Piezoelectric energy collection device optimization method based on finite element method

Abstract

The invention discloses a finite element method-based piezoelectric energy collection device optimization method, which comprises the following steps of: firstly, establishing a bluff body streaming model by utilizing a piezoelectric effect module in finite element analysis, determining a fixed constraint according to solid mechanics, and carrying out transient analysis on the model after setting a wall and an entrance and exit according to fluid mechanics; the method comprises the following steps: calculating to obtain an output voltage on a piezoelectric cantilever beam, then determining structural parameters of a bluff body streaming model body according to the output voltage on the piezoelectric cantilever beam, and finally determining a resistance value of an external circuit resistor according to an impedance matching principle to complete the design of the energy collection circuit. Under the condition of modeling simulation calculation, the optimal structural parameters of the piezoelectric energy collection device can be obtained by utilizing a finite element method, impedance matching of an external energy collection circuit is realized, the output voltage of the piezoelectric transducer device can be effectively improved, and the energy collection efficiency is improved.

Description

Technical Field

[0001] The invention relates to a piezoelectric energy collection device optimization method based on a finite element method, and belongs to the technical field of energy collection. Background Art

[0002] Under the strategic background of sustainable development, the problem of powering a large number of sensors in the Internet of Things is a research focus. In underwater marine environments, self-powered sensors are a better choice than traditional batteries that need to be replaced regularly and may cause environmental pollution. Piezoelectric sensors are typical self-powered sensors. Their working principle is based on the positive piezoelectric effect of piezoelectric materials. External mechanical vibrations cause stress inside the piezoelectric material, which is then converted into electrical signal output. Compared with other forms of power generation, piezoelectric power generation has the advantages of high energy density, no electromagnetic interference, simple structure, and easy miniaturization. In addition, piezoelectric energy harvesting devices have the advantages of simple structure, clean and environmentally friendly, so they have attracted widespread attention from many scholars.

[0003] The main structural parameters of the piezoelectric energy collection device are important factors that affect its output voltage value, energy collection efficiency and conversion efficiency. Therefore, in order to improve the output characteristics and energy utilization rate of the device, it is crucial to optimize the design of the main structural parameters of the device. After collecting the vibration of the external environment and converting the stress generated inside the material into electrical energy, the voltage signal output by the piezoelectric transducer is an AC voltage signal, which cannot directly supply power to the sensor node that requires a DC power supply. It is necessary to connect the piezoelectric energy collection device to an interface circuit that can convert AC power into DC power. Therefore, in addition to the main structural parameters of the piezoelectric energy collection device, the design of the external interface circuit will also have a relatively large impact on the energy conversion efficiency. Therefore, the present invention uses the finite element method and combines the impedance matching principle to propose a piezoelectric energy collection device optimization method based on the finite element method, which can achieve the optimization of the structural size parameters and external circuit design of the energy collection device, and can effectively improve the output voltage of the piezoelectric transducer device and improve the energy collection efficiency of the device. Summary of the invention

[0004] The present invention aims to provide a piezoelectric energy harvesting device optimization method based on the finite element method in order to address the above deficiencies in the prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a piezoelectric energy harvesting device optimization method based on the finite element method, comprising the following steps:

[0006] S1: Establish finite element model;

[0007] S2: Transient analysis, extracting output voltage;

[0008] S3: Determine whether the end condition is met. If the end condition is met, terminate the operation and output the optimal result and parameter setting. Otherwise, perform the optimization of structural parameters and external circuit parameters, and then return to step S2 to continue the loop operation.

[0009] Preferably, in step S1, the steps of establishing the finite element model of the piezoelectric energy harvesting device are as follows:

[0010] A-1: Establish a finite element model of the flow around a blunt body according to the structural parameters of the piezoelectric energy harvesting device, and set the external circuit parameters;

[0011] A-2: Determine fixed constraints based on solid mechanics and set walls and inlets and outlets based on fluid mechanics;

[0012] A-3: Set the material properties of each part of the model and perform meshing.

[0013] Preferably, in step S3, the end condition is a preset voltage value Vp, and the output voltage extracted in step S2 is compared with the preset voltage value Vp. If the extracted output voltage is greater than or equal to Vp, the end condition is satisfied.

[0014] Preferably, in step S3, the optimizing structural parameters includes determining an optimal blunt body curvature θ, an optimal blunt body radius r, an optimal distance l from the piezoelectric sheet to the blunt body, and the like.

[0015] Preferably, in step S3, optimizing the external circuit parameters refers to determining the resistance value R of the external circuit resistor according to the impedance matching principle.

[0016] Beneficial technical effects:

[0017] The present invention discloses a piezoelectric energy collection device optimization method based on the finite element method. First, the piezoelectric effect module in the finite element analysis is used to establish a finite element model of a blunt body flow according to the initial structural parameters of the piezoelectric energy collection device, and the fixed constraints are determined according to solid mechanics. After the walls and inlets and outlets are set according to fluid mechanics, a transient analysis is performed on the model to calculate the output voltage on the piezoelectric cantilever beam, and then the structural parameters of the blunt body flow model body are determined according to the output voltage on the piezoelectric cantilever beam. Finally, according to the impedance matching principle, the resistance value of the external circuit resistor is determined to complete the design of the energy collection circuit. The present invention can effectively improve the output voltage of the piezoelectric transducer device and improve the energy collection and conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Flowchart of the optimization method for piezoelectric energy harvesting devices based on the finite element method.

[0019] Figure 2 This is a simulation diagram of a piezoelectric energy harvesting device based on flow around a blunt body. DETAILED DESCRIPTION

[0020] The drawings are for illustrative purposes only and should not be construed as limiting the present patent;

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] The present invention discloses a piezoelectric energy collection device optimization method based on finite element method, the optimization process is as follows: Figure 1 As shown, the following steps are included:

[0023] S1: Establish finite element model;

[0024] S2: Transient analysis, extracting output voltage;

[0025] S3: Determine whether the end condition is met. If the end condition is met, terminate the operation and output the optimal result and parameter setting. Otherwise, perform the optimization of structural parameters and external circuit parameters, and then return to step S2 to continue the loop operation.

[0026] In this embodiment, the finite element modeling simulation diagram of the piezoelectric energy harvesting device based on the bluff body flow is as follows: Figure 2 In step S1, the steps of establishing the finite element model of the piezoelectric energy harvesting device are as follows:

[0027] A-1: Establish a finite element model of the flow around a blunt body according to the structural parameters of the piezoelectric energy harvesting device, and set the external circuit parameters;

[0028] A-2: Determine fixed constraints based on solid mechanics and set walls and inlets and outlets based on fluid mechanics;

[0029] A-3: Set the material properties of each part of the model and perform meshing.

[0030] In this embodiment, in step S3, the end condition is a preset voltage value V p , the output voltage extracted in step S2 is compared with the preset voltage value V p Compare, if the extracted output voltage is greater than or equal to V p , the end condition is met.

[0031] In this embodiment, in step S3, the optimization of structural parameters includes determining an optimal blunt body curvature θ, an optimal blunt body radius r, an optimal distance from the piezoelectric sheet to the blunt body, and the like.

[0032] In this embodiment, in step S3, optimizing the external circuit parameters refers to determining the resistance value R of the external circuit resistor according to the impedance matching principle.

[0033] In the specific implementation process, the present invention uses the finite element method to establish a blunt body flow model, and combines it with the impedance matching principle to optimize the structural parameters and external circuit design of the energy collection device, effectively improve the output voltage of the piezoelectric transducer device, and improve the energy collection efficiency of the device.

[0034] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A piezoelectric energy harvesting device optimization method based on finite element modeling, characterized in that: The following steps are involved: S1: Establish finite element model; S2: Transient analysis, extracting output voltage; S3: Determine whether the end condition is met. If the end condition is met, terminate the operation and output the optimal result and parameter setting. Otherwise, perform the optimization of structural parameters and external circuit parameters, and then return to step S2 to continue the loop operation.

2. The optimization method of a piezoelectric energy harvesting device based on finite element modeling according to claim 1, characterized in that: In step S1, the steps of establishing the finite element model of the piezoelectric energy harvesting device are as follows: A-1: Establish a finite element model of the flow around a blunt body according to the structural parameters of the piezoelectric energy harvesting device, and set the external circuit parameters; A-2: Determine fixed constraints based on solid mechanics and set walls and inlets and outlets based on fluid mechanics; A-3: Set the material properties of each part of the model and perform meshing.

3. The method for optimizing a piezoelectric energy harvesting device based on finite element modeling according to claim 1, characterized in that: In step S3, the end condition is a preset voltage value Vp. The output voltage extracted in step S2 is compared with the preset voltage value Vp. If the extracted output voltage is greater than or equal to Vp, the end condition is satisfied.

4. The method for optimizing a piezoelectric energy harvesting device based on finite element modeling according to claim 1, characterized in that: In step S3, the optimization of structural parameters includes determining the optimal blunt body curvature θ, the optimal blunt body radius r, the optimal distance from the piezoelectric sheet to the blunt body, and the like.

5. The method for optimizing a piezoelectric energy harvesting device based on finite element modeling according to claim 1, characterized in that: In step S3, the optimization of the external circuit parameters refers to determining the optimal external circuit resistance R according to the impedance matching principle.

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