounded.

[0015] As a further description of the above technical solution, both the energy storage circuit and the discharge control circuit are connected to ground (GND).

[0016] The energy harvesting circuit based on charging time difference includes an energy storage circuit, a discharge control circuit, and an energy-saving control circuit. R0, R1, and R2 are used to implement current limiting function, and R1 is further used to adjust the charging time of the discharge control circuit.

[0017] To achieve multi-source energy harvesting, a unified interface for multi-source energy output is required. This allows for simultaneous energy harvesting from multiple sources and enables the connection of appropriate energy sources as needed in the specific scenario. By connecting all energy harvesting circuits to a voltage regulator circuit and then linking them together, backflow between sources can be prevented, thus enabling parallel connection of multi-source outputs. To prevent excessively high output voltages from some sources from damaging the diodes in the voltage regulator circuit, a Zener diode is connected in parallel at all source output points. Therefore, each source is designed with two output pins: one for VDD and one for GND. When designing the energy harvesting circuit, only multiple sets of 2-pin interfaces need to be designed in the circuit to connect the VDD and GND of each source. The other end of the 2-pin pin is connected to the input terminal of the energy harvesting circuit based on the charging time difference. On the other hand, when multiple energy sources are connected in parallel, since they are all output DC energy, the output current can be increased when multiple DC energy sources are connected in parallel, thereby realizing the function of complementary output of multiple energy sources and improving energy collection efficiency. The complementary output of multiple energy sources can still realize the energy collection function when all sources are relatively weak, thereby expanding the application scenarios. Moreover, the use of energy collection circuit based on charging time difference to replace dedicated energy collection chip also reduces costs. Attached Figure Description

[0018] Figure 1 This is a diagram of the architecture of an existing single-energy-source energy harvesting system.

[0019] Figure 2 This is an architecture diagram of the multi-source energy harvesting system based on charging time difference of this utility model.

[0020] Figure 3 This is a circuit diagram of the energy harvesting circuit based on charging time difference of this utility model. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] This embodiment provides a multi-source energy harvesting system based on charging time difference, such as Figure 2 — Figure 3 As shown, it includes several energy harvesting circuits, each of which is connected to a rectifier circuit. The output terminals of the rectifier circuits are connected in parallel with the input terminal V of the energy harvesting circuit based on the charging time difference. in Electrical connection, output terminal V of the energy harvesting circuit based on charging time difference. out The controller is electrically connected to the load, and a Zener diode is connected in parallel at the output of the rectifier circuit to prevent the Zener diode from being damaged due to excessively high output voltage from certain sources.

[0023] The energy harvesting circuit based on charging time difference includes an energy storage circuit, a discharge control circuit, an inverter, and an energy-saving control circuit. The energy storage circuit is connected between the input terminal of the energy harvesting circuit based on charging time difference and the controller. The discharge control circuit is connected in parallel with the energy storage circuit between the input terminal of the energy harvesting circuit based on charging time difference and the controller. Both the energy storage circuit and the discharge control circuit are connected to ground (GND). The inverter is electrically connected to the energy storage circuit, the discharge control circuit, the controller, and ground (GND) respectively. The energy-saving control circuit is electrically connected to the discharge control circuit, the controller, and ground (GND) respectively.

[0024] As a specific implementation of this embodiment, the energy harvesting circuit includes an electromagnetic energy harvesting circuit, a light energy harvesting circuit, a vibration energy harvesting circuit, and a thermoelectric energy harvesting circuit. The electromagnetic energy harvesting circuit uses a radio frequency energy harvesting source to harvest radio frequency signals, converting the electromagnetic energy of the surrounding environment into electrical energy. The light energy harvesting circuit uses a solar panel to harvest light energy, converting it into electrical energy. The vibration energy harvesting circuit converts mechanical vibration energy into electrical energy using a piezoelectric transducer. The thermoelectric energy harvesting circuit converts temperature gradients and heat flow into electrical energy through thermoelectric energy conversion.

[0025] In one specific embodiment of this invention, the energy storage circuit includes a resistor R0, a diode D0, and a capacitor C0 connected in series; the discharge control circuit includes a resistor R1, a diode D1, and a capacitor C1 connected in series; the inverter includes a PMOS transistor P0, an NMOS transistor N0, and a PMOS switch P1, with the gates of both the PMOS transistor P0 and NMOS transistor N0 connected to the discharge control circuit, and the drains of the PMOS transistor P0 and NMOS transistor N0 connected to the drain of the NMOS transistor N0, and further connected to the PMOS switch P1. The gate, source of PMOS transistor P0, and source of PMOS switch P1 are all connected to the energy storage circuit. The source of NMOS transistor N0 is connected to ground GND. A resistor R3 is connected in series between the source of NMOS transistor N0 and ground GND. The drain of PMOS switch P1 is electrically connected to the controller. The energy-saving control circuit includes NMOS switch N1 and resistor R2. The gate of NMOS switch N1 is electrically connected to the controller. The drain of NMOS switch N1 is connected to the discharge control circuit. The source of NMOS switch N1 is connected to resistor R2 and then grounded.

[0026] To achieve multi-source energy harvesting, a unified interface for multi-source energy output is required. This allows for simultaneous energy harvesting from multiple sources. Furthermore, appropriate energy sources can be connected according to the specific needs of the scenario. By connecting all energy harvesting circuits to a voltage regulator circuit, backflow between sources can be prevented, enabling parallel connection of multiple source outputs. To prevent excessively high output voltages from some sources from damaging the diodes in the voltage regulator circuit, a Zener diode is connected in parallel at all source output points. Therefore, each source is designed with two output pins: one for VDD and one for GND. When designing the energy harvesting circuit, multiple 2-pin interfaces are needed to connect the VDD and GND pins of each source. The other end of the 2-pin pin is connected to the input of the energy harvesting circuit based on charging time difference. On the other hand, when multiple energy sources are connected in parallel, since all outputs are DC energy, the parallel flow of multiple DC energy sources increases the output current, achieving complementary energy outputs and improving energy harvesting efficiency. Complementary multi-source energy outputs can still achieve energy harvesting even when all sources are relatively weak, thus expanding the application scenarios.

[0027] The energy harvesting circuit based on charging time difference includes an energy storage circuit, a discharge control circuit, and an energy-saving control circuit. R0, R1, and R2 are used to implement current limiting, and R1 is further used to adjust the charging time of the discharge control circuit. When the voltage across capacitor C1 causes the inverter output to go low, the energy harvesting circuit begins to supply power to subsequent circuits. The charging times of the energy storage circuit and the discharge control circuit can be expressed as follows:

[0028] T0=(R0+R D0C0 (1)

[0029] T1=(R1+R D1 C1 (2)

[0030] Among them, R D0 and R D1 This is the on-resistance of the diode. To achieve the energy harvesting function, sufficient energy needs to be harvested before powering subsequent circuits. That is, T1 >> T0 needs to be set to ensure that capacitor C0 has enough energy before power is supplied.

[0031] In the initial state, the voltage in C0 and C1 is 0, when V in When the voltage exceeds the diode's turn-on voltage, capacitors C0 and C1 will be charged. The charging rate is determined by T0 and T1. Since T1 >> T0, the energy storage circuit can reach a steady state (collect sufficient energy) faster. Therefore, when capacitor C0 has a lot of energy, the voltage of capacitor C1 is still very low, the inverter output is high, and PMOS switch P1 is off, storing the energy in capacitor C0. When capacitor C1 causes the inverter output to go low, PMOS switch P1 turns on, and C0 begins to power the subsequent circuitry.

[0032] When the label is in working mode, after the label has completed all its functions, E can be set. n When the voltage is high, the NMOS switch N1 is turned on, causing capacitor C1 to discharge through the NMOS switch N1 and resistor R2 until the voltage of capacitor C1 drops to the point that the PMOS switch P1 is turned off. At this point, the energy in capacitor C0 will be stored.

[0033] In the initial state, the voltage changes of the energy storage circuit and the discharge control circuit over time can be obtained from the charging and discharging formula of the RC circuit as follows:

[0034]

[0035] in This refers to the forward voltage drop of the diodes. Here, we assume that the voltage drops of the two diodes C0 and C1 are the same. When the discharge voltage V1 is greater than the minimum threshold voltage of the inverter... When the inverter outputs a low level, PMOS switch P1 is turned on, and capacitor C0 begins to supply power to subsequent circuits. Therefore, it is necessary to... At that time, capacitor C0 has already collected enough energy. To improve the robustness of the system, here we use... To calculate, by formula (4) and The following inequality can be calculated to satisfy time t:

[0036]

[0037] In order for capacitor C0 to reach a stable state (be fully charged) before PMOS switch P1 is turned on, the ratio of T0 to T1 should satisfy the following formula:

[0038]

[0039] Furthermore, from the capacitor energy formula, we can obtain:

[0040]

[0041] Assume V is less than V stop If it cannot supply power to subsequent circuits, then the energy that capacitor C0 can release is:

[0042]

[0043] in, This indicates the maximum energy that can be stored in capacitor C0. Therefore, capacitor C0 can be selected based on actual energy requirements. Assuming that capacitor C0 has a power supply efficiency of 50%, if the tag load requires energy in W... load Then the energy that C0 can release is W. P >2*W load According to formula (8), the capacitance C0 satisfies the following inequality:

[0044]

[0045] From formulas (1), (6) and (9), we can find that T1 satisfies the following equation:

[0046]

[0047] Select a rated voltage greater than With a capacitor of C1, the resistor R0 can be omitted (i.e., R0 = 0), thereby achieving the maximum energy harvesting efficiency. Furthermore, while satisfying formula (10), the capacitor C1 should be increased as much as possible to ensure that at V... in When the capacitance is 0, capacitor C1 can be maintained for a sufficiently long time.

[0048] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it; those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of this utility model.

Claims

1. A multi-source energy harvesting system based on charging time difference, characterized in that: It includes several energy harvesting circuits, each of which is connected to a rectifier circuit. The outputs of the rectifier circuits are connected in parallel with the input V of the energy harvesting circuit based on the charging time difference. in Electrical connection, output terminal V of the energy harvesting circuit based on charging time difference. out The controller is electrically connected to the load. The energy harvesting circuit based on charging time difference includes an energy storage circuit, a discharge control circuit, an inverter, and an energy-saving control circuit. The energy storage circuit is connected between the input terminal of the energy harvesting circuit based on charging time difference and the controller. The discharge control circuit is connected in parallel with the energy storage circuit between the input terminal of the energy harvesting circuit based on charging time difference and the controller. The inverter is connected to the energy storage circuit, the discharge control circuit, the controller, and ground respectively. GND Electrical connections are made, with the energy-saving control circuit connected to the discharge control circuit, the controller, and ground respectively. GND Electrical connection.

2. The multi-source energy harvesting system based on charging time difference as described in claim 1, characterized in that, The energy harvesting circuit includes: The electromagnetic energy harvesting circuit uses a radio frequency energy harvesting source to harvest radio frequency energy from radio frequency signals, converting the electromagnetic energy in the surrounding environment into electrical energy. And / or, a light energy harvesting circuit that uses solar panels to harvest light energy and convert it into electrical energy; And / or, a vibration energy harvesting circuit that converts mechanical vibration energy into electrical energy via a piezoelectric transducer; And / or, a thermoelectric energy harvesting circuit that converts temperature gradients and heat flow into electrical energy through thermoelectric energy conversion.

3. The multi-source energy harvesting system based on charging time difference as described in claim 1, characterized in that: A Zener diode is also connected in parallel at the output of the rectifier circuit.

4. The multi-source energy harvesting system based on charging time difference as described in any one of claims 1 to 3, characterized in that: The energy storage circuit includes resistors connected in series. R 0 ,diode D 0 and capacitor C 0 .

5. The multi-source energy harvesting system based on charging time difference as described in claim 4, characterized in that: The discharge control circuit includes resistors connected in series. R 1 ,diode D 1 and capacitor C 1 .

6. The multi-source energy harvesting system based on charging time difference as described in claim 5, characterized in that: The inverter includes a PMOS transistor. P 0 NMOS transistor N 0 and PMOS switches P 1 PMOS transistor P 0 gate and NMOS transistor N 0 The gates of all PMOS transistors are connected to the discharge control circuit. P 0 drain and NMOS transistor N 0 The drain is connected to the PMOS switch. P 1 The gate of the PMOS transistor P 0 The source and PMOS switch P 1 The sources of all NMOS transistors are connected to the energy storage circuit. N 0 The source is connected to ground (GND), POMS switch P 1 The drain is electrically connected to the controller.

7. The multi-source energy harvesting system based on charging time difference as described in claim 6, characterized in that: NMOS transistor N 0 A resistor is also connected in series between the source and ground (GND). R 3 .

8. The multi-source energy harvesting system based on charging time difference as described in claim 6, characterized in that: The energy-saving control circuit includes an NMOS switch. N 1 and resistance R 2 NMOS switch N 1 The gate of the NMOS switch is electrically connected to the controller. N 1 The drain is connected to the discharge control circuit, and the NMOS switch... N 1 source and resistor R 2 Grounding is required after connection.

9. The multi-source energy harvesting system based on charging time difference as described in claim 1, characterized in that: Both the energy storage circuit and the discharge control circuit are connected to ground (GND).

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