CN102856989A - Resonant type wireless transmission device based on high-temperature superconducting material - Google Patents

Abstract

A resonant wireless power transmission device based on high-temperature superconducting materials, including two parts: a transmitting-side device and a receiving-side device. The transmitting-side device includes a transmitting-side oscillator circuit, a transmitting-side non-metal Dewar (3'), a transmitting-side The top cover (2') and the power supply (1), the power supply (1) are connected in parallel at both ends of the oscillator circuit on the transmitting side; the device on the receiving side includes an oscillating circuit on the receiving side, a non-metallic Dewar (3) on the receiving side, The top cover (2) and the load (6), and the load (6) are connected in parallel at both ends of the receiving side oscillating circuit; the transmitting side oscillating circuit and the receiving side oscillating circuit have the same topology, both of which are composed of superconducting coils and resonant Capacitors are connected in parallel; the superconducting coil is installed in the non-metal Dewar for cooling. The top cover is placed above the non-metallic Dewar; the non-metallic Dewar adopts a multi-layer heat insulation structure; the receiving side device and the transmitting side device are electromagnetically coupled and placed independently of each other.

Description

A resonant wireless power transmission device based on high temperature superconducting materials

technical field

The invention relates to a wireless power transmission device, in particular to a resonant wireless power transmission device realized by using high-temperature superconducting materials. the

Background technique

Wireless power transmission is a method of power transmission that does not require power lines. Wireless power transmission can avoid the defects of electric shock, sparks, wear and other defects of traditional wire power transmission, and realize safe, reliable, flexible and efficient transmission of electric energy. As early as the end of the 19th century, Tesla envisioned a global wireless power transmission system and built a Tesla coil for experimentation. Due to insufficient funds in the later period, it did not continue. In 2007, MIT proposed resonant wireless power transmission, which made breakthroughs in transmission efficiency and transmission distance, making wireless power transmission become an important direction of attention again. the

Due to the existence of the system's own resistance and the difficulty of energy control, at present, the transmission efficiency of wireless power transmission is generally not high; in addition, the transmission distance is short (resonant type is about 2 meters), and the power supply frequency is high (resonant type 10MHz). These defects hinder the wide application of wireless power transmission technology. the

In recent years, researchers have begun to try to apply metamaterials (such as metamaterials with negative refractive index) to power transmission technology in experiments, so that the transmission efficiency and transmission distance have been improved, and the power supply frequency has been reduced. However, there are very few studies on the use of superconducting materials for wireless power supply. Only the University of Maryland has just carried out theoretical research on resonant superconducting wireless. the

Since the transmission efficiency of wireless power transmission is directly related to the self-resistance of the power transmission coil, the smaller the self-resistance of the power transmission coil, the higher the transmission efficiency; if the radiation loss is not considered (at low frequency), if the resistance of the coil is zero, the efficiency is 100% . Therefore, the method of reducing the resistance of the coil can be adopted to improve the transmission efficiency. Since superconductors have the characteristics of zero DC resistance and low AC loss (even at microwave frequencies, their surface resistance is 2 orders of magnitude lower than that of conventional conductors), using superconducting materials to make power transmission coils can greatly improve transmission efficiency. According to our previous research, the transmission rate of superconducting coils is significantly higher than that of copper coils of the same size (more than 3 times), and the power transmission distance under the same efficiency increases more significantly. the

Raymond J.Sedwick of the University of Maryland in the United States carried out theoretical research on the use of superconducting materials for wireless power transmission, using coupling theory to calculate the efficiency of superconducting wireless power transmission, and studying its relationship with frequency and distance, proving that the use of superconducting materials can greatly improve power transmission distance. the

Contents of the invention

The purpose of the present invention is to overcome the defects of low transmission efficiency, short transmission distance and high power supply frequency of the wireless power transmission device, and propose a resonant wireless power transmission device based on high-temperature superconducting materials. The invention can realize long-distance, high-efficiency, high-power wireless power transmission. the

The technical scheme that the present invention adopts is as follows:

The resonant wireless power transmission device of the present invention includes a transmitting-side device and a receiving-side device. The transmitting-side device and the receiving-side device are placed independently, and there is a certain distance between them, and the distance can be adjusted freely. the

The device on the transmitting side includes an oscillating circuit on the transmitting side, a non-metallic Dewar on the transmitting side, a top cover on the transmitting side and a power supply, and the power supply is connected in parallel at both ends of the oscillating circuit on the transmitting side. The receiving-side device includes a receiving-side oscillating circuit, a receiving-side non-metal Dewar, a receiving-side top cover and a load, and the load is connected in parallel at both ends of the receiving-side oscillating circuit. Wherein, both the transmitting-side oscillating circuit and the receiving-side oscillating circuit are parallel resonant circuits composed of superconducting coils and resonant capacitors. the

In the above-mentioned parallel resonant circuit, the above-mentioned superconducting coil is made of Bi-series or Y-series superconducting tape, wound into a cake structure, installed in a non-metal Dewar, cooled by liquid nitrogen, or added by liquid nitrogen. Chiller cooling or chiller direct cooling. Non-metallic Dewar adopts multi-layer insulation structure. The lead wires at both ends of the superconducting coil are led out through the top cover covering the non-metallic Dewar. the

The transmitting side resonant capacitor and the power supply are connected in parallel between the lead wires at both ends of the superconducting coil of the transmitting side device. The receiving-side resonant capacitor and load are connected in parallel between the lead wires at both ends of the superconducting coil of the receiving-side device. The device on the transmitting side and the device on the receiving side are independent of each other, and resonantly transmit signals through electromagnetic coupling. the

The superconducting resonant wireless power transmission device of the present invention can be flexibly changed according to practical applications: both conventional materials and high-temperature superconducting materials can be used for the resonant capacitor. If it is necessary to supply power to a plurality of electrical equipment in different places at the same time, it is sufficient to connect each electrical equipment to a corresponding receiving-side device. The oscillating circuit on the receiving side of the present invention can completely adopt conventional materials, does not need low-temperature devices, is convenient and low in cost, but the corresponding system performance will be reduced. the

The present invention has the following advantages:

1. The high-temperature superconducting resonant wireless power transmission device of the present invention, because the AC loss of the superconductor is very small, the loss of the superconducting power transmission coil will be much lower than that of the conventional coil, which can greatly improve the transmission efficiency and power transmission distance. the

2. The high-temperature superconducting resonant wireless power transmission device designed by the present invention can realize high-power wireless power transmission because the superconductor has a current-carrying density more than 2 orders of magnitude higher than that of conventional conductors. the

3. The lower the frequency of the present invention, the smaller the loss, and the DC resistance is zero. Therefore, the voltage level required for superconducting high-current wireless power transmission is very low, the frequency is also very low, and the radiation is very low, making power transmission safer. the

Description of drawings

Fig. 1 is a structural block diagram of a resonance type wireless power transmission device of the present invention;

Fig. 2 is the schematic diagram of the resonant wireless power transmission device of the present invention;

The lumped circuit model of Fig. 3 resonant type wireless power transmission device of the present invention;

Fig. 4 superconducting coil structure and partial schematic diagram connected with resonant capacitor;

Figure 5 is the energy transmission diagram of the resonant wireless power transmission device based on high temperature superconducting materials;

Fig. 6 The transmission efficiency curve of copper coil and superconducting coil with distance;

In the figure: 1 power supply, 2 top cover on the receiving side, 2' top cover on the transmitting side, 3 non-metallic Dewar on the receiving side, 3' non-metallic Dewar on the transmitting side, 4 superconducting coil on the receiving side, 4' superconducting coil on the transmitting side , 5'transmitting side resonant capacitor, 5 receiving side resonant capacitor, 6 load. the

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. the

Fig. 1 is a structural block diagram of the present invention. Fig. 2 is a schematic diagram of the resonant wireless power transmission device of the present invention. As shown in Figure 1 and Figure 2, the resonant wireless power transmission device of the present invention includes two parts: a transmitting side device and a receiving side device. 'And the power supply 1, the power supply 1 is connected in parallel at both ends of the oscillator circuit on the transmitting side. The receiving-side device includes a receiving-side oscillating circuit, a receiving-side non-metallic Dewar 3, a receiving-side top cover 2 and a load 6, and the load 6 is connected in parallel at both ends of the receiving-side oscillating circuit. The transmitting-side oscillating circuit and the receiving-side oscillating circuit have the same topological structure, and both are composed of a superconducting coil and a resonant capacitor connected in parallel: wherein the transmitting-side oscillating circuit is composed of a transmitting-side superconducting coil 4' and a transmitting-side resonant capacitor 5' connected in parallel, the receiving-side oscillating circuit is composed of receiving-side superconducting coil 4 and receiving-side resonant capacitor 5 in parallel. the

The two superconducting coils 4, 4' are respectively installed in two non-metallic Dewars 3, 3', cooled by liquid nitrogen or liquid nitrogen plus a refrigerator or directly cooled by a refrigerator. The top cover 2, 2' placed above the two non-metallic Dewars 3, 3' can reduce the volatilization of liquid nitrogen on the one hand, and on the other hand can reduce the impact of low temperature on the resonant capacitor 5, 5'. The non-metallic Dewar 3, 3' adopts a multi-layer thermal insulation structure. The device on the receiving side and the device on the transmitting side are electromagnetically coupled and placed independently of each other. The distance between the device on the receiving side and the device on the transmitting side is D. Different distances D have different transmission efficiencies. According to Raymond J.Sedwick’s calculation, the transmission distance When D is 100 meters, it can reach 40% efficiency. the

The transmitting-side superconducting coil 4' is installed in the transmitting-side non-metallic Dewar 3', and the receiving-side superconducting coil 4 is placed in the receiving-side non-metallic Dewar 3. The lead wires at both ends of the superconducting coil 4' on the transmitting side pass through the top cover 2' on the transmitting side covered on the non-metallic Dewar 3' on the transmitting side, and the lead wires at both ends of the superconducting coil 4 on the receiving side pass through the non-metallic Dewar on the receiving side 3 top cover 2 on the receiving side. Transmitting side resonant capacitor 5 ' and power supply 1 are connected in parallel between the lead wires at both ends of the transmitting side superconducting coil 4 ', and receiving side resonant capacitor 5 and load 6 are connected in parallel between the lead wires at receiving side superconducting coil 4 two ends. The ideal circuit structure using lumped parameter equivalents at low frequencies is shown in Figure 3. M is the mutual inductance between the superconducting coil on the transmitting side and the superconducting coil on the receiving side, which characterizes the degree of magnetic coupling between the two coils. According to the most basic Circuit theory can calculate that the ideal transmission efficiency is 100%. the

As shown in Fig. 4, the receiving-side superconducting coil 4 and the transmitting-side superconducting coil 4' are made of multi-turn Bi-based or Y-based superconducting tapes wound into a pie structure. The transmitting side resonant capacitor 5' and the power supply 1 are connected in parallel between the lead wires at both ends of the superconducting coil 4' on the transmitting side, and the receiving side resonant capacitor 5 and load 6 are connected in parallel between the lead wires at both ends of the superconducting coil 4 on the receiving side, as shown in Figure 1 . At a certain frequency, the oscillating circuit on the transmitting side resonates with the oscillating circuit on the receiving side to realize high-efficiency power transmission. The resonant capacitor 5, 5' can be a conventional capacitor or a superconducting capacitor made of a superconducting strip, and the superconducting capacitor can obtain higher efficiency. If a superconducting capacitor is used, the superconducting capacitor needs to be installed in a non-metallic Dewar 3, 3' for cooling. the

Fig. 5 is an energy transmission diagram of the present invention. As shown in Figure 5, the energy is provided by the power supply 1 to the oscillation circuit on the transmitting side, which exists in the form of an alternating electromagnetic field in the oscillation circuit on the transmitting side, and then part of the energy is transferred to the oscillation circuit on the receiving side through the resonant power transmission method, and the other part is lost . The energy in the oscillating circuit on the receiving side also exists in the form of an alternating electromagnetic field, and in addition to the electric energy delivered to the load 6, there is also loss. the

The measurement results of the power transmission efficiency of the copper coil and superconducting coil system as a function of distance are shown in Figure 6. Among them, the resonant frequency of the copper coil is 7KHz, and that of the superconducting coil is 7.8KHz. This difference is due to the difference in permeability between the superconducting material and copper, and the inductance of the superconducting coil made of the same size is smaller than that of the copper coil. It can be seen from Figure 6 that the transmission efficiency when using a superconducting coil is significantly higher than that of a copper coil, which is more than 3 times. the

Claims (3)

1. resonance type wireless power transmitting device based on high temperature superconducting materia, it is characterized in that: described wireless power transmission device comprises emitting side device and reception side apparatus; Described emitting side device comprises emitting side oscillating circuit, the nonmetal Dewar of emitting side (3 '), emitting side top cover (2 ') and power supply (1), and power supply (1) is connected in parallel on the two ends of emitting side oscillating circuit; Described reception side apparatus comprises receiver side oscillating circuit, the nonmetal Dewar of receiver side (3), receiver side top cover (2) and load (6), and load (6) is connected in parallel on the two ends of receiver side oscillating circuit; Described emitting side oscillating circuit is composed in parallel by emitting side superconducting coil (4 ') and emitting side resonant capacitance (5 '), and the receiver side oscillating circuit is composed in parallel by receiver side superconducting coil (4) and receiver side resonant capacitance (5); Described emitting side superconducting coil (4 ') is installed in cooling in the nonmetal Dewar of described emitting side (3 '), and described receiver side superconducting coil (4) is installed in cooling in the nonmetal Dewar of described receiver side (3); Emitting side top cover (2 ') places the top of the nonmetal Dewar of emitting side (3 '), and receiver side top cover (2) places the top of the nonmetal Dewar of receiver side (3); Two nonmetal Dewars (3,3 ') adopt multiple layer heat insulation structure; Reception side apparatus and emitting side device intercouple at electromagnetism, separate placement.

2. the resonance type wireless power transmitting device based on high temperature superconducting materia as claimed in claim 1 is characterized in that: described superconducting coil (4,4 ') is the superconducting tape coiling by multiturn Bi system or Y, adopts cake formula structure.

3. the resonance type wireless power transmitting device based on high temperature superconducting materia as claimed in claim 1 is characterized in that: described resonant capacitance (5,5 ') adopts superconduction electric capacity, and described superconduct is placed in cooling in the nonmetal Dewar (3,3 ').

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