CN114160397A - An underwater array type high-power ultrasonic wireless energy transmission system - Google Patents

Abstract

The invention discloses an underwater array type high-power ultrasonic wireless energy transmission system, which comprises a high-frequency input power supply, a transmitting transducer array and a receiving transducer. Each transducer at the transmitting end and the receiving end is composed of piezoelectric ceramics, a matching layer, a backing and a shell. The core of the invention is to disperse the energy density of the transmitting end through the transmitting transducer array structure, reduce the attenuation of sound waves caused by the cavitation effect, and at the same time locate the receiving transducer at the energy focus, thereby increasing the underwater ultrasonic wireless energy transmission system. transmission power. After the power is turned on, the inverter outputs high-frequency alternating current with the same frequency as the resonant frequency of the transducer, and drives each transducer at the transmitting end simultaneously through the resonant compensation circuit. The energy device receives and outputs electric energy, which can improve the transmission power of underwater ultrasonic wireless energy transmission and achieve 100-watt energy transmission.

Description

An underwater array high-power ultrasonic wireless energy transmission system

technical field

The invention relates to the technical field of underwater ultrasonic wireless energy transmission, in particular to an underwater array type high-power ultrasonic wireless energy transmission system, which adopts the form of a transducer array to increase the transmission power of the system.

Background technique

Wireless energy transfer technology converts electrical energy into other forms of energy, transmits the energy to the receiving end through a certain transmission medium, and then converts it into electrical energy to supply energy for designated equipment. At present, the wireless energy transmission technology using ultrasonic waves is still in the research stage. Using ultrasonic wireless energy transmission technology to supply energy to underwater equipment can not only improve the working efficiency and service life of underwater equipment, but also use ultrasonic waves with strong directionality and energy concentration. Advantages, higher transmission efficiency and power in medium and long distance energy transmission.

The core of ultrasonic wireless energy transmission technology is ultrasonic transducer, using piezoelectric ultrasonic transducer (hereinafter referred to as transducer), using the forward and reverse piezoelectric effect of piezoelectric ceramics to convert electrical energy and mechanical energy (ultrasonic wave) to realize wireless energy transfer. In addition to piezoelectric ceramics, the transducer also needs a suitable matching layer and backing to increase the transmittance of sound waves to water and improve the transmission efficiency.

At present, the transmission power of the ultrasonic wireless energy transmission system used for underwater is generally not high. The energy transmission power of the system is mainly restricted by the liquid cavitation effect in addition to the limitation of the size, structure and strength of the piezoelectric ceramics of the transducer. The cavitation effect means that when the transducer vibrates and pushes the liquid medium to radiate sound waves, a large local negative pressure is generated during the liquid shrinkage strain process. Scattering loss, resulting in a sharp increase in the attenuation of sound waves in water.

In view of the above problems, consider designing a transducer array for underwater ultrasonic wireless energy transmission, disperse the energy density emitted by a single transducer, and receive ultrasonic waves at the focus of the array.

SUMMARY OF THE INVENTION

The invention provides an underwater array type high-power ultrasonic wireless energy transmission system, which is used to solve the problem of the limitation of the transmission power of the system by the liquid cavitation effect in the existing underwater ultrasonic wireless energy transmission system. Disperse the energy density emitted by a single transducer and improve the power transmission capability of the underwater ultrasonic wireless energy transmission system.

To achieve the above object, the implementation of the present invention adopts the following technical solutions:

An underwater array type high-power ultrasonic wireless energy transmission system is composed of an input high-frequency power supply 1-1, a transmitting transducer array 1-2, a liquid transmission medium 1-3, a receiving transducer 1-4, and a receiving load 1 -5 composition. Among them, the transmitting transducer array is in the form of six vibration elements, which is formed by six transducers with a difference of γ angle from each other. Each transducer is installed on a rod with a fixed radius, and the angle θ between the rod and the xy plane is changed. Adjust the corresponding focus distance. Each transducer is composed of quartz glass 2-1, copper sheet 2-3, piezoelectric ceramics 2-5 and transducer shell 2-6. Among them, the copper sheet 2-3 is pasted on one end face of the piezoelectric ceramic 2-5 with conductive adhesive 2-4 as an electrode terminal, and the epoxy resin adhesive 2-2 is used to paste the quartz glass 2-1 on the copper sheet 2 The front end of -3 is used as the matching layer of the transducer, and finally the above part is encapsulated in the transducer housing 2-6.

After the power is turned on, the input high-frequency power supply 1-1 drives the transmitting transducer array 1-2 through the inverter outputting alternating current with the same resonant frequency as the transducer. The transducer uses the inverse piezoelectricity of the piezoelectric ceramics 2-5. The effect converts electrical energy into ultrasonic radiation of the same frequency into the liquid transmission medium 1-3. The sound pressure amplitude generated by the sound wave emitted by a single transducer at any point R(x, y, z) in the liquid transmission medium 1-3 is

Among them, Pi is the sound pressure amplitude at any point, ω is the angular frequency of the sound wave, ρ ₀ is the density of the liquid transmission medium 1-3, _{u a} is the particle vibration velocity, a is the transducer radius, and J ₁ (kasinα) is First-order Bessel function, k is the wave number, α is the angle formed between any point and the center of the transducer and the axis of the transducer, d is the distance from any point to the center of the transducer; The voltage amplitude is

Among them, c ₀ is the sound speed of the sound wave in the liquid transmission medium 1-3, r is the distance from the focus to the center of the transducer; finally, the total sound pressure at any point in space is the sum of the sound pressures generated by each transducer at that point

Compared with the prior art, the beneficial effects achieved by the present invention are:

(1) Using an underwater ultrasonic wireless energy transmission technology in the form of a multi-vibration element array, the energy density emitted by a single transducer is dispersed, and the transmission power of the underwater ultrasonic wireless energy transmission system is effectively improved.

(2) The structure is simple, the use is convenient, and the focus angle can be flexibly adjusted to change the focus position, which makes it easier to achieve long-distance underwater ultrasonic wireless energy transmission, and the energy is only concentrated at the focus, and the energy utilization rate is high.

Description of drawings

Figure 1 is a schematic diagram of the system work.

Figure 2 shows the transducer structure.

FIG. 3 is a plan view of the transducer array.

Fig. 4a, Fig. 4b, Fig. 4c, Fig. 4d, Fig. 4e and Fig. 4f are the simulation results of the sound field of the underwater transducer array when focusing at 5cm, 10cm, 15cm, 20cm, 30cm and 50cm, respectively.

in,

1-1, input high frequency power supply; 1-2, transmit transducer array; 1-3, liquid transmission medium; 1-4, receive transducer; 1-5, receive load.

2-1, quartz glass; 2-2, epoxy resin adhesive; 2-3 copper sheet; 2-4, conductive adhesive; 2-5, piezoelectric ceramics; 2-6, transducer shell.

Detailed ways

The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , the input power source 1-1 includes a DC source, an inverter and a resonance compensation circuit, and outputs an alternating current of a specific frequency to drive the transmitting transducer array 1-2. When the voltage is applied to both ends of the transmitting transducer array 1-2, due to the inverse piezoelectric effect of the piezoelectric ceramic, the piezoelectric ceramic is deformed, and the vibration radiates ultrasonic waves with the same frequency as the voltage. The sound waves radiated by the vibrating elements of the six transducers pass through the liquid transmission medium 1-3 and converge at the focal position where the receiving transducer 1-4 is located. The electrical effect is converted into electrical energy to power the receiving loads 1-5.

Figure 2 shows the structure of a single transducer. The piezoelectric ceramic 2-5 is used as the core, and the copper sheet 2-3 is pasted on one end face of the piezoelectric ceramic 2-5 using conductive glue 2-4 as one electrode. terminal. The quartz glass 2-1 is used as the matching layer, and the epoxy resin adhesive 2-2 is used to paste it on the front end of the copper sheet 2-3, and finally the above part is encapsulated in the transducer shell 2-6. Among them, quartz glass 2-1 has a diameter of 50mm and a thickness of 14mm; copper sheet 2-3 has a diameter of 50mm and a thickness of 0.1mm; piezoelectric ceramics 2-5 has an outer diameter of 50mm, an inner diameter of 17mm and a thickness of 6.5mm mm; the outer diameter of the transducer housing 2-6 is 60mm, the inner diameter is 50mm, and the height is 40mm.

Figure 3 is a plan view of a six-element transducer array, the left figure is a front view of the transducer array, and the right figure is a side view of a natural focus formed in a transmission medium. Among them, the radius of each transducer is a, with the transducer directly above as the benchmark, the position angle of each transducer is represented by γ, γ=(0:pi/3:5pi/3). The angle between the transducer and the xy plane is θ, the natural focus O is formed on the z-axis, and the coordinate system is established with O as the origin, then the coordinates of the transducer center point A are

A(rsinθcosγ,rsinθsinγ,-rcosθ)

Let there be a point R(x, y, z), we can get two vectors

The included angle α and the distance from R to A are

The sound pressure amplitude produced by a single transducer at point R is

Acoustic pressure on a single transducer axis is calculated using a strict solution

Finally, the total sound pressure at point R is the sum of the sound pressures produced by each transducer at that point

In practice, when the radius of the transducer array remains unchanged, the focusing angle θ is changed to obtain focusing results at different focusing distances.

Figure 4a, Figure 4b, Figure 4c, Figure 4d, Figure 4e, and Figure 4f show the calculated sound pressure nephogram of the underwater transducer array. Happening.

It can be seen from Figure 4a, Figure 4b, Figure 4c, Figure 4d, Figure 4e and Figure 4f that the form of the underwater transducer array disperses the energy density emitted by a single transducer, and placing the receiving transducer at the focal position can effectively increase the energy density. Transmission power of large underwater ultrasonic wireless energy transmission system.

Claims (5)

1. An underwater array type high-power ultrasonic wireless energy transmission system is characterized in that: by inputting high-frequency power supply (1-1), transmitting transducer array (1-2), liquid transmission medium (1-3) , a receiving transducer (1-4) and a receiving load (1-5); wherein the transmitting transducer array (1-2) is connected to the input high-frequency power supply (1-1), in the form of multiple vibration elements, consisting of A plurality of transducers differ from each other by a sufficient angle of γ, each transducer is installed on a rod with a fixed radius, and the angle θ between the rod and the xy plane is changed to adjust the corresponding focusing distance; the receiving transducer (1- 4) Set on the focal point of the transmitting transducer array (1-2), the receiving transducer (1-4) is connected to the receiving load (1-5), and the transmitting transducer array (1-2) is connected to the receiving transducer The energy device (1-4) is located in the liquid transmission medium (1-3). 2. A kind of underwater array type high-power ultrasonic wireless energy transmission system according to claim 1, it is characterized in that: after switching on the power supply, the input high-frequency power supply (1-1) outputs and the transducer through the inverter The alternating current with the same resonant frequency drives the transmitting transducer array (1-2), and the transducer in the transmitting transducer array (1-2) utilizes the inverse piezoelectric effect of the piezoelectric ceramic (2-5) to convert electrical energy into Ultrasonic waves of the same frequency are radiated into the liquid transmission medium (1-3); the sound pressure amplitude generated by the sound wave emitted by a single transducer at any point R(x, y, z) in the liquid transmission medium (1-3) is

Among them, Pi is the sound pressure amplitude at any point, ω is the angular frequency of the sound wave, ρ ₀ is the density of the liquid transmission medium, _{u a} is the particle vibration velocity, a is the transducer radius, and J ₁ (kasinα) is the first-order shell Searle function, k is the wave number, α is the angle formed between any point and the center of the transducer and the axis of the transducer, d is the distance from any point to the center of the transducer; the sound pressure amplitude on the transducer axis for

Among them, c ₀ is the sound speed of the sound wave in the liquid transmission medium, r is the distance from the focus to the center of the transducer; finally, the total sound pressure at any point in space is the sum of the sound pressures generated by each transducer at that point

3. a kind of underwater array type high-power ultrasonic wireless energy transmission system according to claim 1, is characterized in that, each transducer in transmitting transducer array (1-2) is made of quartz glass (2-1 ), copper sheet (2-3), piezoelectric ceramics (2-5) and transducer shell (2-6); wherein, the copper sheet (2-3) is pasted with conductive glue (2-4) on the One end face of the piezoelectric ceramic (2-5) is used as an electrode terminal, and the quartz glass (2-1) is pasted on the front end of the copper sheet (2-3) using epoxy resin adhesive (2-2) as a transducer Finally, the above parts are encapsulated in the transducer shell (2-6), and the specific structure formed has a high sound wave transmittance, which improves the transmission of each vibration element transducer to the liquid transmission medium (1-3). ) efficiency of radiating sound waves; the structure of the receiving transducer (1-4) is the same as that of each transducer in the transmitting transducer array (1-2). 4. a kind of underwater array type high-power ultrasonic wireless energy transmission system according to claim 1, is characterized in that, adopts six-vibration element array form, disperses the energy density of single transducer emission, makes the sound power of emission It only focuses on the focal position, reducing the attenuation of sound waves caused by the liquid cavitation effect, and effectively improving the transmission power of the underwater ultrasonic wireless energy transmission system. 5. a kind of underwater array type high-power ultrasonic wireless energy transmission system according to claim 1 is characterized in that, by adjusting the included angle θ of each vibration element in the transducer array and the xy plane, the focusing distance is changed, and the receiving The transducer is placed at the set focus, which effectively improves the transmission distance and energy utilization rate of the underwater ultrasonic wireless energy transmission system.

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