CN104135086A - Resonant wireless energy transfer device - Google Patents

Abstract

A resonant wireless energy transmission device is composed of a transmitting end (2), a receiving end (3), a transmitting end power conditioning module (9) and a receiving end power conditioning module (4). The power supply coil, transmitting coil, load coil and receiving coil are respectively composed of capacitors and inductance coils connected in series or in parallel, and each circuit formed has the same resonant frequency. The capacitors are voltage controlled variable capacitors. Each capacitor is controlled by a voltage with opposite polarity and the same amplitude output by a corresponding capacitance adaptive adjustment module; the capacitance adaptive adjustment module is composed of a current sensor and a processing module. When the inductance of the transmitting coil, the power supply coil, the receiving coil and the load coil changes due to changes in external conditions, the invention can automatically adjust the capacitance of the resonant circuit to restore the resonant frequency to the power frequency.

Description

A resonant wireless energy transmission device

technical field

The invention relates to a wireless energy transmission system, in particular to a transmission device for adaptively adjusting resonance frequency.

Background technique

Non-radiative magnetic coupling resonance is a new type of wireless energy transmission technology, which is based on the principle that two resonators with the same frequency produce strong coupling, while only weak coupling to surrounding non-resonant frequency objects. energy. The magnetically coupled resonant system is usually a two-coil system including a generating resonant coil, a receiving resonant coil and a load; there is also a four-coil system including a power supply coil, a generating coil, a receiving coil and a load coil. This technology was first discovered by the research team of the Massachusetts Institute of Technology (MIT), which can achieve medium and long-distance transmission (that is, the transmission distance is several times the size of the transmitting coil), and still obtain higher efficiency and greater power. Many industries have good application prospects. However, this technology also has some problems such as the sensitivity of system parameters. When some parameters in the system change, the transmission characteristics of the system will change greatly. Therefore, if this technology is used in switch cabinets, transformers and other occasions containing a large number of conductors and magnetizers, it is necessary to solve the problem that it is susceptible to interference and deviates from the resonance point.

In patents CN201310035764.x and CN201310061424.4, the overall transmission efficiency is improved by using one transmitting end and multiple receiving ends, but there is no mention of interference.

The document "Analysis, experimental results and range adaptation of magnetically coupled resonators for wireless power transfer" proposes to adjust the coupling coefficient by adjusting the distance between the power supply coil and the transmitting coil to ensure that the system is at the maximum transmission efficiency. The document "Automated frequency tracking system for efficient mid-rangemagnetic resonance wireless power transfer" proposes to adaptively adjust the system power frequency by detecting the system transmission efficiency so that the system is at the best transmission efficiency point. The document "Fu Wenzhen et al., Frequency Tracking Resonant Coupling Power Wireless Transmission System Research" mentioned that by measuring the current, adjusting the power frequency to make the disturbed system reach the resonance state again. The method mentioned in the above literature has a certain effect on the disturbed system. However, by changing the power frequency, it is only effective for the system that is subject to the same interference at the transmitting end and the receiving end. For the interference at the transmitting end and the receiving end, the resonant frequency Changing to a different frequency has less or no effect.

Patent CN201310208595.5 mentions a wireless power transmission device with anti-stealing function. By comparing the output power of the power supply and the load power, when it is found that there is electricity theft, the frequency of the power supply and the resonant system frequency are adjusted to prevent the continuation of the electricity theft. It adjusts the resonant frequency by adjusting the capacitor, but the adjustable capacitor used only has certain fixed gears. The purpose is to actively tune the system away from the original frequency, and it cannot solve the problem of resonant frequency deviation caused by interference, and the above method The transmitting side needs to communicate with the receiving side, which increases the complexity of the system.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide a resonant wireless energy transmission device based on capacitance self-adaptive adjustment. The invention can solve the problem of deviation of the resonance point caused by interference bodies such as magnetic and conductive materials, and has a simple and convenient implementation method, and has a good effect on solving the problem of different degrees of interference between the transmitting coil and the receiving coil.

In order to achieve the above effects, the structure of the wireless energy transmission device of the present invention is as follows:

The wireless energy transmission device of the present invention includes: a transmitting end, a receiving end, a power conditioning module of the transmitting end, and a power conditioning module of the receiving end. The transmitting end is composed of a power supply coil and a corresponding capacitance adaptive adjustment module, or is composed of a power supply coil and a transmission coil and a capacitance self-adaptive adjustment module corresponding to the power supply coil and the transmission coil. The receiving end is composed of a load coil and a corresponding capacitance adaptive adjustment module, or jointly composed of a receiving coil and a load coil and a capacitance adaptive adjustment module corresponding to the receiving coil and the load coil.

One end of the wireless energy transmission device is connected to a power frequency AC power supply, and the other end is connected to a load.

When the transmitting end is only composed of a power coil and a corresponding capacitance adaptive adjustment module, the power coil is composed of an inductance coil and a capacitor connected in series or in parallel. When in series, the terminals that are not connected between the capacitor and the inductance coil are connected to both ends of the high-frequency AC power supply, and when connected in parallel, both ends of the high-frequency AC power supply are connected to both ends of the capacitor. The inductance value of the inductance coil and the resonant frequency of the capacitor are the same as the frequency of the high-frequency AC power supply.

When the receiving end is only composed of a load coil and a corresponding capacitance adaptive adjustment module, the load coil is composed of an inductance coil and a capacitor connected in series or in parallel. When connecting in series, the unconnected terminals of the capacitor and the inductance coil are respectively connected to both ends of the load, and when connecting in parallel, both ends of the load are respectively connected to both ends of the capacitor. The resonant frequency of the inductance coil and the capacitor is the same as the resonant frequency of the power supply coil.

When the transmitting end is composed of a transmitting coil, a power coil and a capacitance adaptive adjustment module corresponding to the transmitting coil and the power coil, the transmitting coil and the power coil are wound side by side so that the mutual inductance between them is as large as possible. The power coil is composed of an inductance coil and a capacitor connected in series or in parallel. The resonant frequency of the inductance value of the inductance coil in the power supply coil and the capacitance value of the capacitor in the power supply coil is the same as the frequency of the high-frequency AC power supply. The transmitting coil also includes an inductance coil and a capacitor, the inductance coil and the capacitor are short-circuited in series, and the resonant frequency of the inductance coil and the capacitance value of the capacitor is the same as the frequency of the high-frequency AC power supply.

When the receiving end is composed of a receiving coil, a loading coil and a capacitance adaptive adjustment module corresponding to the receiving coil and the loading coil, the receiving coil and the loading coil are wound side by side so that the mutual inductance between them is as large as possible. The load coil is composed of an inductance coil and a capacitor connected in series or in parallel. The resonant frequency of the inductance value of the inductance coil in the load coil and the capacitance value of the capacitor in the load coil is the same as the frequency of the high-frequency AC power supply. The receiving coil includes an inductance coil and a capacitor, and the inductance coil and the capacitor are short-circuited in series. The resonant frequency of the inductance value of the inductance coil and the capacitance value of the capacitor is the same as the frequency of the high-frequency AC power supply.

The transmitter power conditioning module converts the external power frequency AC or DC power supply into two circuits, one is a high-frequency AC power supply, which is connected to the power supply coil of the transmitter; The adaptive adjustment module supplies energy and is connected to the processing module of the capacitance adaptive adjustment module.

The power conditioning module at the receiving end converts the received high-frequency AC power into two circuits, one of which provides power for the load and is connected to the load resistor; Can be connected with the processing module of the capacitance self-adaptive adjustment module.

The capacitor is a variable capacitor controlled by the capacitance adaptive adjustment module, and has four terminals, two of which are AC connection terminals, and the other two are voltage control connection terminals. When the voltages of the two voltage control terminals are both 0, the capacitance of the capacitor is the initial value; when the voltages of the two voltage control terminals are equal in magnitude and opposite in polarity, the capacitance value of the capacitor increases or decreases accordingly.

The capacitance self-adaptive adjustment module includes two parts: a current sensor installed in the inductance or capacitance loop and a processing module; the current sensor is used to detect the current amplitude of the circuit; the processing module has a pair of power terminals and a pair of signal output Terminal, a current signal input terminal. The power supply end of the processing module obtains energy from the transmitting end or the receiving end, and sorts out power supply for the amplitude required by the processing module. The current signal input terminal of the processing module inputs the signal output by the current sensor, and after the current signal measured by the current sensor is compared with the set value, the signal output terminal of the processing module outputs voltages of equal magnitude and opposite polarity according to the comparison result The signal controls the capacitors of the coils at the transmitting end and the receiving end; the processing module has a feedback energy supply, which can realize precise control of the capacitors. The capacitors in the transmitting coil, receiving coil, power supply coil, and load coil are each controlled by a capacitance adaptive adjustment module.

For a device that is connected in parallel to the transmitting coil or receiving coil and works in parallel resonance mode, when it is in the working state, the current transformer collects the current of the inductance coil loop and compares it with the rated current of the loop. When the real-time current and the rated current When the ratio is lower than a certain set value, which is usually set to 0.9, it indicates that the external environment of the wireless power transmission system changes. Usually, the surrounding magnetic and conductive materials change, the resonant inductance value changes, and the capacitance automatically changes. The adaptation adjustment module is triggered, and the processing module adjusts the capacitance of the capacitor through the signal. The greater the difference between the real-time current and the rated current, the higher the output voltage and the greater the capacitance change, making the resonant circuit return to the resonance point. Usually the external interference is because the new ferromagnetic material makes the resonant inductance increase, so the output voltage signal first controls the capacitance value of the capacitor to decrease. If the current cannot be increased by reducing the method, then adjust the initial voltage to make the capacitance value of the capacitor increase. For the device of the present invention that adopts serial connection for the transmitting coil or the receiving coil and works in a series resonance mode, the working process of the self-adaptive adjustment module is the same as that of the parallel connection.

The power supply coil, transmitting coil, receiving coil and load coil are independently adjusted without affecting each other.

Using the above method, that is, using an adaptively adjustable capacitor instead of a fixed capacitor can effectively reduce the changes in the surrounding environment, such as the sudden increase of ferromagnetic materials, conductive materials, etc., which will affect the wireless energy transmission system. At the same time, the implementation method is relatively simple and does not require The transmitter communicates with the receiver, reducing complexity and cost.

Description of drawings

Fig. 1 is a schematic diagram of an embodiment of the present invention;

Fig. 2 is the schematic diagram of the second embodiment of the present invention;

Fig. 3 is the schematic diagram of the third embodiment of the present invention;

Fig. 4 is a schematic diagram of the power supply coil and self-adaptive adjustment of the present invention;

Fig. 5 is a schematic diagram of a variable capacitor used in the present invention.

Detailed ways

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

Fig. 1 is a schematic diagram of an embodiment of the present invention. As shown in FIG. 1 , the resonant wireless transmission device 1 of the present invention includes a transmitting terminal 2 , a receiving terminal 3 , a transmitting terminal voltage conditioning module 9 and a receiving terminal voltage conditioning module 4 . One end of the wireless transmission device 1 is connected to a power frequency AC power supply, and the power frequency AC power supply is connected to the input end of the voltage conditioning module 9 at the transmitting end; the other end of the wireless transmission device 1 is connected to the load 5 through the voltage conditioning module 4 at the receiving end. The transmitting end 2 is composed of a power supply coil and a corresponding capacitance adaptive adjustment module. The power supply coil is composed of the first inductance coil L1 and the first variable capacitor C1 in series, and the power supply coil can also be composed of the first inductance coil L1 and the first variable capacitor C1 in parallel; the receiving end 3 is composed of the load coil and the corresponding The capacitance self-adaptive adjustment modules are jointly formed. The load coil is composed of the fourth inductance coil L4 and the fourth variable capacitor C4 connected in series, and the load coil can also be formed by the fourth inductance coil L4 and the fourth variable capacitor C4 in parallel; the first inductance coil L1, the fourth inductance coil The coil L4 is a helical coil structure, and the two are coaxially aligned. The transmitter power conditioning module 9 is divided into two outputs, one is a high-frequency AC power supply to the power coil of the transmitter 2, and the other is to supply power to the capacitance adaptive adjustment module of the transmitter 2. The power conditioning module 4 at the receiving end converts the high-frequency AC of the load coil into power frequency AC or DC to supply power to the load 5, and supplies power to the capacitance adaptive adjustment module at the receiving end 3 on the other hand. The capacitance adaptive adjustment module corresponding to the power supply coil includes two parts, a current sensor 8 and a processing module 7. The current sensor 8 is installed on the power supply coil circuit to measure the circuit current, and the measurement result is transmitted to the processing module 7, which is provided by the port 71. For the working power supply, the port 71 is connected to the transmitter voltage conditioning module 9 , and the port 72 is connected to the DC control port 62 of the first variable capacitor C1 , as shown in FIG. 4 . The capacitance adaptive adjustment module corresponding to the load coil has the same structure as the capacitance adaptive adjustment module corresponding to the power coil, that is, the corresponding current sensor is installed in the load coil loop to measure the current, and the measurement result is transmitted to the corresponding processing module. The processing module has three Two ports are used to receive current signals, supply power and output control signals respectively. The processing module of the capacitance adaptive adjustment module corresponding to the load coil is powered by the voltage regulation module 4 at the receiving end.

Fig. 2 is a schematic diagram of the second embodiment of the present invention. As shown in Fig. 2, the resonant wireless transmission device 1 of the present invention includes a transmitting end 2, a receiving end 3, a transmitting end voltage conditioning module 9 and a receiving end voltage conditioning module 4. One end of the wireless transmission device 1 is connected to a power frequency AC power supply, and the other end is connected to a load 5 . The transmitting end 2 is composed of a power supply coil, a transmitting coil and a corresponding capacitance adaptive adjustment module. The power supply coil is composed of the first inductance coil L1 and the first variable capacitor C1 in series, and the power supply coil may also be composed of the first inductance coil L1 and the first variable capacitor C1 in parallel, and the transmitting coil is composed of the second inductance coil L2 and the second The variable capacitor C2 is formed in series; the first inductance coil L1 and the second inductance coil L2 are spiral coil structures, and the two are coaxially aligned. The power conditioning module 9 at the transmitting end is divided into two outputs, one of which converts the industrial frequency power of the industrial frequency AC power supply into a high frequency power supply to supply power to the power coil of the transmitting end 2, and the other output to the capacitance adaptive adjustment module of the transmitting end 2 powered by. The connection mode of the power coil, the transmitting coil and the corresponding capacitance adaptive adjustment module is the same as that shown in FIG. 1 .

The receiving end 3 is composed of a receiving coil, a load coil and a corresponding capacitance adaptive adjustment module. The receiving coil is composed of the third inductance coil L3 and the third variable capacitor C3 in series, and the load coil is composed of the fourth inductance coil L4 and the fourth variable capacitor C4 in series; the load coil can also be composed of the fourth inductance coil L4 and the fourth The variable capacitor C4 is connected in parallel; the third inductance coil L3 and the fourth inductance coil L4 are spiral coil structures, and the two are coaxially aligned. The power conditioning module 4 at the receiving end converts the high-frequency AC of the load coil into power frequency AC or DC to supply power to the load 5, and supplies power to the capacitance adaptive adjustment module at the receiving end 3 on the other hand. The connection mode between the load coil and the capacitance adaptive adjustment module is the same as that shown in Figure 1. The capacitance adaptive adjustment module corresponding to the receiving coil also includes two parts: the current sensor and the processing module. The sensor is installed on the receiving coil loop, measures the loop current, and transmits the result to the processing module. The processing module includes three ports, which respectively receive the current signal, supply power and output the control signal. The processing module corresponding to the receiving coil is controlled by the voltage conditioning module at the receiving end. 4 power supply.

The distance between the transmitting end 2 and the receiving end 3 is fixed, and the transmitting coil, the power supply coil, the receiving coil and the load coil are coaxially aligned to ensure stable efficiency.

Fig. 3 is a schematic diagram of a third embodiment of the present invention. As shown in FIG. 3 , the resonant wireless transmission device 1 of the present invention includes a transmitting terminal 2 , a receiving terminal 3 , a transmitting terminal voltage conditioning module 9 and a receiving terminal voltage conditioning module 4 . The difference between this embodiment and the embodiment shown in FIG. 2 is that the power coil is composed of the first inductance coil L1 and the first variable capacitor C1 in parallel; the load coil is composed of the fourth inductance coil L4 and the fourth variable capacitor C4 in parallel.

Fig. 4 is a schematic diagram of the power supply coil and self-adaptive adjustment of the present invention. As shown in FIG. 4 , the power coil is composed of a first inductance coil L1 and a first variable capacitor C1 connected in series; the power coil is powered by a power frequency AC power supply through the port 11 . The connection relationship between the power supply coil and the capacitance adaptive adjustment module is as follows: the capacitance adaptive adjustment module is composed of a current sensor 8 and a processing module 7 . The current sensor 8 is installed on the power supply coil circuit to measure the circuit current. The current sensor 8 provides the power supply coil current signal to the processing module 7 through the port 73. The processing module 7 provides operating power by the port 71, and the port 71 and the transmitter voltage are adjusted. Module 9 is connected. The port 72 is connected to the DC control port 62 of the first variable capacitor C1 to output control voltages with equal magnitude and opposite polarity to control the capacitance value of the first variable capacitor C1.

FIG. 5 is a schematic diagram of a variable capacitor used in the present invention. As shown in FIG. 5 , the variable capacitor 6 includes a capacitor body, an AC power port 61 , and a DC control port 62 . Its characteristic is that the capacitance value of the capacitor varies with the voltage of the DC control port 62 .

Claims (5)

1. A resonant wireless energy transmission device, characterized in that: the wireless energy transmission device (1) includes a transmitter (2), a receiver (3), a transmitter power conditioning module (9) and a receiver power supply A conditioning module (4); one end of the wireless energy transmission device (1) is connected to a power frequency AC power supply, and the other end is connected to a load (5); the transmitting end (2) is composed of a power supply coil and a corresponding capacitance adaptive adjustment module; The receiving end (3) is composed of a load coil and a corresponding capacitance adaptive adjustment module; the power supply coil and the load coil are respectively composed of capacitors and inductance coils connected in series or in parallel; the power conditioning module (9) of the transmitting end has two outputs, One way converts the power frequency power of the power frequency AC power supply into a high frequency power supply to supply power to the power supply coil of the transmitting end (2), and the other way is connected with the processing module of the capacitance adaptive adjustment module on the side of the transmitting end (2); the receiving end The input end of the power conditioning module (4) is connected to the high-frequency power output from the receiving end, and the power conditioning module (4) at the receiving end has two outputs, one of which supplies power to the load (5), and the other is adaptively adjusted with the capacitor on the side of the receiving end The processing modules of the modules are connected; the capacitors in the power supply coil and the load coil are variable capacitors controlled by the capacitance adaptive adjustment module, and are controlled by the corresponding capacitance adaptive adjustment module. 2. According to the resonant wireless energy transmission device according to claim 1, it is characterized in that: when the capacitor of the power supply coil of the transmitting end (2) is connected in series with the inductance coil, the terminals that are not connected to the capacitor and the inductance coil are respectively connected to the high-frequency The two ends of the AC power supply are connected; when the capacitor of the power coil is connected in parallel with the inductor coil, the two ends of the high-frequency AC power supply are respectively connected to the two ends of the capacitor; the inductance value of the inductor coil of the power coil and the resonant frequency of the capacitor are related to the frequency Same; When the inductance coil and the capacitor of the load coil of the receiving end (3) are connected in series, the disconnected terminals of the capacitor and the inductance coil are respectively connected to the two ends of the load (5), and when the inductance coil of the load coil and the capacitor are connected in parallel, the load The two ends of (5) are respectively connected to the two ends of the capacitor; the resonant frequency of the inductance coil of the load coil and the capacitor is the same as the resonant frequency of the power coil. 3. A resonant wireless energy transmission device, characterized in that: the wireless energy transmission device (1) includes a transmitter (2), a receiver (3), a transmitter voltage conditioning module (9) and a receiver voltage conditioning module (4); one end of the wireless transmission device (1) is connected to a power frequency AC power supply, and the other end is connected to a load (5); The adjustment modules are jointly formed; the power supply coil is composed of the first inductance coil (L1) and the first variable capacitor (C1) in series or in parallel, and the transmitting coil is composed of the second inductance coil (L2) and the second variable capacitor (C2) in series ; The transmitter power conditioning module (9) is divided into two outputs, one way is to convert the power frequency power of the power frequency AC power supply into a high-frequency power supply for the power supply coil of the transmitter (2), and the other is for the transmitter (2) ) of the capacitance adaptive adjustment module; the receiving end (3) is composed of a receiving coil and a load coil and a respective corresponding capacitance adaptive adjustment module; the receiving coil is composed of a third inductance coil (L3) and a third variable Capacitors (C3) are connected in series, and the load coil is composed of a fourth inductance coil (L4) and a fourth variable capacitor (C4) connected in series or in parallel; on the one hand, the receiving-end power conditioning module (4) converts the high-frequency alternating current of the load coil Converted into power frequency alternating current or direct current to supply power to the load (5), on the other hand, supply power to the capacitance adaptive adjustment module of the receiving end (3); the resonant frequencies of the power supply coil, transmitting coil, receiving coil and load coil are the same; The above-mentioned variable capacitor (C1), second variable capacitor (C2), third variable capacitor (C3) and fourth variable capacitor (C4) are controlled by corresponding capacitance adaptive adjustment modules. 4. The resonant wireless energy transmission device according to claim 1 or 3, characterized in that: the capacitance adaptive adjustment module includes a current sensor (8) and a processing module (7) installed in the inductance coil or capacitor circuit Two parts; the current sensor (8) is used to measure the amplitude of the circuit current, and provides a coil current signal to the corresponding processing module (7); the processing module (7) outputs control voltages that are equal in magnitude and opposite in polarity , to control the capacitance value of the capacitor of the transmitter and receiver coils; the processing module (7) has a pair of power terminals, a pair of signal output terminals, and a current signal input terminal; the power terminal of the processing module (7) is from the transmitter The terminal or the receiving end obtains energy and arranges power supply for the required amplitude of the processing module; the current signal input terminal of the processing module (7) inputs the signal of the current sensor (1), and the current signal obtained according to the measurement of the current sensor and the setting After the values are compared, the signal output terminal of the processing module (7) outputs voltage signals of equal magnitude and opposite polarity according to the comparison result to control the capacitors of the transmitter coil and the receiver coil. 5. The resonant wireless energy transmission device according to claim 1 or 3, characterized in that: the capacitance adaptive adjustment modules corresponding to the transmitting coil, the power supply coil, the load coil and the receiving coil are independently adjusted.