CN102931736A - Magnetic coupled resonance wireless supply power control system - Google Patents

Abstract

The present invention provides a magnetic coupling resonance wireless power supply control system, including a control circuit, a drive circuit, a power supply, a switch tube, a magnetic coupling resonance circuit, and a rectification and filtering circuit; wherein, the control circuit outputs high-frequency The signal is sent to the drive circuit; the drive circuit receives the high-frequency signal from the control circuit, provides the drive capability required for high-frequency operation for the switch tube, and transmits the electric energy of the power supply to the rectifier filter circuit through the magnetic coupling resonant circuit, and rectifies through the rectifier filter circuit. After filtering, DC power is provided for the load; the control rule is: define M times of the resonance magnetic field oscillation cycle in the magnetic coupling resonant circuit as a control cycle, within one cycle, the drive circuit works in N magnetic field resonance cycles, and the last MN When it is turned off, different average powers can be obtained at the receiving coil end of the magnetically coupled resonant circuit.

Description

A magnetic coupling resonance wireless power supply power control system

technical field

The invention relates to a wireless energy transmission device, in particular to a magnetic coupling resonance wireless power supply power adjustment system, and in particular to the technical field of providing dimming for wireless power supply LED lamps.

Background technique

As a new type of wireless power supply technology, non-radiative magnetic coupling resonance generates strong mutual coupling between two resonant objects of the same frequency, while only weakly couples to the receiving end of the surrounding non-resonant frequency. The magnetically coupled resonant system includes a transmitting resonant coil, a secondary receiving resonant coil and a load.

Assistant Professor Marin Soljacic of MIT is the inventor of the system, and his MIT research group demonstrated wireless power supply. They successfully lit a 60W light bulb from a distance of 2 meters. Magnetic coupling resonance technology can achieve mid-range energy transmission without increasing the magnetic field strength, while traditional magnetic coupling can only achieve relatively good results within a short distance (generally within ten centimeters). It can only be increased by increasing the magnetic field strength. At the same time, an important advantage of the magnetic resonance coupling system is that it can penetrate various non-metallic obstacles, and has no effect on the energy transmission efficiency, power and other indicators of the system.

In many fields where magnetic coupling resonance technology is used for wireless power supply, it is necessary to control and regulate the power of wireless energy. For example, in the application of magnetic coupling resonant wireless power supply LED, we need to adjust its light emission at the LED load end to achieve the purpose of energy saving. Therefore, we need to study power control and regulation methods based on magnetic coupling resonance wireless power supply, especially the magnetic coupling resonance wireless power supply LED dimming method to save energy or achieve the desired lighting adjustment effect.

Contents of the invention

The technical problem to be solved by the present invention is to propose a high-reliability magnetic coupling resonance wireless power supply for the power control and regulation requirements based on magnetic coupling resonance wireless power supply involved in the background technology, especially for the application of magnetic coupling resonance wireless power supply LED applications. Power supply control system.

The present invention adopts the following technical solutions for solving the problems of the technologies described above:

A magnetic coupling resonance wireless power supply control system, including a control circuit, a drive circuit, a power supply, a switch tube, a magnetic coupling resonance circuit, and a rectification and filtering circuit; wherein, the control circuit outputs according to a set control rule within a control cycle The high-frequency signal is sent to the drive circuit; the drive circuit receives the high-frequency signal from the control circuit, drives the switch tube connected to the magnetic coupling resonant circuit to conduct, makes the magnetic coupling resonant circuit work, and passes the electric energy of the power supply through the primary side of the magnetic coupling resonant circuit The circuit is converted into a sine wave current and transmitted to the secondary circuit, and the rectification and filtering circuit rectifies the sine wave current transmitted by the magnetic coupling resonant circuit into a sine half-wave current, and then obtains a DC voltage for the load after low-frequency filtering; wherein the control The rule is: set the electromagnetic field coupling resonance period of the M magnetic coupling resonance circuits as a control period, output high-frequency signals to the drive circuit during the N resonance periods of the M resonance periods, and not output during the remaining M-N resonance periods The high-frequency signal is sent to the drive circuit, so as to realize the control of the average power of the wireless energy transmission to the load side; where M is a natural number greater than 0, N is a natural number greater than 0, and M>N.

所述负载侧电流

其中P_full为负载侧的满载功率，V_负载为负载侧的额定电压。Furthermore, in a magnetic coupling resonance wireless power supply power control system of the present invention, the load side outputs an average power

The load side current

Among them, P _full is the full load power of the load side, and V _load is the rated voltage of the load side.

As a further preferred solution of the magnetic coupling resonance wireless power supply control system of the present invention, the control circuit adopts a programmable control chip.

As a further preferred solution of the magnetic coupling resonance wireless power supply power control system of the present invention, the control circuit adopts a DSP TMS320F2812 programmable control chip.

As a further preferred solution of the magnetic coupling resonant wireless power supply control system of the present invention, the drive circuit adopts a high-frequency drive chip.

As a further preferred solution of the magnetic coupling resonant wireless power supply control system of the present invention, the drive circuit uses an IR2100 drive chip.

As a further preferred solution of the magnetic coupling resonant wireless power supply control system of the present invention, the load is T LED lights connected in series or in parallel, and T is a natural number; the dimming control of the LED lights is realized through the control rules of the control circuit .

As a further preferred solution of the magnetic coupling resonant wireless power supply control system of the present invention, the magnetic coupling resonant system includes a transmitting resonant coil and a receiving resonant coil; wherein the transmitting resonant coil includes a primary winding of a coupling inductor, a second A resonant capacitor, the receiving resonant coil includes a secondary winding of a coupling inductor and a second resonant capacitor; the product of the inductance of the primary winding and the capacitance of the first resonant capacitor is equal to the inductance of the secondary winding and the second The product of the capacitance of the resonant capacitor;

The ends with the same name of the primary winding are respectively connected to the positive pole of the power supply and one end of the first resonant capacitor, and the opposite ends of the primary winding are respectively connected to the other end of the first resonant capacitor and the drain of the switch tube. The grid of the switch tube is connected to the signal output terminal of the drive circuit, and the source of the switch tube is connected to the negative pole of the power supply and then grounded;

The same-named end of the secondary winding is in the same direction as the same-named end of the primary winding; the two ends of the second resonant capacitor are respectively connected to the same-named end and the different-named end of the secondary winding, and connected to the input end of the rectification filter circuit .

As a further preferred solution of the magnetic coupling resonance wireless power supply power control system of the present invention, the rectification and filtering circuit includes a rectification circuit and a filter circuit; wherein the rectification circuit includes first to fourth capacitors, the first capacitor, The third capacitors are connected in series to form the first bridge arm, and the second capacitor and the fourth capacitor are connected in series to form the second bridge arm; the first and second bridge arms are connected in parallel to each other and then connected to the input end of the filter circuit; The midpoint of the first bridge arm and the midpoint of the second bridge arm are respectively used as input ends of the rectification and filtering circuit;

The filter circuit includes a filter inductor and a filter capacitor, wherein one end of the filter inductor is connected to the output end of the rectifier circuit, and the other end of the filter inductor is respectively connected to one end of the filter capacitor and the current input end of the load. The other end of the capacitor is connected to the current output end of the load and grounded.

Compared with the prior art, the present invention adopts the above technical scheme and has the following technical effects:

The magnetic coupling resonant wireless power supply power control system of the present invention has the advantage of simple structure and does not need to provide a dimming feedback signal. At the same time, it can be widely used in occasions where wireless power supply requires average power control and the like, and is not limited to the field of LED open-loop dimming.

Description of drawings

Figure 1 is a magnetic coupling resonant wireless power supply LED open-loop dimming circuit.

Fig. 2 shows the energy transmitted by electromagnetic waves when the magnetic coupling resonance of the preferred example of the present invention works normally.

Fig. 3 is a schematic diagram of a magnetic coupling resonance device wirelessly powered LED open-loop dimming principle of a preferred example of the present invention (M=8, N=4).

Detailed ways

Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:

As shown in Figure 1, in a preferred embodiment of the present invention, the transmitting circuit is composed of a DC power supply V1, a switch tube Q1, a transmitting coil L1, and a transmitting coil resonant capacitor C1; the receiving circuit is a receiving coil L2, a receiving coil resonant capacitor C2 and a rectifier circuit The filter circuit and the load LED lamp, wherein the rectification filter circuit includes a diode D1D4, a filter inductor L3, and a filter capacitor C3. The product of the inductance of the transmitting coil L1 and the capacitance of the resonant capacitor C1 is the same as the product of the inductance of the receiving coil L2 and the capacitance of the resonant capacitor C2.

The control circuit outputs a high-frequency signal to the drive circuit, and the resonant frequency of the transmitting coil on the primary side is The drive circuit receives the high-frequency signal from the control circuit and provides the drive capability required for high-frequency operation for the Q1 switch tube. At this time, the switching frequency provided by the control circuit to Q1 is also f ₁ . Since the coil L ₁ C ₁ =L ₂ C ₂ at the receiving end, the receiving coil L2 can receive the energy transferred by the magnetic resonance and provide DC power for the load LED lamp after being rectified. The control signal controls the conduction of the switch tube Q1 to realize the average power control of the wireless power transmission.

The specific parameters of the preferred example of the present invention are as follows: the input voltage V1 is 24VDC; the resonant inductance of the transmitting coil L1 and the receiving coil L2 is 22uH; the resonant capacitance C1 and C2 are 470nF; the filter inductance L3 is 220uF, and the filter capacitor is 1000uF; The switch tube Q1 is IPB108N15N3G; the rectifier diodes D1-D4 are BYG22D; the chip used in the control circuit is DSP TMS320F2812; the chip used in the drive circuit is IR2100.

As shown in Figure 2, it gives a schematic diagram of the energy transfer characteristics of the magnetic coupling resonant magnetic field. In order to conveniently reflect the idea of this patent, in Fig. 2, only every 8 magnetic field resonance oscillation cycles f ₁ is defined as the control cycle defined in this patent, that is, N=8f ₁ . In fact, we can define any number of magnetic field resonance oscillation cycles as a control cycle to achieve the best control effect.

此时传递无线电能；当开关管Q1始终处于断路状态，此时不能传递无线电能。As shown in FIG. 3 , it shows a schematic diagram of a working condition (M=8, N=4) of a preferred example of the present invention. The control circuit in Fig. 3 gives the high-frequency signal f ₁ , and at the same time realizes the transmission of magnetic resonance energy by controlling the switch tube Q1. When the drive circuit performs high-frequency switching control f ₁ on the switch tube Q1, the resonant frequency of the primary transmitter coil is

At this time, the wireless energy is transmitted; when the switching tube Q1 is always in the off state, the wireless energy cannot be transmitted at this time.

Since the voltage drop V _LED of the LED tube can be considered approximately constant under different operating currents, defining the current at full load as I _LED and the power as P _full , it is easy to obtain:

P _full = V _LED I _LED (1)

If the dimming control method used in this patent is adopted, and M resonance cycles are used as a control cycle, and N resonance cycle electromagnetic waves are sent to the load end, it is easy to obtain:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; out</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; full</span>}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

Combining formulas (1) and (2), it can be seen that for any defined M and N, the dimming current that can be obtained by Yide is:

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; led</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; full</span>}}}{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; led</span>}}}<span\; class="notranslate">\; \&times;</span>\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In Figure 3, we show that there are only N=4 cycles to transmit wireless energy within M=8 electromagnetic wave oscillation cycles, that is, the average power is half of the full-load power, so the current of the LED light can be half of the full-load current.

From the above analysis, we can define any M electromagnetic oscillation periods as a control period, and only send N electromagnetic wave oscillation periods within the defined control period (for example, any combination of M=1000, N=650, etc.) The LED load achieves the desired dimming effect. Through such a design, open-loop dimming of LEDs powered by wireless energy can be realized, which improves system reliability.

For AC load circuits that do not require rectification, we can directly use formula (2) to obtain different output powers.

Claims (10)

1. A magnetic coupling resonance wireless power supply power control system, characterized in that: comprising a control circuit, a drive circuit, a power supply, a switch tube, a magnetic coupling resonance circuit and a rectification filter circuit; The set control rules output high-frequency signals to the drive circuit; the drive circuit receives the high-frequency signal from the control circuit, drives the switch tube connected to the magnetic coupling resonant circuit to conduct, makes the magnetic coupling resonant circuit work, and passes the electric energy of the power supply through the magnetic The primary side circuit of the coupling resonant circuit is converted into a sine wave current and transmitted to the secondary side circuit. The rectification filter circuit rectifies the sine wave current transmitted by the magnetic coupling resonant circuit into a sine half wave current, and then obtains a DC voltage after low-frequency filtering and provides it to the Load; wherein the control rule is: set the electromagnetic field coupling resonance period of the M magnetic coupling resonance circuits as a control period, and output a high-frequency signal to the drive circuit in the N resonance periods of the M resonance periods, and in the remaining M-N No high-frequency signal is output to the drive circuit within one resonant cycle, so as to realize the control of the average power of the wireless power transmission to the load side; where M is a natural number greater than 0, N is a natural number greater than 0, and M>N. 2 . The magnetic coupling resonance wireless power supply power control system according to claim 1 , wherein the control circuit adopts a programmable control chip. 3 . 3. A magnetic coupling resonance wireless power supply power control system according to claim 2, characterized in that: the programmable control chip is a DSP TMS320F2812 programmable control chip. 4 . The magnetic coupling resonance wireless power supply power control system according to claim 1 , wherein the drive circuit adopts a high-frequency drive chip. 5. A magnetic coupling resonance wireless power supply power control system according to claim 4, characterized in that: the high-frequency driver chip is an IR2100 driver chip. 6. A magnetic coupling resonance wireless power supply power control system according to claim 1, characterized in that: said load side outputs average power

Where P _full is the full load power on the load side. 7. A magnetic coupling resonance wireless power supply power control system according to claim 1, characterized in that: the load side current Among them, P _full is the full load power of the load side, and V _load is the rated voltage of the load side. 8. A magnetic coupling resonance wireless power supply power control system according to claim 1, characterized in that: the load is T LED lamps connected in series or in parallel, and T is a natural number; the control rules of the control circuit realize the LED Light dimming control. 9. A magnetic coupling resonance wireless power supply power control system according to claim 1, characterized in that: the magnetic coupling resonance system includes a transmitting resonant coil and a receiving resonant coil; wherein the transmitting resonant coil includes a coupling inductor The primary winding, the first resonant capacitor, the receiving resonant coil includes a secondary winding of a coupling inductor, and a second resonant capacitor; the product of the inductance of the primary winding and the capacitance of the first resonant capacitor is equal to that of the secondary winding The product of the inductance and the capacitance of the second resonant capacitor; The ends with the same name of the primary winding are respectively connected to the positive pole of the power supply and one end of the first resonant capacitor, and the opposite ends of the primary winding are respectively connected to the other end of the first resonant capacitor and the drain of the switch tube. The grid of the switch tube is connected to the signal output terminal of the drive circuit, and the source of the switch tube is connected to the negative pole of the power supply and then grounded; The same-named end of the secondary winding is in the same direction as the same-named end of the primary winding; the two ends of the second resonant capacitor are respectively connected to the same-named end and the different-named end of the secondary winding, and connected to the input end of the rectification filter circuit . 10. A magnetic coupling resonance wireless power supply power control system according to claim 1, characterized in that: the rectification and filtering circuit includes a rectification circuit and a filter circuit; wherein the rectification circuit includes first to fourth capacitors, the The first capacitor and the third capacitor are connected in series with each other to form the first bridge arm, and the second capacitor and the fourth capacitor are connected in series with each other to form the second bridge arm; connection; the midpoint of the first bridge arm and the midpoint of the second bridge arm are respectively used as input terminals of the rectification and filtering circuit; The filter circuit includes a filter inductor and a filter capacitor, wherein one end of the filter inductor is connected to the output end of the rectifier circuit, and the other end of the filter inductor is respectively connected to one end of the filter capacitor and the current input end of the load. The other end of the capacitor is connected to the current output end of the load and grounded.

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