Electromagnetic vibration energy harvesting system adaptive to large-scale vibration source and control method thereof

Abstract

The invention provides an electromagnetic vibration energy harvesting system adaptive to a large-scale vibration source and a control method thereof, and the system comprises a plurality of electromagnetic vibration energy harvesting devices disposed on the large-scale vibration source, and at least one energy storage device. The plurality of self-switching adjustable charging circuits are arranged in one-to-one correspondence with the electromagnetic vibration energy harvesting devices; wherein each self-switching adjustable charging circuit automatically switches the circuit for charging the energy storage device based on the waveform of the real-time current output by the corresponding electromagnetic vibration energy harvesting device; and under the control of the main control unit, the magnitude of the charging current for charging the energy storage device is adjusted. According to the system provided by the invention, the electric energy output by the plurality of electromagnetic vibration energy harvesting devices arranged on the large-scale vibration source can be fully utilized to flexibly and efficiently charge the energy storage device.

Description

Technical Field

[0001] The present application belongs to the technical field of vibration energy collection and conversion, and specifically provides an electromagnetic vibration energy harvesting system adapted to large-scale vibration sources and a control method thereof. Background Art

[0002] The electromagnetic vibration energy harvesting device is a device that converts mechanical vibration energy into electrical energy. It is based on the principle of electromagnetic induction and uses the vibration of vibration sources such as bridges and tracks to generate current. Since the amplitude and frequency of vibration vary greatly, the output current needs to be stored in energy storage devices such as supercapacitors and lithium batteries, thereby meeting the needs of powering low-power micro-electromechanical systems such as wireless sensor networks.

[0003] For large-scale vibration sources, such as bridges with a length of hundreds of meters or even kilometers, it is generally possible to deploy multiple electromagnetic vibration energy capture devices at different locations to improve the ability to convert vibration energy into electrical energy. For vibration sources with larger spans, such as tracks and bridges, due to the large differences in vibration modes at different locations, during the installation and commissioning of the equipment, it may be necessary to select a suitable generator power generation method (that is, the electromagnetic vibration energy capture device can use a DC generator or an AC generator to convert vibration energy into electrical energy) based on the actual vibration conditions at the deployment location. Accordingly, it is necessary to ensure that efficient conversion of vibration energy into electrical energy can be achieved when different types of generators are replaced.

[0004] In addition, unlike conventional current sources with stable current output characteristics, the duration and amplitude of the current output of the electromagnetic vibration energy harvesting device are largely determined by the object (such as a car, train, etc.) that causes the vibration of the vibration source. On the one hand, large-scale vibration sources such as bridges are caused by the movement of objects of different weights, and the amplitude of vibrations varies, and therefore the output voltage amplitude of the vibration energy harvesting device can fluctuate between a few volts, more than ten volts, or even dozens of volts; on the other hand, when the above-mentioned target moves on the large-scale vibration source, it will cause the vibration of the vibration source at different positions at different times, and the vibration duration is closely related to the size and speed of the object, thereby affecting the energy output characteristics of the electromagnetic vibration energy harvesting device at different positions.

[0005] Therefore, there is a need for a system that can uniformly manage multiple electromagnetic vibration energy harvesting devices deployed on a large-scale vibration source, so as to perform flexible and efficient energy management according to the energy output characteristics of the electromagnetic vibration energy harvesting devices at each position. Summary of the invention

[0006] The present application provides an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source through an embodiment, comprising a plurality of electromagnetic vibration energy harvesting devices arranged on the large-scale vibration source, and at least one energy storage device, wherein the electromagnetic vibration energy harvesting device is used to convert the vibration of the large-scale vibration source into a real-time current for output, and the electromagnetic energy harvesting system adapted to the large-scale vibration source also includes:

[0007] A main control unit and a plurality of self-switching adjustable charging circuits arranged one-to-one corresponding to the electromagnetic vibration energy capture device; wherein each of the self-switching adjustable charging circuits automatically switches the circuit for charging the energy storage device based on the waveform of the real-time current output by its corresponding electromagnetic vibration energy capture device; and under the control of the main control unit, the size of the charging current for charging the energy storage device is adjusted.

[0008] The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources provided in the present application is provided with a self-switching adjustable charging circuit corresponding to each of the multiple electromagnetic vibration energy harvesting devices arranged at different positions of the large-scale vibration source. The self-switching adjustable charging circuit can adaptively conduct the AC path or the DC path according to the time-varying characteristics of the real-time current (current waveform), and adjust the charging current in real time, thereby ensuring that no matter what kind of current the electromagnetic vibration energy harvesting device outputs, the current output path can be adaptively adjusted without any manual adjustment, so that the electric energy is effectively transmitted to the charging part described later, which greatly increases the system's compatibility and charging efficiency with different types of electromagnetic vibration energy harvesting devices.

[0009] The present application also provides a control method for an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source through an embodiment, the control method comprising the following steps:

[0010] Each of the electromagnetic vibration energy capture devices converts the vibration generated by the large-scale vibration source at its location into real-time current;

[0011] For each of the electromagnetic vibration energy harvesting devices, based on the waveform of the real-time current outputted by the device, the circuit for charging the energy storage device is automatically switched;

[0012] For each of the electromagnetic vibration energy capture devices, a joint optimization charging strategy that takes into account energy output characteristics and energy storage status is used to adjust the size of the charging current used to charge the energy storage device, wherein the energy output characteristics include the voltage amplitude and change rate information of the real-time current.

[0013] The present application also provides a control method for an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source through an embodiment, which is used to control an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source comprising three or more electromagnetic vibration energy harvesting devices, and the control method comprises the following steps:

[0014] Each of the electromagnetic vibration energy capture devices converts the vibration generated by the large-scale vibration source at its location into real-time current;

[0015] For each of the electromagnetic vibration energy harvesting devices, based on the waveform of the real-time current outputted by the device, the circuit for charging the energy storage device is automatically switched;

[0016] For two adjacent electromagnetic vibration energy harvesting devices that are first affected by an object moving on the large-scale vibration source, a joint optimization charging strategy that takes into account energy output characteristics and energy storage status is used to adjust the magnitude of the charging current used by the two electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object, wherein the energy output characteristics include the voltage amplitude of the real-time current and its rate of change information; and,

[0017] The moving direction and speed of the object are determined based on the energy output characteristics of the two adjacent electromagnetic vibration energy harvesting devices, and the charging current of other electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object is adjusted based on the moving direction and speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the arrangement and energy capture of an existing electromagnetic vibration energy capture device on a large-scale vibration source;

[0019] Figure 2 A schematic diagram of the architecture of an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source provided according to an embodiment of the present application;

[0020] Figure 3 A schematic diagram of the architecture of an energy management unit provided according to an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the internal architecture of a self-switching adjustable charging circuit provided according to an embodiment of the present application;

[0022] Figure 5 A schematic diagram of the internal architecture of an AC / DC selection unit provided according to an embodiment of the present application;

[0023] Figure 6 A circuit diagram of an AC / DC selection unit provided according to an embodiment of the present application;

[0024] Figure 7A schematic diagram of a line switching signal output by a comparison module provided in an embodiment of the present application when an alternating current is input;

[0025] Figure 8 A schematic diagram of a line switching signal output by a comparison module provided in an embodiment of the present application when a direct current is input;

[0026] Fig. 9 A schematic diagram of a three-phase rectifier circuit provided according to an embodiment of the present application;

[0027] Fig.10 A schematic diagram of a filter circuit provided according to an embodiment of the present application;

[0028] Fig.11 A schematic diagram of the architecture of a processing unit provided according to an embodiment of the present application;

[0029] Fig.12 is a schematic diagram of a BMS chip;

[0030] Fig.13 A schematic diagram of the voltage amplitude change of the real-time current output by the electromagnetic vibration energy harvesting device provided according to an embodiment of the present application;

[0031] Fig.14 A schematic diagram of a curve of a charging voltage of an energy storage device and a generator output torque of an electromagnetic vibration energy capture device provided according to an embodiment of the present application;

[0032] Fig.15 A flow chart of a control method for an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source provided in an embodiment of the present application;

[0033] Fig.16 A flowchart of a joint optimization charging strategy considering energy output characteristics and energy storage status provided according to an embodiment of the present application;

[0034] Fig.17 A circuit schematic diagram of a sampling module provided according to an embodiment of the present application;

[0035] Fig.18 A pin diagram of a main control unit provided according to an embodiment of the present application;

[0036] Fig.19 A schematic diagram of a BMS chip machine peripheral circuit provided according to an embodiment of the present application;

[0037] Fig. 20 A schematic diagram of the torque change of the generator of the electromagnetic vibration energy harvesting device when the joint optimization charging strategy is adopted according to the embodiment of the present application;

[0038] Fig.21is a schematic diagram of real-time current output by an electromagnetic vibration energy harvesting device at three different positions according to an embodiment of the present application;

[0039] Fig. 22 A flow chart of a control method for an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source provided in an embodiment of the present application;

[0040] Fig.23 A schematic diagram of an anti-backflow circuit provided according to an embodiment of the present application;

[0041] Fig.24 A schematic diagram comparing power failure of an energy storage device when an anti-backflow circuit is added and when an anti-backflow circuit is not added according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] Hereinafter, the present application will be further described based on preferred embodiments with reference to the accompanying drawings.

[0043] In addition, various components in the drawings are enlarged or reduced in size for ease of understanding, but this practice is not intended to limit the scope of protection of the present application.

[0044] Words importing the singular also include the plural and vice versa.

[0045] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the products of the embodiments of the present application are usually placed when in use, it is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, in the description of the present application, in order to distinguish different units, the words first, second, etc. are used in this specification, but these are not limited by the order of manufacture, nor can they be understood as indicating or implying relative importance, and their names may be different in the detailed description and claims of the present application.

[0046] The vocabulary in this specification is used to illustrate the embodiments of the present application, but is not intended to limit the present application. It should also be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in this application can be specifically understood.

[0047] Figure 1A system for electromagnetic vibration energy capture on a large-scale vibration source is shown. Figure 1 As shown, the bridge 100 acts as a large-scale vibration source. When objects that cause vibrations, such as a car 201 or a tanker 202, travel on it, vibrations will be caused at different positions of the bridge 100 at different times. In order to effectively collect the vibration energy generated by the bridge 100 at different positions and at different times, a plurality of electromagnetic vibration energy harvesting devices (such as electromagnetic vibration energy harvesting devices 301, 302 and 303 arranged from right to left) can be selected to be arranged at appropriate positions according to the vibration conditions at different positions, and the sensed vibration energy can be converted into electrical energy.

[0048] Obviously, since the weight, size, driving speed, driving direction, etc. of the vehicles causing the bridge 100 to vibrate are all random, the current output by the energy capture devices at different positions has obvious intermittent properties, and the current duration, amplitude, etc. are all random. Therefore, a more feasible energy conversion method is to store the electrical energy output by each energy capture device in at least one energy storage device 501, thereby providing stable functions for loads such as low-power wireless gateways 601, wireless routers 602 or access points 603.

[0049] In addition, generally, it is necessary to reasonably select the model and output current form of the generator used in the electromagnetic vibration energy harvesting device according to the vibration characteristics of the bridge 100 at different positions, such as Figure 1 In the figure, the electromagnetic vibration energy harvesting devices 301 and 302 use AC generators, and the electromagnetic vibration energy harvesting device 303 uses a DC generator. Therefore, the electromagnetic vibration energy harvesting devices 301 and 302 need to be equipped with a circuit for rectifying the AC power.

[0050] The current output by each of the above energy capture devices (output by the DC generator or output by the AC generator and rectified) can be managed by using various BMS modules (Battery Management System) known to those skilled in the art. The BMS module generally uses the BMS chip as a core component, and its main function is to monitor and manage the status of the battery pack to ensure the safety, performance and life of the battery. At the same time, by real-time monitoring of the voltage, temperature, charging status and other parameters of the energy storage device 501, it provides charge and discharge control and balance circuit management to ensure that the battery works in the best state.

[0051] Although the existing BMS chip has the function of adjusting the charging current according to the state of the energy storage device such as the battery, such as switching between slow charging current, fast charging current and trickle charging current, when implementing the charging and discharging strategy, it generally uses the mains or a device that can generate stable electricity as a stable current source, that is, the switching of the above charging current does not take into account the impact on the input end device. However, for the electromagnetic vibration energy capture device, since its energy source is extremely random, the voltage amplitude and duration of VDC have great fluctuations. Therefore, in the process of charging control of the energy storage device 501, it is also necessary to take into account the output characteristics of different types of generators on the input side, and combine the vibration characteristics of large-scale vibration sources such as the bridge 100 at different positions to uniformly manage the charging of each electromagnetic vibration energy capture device.

[0052] 1. Overall system architecture:

[0053] In order to solve the above problems, the embodiments of the present application provide an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source, such as Figure 2 As shown, the electromagnetic vibration energy harvesting system includes a plurality of electromagnetic vibration energy harvesting devices (such as Figure 2 There are electromagnetic vibration energy harvesting devices 301, 302 that output alternating current, and an electromagnetic vibration energy harvesting device 303 that outputs direct current, and at least one energy storage device 501, wherein the electromagnetic vibration energy harvesting device is used to convert the vibrations at different positions of the large-scale vibration source into real-time current (such as alternating current as shown by the red arrow, or direct current as shown by the blue arrow) for output.

[0054] Obviously, the number, location and output AC and DC current form of the electromagnetic vibration energy harvesting device can be reasonably selected according to the size, shape, vibration characteristics, etc. of the vibration source, such as setting 2 or more. In addition, it can also be adjusted according to the actual energy harvesting effect during use. The number of energy storage devices 501 can be selected according to parameters such as the number of loads and rated power.

[0055] Furthermore, if Figure 2 As shown, the electromagnetic vibration energy harvesting system also includes an energy management unit 400, which is arranged between each electromagnetic vibration energy harvesting device and the energy storage device 501 to achieve unified management of the energy conversion process between each electromagnetic vibration energy harvesting device and the energy storage device 501.

[0056] Specifically, the energy management unit 400 is composed of a main control unit and a plurality of self-switching adjustable charging circuits, wherein each self-switching adjustable charging circuit is arranged one-to-one corresponding to each electromagnetic vibration energy capture device included in the energy capture system, and each self-switching adjustable charging circuit automatically switches the circuit for charging the energy storage device 501 based on the waveform of the real-time current output by its corresponding electromagnetic vibration energy capture device, and adjusts the size of the charging current for charging the energy storage device 501 under the control of the main control unit.

[0057] Figure 3 The diagram shows the architecture of the energy management unit 400 and the connection method between the energy management unit 400 and various energy capture devices and energy storage devices in some embodiments. Figure 3 In the illustrated embodiment, the system includes a total of three electromagnetic vibration energy capture devices 304, 305, and 306. Therefore, correspondingly, the energy management unit 400 includes three self-switching adjustable charging circuits 414, 415, and 416 which are arranged one-to-one corresponding to the three energy capture devices. The real-time current (which may be a DC current or an AC current) output by the three energy capture devices is converted into a charging current in the form of a DC current after passing through these three circuits to charge the energy storage device 501, and the size of the charging current is adjusted under the control of the main control unit 420.

[0058] Obviously, Figure 3 In the illustrated embodiment, the number of energy-harvesting devices and self-switching adjustable charging circuits are schematic, and those skilled in the art may flexibly adjust the number of energy-harvesting devices and self-switching adjustable charging circuits based on actual size and vibration conditions of the vibration source.

[0059] Figure 4 Taking the self-switching adjustable charging circuit 414 as an example, its internal architecture is shown. Figure 4 As shown, the self-switching adjustable charging circuit 414 includes a DC selection unit, a three-phase rectification circuit, a filtering circuit and a processing unit.

[0060] Among them, the AC / DC selection unit selectively conducts the AC path (red dotted line) or the DC path (blue dotted line) between the magnetic vibration energy capture device 304 and the processing unit based on the time-varying characteristics of the real-time current output by its corresponding electromagnetic vibration energy capture device 304; the three-phase rectifier circuit is arranged in the AC path, and is used to rectify the AC current in the AC path into DC current; the filter circuit is arranged in the DC path, and is used to filter the DC current passing through the DC path; the processing unit charges the energy storage device 501 based on the current input by the AC path or the DC path, and adjusts the size of the charging current under the control of the main control unit.

[0061] 2. AC / DC selection unit:

[0062] As analyzed above, electromagnetic vibration energy harvesting devices with different output current characteristics can be set at different positions of large-scale vibration sources. In addition, during the specific installation and debugging and actual working process, the model of the generator in the electromagnetic vibration energy harvesting device may be replaced or its working mode may be changed according to the actual measurement and analysis of the vibration mode and situation of the installation position to obtain the best energy output effect. In this process, it may be necessary to change the output real-time current from AC current to DC current, or from DC current to AC current. Although the real-time current output from a single current path can be directed to different input ports by manual adjustment, this will inevitably increase and reduce the system compatibility and increase the difficulty of application; if the real-time current is directly directed to the AC input terminal and the DC input terminal at the same time by a one-to-two method, since the AC current and the DC current need to be processed by different rectification or filtering circuits, half of the output current will not be processed at any time, resulting in a decrease in energy utilization.

[0063] In view of the above problems, the energy capture system provided in the present application is provided with an AC / DC selection unit in the self-switching adjustable charging circuit to realize adaptive switching of the DC current path and the AC current path. Figure 5 and Figure 6 , and explain its implementation in detail.

[0064] Figure 5 FIG. 4 shows the architecture of the self-switching adjustable charging circuit 417 corresponding to the electromagnetic vibration energy harvesting device 307 in a specific embodiment. Figure 5 As shown, the AC / DC selection unit included therein includes a first switch device, a second switch device and a comparison module.

[0065] The input ends of the first switch device, the second switch device and the comparison module are all connected to the output ends of the corresponding electromagnetic vibration energy capture device 307 for inputting real-time current.

[0066] The output end of the comparison module outputs a line switching signal Sig_1 to the first switch device and the second switch device at the same time, wherein when the real-time current is an AC current, the line switching signal Sig_1 is a high-level signal, and when the real-time current is a DC current, the line switching signal Sig_1 is a low-level signal. The first switch device turns on the upper AC path when the line switching signal Sig_1 is a high-level signal, and turns off the AC path when the line switching signal Sig_1 is a low-level signal; the second switch device turns on the lower DC path when the line switching signal Sig_1 is a low-level signal, and turns off the DC path when the line switching signal Sig_1 is a high-level signal.

[0067] Figure 6FIG. 1 shows a specific circuit schematic diagram of an AC / DC selection unit in a specific embodiment. Figure 3 As shown, the first switch device is a first NMOS transistor Q located in the upper AC path. S1 , the MOS tube is a high-level conduction type switch device; the second switch device is the first PMOS tube Q located in the DC path below S2 , the MOS tube is a low-level conduction type switch device; the comparison module includes a first diode D1, a first capacitor C1, a second capacitor C2, a first resistor R1, a second resistor R2 and a first comparator U1.

[0068] Specifically, the positive electrode of the first diode D1 is connected to the output end of the electromagnetic vibration energy capture device, and the negative electrode is connected to the first end of the first capacitor C1. The second end of the first capacitor C1 is respectively connected to the first end of the second capacitor C2, the first end of the first resistor R1, and the first end of the second resistor R2. The second end of the second capacitor C2 and the second end of the first resistor R1 are both grounded. The second end of the second resistor R2 is connected to the same-direction input end of the first comparator U1. The inverting input end of the first comparator is used to receive a reference voltage ref (for example, 3V).

[0069] The first NMOS tube Q S1 As the first switch device, its D pole and S pole are connected to the output end of the electromagnetic vibration energy capture device and the input end of the three-phase rectifier circuit respectively; the first PMOS tube Q S2 As the second switch device, its S pole and D pole are connected to the output end of the electromagnetic vibration energy capture device and the input end of the filter circuit respectively; the output end of the first comparator U1 is connected to the first NMOS tube Q S1 The G pole of the first PMOS tube Q S2 The G electrode is connected to output a line switching signal Sig_1 to the two MOS tubes.

[0070] The working principle of the AC / DC selection unit is:

[0071] When the real-time current output by the electromagnetic vibration energy capture device is an alternating current, after passing through the first diode D1, the zero-crossing part of the real-time current is cut off, and the alternating current component can pass through the first capacitor C1. According to the characteristic that the voltage across the capacitor cannot change suddenly, the current is converted into a direct current after passing through the second capacitor C2, and is further input to the same-direction input terminal of the first comparator U1 through the voltage division of the first resistor R1 and the second resistor R2. At this time, the voltage of the same-direction input terminal is greater than the reference voltage ref of the reverse input terminal, and the first comparator U1 outputs a high level, so the first NMOS tube Q S1 The first PMOS tube Q is turned on. S2 When the device is turned off, the AC current output by the electromagnetic vibration energy harvesting device will enter the processing unit through the AC path above.

[0072] When the real-time current output by the electromagnetic vibration energy capture device is a direct current, according to the characteristics of the capacitor blocking direct current and passing alternating current, the direct current will be cut off after passing through the first capacitor C1. Even if a small amount of current passes through the capacitor due to current fluctuations, the voltage input to the same-direction input terminal of the first comparator U1 is approximately 0 after the voltage is divided by the first resistor R1 and the second resistor R2. At this time, the voltage at the same-direction input terminal of the first comparator U1 is less than the reference voltage ref of its reverse input terminal, and the comparator outputs a low level. The first NMOS tube Q S1 Cut off, the first PMOS tube Q S2 When the device is turned on, the DC current output by the electromagnetic vibration energy capture device will enter the processing unit from the DC path below.

[0073] Figure 7 FIG. 1 shows a schematic diagram of a line switching signal Sig_1 output by a comparison module when the real-time current is an alternating current in an embodiment. Correspondingly, Figure 8 FIG. 1 shows a schematic diagram of a line switching signal Sig_1 output by the comparison module when the real-time current is a DC current in another embodiment. Figure 7 , Figure 8 It can be seen that after the AC current passes through the AC / DC selection unit, the first comparator U1 will output a high level, which can then control the first NMOS transistor Q S1 Turn on the AC path and control the first PMOS tube Q S2 After the DC current passes through the AC / DC selection unit, the first comparator U1 will output a low level, which can control the first PMOS tube Q S2 Turn on the DC path and control the first NMOS tube Q S1 The AC path is closed. Therefore, an AC / DC selection unit is set between the output end of the electromagnetic vibration energy capture device and the processing unit, which can adaptively conduct the AC path or the DC path according to the time-varying characteristics of the real-time current (current waveform), thereby ensuring that no matter what kind of current the electromagnetic vibration energy capture device outputs, the current output path can be adaptively adjusted without any manual adjustment, so that the electric energy is effectively transmitted to the charging part described later, which greatly increases the compatibility of the system with different types of electromagnetic vibration energy capture generators.

[0074] It should be noted that, without departing from the technical ideas of the present application, those skilled in the art can flexibly select components to build circuits to realize the function of adaptively switching AC and DC paths that can be realized by the AC / DC selection unit.

[0075] 3. Three-phase rectifier circuit and filter circuit:

[0076] In an embodiment of the present application, the real-time current passing through the AC / DC selection unit needs to be further converted into a DC current and transmitted to the VDC terminal of the BMS chip in the processing unit so that the processing unit can perform a charging operation in a DC-DC mode. Therefore, a three-phase rectifier circuit is required in the AC path to convert the AC current into a DC current.

[0077] Fig. 9 FIG. 2 shows a schematic diagram of a three-phase rectifier circuit in some preferred embodiments. Fig. 9 As shown, the three-phase rectifier module consists of a three-phase rectifier bridge composed of six Schottky diodes and filtering and voltage-stabilizing capacitors, which can rectify the three-phase AC voltage from low frequency to high frequency (less than or equal to 1MHz) into a DC voltage to output to the VDC+ terminal.

[0078] In addition, since the excitation frequency of the electromagnetic vibration energy capture device is relatively low in some cases, the main shaft speed of the DC generator is also relatively low, that is, the DC generator generates electricity at a relatively low speed in some cases. According to the output characteristics of the DC generator, the output at a relatively low speed is not stable DC power, but relatively fluctuating electric energy containing a small amount of AC components. At the same time, the electromagnetic vibration energy capture device may experience uneven transmission due to installation errors and other factors during operation, which may also cause fluctuations in the output electric energy. In addition, due to the electromagnetic interference inside the generator, noise interference from the environment and mechanical vibrations, etc., the electric energy output by the DC generator needs to be further rectified and filtered. For this reason, preferably, a filtering module is provided in the DC path.

[0079] Fig.10 In some preferred embodiments, the schematic diagram of the filter circuit is shown, as Fig.10 As shown, the filtering circuit includes a second diode D r , the third capacitor C f1 , the fourth capacitor C f2 and the first inductor L f , through the second diode D r The unidirectional conductivity of the DC generator cuts off the AC component of the output current, achieving the effect of rectification. The third capacitor C f1 The fourth capacitor C f2 and the first inductor L f A CLCπ-type filter is formed. Preferably, the third capacitor C f1 A relatively small value can be used to filter high-frequency signals in the output power. The first inductor L f The value of needs to be selected according to the filtering effect to be achieved and the value of the capacitor, which is used to further filter out the high-frequency interference signal in the output power and suppress the pulsating signal in the power. f2A relatively large value can be taken to smooth the fluctuation components in the electric energy and maintain the stability of the output voltage. Through the rectification and filtering module, the electric energy output by the DC generator is converted into stable DC power for use by the subsequent power management module.

[0080] In some preferred embodiments, the second diode D r Schottky diodes can be used to reduce voltage drop and improve power conversion efficiency. Furthermore, the number of capacitors in the CLC π-type filter is not limited to 2. Multiple capacitors can be placed according to the output characteristics of different generators and actual application scenarios to achieve better filtering effects.

[0081] 4. Processing unit and its cooperation with the main control unit - joint optimization charging strategy:

[0082] Fig.11 FIG. 4 shows the architecture of the processing unit and the connection method with the main control unit in some preferred embodiments. Fig.11 As shown, the processing unit includes a sampling module, a BMS chip and a current switching module.

[0083] Among them, the sampling module is connected to the current input terminal VDC of the BMS chip, and obtains the voltage amplitude distribution of the real-time current by sampling the current output from the three-phase rectifier circuit or the filter circuit to the VDC terminal; at the same time, it is connected to the voltage terminal VBAT of the energy storage device through the BMS chip (or it can also be directly connected to the VBAT terminal) to collect the voltage condition of the energy storage device.

[0084] The BMS chip is used to convert the current input to the VDC terminal through the three-phase rectification circuit or the filtering circuit into a charging current for charging the energy storage device.

[0085] The main control unit is connected to the sampling module and the current switching module respectively, and obtains the voltage amplitude and change rate information of the real-time current by receiving the voltage amplitude distribution of the real-time current output from the sampling module, and combines the voltage condition of the energy storage device obtained from the sampling module to generate a current switching signal Sig_2, and sends it to the current switching module. The current switching module switches the charging current output by the BMS chip according to the current switching signal Sig_2 sent by the main control unit.

[0086] By comparison Fig.11 and Figure 1It can be seen that in the embodiment of the present application, compared with the currently common solution of directly using the BMS chip for charging current management, the charging part adds the sampling of the voltage amplitude distribution of the real-time current output by the generator side of the electromagnetic vibration energy capture device. On this basis, the voltage amplitude and its change rate of the real-time current are considered by the main control unit, and the charging current is adjusted in combination with the voltage conditions on the energy storage device side.

[0087] The method of regulating the charging current only through the charging management strategy of the BMS chip is generally suitable for scenarios with a relatively stable current input source. For example, when photovoltaic equipment is used as the current input, the voltage at the VDC end remains basically constant over a period of time, so the energy storage device can be stably charged for a long time.

[0088] by Fig.12 Taking a BMS chip D1 as an example, the BMS chip model used is BQ24650RVAR, and its input port VCC supports input of 5V-30V DC current. At the same time, it can adjust the charging current according to the comparison between the voltage VBAT of the energy storage device received by feedback and the preset voltage.

[0089] For example, when the load is a wireless network device with an operating voltage of about 5V, a supercapacitor with a full-charge voltage of 5.5V or slightly higher can be selected, and a reasonable capacity (such as 10F to 100F or higher) can be selected according to the load conditions of the function to be performed. Under this condition, the BMS chip D1 can set the slow charge threshold voltage (such as 3V) and the fast charge threshold voltage (4.1V), and according to the comparison result of the feedback input VBAT and the above two threshold voltages, respectively control the energy storage device to charge with a smaller slow charge current or a larger fast charge current: Specifically, under this setting, when the BMS chip input When the DC current exceeds 5V (not exceeding 30V), D1 enters the charging working state. When the terminal voltage VBAT of the energy storage device does not exceed 3V, the BMS charges the energy storage device with a preset slow charging current, such as about 0.8A; when VBAT is between 3V and 4.1V, the energy storage device is charged with a preset fast charging current much greater than 0.8A, such as about 10*0.8A=8A; when VBAT exceeds 4.1V, the supercapacitor is close to full charge, while continuing to charge and discharging the load. At this time, the energy storage device can be charged with a smaller trickle current.

[0090] The above charging current adjustment strategy of the BMS chip is suitable for most stable current source charging scenarios. However, for electromagnetic vibration energy harvesting devices, their energy sources are extremely random, resulting in large fluctuations in the current, voltage amplitude and duration of real-time input.

[0091] Fig.13 FIG. 4 shows the change of the voltage amplitude (i.e., the VDC terminal voltage) of the real-time current output by an electromagnetic vibration energy capture device arranged on a locomotive track in a specific embodiment over a period of time. Fig.13 As shown in the figure, the duration of the first real-time current on the left is short, and the maximum value of its voltage amplitude is low, which means that the moving object causing the vibration may be short (such as the locomotive head), and the generator has not entered the ideal working state after starting (that is, its output voltage has not yet reached the working threshold voltage value U out ) means that the vibration stops; the second real-time current in the middle represents that a moving object may pass by the vibration source at high speed. Although its voltage peak is higher, its duration is shorter and it cannot output energy stably; the third current on the right represents that a longer object (such as a complete locomotive) passes by the vibration source at a constant speed. Its real-time current waveform has a stable voltage value U that exceeds the generator's optimal working threshold voltage value U out period of time.

[0092] Fig.14 A schematic diagram showing a curve of a charging voltage of an energy storage device and a generator output torque of an electromagnetic vibration energy harvesting device in some embodiments is shown. Fig.14 It can be seen that when the generator of the electromagnetic vibration energy capture device begins to output energy due to vibration, if it is charged with a large current, due to the influence of electromechanical coupling, the excessive current will cause the torque of the generator shaft to increase rapidly, which will have a braking effect on the rotation of the generator shaft, and then cause a large amplitude vibration of the energy capture device, which may cause damage to the device and shorten its service life. Only when the operating state of the generator of the electromagnetic vibration energy capture device is stable, it is suitable to output a larger current in a relatively stable state.

[0093] It can be seen that for electromagnetic vibration energy capture devices with large randomness in output energy, since they cannot output electrical energy continuously and stably like voltage stabilizers, current stabilizers and other devices, when controlling their charging, in addition to considering the charging state of the energy storage side, the output characteristics such as energy amplitude and stability (or rate of change) on the output side also need to be taken into consideration.

[0094] To this end, in some preferred embodiments of the present application, Fig.11 As shown, by adding a sampling module, a main control unit and a current switching module, the conventional method of charging management only through a BMS chip is improved, so that the charging process of the energy storage device can be adjusted using a joint optimization charging strategy that considers energy output characteristics and energy storage status.

[0095] Fig.15 FIG. 1 is a flow chart showing a control method of the electromagnetic vibration energy harvesting system adapted to a large-scale vibration source provided in some embodiments of the present application. Fig.15 As shown, the control method of the energy capture system includes the following steps:

[0096] Step S710, each electromagnetic vibration energy harvesting device converts the vibration generated by the large-scale vibration source at its location into real-time current;

[0097] Step S720, for each electromagnetic vibration energy harvesting device, based on the waveform of the real-time current outputted by the device, automatically switching the circuit for charging the energy storage device;

[0098] Step S730, for each electromagnetic vibration energy capture device, a joint optimization charging strategy considering energy output characteristics and energy storage status is adopted to adjust the charging current for charging the energy storage device, wherein the energy output characteristics include the voltage amplitude and change rate information of the real-time current.

[0099] In some specific embodiments, the above steps S710 to S730 can be repeatedly executed during the operation of the electromagnetic vibration energy capture system, wherein step S710 and step S720 are respectively implemented by each electromagnetic vibration energy capture device and the corresponding AC / DC selection unit in the self-switching adjustable charging circuit, and step S730 is implemented by the processing unit and the main control unit in the self-switching adjustable charging circuit. The joint optimization charging strategy adopted in step S730 is described in detail below.

[0100] Fig.16 A flowchart of a joint optimization charging strategy considering energy output characteristics and energy storage status in a specific embodiment is shown.

[0101] Combination Fig.11 and Fig.16 During the implementation of the joint optimization strategy, the acquisition module monitors the voltage value of the VDC port in real time to obtain the effective voltage amplitude and its change rate information of the real-time current output by the electromagnetic vibration energy harvesting device; at the same time, the voltage VBAT of the energy storage device is monitored in real time.

[0102] Next, the main control unit determines whether the voltage of the energy storage device (i.e., the voltage at the VBAT terminal) is greater than or equal to the slow charging threshold voltage. If VBAT is less than the slow charging threshold voltage at this time, the charging current will be limited to a level not exceeding the first current value regardless of whether the electromagnetic vibration energy capture device outputs real-time current.

[0103] If the main control unit determines that the voltage at the VBAT terminal is greater than or equal to the slow charge threshold voltage, it further determines whether it is less than the fast charge threshold voltage. As shown above, the fast charge threshold voltage represents the voltage corresponding to the energy storage device being close to the fully charged state. For example, when the full charge voltage of the energy storage device is 5V, the fast charge threshold voltage can be set to about 4.1V. When the voltage of the energy storage device exceeds the fast charge threshold voltage, regardless of whether the electromagnetic vibration energy capture device outputs real-time current, the charging current value is set to a level not exceeding the third current value.

[0104] Since the fast charging threshold voltage represents that the energy storage device is close to being fully charged, the third current value can be set to a micro-current state of, for example, 0.1A to 0.2A. That is, when the energy storage device is close to being fully charged, it is charged in real time with a micro-current to ensure that it can be safely fully charged and maintained at the optimal charging and discharging level.

[0105] When the voltage of the energy storage device is between the slow charge threshold voltage and the fast charge threshold voltage, it means that the energy storage device is ready for high current fast charge. Fig.16 As shown, the real-time current characteristics of the output of the electromagnetic vibration energy harvesting device are further judged. Specifically, it can be judged in turn whether the voltage amplitude of the real-time current output by the electromagnetic vibration energy harvesting device exceeds the working threshold voltage of its generator, and whether the change rate of the voltage amplitude is lower than the preset change rate threshold. If any one of the two does not meet the judgment conditions, it means that the electromagnetic vibration energy harvesting device is either in the start-up / end stage, or its output has not reached a steady state. At this time, the charging current is still limited to not more than the first current value to provide protection for the mechanical structure of the vibration energy harvesting device; when both meet the judgment conditions, the charging current is set to a second current value much larger than the first current value (such as when the first current value is 0.8A, the second current value is set to about 8A) to fully utilize the energy output by the vibration energy harvesting device more stably to charge the energy storage device.

[0106] For the specific implementation of the sampling module, BMS chip, current switching module and main control unit, see Figures 17 to 19 ,in, Fig.17 The circuit schematic diagram of the sampling module is shown; Fig.18 shows a pin diagram of a control chip used in an optional main control unit, Fig.19 The schematic diagram of the BMS chip D1 and its peripheral circuits is shown, and the figure also shows a current switching module arranged between the charging current output terminal of the BMS chip and the charging terminal VBAT of the energy storage device.

[0107] As shown in the figure, the sampling module may include a plurality of voltage divider resistors (R re1 To R re5) is a voltage divider circuit, one end of which is grounded and the other end is used to input the working threshold voltage U of the generator. out The working threshold voltage of the generator can be determined according to the specific generator model used by the electromagnetic vibration energy harvesting device. For example, when it outputs 10V, it can enter the ideal working state, and the working threshold voltage U out Set to 10V.

[0108] Furthermore, when a dry cell or button cell is used as the power supply module of the system, it is generally impossible to directly provide a 10V operating threshold voltage. Therefore, Fig.17 As shown, the voltage boost chip U2 is used to boost the voltage to obtain a 10V U out .

[0109] Furthermore, if Fig.17 As shown, multiple comparison voltages are drawn between each voltage-dividing resistor and connected to the same-direction input terminal of the corresponding second comparator (U3 to U7), the VDC+ terminal is connected to the reverse input terminal of each second comparator, and the output terminal of each second comparator is respectively connected to the IO1 to IO5 ports of the main control unit. By adjusting the resistance value of each voltage-dividing resistor, each comparison voltage value can be set according to a preset step size. For example, the comparison voltages input to the same-direction input terminals of U3 to U7 are 10V, 9V, 8V, 7V and 6V respectively.

[0110] like Fig.18 As shown, the main control unit adopts a microcontroller M1 of model STM32L051X6, which receives the combination of high and low level signals output by the above-mentioned second comparators through multiple IO ports, and can determine whether the effective voltage amplitude of the real-time current output by the electromagnetic vibration energy capture device exceeds the working threshold voltage U out， , and obtain its rate of change information by taking the difference between the amplitudes in two time intervals.

[0111] Furthermore, if Fig.17 As shown, the sampling module also includes a third comparator U8, which is used to compare the voltage VBAT of the energy storage device with a reference voltage ref (such as 3V). The comparison result is also input into the IO9 port of the main control unit to determine whether the energy storage device enters the fast charging stage.

[0112] like Fig.19 As shown, the BMS chip can be selected with Fig.12 The current switching module is arranged between the charging current output port of the BMS chip and the charging terminal VBAT of the energy storage device, and includes a first current limiting resistor R SR1 , the second current limiting resistor R SR2 And the third switch device (i.e. the second NMOS tube Q S3) and the fourth switch device (i.e., the second PMOS tube Q S4 ), the third switching device Q S3 and the fourth switching device Q S4 Connect the first current limiting resistor R SR1 and the second current limiting resistor R SR2 The main control unit outputs a current switching signal to the gates of the two switching devices through the IO6 port at the same time to control the charging current to selectively pass through the third switching device Q S3 Or the fourth switching device Q S4 When IO6 outputs high level, Q S3 Open, Q S4 shut down, so that R SR1 The first charging path is turned on, R SR2 The second charging path is turned off; when IO6 outputs a low level, Q S3 Shutdown, Q S4 The first charging path is turned on, thereby closing the first charging path and opening the second charging path.

[0113] The working principles of the acquisition module, main control unit, BMS chip and current switching module are as follows:

[0114] 1) When the voltage value VBAT of the energy storage module is less than or equal to the slow charge threshold voltage of 3V, the voltage value is fed back to the BMS chip, and the BMS chip outputs its preset slow charge current; at this time, since the voltage value VBAT of the energy storage module is also collected by the sampling module and input to the main control unit, when the main control unit determines that the voltage value of the energy storage module does not exceed the slow charge threshold voltage, no matter what state the VDC value collected on the electromagnetic vibration energy capture device side is, IO6 is set to a high level, thereby conducting R SR1 The path is configured to output a first charging current;

[0115] 2) When VBAT is in the range of 3V to 4.1V, the BMS chip outputs a preset fast charging current by feeding back the VBAT voltage value, which is generally 10 times the slow charging current. At this time, the main control unit further determines whether fast charging can be performed with the second charging current. If the judgment result is no, IO6 is set to a low level. At this time, R SR2 The path is turned on. Although the BMS chip outputs a fast charge current much larger than its slow charge current, by setting R SR1 , R SR2 The resistance ratio, for example, R SR2 The resistance value is set to approximately R SR1 10 times, which can make the SR2 The output current remains the first charging current; if the judgment result is yes, IO6 is set to a high level, thereby turning on RSR1 The path in which the battery is located can now be charged with the second charging current.

[0116] 3) When VBAT exceeds 4.1V, the BMS chip will output a relatively small regulation current. Therefore, regardless of the level of IO06, the R SR1 or R SR2 The charging currents of the paths are all extremely weak, that is, a third charging current that is smaller than the first charging current can be used for charging.

[0117] Obviously, without departing from the working principle of the above-mentioned current switching module, the on-off characteristics of the above-mentioned switching devices and the resistance ratio of the current limiting resistors can also be exchanged, as long as it is ensured that the charging circuit can be selectively turned on by the current switching signal Sig_2 and different charging current sizes can be switched.

[0118] Fig.18 In the embodiment shown, the operating voltage of the microcontroller M1 used in the main control unit is 3.3V, the power consumption in the working state is not more than 2.7mW, and it has multiple IO ports for reading and writing data. Obviously, as the number of electromagnetic vibration energy harvesting devices increases, other controllers / microcontrollers with more IO ports can also be selected as the main control unit, or multiple controllers / microcontrollers can be cascaded to form the main control unit.

[0119] Fig. 20 In a specific embodiment, the torque of the generator of the electromagnetic vibration energy harvesting device is shown when the above-mentioned joint optimization charging strategy is used. For comparison, the torque of the motor without optimization is also shown in the figure. Fig. 20 It can be seen that according to the combined optimization charging strategy, the energy storage device can be fully charged quickly, and the generator shaft torque is at a safe level, which will not cause severe vibration of the structure; if an unoptimized charging strategy is used for charging, it will cause a sharp increase and change in torque, which will cause severe vibration of the structure and shorten its service life.

[0120] 5. Further optimization of charging strategies for multiple energy harvesting devices:

[0121] use Fig.16The combined charging optimization strategy shown can achieve a good balance between the charging effect and the protection of the generator of the electromagnetic vibration energy harvesting device. The core reason is that the vibration of the vibration source caused by moving objects such as cars and locomotives is random. For large-scale vibration sources, since multiple electromagnetic vibration energy harvesting devices can be set, the output current characteristics of at least two adjacent energy harvesting devices can be used to estimate the motion state information of the moving object, and its motion state information can be used to eliminate the randomness of the real-time current output by other energy harvesting devices, so as to achieve more effective charging control.

[0122] by Figure 2 For example, when a moving object, such as a truck or a tanker truck, passes the bridge 100 from right to left, the three electromagnetic vibration energy harvesting devices 301, 302 and 303 are arranged on the bridge 100 from right to left. Fig.21 As shown, real-time currents Ureal_1, Ureal_2, and Ureal_3 are output in sequence. Obviously, the speed and direction of the vehicle causing the vibration cannot be determined only by the real-time current Ureal_1 output by the electromagnetic vibration energy capture device 301 on the far right. However, when the electromagnetic vibration energy capture device 302 outputs the real-time current Ureal_2 with the same or similar vibration amplitude and change rate after a period of time, the order and time interval of the appearance of Ureal_1 and Ureal_2 can be used to estimate the speed and direction of the moving object. In this case, for other electromagnetic vibration energy capture devices, such as the electromagnetic vibration energy capture device 303 located on the far left, since the time and amplitude of the vibration caused by the moving object at that location can be estimated in advance, the moment and waveform of the real-time current Ureal_3 corresponding to its output can be predicted in advance, so that a more effective charging strategy can be adopted to control its charging process.

[0123] Specifically, when the electromagnetic vibration energy harvesting system adapted to a large-scale vibration source provided by the present application includes three or more electromagnetic vibration energy harvesting devices, in some preferred embodiments, the following can be used: Fig. 22 The control method shown comprises the following steps:

[0124] Step S810, each electromagnetic vibration energy harvesting device converts the vibration generated by the large-scale vibration source at its location into real-time current;

[0125] Step S820, for each electromagnetic vibration energy harvesting device, based on the waveform of the real-time current outputted by the device, automatically switching the circuit for charging the energy storage device;

[0126] Step S830, for two adjacent electromagnetic vibration energy harvesting devices that are first affected by an object moving on a large-scale vibration source, a joint optimization charging strategy that takes into account energy output characteristics and energy storage status is used to adjust the magnitude of the charging current of the two electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object, wherein the energy output characteristics include the voltage amplitude of the real-time current and its change rate information;

[0127] Step S840, determining the movement direction and speed of the object based on the energy output characteristics of the two adjacent electromagnetic vibration energy harvesting devices, and adjusting the charging current of other electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object based on the movement direction and speed.

[0128] refer to Fig.21 and Fig. 22 Regardless of the direction of movement of the object causing the vibration, two adjacent electromagnetic vibration energy harvesting devices are affected in turn and output real-time currents Ureal_1 and Ureal_2. By using the time and order of occurrence of these two real-time currents, the time of occurrence of Ureal_3 can be estimated, so that different strategies can be used to control the charging current in steps S830 and S840.

[0129] For example, Fig.21 In the above, for the first two electromagnetic vibration energy harvesting devices affected by the same moving object, the joint optimization charging strategy considering the energy output characteristics and the energy storage state is still adopted, and the charging current is switched to the second current at time T1 and time T2 respectively; for the third electromagnetic vibration energy harvesting device affected by the moving object, since the waveform of its output Ureal_3 can be predicted to change with time, and it is known that it will maintain a stable output for a period of time after exceeding the working threshold voltage of the generator, the charging current can be set to the second current at time T3 (observation Fig.21 It can be seen that at this time its amplitude is close to but has not exceeded the working threshold voltage of the generator). Using this method, there is no need to judge the change rate of the real-time current output by other electromagnetic vibration energy capture devices, so that the charging can enter the fast charging state in advance, further improving the overall charging effect.

[0130] 6. Anti-backflow circuit and system power supply module:

[0131] Unlike a stable power supply, the electromagnetic vibration energy capture device will not always output electrical energy because the vibration in the environment will not always exist. In order to prevent the electrical energy stored in the energy storage device from flowing back into the charging management unit when the vibration energy capture device stops working, thereby damaging the module, in some preferred embodiments of the present application, an anti-backflow circuit is also provided between the charging management unit and the energy storage device to achieve unidirectional control of the charging direction and prevent current from flowing from the energy storage device to the charging management unit.

[0132] Fig.23 Schematic diagram of the anti-backflow circuit in some specific embodiments is shown, Fig.14 As shown, the anti-backflow circuit includes a first transistor Q1, a second transistor Q2, a first switch tube Q3, and a third current limiting resistor R cl1 and the fourth current limiting resistor R cl2 Among them, the first transistor Q1 and the second transistor Q2 are both PNP transistors, and the first switch tube Q3 is a P-type MOS tube.

[0133] Specifically, the emitter of the first transistor Q1 is connected to the positive electrode of the output terminal of the BMS chip and the drain (D electrode) of the first switch tube Q3, and the base is connected to the third current limiting resistor R cl1 The first end of the transistor Q2 is connected to the base of the second transistor Q2, and the collector is connected to the third current limiting resistor R cl1 The emitter of the second triode Q2 is connected to the source of the first switch tube Q3 and the positive electrode of the input end of the energy storage device, and the collector is connected to the gate (G electrode) of the first switch tube Q3 and the fourth current limiting resistor R cl2 The first end of the BMS chip output terminal is connected to the negative electrode of the third current limiting resistor R cl1 and the second end, the fourth current limiting resistor R cl2 The second end and the negative electrode of the energy storage device input terminal are commonly connected to the ground.

[0134] The working principle of the anti-backflow circuit is:

[0135] When the vibration energy capture device operates normally, the charging management unit outputs electric energy. On the one hand, the voltage difference between the emitter and the base of the first transistor Q1 is greater than the conduction voltage drop of the transistor, the first transistor Q1 is turned on, and the bases of the first transistor Q1 and the second transistor Q2 both follow the output voltage of the charging management unit; on the other hand, it flows to the subsequent stage through the body diode of the first switch tube Q3, so that the source of the first switch tube Q3 and the emitter of the second transistor Q2 also follow the output voltage of the charging management unit, and the voltage difference between the gate and the source of the first switch tube Q3 reaches the conduction condition, the first switch tube Q3 is turned on, and there is no voltage difference between the emitter and the base of the second transistor Q2, and the second transistor Q2 is cut off. Therefore, when the vibration energy capture device operates normally, the electric energy output by the charging management unit will continuously flow into the energy storage device.

[0136] When the vibration energy capture device stops working, the charging management unit stops outputting electric energy, there is no voltage difference between the emitter and the base of the first transistor Q1, the first transistor Q1 is cut off, and the energy storage device starts to output electric energy forward, so that the voltage difference between the emitter and the base of the second transistor Q2 is greater than the conduction voltage drop of the transistor, the second transistor Q2 is turned on, the base of the second transistor Q2 and the source of the first switch tube Q3 both follow the output voltage of the energy storage device, there is no voltage difference between the gate and the source of the first switch tube Q3, and the first switch tube Q3 is cut off. Therefore, when the vibration energy capture device stops working, the electric energy in the energy storage device will not flow back into the charging management unit.

[0137] The introduction of the anti-backflow circuit ensures that when the vibration energy capture device is working normally, the electric energy output by the charging management unit can flow into the energy storage device with extremely low loss. When the vibration energy capture device stops working, the electric energy stored in the energy storage device will not flow back to the charging management unit to cause circuit damage. Fig.24 The comparison results of the power-off of the supercapacitor as an energy storage device when the anti-backflow circuit is added and when the anti-backflow circuit is not added in a specific embodiment are shown. Through experimental comparison, it can be seen that after adding the anti-backflow circuit, the power-off speed of the supercapacitor is significantly reduced compared with the absence of the anti-backflow circuit. In addition to the anti-backflow circuit itself consuming a very small amount of electricity, the electric energy will not flow back from the energy storage module to the charging management unit, which also verifies the effectiveness of applying the anti-backflow circuit in the energy management circuit of the vibration energy capture system.

[0138] In order to ensure the stable operation of each functional module in the system, in some preferred embodiments, the electromagnetic vibration energy capture system adapted to the large-scale vibration source also includes a system power supply module. The system power supply module can select suitable dry batteries, button batteries, lithium batteries, etc. for power supply according to the specification parameters of multiple comparators and the main control unit in the system. For example, Fig.18 The main control unit shown can use a 3.3V operating voltage, and its power consumption in the working state is no more than 2.7mW. It can be used as the core, and the power consumption of other power-consuming modules can be comprehensively considered to select a suitable power supply module.

[0139] The above is a detailed introduction to the specific implementation methods of the present application. For those skilled in the art, several improvements and modifications may be made to the present application without departing from the principles of the present application. These improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. An electromagnetic vibration energy harvesting system adapted to a large-scale vibration source, comprising a plurality of electromagnetic vibration energy harvesting devices arranged on the large-scale vibration source, and at least one energy storage device, wherein the electromagnetic vibration energy harvesting device is used to convert the vibration of the large-scale vibration source into real-time current for output, characterized in that: Also includes: A main control unit and a plurality of self-switching adjustable charging circuits arranged one-to-one corresponding to the electromagnetic vibration energy capture devices; Wherein, each of the self-switching adjustable charging circuits automatically switches the circuit for charging the energy storage device based on the waveform of the real-time current output by its corresponding electromagnetic vibration energy capture device; as well as, Under the control of the main control unit, the magnitude of the charging current for charging the energy storage device is adjusted.

2. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 1 is characterized in that: The self-switching adjustable charging circuit includes an AC / DC selection unit, a three-phase rectification circuit, a filtering circuit and a processing unit; The AC / DC selection unit selectively conducts an AC path or a DC path between the corresponding electromagnetic vibration energy harvesting device and the processing unit based on the time-varying characteristics of the real-time current output by the corresponding electromagnetic vibration energy harvesting device; The three-phase rectifier circuit is used to rectify the AC current in the AC path into a DC current; The filtering circuit is used to filter the DC current passing through the DC path; The processing unit charges the energy storage device based on the current input from the AC path or the DC path, and adjusts the magnitude of the charging current under the control of the main control unit.

3. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 2 is characterized in that: The AC / DC selection unit includes a first switch device, a second switch device and a comparison module; The input ends of the first switch device, the second switch device and the comparison module are all connected to the output ends of their corresponding electromagnetic vibration energy capture devices for inputting the real-time current; The output end of the comparison module outputs a line switching signal to the first switch device and the second switch device at the same time, wherein when the real-time current is an alternating current, the line switching signal is a high level signal, and when the real-time current is a direct current, the line switching signal is a low level signal; The first switch device turns on the AC path when the line switching signal is a high level signal, and turns off the AC path when the line switching signal is a low level signal; The second switch device turns on the DC path when the line switching signal is a low level signal, and turns off the DC path when the line switching signal is a high level signal.

4. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 3 is characterized in that: The first switch device is a first NMOS tube, the second switch device is a first PMOS tube, and the comparison module includes a first diode, a first capacitor, a second capacitor, a first resistor, a second resistor and a first comparator; The positive electrode of the first diode is connected to the output end of the electromagnetic vibration energy capture device, the negative electrode is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the first end of the second capacitor, the first end of the first resistor and the first end of the second resistor, the second end of the second capacitor and the second end of the first resistor are both grounded, the second end of the second resistor is connected to the same-direction input end of the first comparator, and the inverting input end of the first comparator is used to receive a reference voltage; The D pole and S pole of the first switching device are respectively connected to the output end of the electromagnetic vibration energy harvesting device and the input end of the three-phase rectifier circuit, the S pole and D pole of the second switching device are respectively connected to the output end of the electromagnetic vibration energy harvesting device and the input end of the filter circuit, and the output end of the first comparator is connected to the G pole of the first switching device and the G pole of the second switching device.

5. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 2, characterized in that: The processing unit includes a sampling module, a BMS chip and a current switching module; The sampling module is used to obtain the voltage amplitude distribution of the real-time current and the voltage condition of the energy storage device; The BMS chip is used to convert the current input by the three-phase rectifier circuit or the filter circuit into a charging current for charging the energy storage device; The current switching module switches the charging current output by the BMS chip based on the current switching signal sent by the main control unit, wherein the main control unit obtains the voltage amplitude and its change rate information of the real-time current based on the voltage amplitude distribution of the real-time current output by the sampling module, and generates the current switching signal in combination with the voltage condition of the energy storage device.

6. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 5 is characterized in that: The sampling module comprises: A plurality of voltage-dividing resistors and a plurality of second comparators corresponding thereto, wherein the plurality of voltage-dividing resistors are connected in series between the working threshold voltage output terminal and the ground terminal of the generator of the electromagnetic vibration energy harvesting device, and are used to output a corresponding comparison voltage to the same-direction input terminal of the corresponding second comparator, and the reverse input terminal of the second comparator is used to receive the voltage amplitude of the real-time current, and the output terminal is connected to the main control unit; A third comparator, wherein the non-inverting input terminal of the third comparator is used to receive the voltage of the energy storage device, the reverse input terminal is used to receive the reference voltage, and the output terminal is connected to the main control unit.

7. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 5, characterized in that: The current switching module includes a third switch device, a fourth switch device, a first current limiting resistor and a second current limiting resistor; The input end and the output end of the third switch device are respectively connected to the charging current output end of the BMS chip and the first end of the first current limiting resistor, and the second end of the first current limiting resistor is connected to the charging current input end of the energy storage device; The input end and the output end of the fourth switch device are respectively connected to the charging current output end of the BMS chip and the first end of the second current limiting resistor, and the second end of the second current limiting resistor is connected to the charging current input end of the energy storage device; The current switching signal output end of the main control unit is connected to the enable ends of the third switch device and the fourth switch device at the same time, wherein the third switch device and the fourth switch device have opposite high and low level on-off characteristics, and the ratio of the first current limiting resistor to the second current limiting resistor is much greater than 1 or much less than 1.

8. The electromagnetic vibration energy harvesting system adapted to a large-scale vibration source according to claim 1, characterized in that: Also includes: an anti-backflow circuit, used to prevent current from flowing from the energy storage device to the self-switching adjustable charging circuit; as well as, The system power supply module is used to supply power to the power consumption module in the electromagnetic vibration energy capture system adapted to the large-scale vibration source.

9. A control method for controlling the electromagnetic vibration energy harvesting system adapted to a large-scale vibration source as claimed in claim 1, characterized in that: The following steps are involved: Each of the electromagnetic vibration energy capture devices converts the vibration generated by the large-scale vibration source at its location into real-time current; For each of the electromagnetic vibration energy harvesting devices, based on the waveform of the real-time current outputted by the device, the circuit for charging the energy storage device is automatically switched; For each of the electromagnetic vibration energy capture devices, a joint optimization charging strategy that takes into account energy output characteristics and energy storage status is used to adjust the size of the charging current used to charge the energy storage device, wherein the energy output characteristics include the voltage amplitude and change rate information of the real-time current.

10. The control method according to claim 9, characterized in that: For one of the electromagnetic vibration energy harvesting devices, a joint optimization charging strategy considering energy output characteristics and energy storage state is adopted to adjust the magnitude of the charging current for charging the energy storage device, specifically including the following operations: Real-time acquisition of the voltage of the energy storage device and the voltage amplitude and change rate of the real-time current output by the electromagnetic vibration energy capture device; When the voltage of the energy storage device is less than the slow-charge threshold voltage, controlling the charging current to not exceed a first current value; When the voltage of the energy storage device is greater than or equal to the slow charge threshold voltage and less than the fast charge threshold voltage, further determine whether the real-time current output by the electromagnetic vibration energy capture device satisfies the voltage amplitude greater than or equal to the working threshold voltage of its generator and the change rate of the voltage amplitude is less than or equal to the change rate threshold. If both conditions are met, the charging current is controlled to be a second current value, otherwise the charging current is controlled to be no more than the first current value, wherein the second current value is much greater than the first current value; When the voltage of the energy storage device is greater than or equal to the fast-charge threshold voltage, the charging current is controlled to not exceed a third current value, wherein the third current value is less than or equal to the first current value.

11. A control method for controlling the electromagnetic vibration energy harvesting system adapted to a large-scale vibration source as claimed in claim 1, characterized in that: The number of electromagnetic vibration energy harvesting devices included in the electromagnetic vibration energy harvesting system adapted to a large-scale vibration source is greater than or equal to 3, and the control method comprises the following steps: Each of the electromagnetic vibration energy capture devices converts the vibration generated by the large-scale vibration source at its location into real-time current; For each of the electromagnetic vibration energy harvesting devices, based on the waveform of the real-time current outputted by the device, the circuit for charging the energy storage device is automatically switched; For two adjacent electromagnetic vibration energy harvesting devices that are first affected by an object moving on the large-scale vibration source, a joint optimization charging strategy that takes into account energy output characteristics and energy storage status is used to adjust the magnitude of the charging current used by the two electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object, wherein the energy output characteristics include the voltage amplitude of the real-time current and its rate of change information; and, The moving direction and speed of the object are determined based on the energy output characteristics of the two adjacent electromagnetic vibration energy harvesting devices, and the charging current of other electromagnetic vibration energy harvesting devices to charge the energy storage device under the influence of the object is adjusted based on the moving direction and speed.

12. The control method according to claim 11, characterized in that: For one of the electromagnetic vibration energy harvesting devices, a joint optimization charging strategy considering energy output characteristics and energy storage state is adopted to adjust the magnitude of the charging current for charging the energy storage device, specifically including the following operations: Real-time acquisition of the voltage of the energy storage device and the voltage amplitude and change rate of the real-time current output by the electromagnetic vibration energy capture device; When the voltage of the energy storage device is less than the slow-charge threshold voltage, controlling the charging current to not exceed a first current value; When the voltage of the energy storage device is greater than or equal to the slow charge threshold voltage and less than the fast charge threshold voltage, further determine whether the real-time current output by the electromagnetic vibration energy capture device satisfies the voltage amplitude greater than or equal to the working threshold voltage of its generator and the change rate of the voltage amplitude is less than or equal to the change rate threshold. If both conditions are met, the charging current is controlled to be a second current value, otherwise the charging current is controlled to be no more than the first current value, wherein the second current value is much greater than the first current value; When the voltage of the energy storage device is greater than or equal to the fast-charge threshold voltage, the charging current is controlled to not exceed a third current value, wherein the third current value is less than or equal to the first current value.

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