CN101860087B - Method and system for improving wireless energy transmission efficiency by using feedback tuning method - Google Patents

Abstract

The invention discloses a method and a system for improving wireless energy transmission efficiency by using a feedback tuning method. The system comprises a phase-locked loop oscillating circuit, a drive amplifying circuit, a transmitting resonant circuit, a current extracting circuit, a receiving and tuning circuit, a rectifying and filtering circuit and a digital control circuit. The method comprises the following steps of: transmitting the output frequency of the oscillating circuit at the transmitting end and locking the frequency on the oscillation frequency of the transmitting resonant circuit in a phase-locked loop way; controlling the resonant frequency of the receiving and tuning circuit at the receiving end in a digital feedback way according to the output of the rectifying and filtering circuit; and coupling the transmitting end and the receiving end by a magnetic field. The output frequency of the phase-locked loop oscillating circuit and the resonant frequency of the receiving and tuning circuit are self-adaptively tuned on the resonant frequency of the transmitting resonant circuit, thereby improving the voltage output frequency of a wireless energy transmission system.

Description

Method and system for improving wireless energy transmission efficiency by feedback tuning method

technical field

The invention relates to a method and a system for improving the efficiency of wireless energy transmission by a feedback tuning method.

Background technique

For a long time, my country's power transmission is mainly realized through wired transmission. It has the disadvantages of complex wiring and inconvenient use. In recent years, with the continuous advancement of science and technology, fields such as household appliance power supply, battery charging, and radio frequency identification have gradually begun to use wireless methods to transmit energy.

Wireless energy transmission uses the principle of magnetic field resonance to couple electric energy from the transmitting resonant circuit to the receiving resonant circuit. When factors such as external temperature, system load, and transmission distance change, the resonant frequency of the transmitting resonant circuit and the resonant frequency of the receiving resonant circuit will deviate from the output frequency of the oscillating circuit, which will seriously affect the transmission efficiency of the system.

Contents of the invention

The purpose of the present invention is to provide a method and system for improving the efficiency of wireless energy transmission by feedback tuning method, adaptively tune the output frequency of the phase-locked loop oscillating circuit and the resonant frequency of the receiving tuning circuit to the resonant frequency of the transmitting oscillating circuit , so as to improve the transmission efficiency of the wireless energy transmission system.

The technical scheme adopted in the present invention is:

1. A feedback tuning method to improve the efficiency of wireless energy transmission:

At the transmitting end, the output frequency of the transmitting oscillating circuit is locked on the oscillating frequency of the transmitting resonant circuit by means of a phase-locked loop; at the receiving end, according to the output of the rectifying and filtering circuit, digital feedback is used to control the receiving tuning The resonant frequency of the circuit; the transmitting end and the receiving end are realized by magnetic field coupling; the output frequency of the phase-locked loop oscillating circuit and the resonant frequency of the receiving tuning circuit are adaptively tuned to the resonant frequency of the transmitting resonant circuit, thereby improving wireless energy The voltage output efficiency of the transmission system.

2. A feedback tuning method to improve the efficiency of wireless energy transmission system:

The invention includes a phase-locked loop oscillating circuit, a driving amplifier circuit, a transmitting resonant circuit, a current extraction circuit, a receiving tuning circuit, a rectification filter circuit and a digital control circuit; Then it is connected with the phase-locked loop oscillation circuit; the receiving tuning circuit is connected with the receiving tuning circuit through the rectification and filtering circuit and the digital control circuit, and the voltage of the rectification and filtering circuit is output; the magnetic field coupling between the transmitting resonance circuit and the receiving tuning circuit.

The phase-locked loop oscillating circuit is a phase-locked loop oscillating circuit built by CD4046, using a chip CD4046, its IN terminal is connected to a current extraction circuit, and its OUT terminal is connected to a driving amplifier circuit.

The drive amplifier circuit is a Class B drive amplifier circuit, the emitter of the NPN transistor is connected to the PNP transistor and then connected to the emission resonant circuit, and the negative pole of one bipolar transistor D1 is connected to the positive pole of the other bipolar transistor D2. The OUT terminal of the phase-locked loop oscillator circuit.

The transmitting resonant circuit is that the inductance coil L1 is coupled with the capacitor C3, the capacitor C3 is connected to the port where the emitter of the NPN triode of the driving amplifier circuit is connected to the PNP triode, and the inductance coil L1 is connected to the current extraction circuit.

The current extraction circuit is a mutual inductance current extraction circuit, wherein the first port of the primary side is connected to the L1 port of the inductance coil of the transmitting resonant circuit, and the fourth port of the secondary side is connected to the IN terminal of the phase-locked loop oscillation circuit.

The receiving tuning circuit is coupled with an inductance coil L2 and an adjustable capacitor VC, and the output terminal is connected with a rectification filter circuit and a digital control circuit.

In the rectifying and filtering circuit, the positive terminal of the diode D3 is connected to the output terminal of the receiving tuning circuit, and the terminal of the adjustable capacitor VC is used as the voltage output terminal, and is connected to the digital control circuit at the same time.

The digital control circuit described above is a digital control circuit built by MSP430F2013. The ADC1 terminal of the chip MSP430F2013 is connected to the adjustable capacitor VC terminal of the rectification filter circuit, and the P1.5 terminal and the TA1 terminal are used as the interface J2, which is connected to the adjustable capacitor VC terminal of the rectification filter circuit. .

The signal working path is as follows: the high-frequency oscillation signal generated by the phase-locked loop oscillating circuit flows to the transmitting resonant circuit after passing through the drive amplifier; the receiving tuning circuit uses the principle of magnetic field resonance to couple part of the energy from the transmitting resonant circuit to generate high-frequency oscillating current ; The rectification filter circuit converts the high-frequency oscillating current into a DC voltage. When factors such as external temperature, system load, or transmission distance change, there will be a deviation between the resonant frequency of the transmitting resonant circuit, the resonant frequency of the receiving resonant circuit and the output frequency of the oscillating circuit, which will affect the transmission efficiency of the system. At the transmitting end, the current extraction circuit extracts the current passing through the transmitting resonant circuit, and then uses the phase-locked loop technology to lock the output frequency of the oscillating circuit on the resonant frequency of the transmitting resonant circuit; at the receiving end, the digital control circuit continuously detects the rectification filter The output voltage of the circuit is fed back to the adjustable capacitor of the receiving tuning circuit to change the resonant frequency of the receiving tuning circuit so that the output of the rectifying and filtering circuit gradually reaches the maximum value.

The beneficial effect that the present invention has:

The invention proposes a method and system implementation for improving the efficiency of wireless energy transmission by a feedback tuning method. When the resonant frequency of the transmitting resonant circuit changes with factors such as external temperature, system load or transmission distance, the phase-locked loop technology is used to lock the output frequency of the oscillating circuit to the resonant frequency of the transmitting resonant circuit to solve the frequency mismatch at the transmitting end question. For the receiving end, by continuously detecting the output of the rectifying and filtering circuit, the resonant frequency of the receiving tuning circuit is adjusted by means of digital feedback, so that the output of the rectifying and filtering circuit reaches the maximum value. Through the above method, the output frequency of the phase-locked loop oscillating circuit and the resonant frequency of the receiving tuning circuit are adaptively tuned to the resonant frequency of the transmitting oscillating circuit, thereby improving the transmission efficiency of the wireless energy transmission system.

Description of drawings

Fig. 1 is a functional block diagram of the realization of the present invention.

Figure 2 is a schematic diagram of the phase-locked loop oscillation circuit built by CD4046.

Figure 3 is a schematic diagram of the Class B drive amplifier circuit.

Figure 4 is a schematic diagram of the launch resonant circuit.

Figure 5 is a schematic diagram of the mutual inductance current extraction circuit.

Figure 6 is a schematic diagram of the receiving tuning circuit.

Fig. 7 is a schematic diagram of a half-wave rectification filter circuit.

Figure 8 is a schematic diagram of the digital control circuit built by MSP430F2013.

In the figure: 1 PLL oscillating circuit, 2 driving amplifying circuit, 3 transmitting resonant circuit, 4 current extracting circuit, 5 receiving tuning circuit, 6 rectifying and filtering circuit and 7 digital control circuit.

Detailed ways

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

As shown in Fig. 1, the present invention includes phase-locked loop oscillation circuit 1, driving amplifying circuit 2, transmitting resonance circuit 3, current extraction circuit 4, receiving tuning circuit 5, rectification filter circuit 6 and digital control circuit 7; phase-locked loop oscillation The circuit 1 is connected to the phase-locked loop oscillation circuit 1 through the driving amplifier circuit 2, the transmitting resonance circuit 3, and the current extraction circuit 4; the receiving tuning circuit 5 is connected to the receiving tuning circuit 5 through the rectifying and filtering circuit 6 and the digital control circuit 7, and rectified The voltage output of the filter circuit 6 ; the magnetic field coupling between the transmitting resonant circuit 3 and the receiving tuning circuit 5 .

As shown in Figure 2, the phase-locked loop oscillation circuit 1 is a phase-locked loop oscillation circuit built by CD4046, using a chip CD4046, its IN terminal is connected to the current extraction circuit 4, and its OUT terminal is connected to the driving amplifier circuit 2.

As shown in Figure 3, the drive amplifier circuit 2 is a Class B drive amplifier circuit, the emitter of the NPN triode is connected to the PNP transistor and then connected to the emission resonant circuit 3, and the negative pole of one bipolar tube D1 is connected to the negative pole of the other bipolar tube D2 The anode of the positive pole is connected to the OUT end of the phase-locked loop oscillation circuit 1.

As shown in FIG. 4 , the transmitting resonant circuit 3 is coupled with the inductance coil L1 and the capacitor C3 , the capacitor C3 is connected to the port where the emitter of the NPN triode of the driving amplifier circuit is connected to the PNP triode, and the inductance coil L1 is connected to the current extraction circuit 4 .

As shown in Figure 5, the described current extraction circuit 4 is a mutual inductance current extraction circuit, wherein the first port of the primary side is connected to the launch resonant circuit 3 inductance coil L1 port, and the fourth port of the secondary side is connected to the phase-locked loop oscillation circuit 1 IN terminal.

As shown in FIG. 6 , the receiving tuning circuit 5 is coupled with an inductance coil L2 and an adjustable capacitor VC, and the output terminal is connected with a rectifying and filtering circuit 6 and a digital control circuit 7 .

As shown in FIG. 7 , the positive terminal of the diode D3 of the rectifying and filtering circuit 6 is connected to the output terminal of the receiving tuning circuit 5 , and the terminal of the capacitor C4 is used as the voltage output terminal, and is connected to the digital control circuit 7 at the same time.

As shown in Figure 8, the digital control circuit 7 is a digital control circuit built by MSP430F2013. The ADC1 terminal of the chip MSP430F2013 is connected to the VC terminal of the rectification filter circuit 6, and the P1.5 terminal and TA1 terminal are used as the interface J2 to connect to the rectification filter circuit. 6 adjustable capacitor VC terminal.

a) An oscillating signal of a specific frequency generated by a phase-locked loop oscillating circuit.

b) drive the amplification circuit to amplify the power of the high-frequency oscillation signal generated in the previous step, so as to provide enough energy for wireless transmission.

c) The transmitting tuning circuit converts the energy of the high-frequency oscillation signal into magnetic field energy.

d) The receiving tuning circuit couples part of the energy from the periodically changing magnetic field through magnetic field resonance, and converts it into a high-frequency oscillating current.

e) The rectification and filtering circuit converts the high-frequency oscillating current into a DC voltage.

f) When factors such as external temperature, system load or transmission distance change, the resonant frequency of the transmitting resonant circuit and the resonant frequency of the receiving resonant circuit will deviate from the output frequency of the oscillating circuit.

g) At the transmitting end, the current extracting circuit extracts the current passing through the transmitting resonant circuit. Then, the output frequency of the oscillator circuit is locked to the resonance frequency of the transmitting resonance circuit by using the phase-locked loop technology.

h) At the receiving end, the digital control circuit continuously detects the output voltage of the rectifying and filtering circuit, and feeds back to the adjustable capacitor of the receiving tuning circuit to change its resonance frequency. Make the output of the rectification filter circuit reach the maximum value.

i) Through steps g and h, adaptively tune the output frequency of the phase-locked loop oscillating circuit and the resonant frequency of the receiving tuning circuit to the resonant frequency of the transmitting oscillating circuit, thereby reducing the influence of external factors on the transmission efficiency of the system.

The implementation of each part is described in detail below:

The phase-locked loop oscillation circuit is built with an integrated phase-locked loop chip, such as the schematic diagram of the circuit built with the chip CD4046 as shown in Figure 2.

The drive amplifier circuit uses a class B, class D or class E power amplifier circuit. When using the class B push-pull complementary amplifier circuit, the circuit schematic diagram is shown in Figure 3. On the one hand, the circuit architecture can provide sufficient output power, and on the other hand, it can reduce the influence of its output impedance on the quality factor of the transmitting resonant circuit.

The transmit tuning circuit uses a series resonant circuit, as shown in Figure 4. Among them, the inductance coil L1 uses an enameled wire to spirally wind an air-core inductor, or a planar spiral inductor is printed on a circuit board; the capacitor C3 uses a fixed capacitor.

The current extraction circuit uses a mutual inductance current extraction circuit, as shown in Figure 5; or a photoelectric coupling current extraction circuit is suitable. It is used to reduce its influence on the quality factor of the transmitting resonant circuit and play the role of isolation.

The receiving tuning circuit uses a parallel resonant circuit, as shown in Figure 6. Among them, the inductance coil L2 uses an enameled wire to coil an air-core inductor, or prints a planar spiral inductor on a circuit board; the adjustable capacitor VC uses a high-power fixed capacitor and an electrically adjustable capacitor (such as MAX1474 produced by MAXIM) in parallel. constitute.

The rectification filter circuit uses a half-wave rectification circuit in low-power applications, as shown in Figure 7; it uses a full-wave rectification circuit in high-power applications.

The digital control circuit is implemented with a low-power single-chip microcomputer with analog-to-digital conversion function, such as the chip MSP430F2013 produced by Texas Instruments, and its circuit schematic diagram is shown in Figure 8. Among them, the analog-to-digital conversion function is used to collect the output voltage of the rectifier and filter circuit; the J1 interface is a SpyBiWire interface for microcontroller programming; the J2 interface is used to control the adjustable capacitor in the receiving tuning circuit.

Claims (2)

1. A feedback tuning method improves the efficiency of wireless energy transmission, which is characterized in that: at the transmitting end, the output frequency of the transmitting oscillating circuit uses a phase-locked loop mode to lock the frequency on the oscillating frequency of the transmitting resonant circuit; At the end, the digital control circuit continuously detects the output voltage of the rectifier filter circuit, and feeds back to the adjustable capacitor of the receiving tuning circuit to change its resonant frequency; the transmitting end and the receiving end are realized by magnetic field coupling; the output of the phase-locked loop oscillation circuit Both the frequency and the resonant frequency of the receiving tuning circuit are adaptively tuned to the resonant frequency of the transmitting resonant circuit, thereby improving the voltage output efficiency of the wireless energy transmission system. 2. by a kind of feedback tuning method of the method described in claim 1, improve the system of wireless energy transmission efficiency, comprise phase-locked loop oscillation circuit (1), driving amplifying circuit (2), launch resonant circuit (3), electric current extracting circuit (4), receiving tuning circuit (5), rectifying and filtering circuit (6) and digital control circuit (7); The circuit (4) is connected with the phase-locked loop oscillation circuit (1) again; the receiving tuning circuit (5) is connected with the receiving tuning circuit (5) through the rectifying and filtering circuit (6) and the digital control circuit (7), and the rectifying and filtering circuit ( 6) Voltage output; magnetic field coupling between the transmitting resonant circuit (3) and the receiving tuning circuit (5); characterized in that: Described phase-locked loop oscillatory circuit (1) is the phase-locked loop oscillatory circuit that CD4046 builds, and uses chip CD4046, and its IN terminal is connected with current extracting circuit (4), and its OUT terminal is connected with driving amplifying circuit (2); The drive amplifier circuit (2) is a Class B drive amplifier circuit, the emitter of the NPN triode is connected to the PNP transistor and then connected to the emission resonant circuit (3), and the negative pole of one diode D1 is connected to the positive pole of the other diode D2 Connect to the OUT end of the phase-locked loop oscillation circuit (1); Described emission resonant circuit (3) is the coupling of inductance coil L1 and electric capacity C3, electric capacity C3 connects the port that the emitter of NPN triode and PNP triode are connected to each other, and inductance coil L1 connects current extracting circuit (4); The current extraction circuit (4) is a mutual induction current extraction circuit, wherein the first port of the primary side is connected to the L1 port of the transmitting resonant circuit (3), and the fourth port of the secondary side is connected to the phase-locked loop oscillation circuit (1) IN terminal; The receiving tuning circuit (5) is coupled with an inductance coil L2 and an adjustable capacitor VC, and the output terminal is connected with a rectification filter circuit (6) and a digital control circuit (7); In the rectifying and filtering circuit (6), the positive terminal of the diode D3 is connected to the output terminal of the receiving tuning circuit (5), and the capacitor C4 terminal is used as the voltage output terminal, and is connected to the digital control circuit (7) at the same time; The digital control circuit (7) is a digital control circuit built by MSP430F2013, the ADC1 terminal of the chip MSP430F2013 is connected to the rectification filter circuit (6) adjustable capacitor VC terminal, the P1.5 terminal and the TA1 terminal are used as the interface J2, and are connected to the rectification filter circuit Circuit (6) is an adjustable capacitor VC terminal.

Images