Multi-source vibration energy capturing device for self-powered monitoring of high-speed railway roadbed in cold region
By installing piezoelectric energy traps and energy storage components on the high-speed railway subgrade to capture and store vibration energy, the problem of unstable traditional power supply methods in cold areas is solved, and reliable power supply and long-term stable energy supply are achieved under extreme temperatures.
Patent Information
- Application Number
- CN202411753298.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-04-25
AI Technical Summary
In cold areas, traditional external power supply methods may be affected by temperature changes and damage to power supply lines, resulting in unstable or interrupted power supply of high-speed railway subgrade monitoring equipment, affecting real-time monitoring and safety assessment.
A multi-source vibration energy capture device based on piezoelectric effect is adopted to capture and store the vibration energy of the railway subgrade by installing piezoelectric energy capture devices and energy storage elements on the track beams, providing a stable power supply.
Reliable power supply under extreme temperature conditions is achieved, the problems of damage and interruption of power supply lines are avoided, the long-term and stable energy demand for high-speed railway subgrade monitoring is met, and energy consumption and environmental impact are reduced.
Smart Images
Figure CN119891812A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an energy capture device, in particular to a multi-source vibration energy capture device for self-powered monitoring of a cold region high-speed railway roadbed. Background Art
[0002] Maintaining the long-term stable service of the roadbed in a complex environment is very important for maintaining the safe and smooth operation of high-speed railways. Selecting typical sections for automatic monitoring can grasp the service status of the roadbed in real time and evaluate the evolution trend of the roadbed stability. At present, the automatic roadbed monitoring system generally adopts a solar + battery power supply solution, but it is greatly affected by weather, temperature, installation environment, etc. In cold areas, traditional external power supply methods may be affected by temperature changes and damage to power supply lines, resulting in unstable or even interrupted power supply. This will make the monitoring equipment unable to work properly, thus affecting the real-time monitoring and safety assessment of the high-speed railway roadbed. The energy density of train vibration is high and continuous. Converting railway vibration energy into electrical energy is one of the technical options for achieving long-term power supply for the roadbed monitoring system. Summary of the invention
[0003] In order to solve the above problems existing in the background technology, the present invention is based on the piezoelectric effect and utilizes the advantages of piezoelectric elements such as low price, easy installation, high voltage generation, and high electromechanical energy conversion efficiency to provide a multi-source vibration energy capture device for self-powered monitoring of cold-region high-speed railway subgrades. The present invention studies the piezoelectric materials, structures, and electrical connection methods of railway subgrade piezoelectric energy capture devices, and develops railway subgrade piezoelectric energy capture and energy storage devices suitable for stable power supply in cold regions. The device can effectively capture and utilize the vibration energy of cold-region high-speed railway subgrades to meet the energy needs of cold-region high-speed railway subgrade monitoring.
[0004] The objective of the present invention is achieved through the following technical solutions:
[0005] A multi-source vibration energy capture device for self-powered monitoring of cold-region high-speed railway subgrade includes a piezoelectric energy harvester and an energy storage element. The piezoelectric energy harvesters are attached to the middle of the span of the track beam and connected in parallel to monitor the relationship between voltage changes over time and capture voltage signals, wherein:
[0006] The piezoelectric energy harvester is composed of a primary force amplifier plate, a secondary amplifier plate, a support plate, a piezoelectric stack, a top plate, a bottom plate, and a flexible plate;
[0007] The upper and lower end surfaces of the support plate are connected to the top plate, the top plate is connected to the bottom plate, a secondary amplifier plate is arranged between the top plate and the bottom plate, and the bottom plate located on the upper end surface of the support plate is connected to the primary amplifier plate, the left and right end surfaces of the support plate are respectively connected to one end of the piezoelectric stack, and the other end of the piezoelectric stack is connected to the flexible plate to buffer the stress condition;
[0008] The piezoelectric stack is composed of a plurality of piezoelectric stack structures, each of which is formed by stacking a plurality of PZT-5H piezoelectric ceramic sheets. The positive and negative electrodes of the piezoelectric ceramic sheets are connected respectively in each piezoelectric stack structure, and the positive and negative electrodes of the plurality of piezoelectric stack structures are finally connected together. The polarization directions of adjacent piezoelectric ceramic sheets in the same piezoelectric stack structure are opposite.
[0009] The piezoelectric stack is connected to the first-level amplification plate to sense the vibration energy generated in the vertical direction of the roadbed, and converts it into an electrical signal to transmit to the support plate, and the second-level amplification plate senses the vibration energy generated in other directions and converts it into an electrical signal;
[0010] The energy storage element is composed of a cubic support, a cubic mass block, and two sets of elastic transducer strips connecting the two;
[0011] The cubic mass block is arranged at the center position inside the cubic support;
[0012] The elastic transducer strip is a universal junction structure composed of a vertical transducer strip and a transverse transducer strip, the vertical transducer strip is vertically arranged on the left and right sides of the cubic support, and the cubic mass block is connected to the vertical transducer strip through the transverse transducer strip;
[0013] One side of the piezoelectric stack is pasted on the mid-span position of the track beam, and the other side is pasted on the vertical transducer strip.
[0014] Compared with the prior art, the present invention has the following advantages:
[0015] 1. The present invention captures the vibration energy generated in different directions of the railway roadbed and utilizes the piezoelectric effect of the piezoelectric element, that is, the effect of generating charge output under the action of external force to collect vibration energy, which can achieve a solution for reliable power supply under extreme temperature conditions.
[0016] 1. In order to improve the efficiency of piezoelectric energy capture for railway subgrade, the present invention selects the widely used PZT-5H piezoelectric ceramic material for railway subgrade piezoelectric energy capture and energy empowerment device. Compared with other piezoelectric materials, this material has the advantages of high piezoelectric performance, high compressive strength, high dielectric constant, etc., and is suitable for application in railway subgrade piezoelectric energy capture technology.
[0017] 2. In order to ensure that each piezoelectric stack in the railway roadbed piezoelectric energy capture device is uniformly stressed so as to obtain more stable output electrical energy, the piezoelectric stack structure in the device is arranged in a centrally symmetrical manner.
[0018] 3. The forces in the railway subgrade are complex and there are risks of various diseases. Therefore, the present invention directly buries the piezoelectric energy capture device inside the subgrade to reduce its service life. At the same time, in order to prevent moisture or railway subgrade powder particles from entering the device and affecting the piezoelectric energy capture efficiency, and to prevent it from becoming a water channel in the railway subgrade and inducing mud and mud diseases in the railway subgrade, it is sealed.
[0019] 4. The present invention designs an electromechanical conversion structure capable of collecting multi-directional vibration energy to ensure that the structure can effectively convert energy regardless of the direction of the vibration.
[0020] 5. The storage device has a relatively simple structure, is relatively easy to manufacture, and uses only two sets of transducer strips. Therefore, the energy generated by the vibration of the mass block can be concentrated on the transducer strips, which can greatly improve the energy recovery efficiency of the subsequent charging circuit. Compared with the friction generated by the shaft part and the energy consumed in the process of adjusting the direction caused by the complex cube-sphere structure, this structure responds more quickly to external vibration adjustment, is more sensitive to vibrations with small external excitation levels, and will not cause wear of components when vibrating for a long time in the vertical vibration direction. In addition, this technology reduces dependence on external power supplies, and avoids problems of power supply line damage and interruption through multi-source vibration energy capture and conversion; it reduces energy consumption and has the advantages of environmental friendliness and sustainable development.
[0021] 6. The present invention utilizes multi-source vibration energy, and the storage unit can solve the discontinuity problem of vibration energy, ensure continuous and stable energy supply, meet the needs of long-term monitoring, and reduce energy waste and environmental impact. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is the equivalent diagram of the circuit layout of the piezoelectric energy harvesting device.
[0023] Figure 2 This is a vertical cross-sectional view of the simplified model of the electrical connection of the piezoelectric material in the railway roadbed piezoelectric energy capture device. In the figure: 1 represents the positive electrode, 2 represents the negative electrode, 3 represents the circuit polarization direction, 4 represents a thin copper sheet with the same side length as the PZT-5H material, which is used to connect the piezoelectric ceramic material, and 5 represents the line connection electrode layer.
[0024] Figure 3 It is a piezoelectric stacked structural element. In the figure: 1 represents a cubic mass block, 2 represents a cubic bracket, and 3 represents an elastic transducer strip.
[0025] Figure 4 It is a cross-sectional schematic diagram of a railway roadbed piezoelectric energy capture device, in which: 1 represents the first-level force amplification plate, 2 represents the second-level force amplification plate, 3 represents the support plate, 4 represents the piezoelectric stack, 5 represents the bottom plate, 6 represents the top plate, and 7 represents the flexible plate.
[0026] Figure 5 Arrange a location for the device. DETAILED DESCRIPTION
[0027] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.
[0028] The present invention provides a multi-source vibration energy capture device for self-powered monitoring of cold-region high-speed railway roadbed. The device comprises a piezoelectric energy harvester and an energy storage element. Completely identical piezoelectric energy harvesters are attached to the mid-span of the track beam and connected in parallel to monitor the relationship between voltage changes over time and capture voltage signals.
[0029] like Figure 4 As shown, the piezoelectric energy harvester is composed of a first-level force amplifier plate 1, a second-level amplifier plate 2, a support plate 3, a piezoelectric stack, a top plate 6, a bottom plate 5, and a flexible plate 7. The upper and lower end surfaces of the support plate 3 are connected to the top plate 6, the top plate 6 is connected to the bottom plate 5, and a second-level amplifier plate 2 is arranged between the top plate 6 and the bottom plate 5. The bottom plate 5 located on the upper end surface of the support plate 3 is connected to the first-level force amplifier plate 1. The left and right end surfaces of the support plate 3 are respectively connected to one end of the piezoelectric stack, and the other end of the piezoelectric stack is connected to the flexible plate 7 to buffer the force. The piezoelectric stack is composed of eight piezoelectric stack structures, each of which is formed by stacking multiple PZT-5H piezoelectric ceramic sheets. The positive and negative electrodes of each piezoelectric ceramic sheet are respectively connected in each piezoelectric stack structure, and the positive and negative electrodes of the eight piezoelectric stack structures are finally connected together. The polarization directions of adjacent piezoelectric ceramic sheets in the same piezoelectric stack structure are opposite, and a thin copper sheet 4 with a thickness of 0.1 mm and the same side length as the PZT-5H piezoelectric ceramic sheet is used to connect the piezoelectric ceramic material. The piezoelectric stack is connected to the first-level force amplifier plate to sense the vibration energy generated by the roadbed in the vertical direction, and convert it into electrical signals to transmit to the support plate and the second-level amplifier plate to sense the vibration energy generated in other directions and convert it into electrical signals to improve the efficiency of piezoelectric energy capture. The flexible board uses polyimide as the packaging material, which is compatible with the railway roadbed and has good adhesion. It has sufficient strength and rigidity. It also has excellent fatigue resistance, corrosion resistance and impermeability, which improves the durability of the device. The electrical connection method of all piezoelectric ceramic sheets in the piezoelectric stack structure is in parallel, which can generate more charge and electrical energy than the series connection method, and the output current is larger. When the series connection is used, the output voltage is larger. The railway roadbed piezoelectric energy capture technology is designed to output greater energy rather than higher voltage, so the electrical connection method of all piezoelectric ceramic sheets in the eight piezoelectric stack structures is in parallel. The simplified model of the electrical connection of piezoelectric materials in the railway roadbed piezoelectric energy capture device can be found in Figure 2 In order to reduce the impact of the piezoelectric energy harvester on the quality of the high-speed railway subgrade, the piezoelectric energy harvester was finally designed to be 80mm in height and 280mm in diameter.
[0030] like Figure 3As shown, the energy storage element consists of a cubic bracket, a cubic mass block, and two sets of elastic transducers connecting the two. The cubic mass block 1 is set at the central position inside the cubic bracket 2. The elastic transducer 3 is a universal joint structure composed of vertical transducers and horizontal transducers. The vertical transducers are vertically arranged on the left and right sides of the cubic bracket. The cubic mass block is connected to the vertical transducers through the horizontal transducers. One side of the piezoelectric stack is pasted at the mid-span position of the track beam through a pre-bent spring piece, and the other side is pasted on the vertical transducer through a pre-bent spring piece and is symmetrically arranged along the center on the vertical transducer. Since the structure is simple and the components are easy to process, and the function of multi-directional vibration energy harvesting can be realized. The elastic transducers are vertically connected in the form of a universal joint by pre-bent spring pieces to ensure that the transducers can be stretched or compressed regardless of how the mass block elastically vibrates. The working principle of this structure is that when the external environment vibrates, the middle mass block will also vibrate accordingly, thereby driving the stretching or compression of the elastic transducers, so that the piezoelectric material pasted on the vertical transducers generates charge output, thereby realizing energy recovery and converting the electrical signal into storable electrical energy.
[0031] Because the energy storage capacitor has an initial voltage, it is assumed that when 0 < t < t1, the diode D1 is open and cannot conduct electricity; at t = t1, the diode D2 is closed, and the piezoelectric energy harvester starts to charge the energy storage capacitor until t = t2. It is assumed that the load reaches the amplitude at the moment t2. After that, the load decreases, then the piezoelectric energy harvester starts to decompress, resulting in the diode D1 being disconnected again until the output voltage of the piezoelectric energy harvester is greater than the voltage across the battery again next time.
[0032] Based on this process, the variation between the voltage V across the piezoelectric energy harvester and the voltage across the battery will be given below.
[0033] At the moment t1, the voltage of the piezoelectric energy harvester is just equal to the initial voltage of the energy storage capacitor. When 0 < t < t1, the diode D1 is open. Therefore, the voltage of the piezoelectric energy harvester is:
[0034] At the moment t, the diode D1 is closed, and the voltage across the piezoelectric energy harvester is equal to the voltage across the energy storage capacitor (neglecting the potential difference across the diode), that is:
[0035] As the time t changes, the voltages of the piezoelectric energy harvester and the energy storage capacitor are: V = Q(t) / C p ;
[0036] At the moment t1, the voltages of the piezoelectric energy harvester and the energy storage capacitor are: V t1 = V0 = Q(t1) / C p ;
[0037] where C p is the capacitance value, C is the external capacitance, V0 is the voltage in the initial state, and the voltage is: V(t) = Vc (t) = V0 + Q(t-t1) / C p +C;
[0038] At time t2, the voltage across the piezoelectric energy harvester and the external capacitor is: V(t2) = V c (t2) = V0 + Q(t2) / C p +C.
[0039] The first charging cycle is now completed, and the initial voltage on the energy storage capacitor in the next cycle becomes Ve(t2). It can be seen that after each charging, the voltage value of the external capacitor is only related to the maximum load moment t2, and has nothing to do with t1. V = Q(t2) / C p is the maximum open circuit voltage. By analogy, the voltage of the energy storage capacitor after n times of charging under periodic load can be expressed as: V n =α n V0+(1-α n )Q(t2) / C p The circuit layout equivalent diagram of the piezoelectric energy harvester is shown in Figure 1 As shown in the formula: V-capacitor voltage change; C-external capacitance; Q-added charge.
[0040] In the present invention, the piezoelectric energy harvester is arranged inside the high-speed railway roadbed. In order to maximize the dynamic stress on the piezoelectric energy harvester and thus convert more electrical energy, its top surface is at the same height as the top surface of the base bed surface.
[0041] In the present invention, energy harvester selection and arrangement: Select appropriate vibration sensors, such as accelerometers or vibration sensors, to capture vibration signals on the high-speed railway subgrade. According to monitoring requirements, sensors are reasonably arranged on the subgrade to cover key areas and ensure the stability and reliability of the sensors.
[0042] In the present invention, energy conversion device (piezoelectric stack) design and manufacturing: design and manufacture a device that can convert vibration energy into electrical energy, such as piezoelectric materials, electromagnetic inductors or micro generators, etc. Determine the structure and parameters of the device to improve the energy conversion efficiency and ensure the durability and reliability of the device.
[0043] In the present invention, energy storage unit (energy storage element) selection and management: Select energy storage units suitable for self-powered monitoring systems, such as rechargeable batteries or supercapacitors. Determine the capacity and characteristics of the energy storage unit to meet the energy requirements of the monitoring system. Design an energy management system, including charging and discharging control, to ensure stable charging and discharging and long-term reliability of the energy storage unit.
[0044] In the present invention, system integration and communication: the energy conversion device and energy storage unit are integrated with the self-powered monitoring system to ensure the smooth operation of energy capture, conversion and storage. A reliable communication network is established to transmit the monitoring data to the monitoring equipment and data center for data analysis and processing.
Claims
1. A multi-source vibration energy capture device for self-powered monitoring of high-speed railway roadbed in cold regions, characterized in that The multi-source vibration energy capture device includes a piezoelectric energy harvester and an energy storage element. A completely identical piezoelectric energy harvester is attached to the mid-span of the track beam. The piezoelectric energy harvesters are connected in parallel to monitor the relationship between voltage changes over time and capture voltage signals. The energy storage element consists of a cubic bracket, a cubic mass block and two groups of elastic transducer strips connecting the two. The cubic mass block is arranged at the center position inside the cubic bracket. The elastic transducer strip is a universal junction structure composed of a vertical transducer strip and a transverse transducer strip. The vertical transducer strip is vertically arranged on the left and right sides of the cubic bracket, and the cubic mass block is connected to the vertical transducer strip through the transverse transducer strip. One side of the piezoelectric stack is attached to the mid-span position of the track beam, and the other side is attached to the vertical transducer strip.
2. The multi-source vibration energy capture device for self-powered monitoring of cold region high-speed railway roadbed according to claim 1 is characterized in that The piezoelectric energy harvester consists of a first-level force amplifier plate, a second-level amplifier plate, a support plate, a piezoelectric stack, a top plate, a bottom plate, and a flexible plate; the upper and lower end surfaces of the support plate are connected to the top plate, the top plate is connected to the bottom plate, a second-level amplifier plate is arranged between the top plate and the bottom plate, and the bottom plate located on the upper end surface of the support plate is connected to the first-level force amplifier plate, the left and right end surfaces of the support plate are respectively connected to one end of the piezoelectric stack, and the other end of the piezoelectric stack is connected to the flexible plate to buffer the force conditions; the piezoelectric stack is connected to the first-level force amplifier plate to sense the vibration energy generated by the roadbed in the vertical direction, and converts it into electrical signals and transmits it to the support plate, and the second-level amplifier plate senses the vibration energy generated in other directions and converts it into electrical signals.
3. The multi-source vibration energy capture device for self-powered monitoring of cold region high-speed railway roadbed according to claim 2 is characterized in that The piezoelectric stack is composed of multiple piezoelectric stacking structures, each of which is composed of multiple PZT-5H piezoelectric ceramic sheets stacked together. The positive and negative electrodes of each piezoelectric ceramic sheet are connected separately in each piezoelectric stacking structure, and the positive and negative electrodes of multiple piezoelectric stacking structures are finally connected together. The polarization directions of adjacent piezoelectric ceramic sheets in the same piezoelectric stacking structure are opposite.
4. The multi-source vibration energy capture device for self-powered monitoring of cold region high-speed railway roadbed according to claim 1 is characterized in that The flexible board uses polyimide as packaging material.
5. The multi-source vibration energy capture device for self-powered monitoring of cold region high-speed railway roadbed according to claim 1 is characterized in that The piezoelectric stacks are symmetrically arranged along the center of the vertical transducer strip.