Electromagnetic vibration energy harvesting system adapted to large scale vibration sources and control method thereof

Abstract

The application provides an electromagnetic vibration energy capturing system suitable for a large-scale vibration source and a control method thereof. The system comprises a plurality of electromagnetic vibration energy capturing devices arranged on the large-scale vibration source, at least one energy storage device, a master control unit, and a plurality of self-switching adjustable charging circuits corresponding to the electromagnetic vibration energy capturing devices one by one. 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 capturing device, and adjusts the size of the charging current for charging the energy storage device under the control of the master control unit. The system provided by the application can fully utilize the electric energy output by the plurality of electromagnetic vibration energy capturing devices arranged on the large-scale vibration source to flexibly and efficiently charge the energy storage device.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vibration energy harvesting and conversion, and particularly provides an electromagnetic vibration energy harvesting system suitable for large-scale vibration sources and a control method thereof. BACKGROUND

[0002] The electromagnetic vibration energy harvesting device is a device for converting mechanical vibration energy into electrical energy. It is based on the principle of electromagnetic induction and uses the vibration of a vibration source such as a bridge or a track to generate an electric current. Since the amplitude and frequency of vibration vary greatly, the output current needs to be stored by a super capacitor, a lithium battery or other electrical energy storage device to meet the power supply needs of low-power micro-electromechanical systems such as wireless sensor networks.

[0003] For large-scale vibration sources such as bridges with a length of several hundred meters or even several kilometers, multiple electromagnetic vibration energy harvesting devices can be arranged at different positions to improve the ability to convert vibration energy into electrical energy. For such large-span vibration sources such as tracks and bridges, there are large differences in vibration modes at different positions. Therefore, during equipment installation and debugging, the appropriate generator power generation method (i.e., the electromagnetic vibration energy harvesting device can use a direct current generator or an alternating current generator to convert vibration energy into electrical energy) needs to be selected according to the actual vibration situation at the arrangement position. Correspondingly, 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 objects (such as cars, trains, etc.) that cause the vibration of the vibration source. On the one hand, the amplitude of the vibration caused by the movement of objects of different weights on a large-scale vibration source such as a bridge varies, which leads to fluctuations in the output voltage amplitude of the vibration energy harvesting device between a few volts, tens of volts or even hundreds of volts. On the other hand, when the above objects move on a large-scale vibration source, they will cause the vibration source to vibrate at different positions at different times, and the vibration duration is closely related to the size and speed of the object, which affects the energy output characteristics of the electromagnetic vibration energy harvesting device at different positions.

[0005] Therefore, a system is needed that can uniformly manage multiple electromagnetic vibration energy harvesting devices arranged on a large-scale vibration source to flexibly and efficiently manage energy according to the energy output characteristics of the electromagnetic vibration energy harvesting devices at each position. SUMMARY

[0006] The application provides an electromagnetic vibration energy capturing system adapted to a large-scale vibration source, comprising a plurality of electromagnetic vibration energy capturing devices arranged on the large-scale vibration source, and at least one energy storage device, wherein the electromagnetic vibration energy capturing devices are used to convert the vibration of the large-scale vibration source into real-time current for output, and the electromagnetic vibration energy capturing system further comprises:

[0007] a master control unit and a plurality of self-switching adjustable charging circuits arranged one-to-one with the electromagnetic vibration energy capturing 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 capturing device, and adjusts the size of the charging current for charging the energy storage device under the control of the master control unit.

[0008] The electromagnetic vibration energy capturing system adapted to the large-scale vibration source provided by the application is provided with self-switching adjustable charging circuits one-to-one with the plurality of electromagnetic vibration energy capturing devices arranged at different positions of the large-scale vibration source, the self-switching adjustable charging circuits can automatically switch the AC path or the DC path according to the time-varying characteristics (current waveform) of the real-time current, and adjust the charging current in real time, so as to ensure that the electromagnetic vibration energy capturing devices can automatically adjust the current output path without any manual adjustment, so that the electric energy is effectively transmitted to the charging part, and the compatibility and charging efficiency of the system for different types of electromagnetic vibration energy capturing devices are greatly increased.

[0009] The application also provides a control method of the electromagnetic vibration energy capturing system adapted to the large-scale vibration source, which comprises the following steps:

[0010] Each electromagnetic vibration energy capturing device converts the vibration generated by the large-scale vibration source at the position of the electromagnetic vibration energy capturing device into real-time current;

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

[0012] For each electromagnetic vibration energy capturing device, the size of the charging current for charging the energy storage device is adjusted by using a joint optimization charging strategy considering the energy output characteristics and the energy storage state, wherein the energy output characteristics include the voltage amplitude of the real-time current and the change rate information thereof.

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

[0014] Each electromagnetic vibration energy harvesting device converts the vibration generated by the large-scale vibration source at the position of the electromagnetic vibration energy harvesting device into real-time current;

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

[0016] For the adjacent two electromagnetic vibration energy harvesting devices affected by an object moving on the large-scale vibration source earliest, the joint optimization charging strategy considering the energy output characteristics and the energy storage state is adopted to adjust the size of the charging current of the two electromagnetic vibration energy harvesting devices for charging 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 the rate information thereof; and

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

[0018] Figure 1 A schematic diagram of the existing electromagnetic vibration energy harvesting device arranged on the large-scale vibration source and harvesting energy;

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

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

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

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

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

[0024] Figure 7The schematic diagram of the line switching signal outputted by the comparison module provided by the embodiment of the application when inputting alternating current;

[0025] Figure 8 The schematic diagram of the line switching signal outputted by the comparison module provided by the embodiment of the application when inputting direct current;

[0026] Figure 9 The schematic diagram of the three-phase rectifier circuit provided by the embodiment of the application;

[0027] Figure 10 The schematic diagram of the filter circuit provided by the embodiment of the application;

[0028] Figure 11 The schematic diagram of the architecture of the processing unit provided by the embodiment of the application;

[0029] Figure 12 The schematic diagram of a BMS chip;

[0030] Figure 13 The schematic diagram of the voltage amplitude change of the real-time current outputted by the electromagnetic vibration energy harvesting device provided by the embodiment of the application;

[0031] Figure 14 The schematic diagram of the change curve of the charging voltage of the energy storage device and the generator output torque of the electromagnetic vibration energy harvesting device provided by the embodiment of the application;

[0032] Figure 15 The flow chart of the control method of the electromagnetic vibration energy harvesting system adapted to large-scale vibration sources provided by the embodiment of the application;

[0033] Figure 16 The flow chart of the joint optimization charging strategy considering the energy output characteristics and the energy storage state provided by the embodiment of the application;

[0034] Figure 17 The circuit schematic diagram of the sampling module provided by the embodiment of the application;

[0035] Figure 18 The pin schematic diagram of the master control unit provided by the embodiment of the application;

[0036] Figure 19 The schematic diagram of the BMS chip machine peripheral circuit provided by the embodiment of the application;

[0037] Figure 20 The schematic diagram of the generator torque change of the electromagnetic vibration energy harvesting device when adopting the joint optimization charging strategy provided by the embodiment of the application;

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

[0039] Figure 22 A flow chart of the control method of the electromagnetic vibration energy harvesting system according to the embodiment of the present application for adapting to large-scale vibration sources;

[0040] Figure 23 A schematic diagram of the anti-backflow circuit according to the embodiment of the present application;

[0041] Figure 24 A comparison diagram of the power storage device power-off situation when the anti-backflow circuit is added and when the anti-backflow circuit is not added according to the embodiment of the present application. DETAILED DESCRIPTION

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

[0043] In addition, in order to facilitate understanding, various components on the drawing paper are enlarged or reduced, but this practice is not intended to limit the protection scope of the present application.

[0044] The singular form also includes the plural meaning, and vice versa.

[0045] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the embodiments of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, in the description of the present application, in order to distinguish different units, the first, second and the like are used in the specification, but these are not limited by the order of manufacture, and cannot be understood as indicating or implying relative importance, and the name may be different in the detailed description and claims of the present application.

[0046] The words in the specification are used to illustrate the embodiments of the present application, but are not intended to limit the present application. It should be noted that, unless otherwise explicitly specified and limited, if the terms "provided", "connected", "connected" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, can be directly connected, or indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be specifically understood.

[0047] Figure 1A system for electromagnetic vibration energy harvesting on a large-scale vibration source is shown, such as Figure 1 As shown, the bridge 100 is a large-scale vibration source, when the objects causing vibration, such as cars 201, tank trucks 202, etc. drive on it, it will cause vibrations 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, multiple electromagnetic vibration energy harvesting devices (such as electromagnetic vibration energy harvesting devices 301, 302 and 303 arranged from right to left) can be selected and arranged at appropriate positions according to the vibration conditions at their different positions, and the vibration energy sensed by them can be converted into electrical energy.

[0048] Obviously, due to the randomness of the weight, size, driving speed, driving direction, etc. of the vehicles causing the vibration of the bridge 100, the output current of the energy harvesting devices at different positions has obvious intermittence, and the current duration, amplitude, etc. are random, therefore, the more feasible energy conversion mode is to store the electrical energy output by each energy harvesting device into at least one energy storage device 501, thereby providing stable functions for low-power wireless gateways 601, wireless routers 602 or access points 603 and other loads.

[0049] In addition, generally, the model of the generator used by the electromagnetic vibration energy harvesting device and the form of the output current need to be reasonably selected according to the vibration characteristics of the bridge 100 at different positions, such as Figure 1 In the above, the electromagnetic vibration energy harvesting devices 301 and 302 use alternating current generators, and the electromagnetic vibration energy harvesting device 303 uses a direct current generator, therefore, the electromagnetic vibration energy harvesting devices 301 and 302 also need to be equipped with a circuit for rectifying alternating current.

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

[0051] The existing BMS chip has the function of adjusting the charging current according to the state of the battery and other energy storage devices, such as switching between slow charging current, fast charging current and trickle charging current, but when implementing the charging and discharging strategy, it generally uses the mains or devices that can stably generate electricity as a stable current source, that is, the above-mentioned switching of charging current does not consider the influence on the input device. However, for the electromagnetic vibration energy harvesting device, due to the strong randomness of its energy source, the voltage amplitude and duration of VDC have great fluctuations, therefore, in the process of charging control of the energy storage device 501, the output characteristics of the input side of the generator of different types also need to be considered, and combined with the vibration characteristics of the large-scale vibration source such as the bridge 100 at different positions, the charging management of each electromagnetic vibration energy harvesting device is unified.

[0052] I. Overall architecture of the system:

[0053] In order to solve the above problems, the embodiment of the present application provides an electromagnetic vibration energy harvesting system suitable for large-scale vibration sources, as shown in Figure 2 , the electromagnetic vibration energy harvesting system includes a plurality of electromagnetic vibration energy harvesting devices (such as Figure 2 , the electromagnetic vibration energy harvesting device 301, 302 outputs alternating current, and the electromagnetic vibration energy harvesting device 303 outputs direct current) arranged on the large-scale vibration source (such as the bridge 100), and at least one energy storage device 501, wherein the electromagnetic vibration energy harvesting device is used to convert the vibration at different positions of the large-scale vibration source into real-time current (such as alternating current shown by the red arrow, or direct current shown by the blue arrow) for output.

[0054] Obviously, the number, arrangement position and output AC / DC current form of the electromagnetic vibration energy harvesting device can be reasonably selected according to the size, shape, vibration characteristics and the like of the vibration source, for example, 2 or more can be arranged, in addition, the actual energy harvesting effect can also be adjusted during use. The number of energy storage devices 501 can be selected according to the number of loads, rated power and other parameters.

[0055] Further, as shown in Figure 2 , the electromagnetic vibration energy harvesting system further includes an energy management unit 400 arranged between each electromagnetic vibration energy harvesting device and the energy storage device 501 to realize 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 master 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 harvesting device included in the energy harvesting 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 harvesting device, and adjusts the size of the charging current for charging the energy storage device 501 under the control of the master control unit.

[0057] Figure 3 The architecture of the energy management unit 400 and its connection mode with each energy harvesting device and energy storage device are shown in some embodiments. Figure 3 In the shown embodiment, the system includes three electromagnetic vibration energy harvesting devices 304, 305, 306 in total, and accordingly, the energy management unit 400 includes three self-switching adjustable charging circuits 414, 415, 416 arranged one-to-one corresponding to the three energy harvesting devices, the real-time current (which can be direct current or alternating current) output by the three energy harvesting devices is converted into charging current in the form of direct current after passing through the three circuits, to charge the energy storage device 501, and the size of the charging current is adjusted under the control of the master control unit 420.

[0058] Obviously, Figure 3 In the shown embodiment, the number of energy harvesting devices and self-switching adjustable charging circuits is illustrative, and those skilled in the art can flexibly adjust the number of energy harvesting devices and self-switching adjustable charging circuits based on the actual size and vibration condition of the vibration source.

[0059] Figure 4 Taking the self-switching adjustable charging circuit 414 as an example, the internal architecture thereof is shown as follows: Figure 4 As shown, the self-switching adjustable charging circuit 414 includes a direct-current selection unit, a three-phase rectifier circuit, a filter circuit, and a processing unit.

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

[0061] II. AC / DC selection unit:

[0062] As analyzed before, the electromagnetic vibration energy harvesting devices with different output current characteristics can be arranged at different positions of the large-scale vibration source, and during the specific installation, debugging and actual operation, the type of the generator in the electromagnetic vibration energy harvesting device can be replaced or the working mode thereof can be changed according to the actual measurement and analysis of the vibration mode and situation of the installation position, so as to obtain the optimal energy output effect. During this process, it can be necessary to change the real-time current output from alternating current to direct current or from direct current to alternating current. Although the real-time current output from a single current path can be manually adjusted to be directed to different input ports, this will inevitably reduce the system compatibility and increase the application difficulty. If the real-time current is directly introduced into the alternating current input end and the direct current input end in a one-to-two way, since the alternating current and the direct current need to be processed by different rectification or filtering circuits, half of the output current will not be processed at any time, which will cause the problem of energy utilization rate reduction.

[0063] In view of the above problems, the energy harvesting 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 direct current path and the alternating current path. The implementation manner of the energy harvesting system will be described in detail below in combination with Figure 5 and Figure 6 .

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

[0065] The input end of each of the first switching device, the second switching device and the comparison module is connected to the output end of the corresponding electromagnetic vibration energy harvesting device 307 for inputting the real-time current.

[0066] The output end of the comparison module simultaneously outputs a line switching signal Sig_1 to the first switching device and the second switching device. When the real-time current is alternating current, the line switching signal Sig_1 is a high-level signal, and when the real-time current is direct current, the line switching signal Sig_1 is a low-level signal. The first switching device is turned on when the line switching signal Sig_1 is a high-level signal, and is turned off when the line switching signal Sig_1 is a low-level signal. The second switching device is turned on when the line switching signal Sig_1 is a low-level signal, and is turned off when the line switching signal Sig_1 is a high-level signal.

[0067] Figure 6 ​The specific circuit schematic diagram adopted by the AC-DC selection unit in one specific embodiment is shown as Figure 3 The first switch device is a first NMOS tube Q S1 , which is a high-level on-type switch device; the second switch device is a first PMOS tube Q S2 , which is a low-level on-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 anode of the first diode D1 is connected with the output end of the electromagnetic vibration energy harvesting device, the cathode is connected with the first end of the first capacitor C1, the second end of the first capacitor C1 is connected with 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 respectively, 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 with the same direction input end of the first comparator U1, and the opposite direction 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, has its D pole and S pole connected with the output end of the electromagnetic vibration energy harvesting device and the input end of the three-phase rectification circuit respectively; the first PMOS tube Q S2 , as the second switch device, has its S pole and D pole connected with the output end of the electromagnetic vibration energy harvesting device and the input end of the filter circuit respectively; the output end of the first comparator U1 is connected with the G pole of the first NMOS tube Q S1 and the G pole of the first PMOS tube Q S2 respectively, for outputting a line switching signal Sig_1 to the two MOS tubes.

[0070] The working principle of the AC-DC selection unit is as follows:

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

[0072] When the real-time current output by the electromagnetic vibration energy harvesting device is direct current, according to the characteristic of the capacitor, the direct current is cut off after passing through the first capacitor C1. Even if a small amount of current passes through the capacitor due to current fluctuation, the voltage input into the same direction input end of the first comparator U1 after voltage division by the first resistor R1 and the second resistor R2 is approximately 0. At this time, the voltage at the same direction input end of the first comparator U1 is less than the reference voltage ref at the reverse direction input end, the comparator outputs a low level, the first NMOS transistor Q S1 is cut off, and the first PMOS transistor Q S2 is turned on. The direct current output by the electromagnetic vibration energy harvesting device enters the processing unit from the lower direct current path.

[0073] Figure 7 Fig. 3 shows a schematic diagram of the line switching signal Sig_1 output by the comparison module when the real-time current is alternating current in an embodiment. Correspondingly, Figure 8 Fig. 4 shows a schematic diagram of the line switching signal Sig_1 output by the comparison module when the real-time current is direct current in another embodiment. Through Figure 7 Figure 8 It can be seen that the alternating current passing through the AC / DC selection unit makes the first comparator U1 output a high level, which in turn controls the first NMOS transistor Q S1 to turn on the alternating current path and controls the first PMOS transistor Q S2 to turn off the direct current path. The direct current passing through the AC / DC selection unit makes the first comparator U1 output a low level, which in turn controls the first PMOS transistor Q S2 to turn on the direct current path and controls the first NMOS transistor Q S1 to turn off the alternating current path. Therefore, by arranging the AC / DC selection unit between the output end of the electromagnetic vibration energy harvesting device and the processing unit, the alternating current path or the direct current path can be adaptively turned on according to the time-varying characteristic (current waveform) of the real-time current, so as to ensure that the electromagnetic vibration energy harvesting device can adaptively adjust the current output path without any manual adjustment, so that the electric energy is effectively transmitted to the charging part to be described later, and the compatibility of the system to different types of electromagnetic vibration energy harvesting generators is greatly increased.

[0074] It should be noted that those skilled in the art can flexibly select components to build a circuit to achieve the function of adaptively switching the alternating current path and the direct current path as can be achieved by the AC / DC selection unit without departing from the technical idea of the present application.

[0075] Three, three-phase rectifier circuit and filter circuit:

[0076] ​In the embodiments of the present application, the real-time current passing through the AC-DC selection unit needs to be further converted into DC current and transmitted to the VDC end of the BMS chip in the processing unit for the charging operation in the DC-DC mode of the processing unit, therefore, the three-phase rectifying circuit needs to be used in the AC path to convert the AC current into DC current.

[0077] Figure 9 The schematic diagram of the three-phase rectifying circuit in some preferred embodiments is shown. Figure 9 As shown, the three-phase rectifying module is composed of a three-phase rectifying bridge composed of six Schottky diodes and a filter and voltage stabilizing capacitor, which can rectify the three-phase AC voltage from low frequency to high frequency (less than or equal to 1 MHz) into DC voltage to output to the VDC+ end.

[0078] In addition, since the excitation frequency of the electromagnetic vibration energy capturing device is low in some cases, the main shaft rotating speed of the DC generator is also low, that is, the DC generator operates at a low speed to generate electricity in some cases, according to the output characteristics of the DC generator, the output at a low speed is not stable DC but relatively fluctuating electric energy containing a small amount of AC component; at the same time, due to the influence of installation errors and the like, the electromagnetic vibration energy capturing device will appear transmission unevenness during operation, which will also cause the fluctuation of the output electric energy, combined with the electromagnetic interference in the generator, noise interference in the environment and mechanical vibration, etc., therefore, the output electric energy of the DC generator needs to be further rectified and filtered, for this purpose, the filter module is preferably arranged on the DC path.

[0079] Figure 10 The schematic diagram of the filter circuit in some preferred embodiments is shown. Figure 10 As shown, the filter circuit includes a second diode D r , a third capacitor C f1 , a fourth capacitor C f2 and a first inductor L f , through the one-way conductivity of the second diode D r , the AC component in the output current of the DC generator is cut off, achieving the effect of rectification, wherein the third capacitor C f1 , the fourth capacitor C f2 and the first inductor L f comprise a CLCπ type filter, preferably, the third capacitor C f1 can take a relatively small value to filter the high frequency signal in the output electric energy, the value of the first inductor L f needs to be selected according to the desired filtering effect and the value of the capacitor to further filter out the high frequency interference signal in the output electric energy, while playing a role in suppressing the pulsating signal in the electric energy, the fourth capacitor C f2The relatively large value can be taken to smooth the fluctuation component in the electric energy, maintain the stability of the output voltage. Through the rectification filter module, the electric energy output by the DC generator is converted into stable DC power for subsequent power management module.

[0080] In some preferred embodiments, the second diode D r The Schottky diode can be used to reduce the voltage drop and improve the electric energy conversion efficiency. Further, the number of capacitors in the CLCπ filter is not limited to two, and multiple capacitors can be placed according to the output characteristics of different generators and actual application scenarios to achieve better filtering effect.

[0081] Four, the processing unit and its cooperation mode with the master control unit - jointly optimize the charging strategy:

[0082] Figure 11 The architecture of the processing unit and its connection mode with the master control unit in some preferred embodiments are shown. As shown in Figure 11 The processing unit includes a sampling module, a BMS chip, and a current switching module.

[0083] The sampling module is connected with the current input end VDC of the BMS chip, and the voltage amplitude distribution of the real-time current is obtained by sampling the current output from the three-phase rectification circuit or the filter circuit to the VDC end. At the same time, it is connected with the voltage end VBAT of the energy storage device through the BMS chip (or it can also be directly connected with the VBAT end), so as to collect the voltage condition of the energy storage device.

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

[0085] The master control unit is connected with the sampling module and the current switching module respectively, and the voltage amplitude and its change rate information of the real-time current are obtained by receiving the voltage amplitude distribution of the real-time current output from the sampling module, and the voltage condition of the energy storage device obtained from the sampling module is combined to generate the current switching signal Sig_2, which is sent 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 master control unit.

[0086] By comparing Figure 11 and Figure 1As can be seen, in the embodiments of this application, compared with the current common scheme of directly using BMS chip for charging current management, the charging part adds sampling of the voltage amplitude distribution of the real-time current output by the generator side of the electromagnetic vibration energy harvesting device. On this basis, the main control unit considers the voltage amplitude and its rate of change of the real-time current, and adjusts the charging current in combination with the voltage situation on the energy storage device side.

[0087] The method of regulating charging current solely through the charging management strategy built into the BMS chip is generally suitable for scenarios with a relatively stable current input source. For example, when using photovoltaic equipment as the current input, the voltage at the VDC terminal remains basically constant for a period of time, thus enabling stable charging of the energy storage device over a longer period of time.

[0088] by Figure 12 Taking the BMS chip D1 as an example, the BMS chip used is model BQ24650RVAR. Its input port VCC supports input DC current of 5V-30V. 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 around 5V, a supercapacitor with a full-charge voltage of 5.5V or slightly higher can be selected. The appropriate capacity (e.g., 10F to 100F or higher) can be chosen based on the required functional load. Under these conditions, the BMS chip D1 can set a slow-charge threshold voltage (e.g., 3V) and a fast-charge threshold voltage (4.1V). Based on the comparison between the feedback input VBAT and the above two threshold voltages, it controls the charging of the energy storage device with either a smaller slow-charge current or a larger fast-charge current. Specifically, under this setting, when the BMS chip inputs... When the DC current exceeds 5V (but does not exceed 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 pre-set slow charging current of about 0.8A. When VBAT is between 3V and 4.1V, it charges the energy storage device with a pre-set fast charging current much greater than 0.8A, for example, about 10*0.8A=8A. When VBAT exceeds 4.1V, the supercapacitor is close to full charge. On the one hand, it continues to charge, and on the other hand, it discharges to the load. At this time, the energy storage device can be charged with a small trickle current.

[0090] The charging current adjustment strategy of the BMS chip is applicable to most scenarios where the current source is stable. However, for electromagnetic vibration energy harvesting devices, the energy source has a strong randomness, which causes the amplitude and duration of the real-time input current and voltage to fluctuate greatly.

[0091] Figure 13 The figure shows the voltage amplitude of the real-time current outputted by the electromagnetic vibration energy harvesting device arranged on the track of a locomotive in a specific embodiment in a period of time, i.e. the voltage of the VDC terminal, as shown in the figure Figure 13 As shown, the first section of the left side real-time current has a short duration and a low maximum voltage amplitude, which represents that the size of the moving object causing the vibration is possibly short (such as the locomotive head), and the generator has not entered the ideal working state (i.e. the output voltage has not reached the working threshold voltage U out ) after starting, and stops due to the disappearance of the vibration; the second section of the middle represents that there is a moving object passing by the vibration source at a high speed, although the voltage peak is high, the duration is shorter, and the energy cannot be stably outputted; the third section of the right side represents that a long object (such as a complete locomotive) passes by the vibration source at a constant speed, and the real-time current waveform has a period of stable time which exceeds the preferred working threshold voltage U out of the generator.

[0092] Figure 14 The figure shows the charging voltage of the energy storage device and the output torque variation curve of the generator of the electromagnetic vibration energy harvesting device in some embodiments, as shown in the figure Figure 14 As can be seen, in the stage when the generator of the electromagnetic vibration energy harvesting device starts to output energy due to the vibration, if a large current is charged, due to the influence of the electromechanical coupling, the excessive current will cause the torque of the main shaft of the generator to rapidly increase, which will have a braking effect on the rotation of the main shaft of the generator, and further cause a large vibration of the energy harvesting 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 harvesting device is stable, it is suitable to output a large current in a relatively stable state.

[0093] It can be seen that, for the electromagnetic vibration energy harvesting device with large randomness of energy output, since it cannot continuously and stably output electric energy like a stable voltage and current source, when the charging control is performed, in addition to considering the charging state of the energy storage side, the energy amplitude, stability (or variation rate) and other output characteristics of the output side also need to be considered.

[0094] Therefore, in some preferred embodiments of the present application, as shown in the figure Figure 11 , by adding a sampling module, a master control unit and a current switching module, the conventional charging management method only through the BMS chip is improved, so that the joint optimization charging strategy considering the energy output characteristics and the energy storage state can be used to adjust the charging process of the energy storage device.

[0095] Figure 15 The figure shows the flow chart of the control method of the electromagnetic vibration energy harvesting system adapted to large-scale vibration sources according to some embodiments of the present application, as shown in the figureFigure 15 As shown, the control method of the energy-harvesting system comprises 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 output by it, automatically switch the circuit for charging the energy storage device;

[0098] Step S730, for each electromagnetic vibration energy-harvesting device, adjust the size of the charging current for charging the energy storage device by using a joint optimization charging strategy considering the energy output characteristics and the energy storage state, wherein the energy output characteristics include the voltage amplitude of the real-time current and its rate of change information.

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

[0100] Figure 16 The flow chart of the joint optimization charging strategy considering the energy output characteristics and the energy storage state in one specific embodiment is shown.

[0101] In combination Figure 11 and Figure 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 of the real-time current output by the electromagnetic vibration energy-harvesting device and its rate of change information; at the same time, the voltage VBAT of the energy storage device is monitored in real time.

[0102] Then, the master control unit determines whether the voltage of the energy storage device (i.e. the voltage of the VBAT terminal) is greater than or equal to the buffer charging threshold voltage. If VBAT is less than the buffer 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-harvesting device outputs real-time current.

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

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

[0105] When the voltage of the energy storage device is between the slow charging threshold voltage and the fast charging threshold voltage, it indicates that the energy storage device has the condition to perform fast charging with large current. At this time, as shown in Figure 16 , the real-time current characteristics output by the electromagnetic vibration energy harvesting device are further determined. Specifically, it can be determined in sequence whether the voltage amplitude of the real-time current output by the electromagnetic vibration energy harvesting device exceeds the operating threshold voltage of the generator thereof, and whether the change rate of the voltage amplitude is lower than a preset change rate threshold. If either of the two does not meet the determination condition, it indicates that the electromagnetic vibration energy harvesting device is in the start / end phase or its output has not reached a steady state. At this time, the charging current is still limited to not exceed the first current value to provide protection to the mechanical structure of the vibration energy harvesting device. When both of the two meet the determination condition, the charging current is set to the second current value (e.g., when the first current value is 0.8A, the second current value is set to about 8A) which is much greater than the first current value, so as to fully utilize the relatively stable energy output by the vibration energy harvesting device to charge the energy storage device.

[0106] The specific implementation modes of the sampling module, the BMS chip, the current switching module, and the host unit are described in Figures 17 to 19 , wherein Figure 17 a circuit schematic diagram of the sampling module is shown; Figure 18 a pin schematic diagram of a control chip used by an optional host unit is shown, Figure 19 a schematic diagram of a BMS chip D1 and its peripheral circuit is shown, and the current switching module arranged between the charging current output terminal of the BMS chip and the charging terminal VBAT of the energy storage device is also shown.

[0107] As shown in the figure, the sampling module can include a plurality of voltage division resistors (R re1 to R re5The voltage divider circuit is connected at one end to ground and at the other end to input the operating threshold voltage U of the generator out The operating threshold voltage of the generator can be determined according to the type of the generator used in the specific electromagnetic vibration energy harvesting device. For example, when the output is 10V, the ideal working state can be entered, and the operating threshold voltage U can be set to 10V. out

[0108] Further, when using a dry battery or a button battery as a system power supply module, it is generally not possible to directly provide a 10V operating threshold voltage. Therefore, as shown in Figure 17 , a voltage boosting chip U2 can be used to raise the voltage to obtain a 10V U out .

[0109] Further, as shown in Figure 17 , multiple comparison voltages are led out between the respective voltage dividing resistors and connected to the same input terminals of the corresponding second comparators (U3 to U7), and the VDC+ terminal is connected to the opposite input terminals of the respective second comparators. The output terminals of the respective second comparators are respectively connected to the IO1 to IO5 ports of the main control unit. By adjusting the resistance values of the respective voltage dividing resistors, the respective comparison voltage values can be set according to a predetermined step size. For example, the comparison voltages input to the same input terminals of U3 to U7 are respectively 10V, 9V, 8V, 7V and 6V.

[0110] As shown in Figure 18 , the main control unit uses a microcontroller M1 of model STM32L051X6, which receives the combination of high and low level signals output by the respective second comparators through multiple IO ports, so as to determine whether the effective voltage amplitude of the real-time current output by the electromagnetic vibration energy harvesting device exceeds the operating threshold voltage U out， , and obtains the change rate information by the difference between the amplitudes in the two time intervals.

[0111] Further, as shown in Figure 17 , the sampling module further includes a third comparator U8 for comparing the voltage VBAT of the energy storage device with a reference voltage ref (such as 3V), and the comparison result is also input to the IO9 port of the main control unit to determine whether the energy storage device enters the fast charging stage.

[0112] As shown in Figure 19 , the BMS chip can be of the same model as the embodiment shown in Figure 12 , and the current switching module is arranged between the BMS chip charging current output port and the charging terminal VBAT of the energy storage device, and includes a first current limiting resistor R SR1 , a second current limiting resistor R SR2 and a third switching device (i.e. a second NMOS tube Q S3 ​) and the fourth switching device (i.e., the second PMOS transistor Q) S4 The third switching device Q S3 and the fourth switching device Q S4 Connect the first current-limiting resistor R respectively SR1 Second current-limiting resistor R SR2 The main control unit simultaneously outputs current switching signals to the gates of two switching devices through the IO6 port 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 a high level, Q... S3 Open, Q S4 Turn off, thus making R SR1 The first charging path is activated, R SR2 The second charging path is turned off; when IO6 outputs a low level, Q... S3 Off, Q S4 This opens the circuit, thereby shutting off 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 3V slow-charge threshold voltage, this 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, regardless of the state of the VDC value collected by the electromagnetic vibration energy harvesting device, it sets IO6 to a high level, thereby turning on R... SR1 The current is output through the current-carrying circuit.

[0115] 2) When VBAT is in the 3V~4.1V range, the BMS chip outputs its preset fast charging current based on the feedback VBAT voltage value. This fast charging current 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 determination result is no, IO6 is set to low level. At this time, R SR2 When the circuit is open, although the BMS chip outputs a much larger fast charging current than its slow charging current, by setting R... SR1 R SR2 The ratio of resistance values, for example, R SR2 The resistance value is set to approximately R. SR1 10 times that of R SR2 The output current remains the first charging current; if the judgment result is yes, then R is turned on by setting IO6 to a high level.SR1 The charging current in the path can be very weak, and the charging can be performed using a third charging current smaller than the first charging current.

[0116] 3) When VBAT exceeds 4.1V, since the BMS chip will output a relatively small adjustment current at this time, whether the level of IO06 is high or low, the charging current through R SR1 or R SR2 The charging current in the path can be very weak, and the charging can be performed using a third charging current smaller than the first charging current.

[0117] Obviously, without departing from the working principle of the current switching module described above, 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 the charging circuit can be selectively turned on by the current switching signal Sig_2 and the different charging currents can be switched.

[0118] Figure 18 In the embodiment shown, the microcontroller M1 used by the master control unit has a working voltage of 3.3V, a power consumption of no more than 2.7mW in the working state, and 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 master control unit, or multiple controllers / microcontrollers can be used in a cascaded manner to form the master control unit.

[0119] Figure 20 The generator torque of the electromagnetic vibration energy harvesting device when using the above-mentioned joint optimization charging strategy is shown in a specific embodiment. As a comparison, the motor torque in the unoptimized state is also shown in the figure. By comparing the two, it can be seen that Figure 20 It can be seen that according to the joint optimization charging strategy, the energy storage device can be quickly charged to full capacity, and the generator main shaft torque is at a safe level and will not cause severe vibration of the structure; if the unoptimized charging strategy is used for charging, it will cause a sharp increase and change in torque, which will in turn cause severe vibration and service life of the structure.

[0120] Five, further optimization of the charging strategy for multiple energy harvesting devices:

[0121] The joint optimization charging strategy is adopted Figure 16The combined charging optimization strategy shown can achieve a good balance between charging effect and 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 the 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 Taking the three electromagnetic vibration energy harvesting devices 301, 302, and 303, arranged from right to left on bridge 100, as an example, when a moving object, such as a truck or tanker truck, travels across bridge 100 from right to left, the three energy harvesting devices... Figure 21 As shown, real-time currents Ureal_1, Ureal_2, and Ureal_3 are output sequentially. Obviously, the real-time current Ureal_1 output by the rightmost electromagnetic vibration energy harvesting device 301 alone cannot determine the speed and direction of the vehicle causing the vibration. However, when the electromagnetic vibration energy harvesting device 302 outputs a real-time current Ureal_2 with the same or similar vibration amplitude and rate of change after a period of time, the speed and direction of the moving object can be estimated by using the order and time interval of Ureal_1 and Ureal_2. In this case, for other electromagnetic vibration energy harvesting devices, such as the electromagnetic vibration energy harvesting 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 time and waveform of the corresponding real-time current Ureal_3 can be predicted in advance, thereby adopting a more effective charging strategy to control its charging process.

[0123] Specifically, when the electromagnetic vibration energy harvesting system adapted to large-scale vibration sources provided in this application includes three or more electromagnetic vibration energy harvesting devices, in some preferred embodiments, the following can be used: Figure 22 The control method shown includes 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 a real-time current.

[0125] Step S820: For each electromagnetic vibration energy harvesting device, based on the waveform of its output real-time current, automatically switch the circuit that charges the energy storage device.

[0126] Step S830, for the two adjacent electromagnetic vibration energy harvesting devices earliest affected by an object moving on a large-scale vibration source, a joint optimization charging strategy considering energy output characteristics and energy storage state is adopted to adjust the size of the charging current of the two electromagnetic vibration energy harvesting devices to 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, based on the energy output characteristics of the two adjacent electromagnetic vibration energy harvesting devices, the motion direction and speed of the object are determined, and based on the motion direction and speed, the size of the charging current of other electromagnetic vibration energy harvesting devices to the energy storage device under the influence of the object is adjusted.

[0128] Reference Figure 21 and Figure 22 No matter the motion direction of the object causing vibration, there are two adjacent electromagnetic vibration energy harvesting devices affected in turn, and output real-time current Ureal_1, Ureal_2, using the time of occurrence of the two real-time currents and the order before and after, the occurrence time of Ureal_3 can be estimated, so that different strategies are adopted in steps S830 and S840 to control the charging current.

[0129] For example, Figure 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 energy output characteristics and energy storage state is still adopted, and the charging current is switched to the second current at T1 and T2 respectively; for the third electromagnetic vibration energy harvesting device affected by the moving object, since the waveform of its output Ureal_3 changing with time can be predicted, and it is known that it will maintain stable output for a period of time after exceeding the working threshold voltage of the generator, therefore, the charging current can be set to the second current at T3 (it can be observed that at this time its amplitude is close to but has not yet exceeded the working threshold voltage of the generator), using this way, there is no need to judge the change rate of the real-time current output by other electromagnetic vibration energy harvesting devices, so that the charging is advanced into the fast charging state, further improving the overall charging effect. Figure 21

[0130] Six, anti-inverted circuit and system power supply module:

[0131] ​Unlike the stable power supply, the electromagnetic vibration energy harvesting device does not output power all the time because the vibration in the environment does not exist all the time. In order to avoid the power stored in the energy storage device from flowing back to the charge management unit when the vibration energy harvesting device stops working, thereby damaging the module, in some preferred embodiments of the present application, a backflow prevention circuit is further arranged between the charge management unit and the energy storage device to realize one-way control of the charging direction and prevent current from flowing from the energy storage device to the charge management unit.

[0132] Figure 23 The schematic diagram of the backflow prevention circuit in some specific embodiments is shown in FIG. 3. Figure 14 As shown in FIG. 3, the backflow prevention circuit comprises a first triode Q1, a second triode Q2, a first switch tube Q3, a third current-limiting resistor R cl1 and a fourth current-limiting resistor R cl2 . The first triode Q1 and the second triode Q2 are both PNP triodes, and the first switch tube Q3 is a P-type MOS tube.

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

[0134] The working principle of the backflow prevention circuit is as follows:

[0135] When the vibration energy harvesting device works normally, the charge management unit outputs power, on the one hand, the voltage difference between the emitter and the base of the first triode Q1 is greater than the conduction voltage drop of the triode, the first triode Q1 is turned on, and the bases of the first triode Q1 and the second triode Q2 follow the output voltage of the charge management unit; on the other hand, the body diode of the first switch tube Q3 flows back to the rear stage, so that the source of the first switch tube Q3 and the emitter of the second triode Q2 also follow the output voltage of the charge management unit, 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 triode Q2, so the second triode Q2 is cut off. Therefore, when the vibration energy harvesting device works normally, the power output by the charge management unit will continuously flow into the energy storage device.

[0136] When the vibration energy harvesting device stops working, the charge 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, 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 are both followed by 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, the first switch tube Q3 is cut off, therefore, when the vibration energy harvesting device stops working, the electric energy in the energy storage device cannot flow back to the charge management unit.

[0137] The introduction of the anti-backflow circuit makes the electric energy output by the charge management unit flow into the energy storage device with extremely low loss when the vibration energy harvesting device is working normally, and the electric energy stored in the energy storage device cannot flow back to the charge management unit to cause circuit damage when the vibration energy harvesting device stops working. Figure 24 The comparison results of the power-off situation of the super capacitor as the energy storage device when the anti-backflow circuit is added and when the anti-backflow circuit is not added in one specific embodiment are shown. It can be seen from the experimental comparison that after the anti-backflow circuit is added, the power-off speed of the super capacitor is obviously reduced compared with the case without the anti-backflow circuit. Except that the anti-backflow circuit itself consumes a small part of the electric energy, the electric energy cannot flow back from the energy storage module to the charge management unit, which also verifies the effectiveness of applying the anti-backflow circuit to the energy management circuit of the vibration energy harvesting system.

[0138] In order to ensure the stable work of each functional module in the system, in some preferred embodiments, the electromagnetic vibration energy harvesting system adapted to large-scale vibration sources further comprises a system power supply module. The system power supply module can select appropriate dry batteries, button batteries, lithium batteries, etc. for power supply according to the specification parameters of the plurality of comparators and the master control unit in the system, for example, Figure 18 The master control unit shown can use a working voltage of 3.3V, and the power consumption in the working state is not greater than 2.7mW. The appropriate power supply module can be selected by taking the power consumption of other power modules into consideration.

[0139] The specific embodiments of the present application are described in detail above, and those skilled in the art can make some improvements and modifications to the present application without departing from the principles of the present application. These improvements and modifications also belong to the protection scope of the claims of the present application.

Claims

1. An electromagnetic vibration energy harvesting system adapted to a large-scale vibration source, comprising multiple electromagnetic vibration energy harvesting devices disposed on the large-scale vibration source, and at least one energy storage device, wherein the electromagnetic vibration energy harvesting devices are used to convert the vibration of the large-scale vibration source into a real-time current for output, characterized in that, Also includes: The main control unit and multiple self-switching adjustable charging circuits are provided one-to-one with the electromagnetic vibration energy harvesting device. Each of the self-switching adjustable charging circuits automatically switches the circuit that charges the energy storage device based on the waveform of the real-time current output by its 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; The self-switching adjustable charging circuit includes an AC / DC selection unit, a three-phase rectifier circuit, a filter circuit, and a processing unit. The AC / DC selection unit selectively connects the AC or DC path between its corresponding electromagnetic vibration energy harvesting device and the processing unit based on the time-varying characteristics of the real-time current output by its corresponding electromagnetic vibration energy harvesting device. The three-phase rectifier circuit is used to rectify the AC current in the AC path into DC current. The filter 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 through the AC or DC path, and adjusts the magnitude of the charging current under the control of the main control unit. 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 status of the energy storage device; The BMS chip is used to convert the current input to the three-phase rectifier circuit or 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. The main control unit obtains the voltage amplitude and rate of change 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 by combining it with the voltage status of the energy storage device. The current switching module includes a third switching device, a fourth switching device, a first current-limiting resistor, and a second current-limiting resistor; The input and output terminals of the third switching device are respectively connected to the charging current output terminal of the BMS chip and the first terminal of the first current limiting resistor, and the second terminal of the first current limiting resistor is connected to the charging current input terminal of the energy storage device. The input and output terminals of the fourth switching device are respectively connected to the charging current output terminal of the BMS chip and the first terminal of the second current limiting resistor, and the second terminal of the second current limiting resistor is connected to the charging current input terminal of the energy storage device. The current switching signal output terminal of the main control unit is simultaneously connected to the enable terminals of the third and fourth switching devices, wherein the third and fourth switching devices have opposite high and low level switching characteristics.

2. The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources according to claim 1, characterized in that: The AC / DC selection unit includes a first switching device, a second switching device, and a comparison module; The input terminals of the first switching device, the second switching device, and the comparison module are all connected to the output terminal of their corresponding electromagnetic vibration energy harvesting devices for inputting the real-time current. The output of the comparison module simultaneously outputs a line switching signal to the first switching device and the second switching device. When the real-time current is an AC current, the line switching signal is a high-level signal, and when the real-time current is a DC current, the line switching signal is a low-level signal. The first switching 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 switching 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.

3. The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources according to claim 2, characterized in that, The first switching device is a first NMOS transistor, the second switching device is a first PMOS transistor, 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 terminal of the first diode is connected to the output terminal of the electromagnetic vibration energy harvesting device, and the negative terminal is connected to the first terminal of the first capacitor. The second terminal of the first capacitor is connected to the first terminal of the second capacitor, the first terminal of the first resistor, and the first terminal of the second resistor. The second terminal of the second capacitor and the second terminal of the first resistor are both grounded. The second terminal of the second resistor is connected to the non-inverting input terminal of the first comparator. The inverting input terminal of the first comparator is used to receive the reference voltage. The drain (D) and source (S) terminals of the first switching device are connected to the output terminal of the electromagnetic vibration energy harvesting device and the input terminal of the three-phase rectifier circuit, respectively. The source (S) and drain (D) terminals of the second switching device are connected to the output terminal of the electromagnetic vibration energy harvesting device and the input terminal of the filter circuit, respectively. The output terminal of the first comparator is connected to the gate (G) terminals of the first and second switching devices.

4. The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources according to claim 1, characterized in that, The sampling module includes: Multiple voltage divider resistors and multiple corresponding second comparators are provided. The multiple voltage divider 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. They are used to output the corresponding comparison voltage to the non-inverting input terminal of the corresponding second comparator. The inverting input terminal of the second comparator is used to receive the voltage amplitude of the real-time current. The output terminal is connected to the main control unit. The third comparator has a non-inverting input terminal for receiving the voltage of the energy storage device, an inverting input terminal for receiving a reference voltage, and an output terminal connected to the main control unit.

5. The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources according to claim 1, characterized in that, Also includes: An anti-backflow circuit is 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 modules in the electromagnetic vibration energy harvesting system adapted to large-scale vibration sources.

6. A control method for controlling an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source as described in claim 1, characterized in that, Includes the following steps: Each of the electromagnetic vibration energy harvesting devices converts the vibration generated by the large-scale vibration source at its location into a real-time current. For each of the electromagnetic vibration energy harvesting devices, the circuit for charging the energy storage device is automatically switched based on the waveform of the real-time current output. For each of the electromagnetic vibration energy harvesting devices, a joint optimization charging strategy that considers energy output characteristics and energy storage state is adopted to adjust the magnitude of the charging current that charges the energy storage device, wherein the energy output characteristics include the voltage amplitude and rate of change information of the real-time current. 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 to charge the energy storage device, specifically including the following operations: The voltage of the energy storage device and the voltage amplitude and rate of change of the real-time current output by the electromagnetic vibration energy harvesting device are acquired in real time. When the voltage of the energy storage device is less than the slow charging threshold voltage, the charging current is controlled to not exceed the first current value; When the voltage of the energy storage device is greater than or equal to the slow charging threshold voltage and less than the fast charging threshold voltage, it is further determined whether the real-time current output by the electromagnetic vibration energy harvesting device simultaneously satisfies that the voltage amplitude is greater than or equal to the working threshold voltage of its generator and the rate of change of the voltage amplitude is less than or equal to the rate of change threshold. If both conditions are met, the charging current is controlled to the second current value; otherwise, the charging current is controlled to not exceed 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 charging threshold voltage, the charging current is controlled to not exceed the third current value, wherein the third current value is less than or equal to the first current value.

7. A control method for controlling an electromagnetic vibration energy harvesting system adapted to a large-scale vibration source as described in claim 1, characterized in that, The electromagnetic vibration energy harvesting system adapted to large-scale vibration sources includes at least three electromagnetic vibration energy harvesting devices, and the control method includes the following steps: Each of the electromagnetic vibration energy harvesting devices converts the vibration generated by the large-scale vibration source at its location into a real-time current. For each of the electromagnetic vibration energy harvesting devices, the circuit for charging the energy storage device is automatically switched based on the waveform of the real-time current output. For two adjacent electromagnetic vibration energy harvesting devices that are first affected by an object moving on the large-scale vibration source, a joint optimized charging strategy considering energy output characteristics and energy storage state is adopted to adjust the magnitude of the charging current from the two electromagnetic vibration energy harvesting devices to the energy storage device under the influence of the object. The energy output characteristics include the voltage amplitude and rate of change information of the real-time current; and... The direction and speed of the object's motion are determined based on the energy output characteristics of the two adjacent electromagnetic vibration energy harvesting devices. The magnitude of the charging current of other electromagnetic vibration energy harvesting devices charging the energy storage device under the influence of the object is adjusted based on the direction and speed of motion. 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 to charge the energy storage device, specifically including the following operations: The voltage of the energy storage device and the voltage amplitude and rate of change of the real-time current output by the electromagnetic vibration energy harvesting device are acquired in real time. When the voltage of the energy storage device is less than the slow charging threshold voltage, the charging current is controlled to not exceed the first current value; When the voltage of the energy storage device is greater than or equal to the slow charging threshold voltage and less than the fast charging threshold voltage, it is further determined whether the real-time current output by the electromagnetic vibration energy harvesting device simultaneously satisfies that the voltage amplitude is greater than or equal to the working threshold voltage of its generator and the rate of change of the voltage amplitude is less than or equal to the rate of change threshold. If both conditions are met, the charging current is controlled to the second current value; otherwise, the charging current is controlled to not exceed 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 charging threshold voltage, the charging current is controlled to not exceed the third current value, wherein the third current value is less than or equal to the first current value.

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