A high voltage cable vibration energy collection device

Abstract

The present invention discloses a high-voltage cable vibration energy collection device, which relates to the technical field of piezoelectric energy collection, including a rectifier module for converting an AC signal input by a piezoelectric energy collector into a DC signal; an energy storage capacitor for collecting energy input by the piezoelectric energy collector; an energy storage capacitor voltage detection module, including a voltage comparator and a peripheral resistor, wherein the peripheral resistor and the voltage comparator constitute a hysteresis comparator; wherein, when the energy storage capacitor is charged to a voltage greater than an upper threshold, the hysteresis comparator outputs a high level to control instantaneous discharge, and when the energy storage capacitor is discharged to a voltage less than a lower threshold, the hysteresis comparator outputs a low level to control energy storage. The instantaneous discharge voltage stabilizing circuit of the present invention realizes efficient storage of piezoelectric energy and stable 5V DC output through a dual piezoelectric energy collector input design and an instantaneous discharge strategy controlled by a hysteresis comparator, thereby improving the energy utilization efficiency of the system and providing continuous power supply for low-power electronic devices.

Description

Technical Field

[0001] The invention relates to the technical field of piezoelectric energy collection, and in particular to a high-voltage cable vibration energy collection device. Background Art

[0002] With the rapid development of Internet of Things systems and microelectronic devices, energy harvesting technology has received widespread attention as an important means to solve their power supply problems. Piezoelectric energy harvesting technology occupies an important position in the field of power supply for low-power electronic devices due to its advantages such as high energy conversion density, wide applicable environment and long service life. The existing piezoelectric energy harvesting system mainly includes three parts: piezoelectric conversion unit, energy management unit and energy storage unit. Among them, the energy management unit is the key link to achieve effective utilization of piezoelectric energy. It is mainly responsible for converting the AC power generated by the piezoelectric element into DC power and providing stable power output to the load through the power management circuit. At present, the energy management circuit of the piezoelectric energy harvester mainly adopts a combination of AC-DC rectifier circuit, DC-DC conversion circuit and energy storage circuit. By rectifying, buck-boosting and energy storage processing of the AC signal output by the piezoelectric energy harvester, a stable DC voltage output is finally achieved.

[0003] However, the existing energy management circuits for piezoelectric energy harvesters have the following technical defects: first, the voltage and current output by the piezoelectric energy harvester will fluctuate with the frequency and amplitude of the environmental vibration, resulting in unstable energy conversion efficiency; second, the traditional energy management circuit generally adopts a continuous discharge mode, which cannot meet the instantaneous power demand of the load when the output power of the piezoelectric energy harvester is low; third, most of the existing energy management circuits adopt a fixed voltage threshold control strategy, lacking the ability to adaptively adjust for different working environments and load requirements; finally, the output power of a single piezoelectric energy harvester is limited, and the existing energy management circuit lacks a coordinated management mechanism for the output of multiple piezoelectric energy harvesters. These technical problems have seriously restricted the application of piezoelectric energy harvesting systems in the field of power supply for low-power electronic devices. Summary of the invention

[0004] In view of the above problems or problems existing in the prior art, the present invention is proposed.

[0005] Therefore, an object of the present invention is to provide a high-voltage cable vibration energy collection device, which.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a high-voltage cable vibration energy harvesting device, comprising a rectifier module for converting an AC signal input by a piezoelectric energy harvester into a DC signal;

[0007] Energy storage capacitor, used to collect energy input from the piezoelectric energy harvester;

[0008] The energy storage capacitor voltage detection module includes a voltage comparator and a peripheral resistor, wherein the peripheral resistor and the voltage comparator constitute a hysteresis comparator; wherein, when the energy storage capacitor is charged to a voltage greater than an upper threshold, the hysteresis comparator outputs a high level to control instantaneous discharge, and when the energy storage capacitor is discharged to a voltage less than a lower threshold, the hysteresis comparator outputs a low level to control energy storage.

[0009] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, wherein: the input end of the piezoelectric energy harvester is provided with PZT1 and PZT2, which is used to simultaneously connect two piezoelectric energy harvesters; the rectifier module includes DC1 and DC2 corresponding to the PZT1 and PZT2 respectively, which are used to rectify the AC outputs of the two piezoelectric energy harvesters and input them in parallel to the energy storage capacitor.

[0010] As a preferred solution of the high-voltage cable vibration energy harvesting device of the present invention, it also includes a voltage control unit, which includes D1 and D2 corresponding to the PZT1 and PZT2 respectively, and is used to limit the maximum voltage input by the piezoelectric energy harvester.

[0011] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, the voltage comparator is MAX917EUK, the peripheral resistors include R1, R2 and R3, and the upper and lower thresholds of the hysteresis comparator are changed by adjusting the resistance values ​​of R1, R2 and R3.

[0012] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, it also includes a voltage detection switch, and the voltage detection switch adopts FDC6331L, which is used to control the charging and discharging state of the energy storage capacitor according to the output level of the hysteresis comparator.

[0013] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, it also includes a voltage stabilizing module, which is a DC-DC converter that converts the energy released by the energy storage capacitor into a 5V stabilized DC output.

[0014] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, the difference between the upper threshold and the lower threshold of the hysteresis comparator is dynamically adjusted according to the load power demand. When the load power demand is large, the difference is increased to extend the energy storage time, and when the load power demand is small, the difference is reduced to increase the power supply frequency.

[0015] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, the input end of the piezoelectric energy harvester is provided with n input interfaces, where n≥3, for expanding the access to the array-type piezoelectric energy harvester; accordingly, the rectifier module includes n rectifier units, which are used to rectify the AC outputs of n piezoelectric energy harvesters and input them in parallel to the energy storage capacitor.

[0016] As a preferred solution of the high-voltage cable vibration energy harvesting device described in the present invention, it also includes an energy harvesting efficiency detection circuit for real-time detection of the energy harvesting efficiency of each piezoelectric energy harvester, and dynamically adjusts the working state of each piezoelectric energy harvester according to the detection result.

[0017] As a preferred solution of the high-voltage cable vibration energy collection device described in the present invention, the energy storage capacitor includes a main energy storage capacitor and a backup energy storage capacitor. When one of the energy storage capacitors is in a discharging state, the other energy storage capacitor is in a charging state, thereby achieving continuous and stable power supply.

[0018] Beneficial effects of the present invention: The instantaneous discharge voltage stabilization circuit provided by the present invention has the following advantages: by setting a dual piezoelectric energy harvester input end, the parallel input of multiple piezoelectric energy harvesters can be realized, and it can be expanded to support array-type piezoelectric energy harvesters; a voltage control unit is used to limit the input voltage, which effectively protects the circuit; the hysteresis comparator in the energy storage capacitor voltage detection module is used to implement an instantaneous discharge control strategy based on an adjustable voltage threshold, and the upper and lower thresholds can be flexibly adjusted according to actual application requirements, thereby optimizing the instantaneous discharge cycle scheme; the introduction of the voltage detection switch FDC6331L improves the reliability of the switch control; the overall circuit design enables the energy generated by the piezoelectric energy harvester to be efficiently stored and released instantaneously, achieving a stable 5V DC output, which can continuously power low-power electronic devices, and significantly improves the energy utilization efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 The invention discloses an instantaneous discharge voltage stabilizing circuit for a piezoelectric energy harvester. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0023] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0024] Example 1, reference Figure 1 , which is the first embodiment of the present invention, and provides a high-voltage cable vibration energy collection device, including a piezoelectric energy harvester input end, a voltage control unit, a rectifier module, an energy storage capacitor, an energy storage capacitor voltage detection module, a voltage detection switch and a voltage stabilizing module. Among them, the piezoelectric energy harvester input end includes two input interfaces, PZT1 and PZT2, for connecting two independent piezoelectric energy harvesters; the voltage control unit includes two transient suppression diodes, D1 and D2, which are connected in series with PZT1 and PZT2 respectively; the rectifier module includes two rectifier bridges, DC1 and DC2, for converting the AC signal output by the piezoelectric energy harvester into a DC signal; the energy storage capacitor uses a large-capacity electrolytic capacitor C3; the energy storage capacitor voltage detection module is composed of a voltage comparator MAX917EUK and peripheral resistors R1, R2, R3 to form a hysteresis comparator; the voltage detection switch uses FDC6331L; the voltage stabilizing module is a DC-DC converter, which outputs a stable 5V DC voltage.

[0025] In this embodiment, the piezoelectric energy harvester input terminals PZT1 and PZT2 are connected in parallel, and two piezoelectric energy harvesters can be connected at the same time to improve the energy harvesting capability of the system. Each input terminal is connected in series with a transient suppression diode (D1, D2), which can effectively limit the maximum voltage of the piezoelectric energy harvester input. When the output voltage of the piezoelectric energy harvester exceeds the breakdown voltage of the transient suppression diode, the excess voltage will be clamped, thereby protecting the subsequent circuit from overvoltage damage. The rectifier modules DC1 and DC2 use a full-bridge rectifier circuit to convert the AC signal output by the piezoelectric energy harvester into a DC signal, and the rectified DC signal is input in parallel to the energy storage capacitor C3.

[0026] The energy storage capacitor voltage detection module is the core unit of the present invention, and the voltage comparator MAX917EUK and peripheral resistors R1, R2, and R3 are used to form a hysteresis comparator. By reasonably designing the resistance values ​​of R1, R2, and R3, the upper and lower thresholds of the hysteresis comparator can be set. Specifically, R1 takes a value of 10kΩ, R2 takes a value of 100kΩ, and R3 takes a value of 1MΩ. At this time, the upper threshold of the hysteresis comparator is 12V and the lower threshold is 8V. When the voltage of the energy storage capacitor C3 exceeds 12V, the hysteresis comparator outputs a high level, drives the voltage detection switch FDC6331L to turn on, and the energy storage capacitor C3 releases energy to the load through the DC-DC converter; when the voltage of the energy storage capacitor C3 drops below 8V, the hysteresis comparator outputs a low level, the voltage detection switch FDC6331L is turned off, and the energy storage capacitor C3 re-enters the charging stage.

[0027] The voltage stabilization module uses a DC-DC converter to convert the energy released by the energy storage capacitor into a stable 5V DC output. The input voltage range of the DC-DC converter is 8V-12V, and the conversion efficiency can reach more than 85%. The instantaneous discharge strategy controlled by the hysteresis comparator can ensure that the DC-DC converter always operates within its optimal operating voltage range, improving the energy conversion efficiency.

[0028] Example 2, reference Figure 1 , which is the second embodiment of the present invention, based on embodiment 1, this embodiment optimizes the threshold setting of the energy storage capacitor voltage detection module. Taking into account the differences in power requirements of the load in different application scenarios, this embodiment provides a dynamic threshold adjustment scheme. Specifically, the upper and lower thresholds of the hysteresis comparator are changed by adjusting the resistance values ​​of resistors R1, R2, and R3. When the load power demand is large, the difference between the upper and lower thresholds can be increased to extend the energy storage time and ensure that each discharge can provide sufficient energy; when the load power demand is small, the difference between the upper and lower thresholds can be reduced to increase the power supply frequency and make the system work more smoothly.

[0029] Take a low-power sensor node as an example. Its operating voltage is 5V and its average power consumption is 1mW. However, it will have an instantaneous power demand of 20mW during data transmission. At this time, R1 can be adjusted to 20kΩ, R2 to 200kΩ, and R3 to 2MΩ, so that the upper threshold of the hysteresis comparator is increased to 15V and the lower threshold is reduced to 6V. In this way, the energy storage capacitor can store more energy during the charging stage to meet the instantaneous power demand of the sensor node during data transmission.

[0030] Embodiment 3, this embodiment provides an expansion scheme supporting array-type piezoelectric energy harvesters. Based on Embodiment 1, the input end of the piezoelectric energy harvester is expanded to n (n≥3), and each input end is configured with a corresponding transient suppression diode and a rectifier bridge. The outputs of multiple piezoelectric energy harvesters are connected in parallel to the same energy storage capacitor after rectification to achieve centralized energy management.

[0031] This embodiment also adds an energy collection efficiency detection circuit for real-time monitoring of the output power of each piezoelectric energy harvester. When it is detected that the output power of a piezoelectric energy harvester is lower than the preset threshold, the system will automatically disconnect it to avoid the overall efficiency being affected by the continuous current loss of the inefficient energy harvester. At the same time, the energy collection efficiency detection circuit can also dynamically adjust the number of working piezoelectric energy harvesters according to the load power demand to achieve intelligent management.

[0032] Embodiment 4, this embodiment provides an optimization scheme for alternating operation of dual energy storage capacitors. On the basis of embodiment 1, the energy storage capacitor unit adopts two capacitors C3A and C3B of the same specifications, and realizes alternating charging and discharging through a switching circuit. Specifically, when C3A is in a discharging state, C3B is charged; when the voltage of C3A drops to the lower threshold, the switching circuit switches C3B to a discharging state, and C3A starts charging at the same time. This scheme of alternating operation of dual energy storage capacitors can realize continuous output of energy and avoid the output voltage fluctuation that may be caused by the charging and discharging switching process in a single energy storage capacitor scheme.

[0033] This embodiment also adds an energy collection efficiency detection circuit for real-time monitoring of the output power of each piezoelectric energy harvester. When it is detected that the output power of a piezoelectric energy harvester is lower than the preset threshold, the system will automatically disconnect it to avoid the overall efficiency being affected by the continuous current loss of the inefficient energy harvester. At the same time, the energy collection efficiency detection circuit can also dynamically adjust the number of working piezoelectric energy harvesters according to the load power demand to achieve intelligent management.

[0034] It is important to note that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high-voltage cable vibration energy collection device, characterized in that: include, A rectifier module, used to convert the AC signal input by the piezoelectric energy harvester into a DC signal; Energy storage capacitor, used to collect energy input from the piezoelectric energy harvester; The energy storage capacitor voltage detection module includes a voltage comparator and a peripheral resistor, wherein the peripheral resistor and the voltage comparator constitute a hysteresis comparator; wherein, when the energy storage capacitor is charged to a voltage greater than an upper threshold, the hysteresis comparator outputs a high level to control instantaneous discharge, and when the energy storage capacitor is discharged to a voltage less than a lower threshold, the hysteresis comparator outputs a low level to control energy storage.

2. The high-voltage cable vibration energy collection device according to claim 1, characterized in that: The input end of the piezoelectric energy harvester is provided with PZT1 and PZT2 for simultaneously connecting two piezoelectric energy harvesters; the rectifier module includes DC1 and DC2 corresponding to PZT1 and PZT2 respectively, for rectifying the AC outputs of the two piezoelectric energy harvesters and inputting them in parallel to the energy storage capacitor.

3. The high-voltage cable vibration energy collection device according to claim 2, characterized in that: It also includes a voltage control unit, which includes D1 and D2 corresponding to the PZT1 and PZT2 respectively, and is used to limit the maximum voltage input by the piezoelectric energy harvester.

4. The high-voltage cable vibration energy collection device according to claim 3, characterized in that: The voltage comparator is MAX917EUK, and the peripheral resistors include R1, R2 and R3. The upper and lower thresholds of the hysteresis comparator are changed by adjusting the resistance values ​​of R1, R2 and R3.

5. The high-voltage cable vibration energy collection device according to claim 4, characterized in that: It also includes a voltage detection switch, which adopts FDC6331L and is used to control the charging and discharging state of the energy storage capacitor according to the output level of the hysteresis comparator.

6. The high-voltage cable vibration energy collection device according to claim 5, characterized in that: It also includes a voltage stabilizing module, which is a DC-DC converter that converts the energy released by the energy storage capacitor into a 5V regulated DC output.

7. The high-voltage cable vibration energy collection device according to any one of claims 1 to 6, characterized in that: The difference between the upper threshold and the lower threshold of the hysteresis comparator is dynamically adjusted according to the load power demand. When the load power demand is large, the difference is increased to extend the energy storage time, and when the load power demand is small, the difference is reduced to increase the power supply frequency.

8. The high-voltage cable vibration energy collection device according to claim 7, characterized in that: The input end of the piezoelectric energy harvester is provided with n input interfaces, where n≥3, for expanding access to an array-type piezoelectric energy harvester; accordingly, the rectifier module includes n rectifier units, for rectifying the AC outputs of the n piezoelectric energy harvesters and inputting them in parallel to the energy storage capacitor.

9. The high-voltage cable vibration energy collection device according to claim 8, characterized in that: It also includes an energy collection efficiency detection circuit for real-time detection of the energy collection efficiency of each piezoelectric energy harvester and dynamically adjusting the working state of each piezoelectric energy harvester according to the detection result.

10. The high-voltage cable vibration energy collection device according to claim 9, characterized in that: The energy storage capacitor includes a main energy storage capacitor and a backup energy storage capacitor. When one of the energy storage capacitors is in a discharging state, the other energy storage capacitor is in a charging state, thereby achieving continuous and stable power supply.

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