RU124852U1 - WIRELESS CHARGING SYSTEM FOR LOW-POWER ELECTRIC POWER CONSUMERS - Google Patents

Abstract

1. A wireless charging system for low-power consumers of electric energy, comprising a charging station with a radiator and a receiver of a consumer of electric energy, made with coils operating using feedback, characterized in that the radiator coil is made with two windings, the wire length of which is a multiple of λ / 4 , where λ is the wavelength used, while the receiver consists of an oscillatory circuit, including a parallel connected spiral flat coil with a wire length that is a multiple of λ / 4 or λ / 2, and n an adjustment capacitor through a controlled rectifier connected in series with a storage capacitor and a generator with a pulse-width modulator and a controller that is connected to a pulse generator and a battery. 2. The system according to claim 1, characterized in that the length of the primary winding of the emitter coil is λ / 4, and the secondary winding is λ.3. The system according to claim 1, characterized in that the charging station is made with an amplifier receiving a signal arriving at the antenna of the charging station from the antenna of the receiver. The system according to claim 1, characterized in that a radiation range from 100 kHz to 40 MHz is used. The system according to claim 1, characterized in that the controlled rectifier is made in the form of an RF dynistor with a predetermined threshold voltage. The system according to claim 1, characterized in that the resonant frequency of the emitter is modulated by a low frequency from 10 Hz to 30 Hz to provide a stimulating effect on the human body and prevent negative effects. The system according to claim 1, characterized in that the resonant frequency of the emitter is modulated by a low frequency from 0 Hz to 10 Hz to provide bactericidal

Description

The utility model relates to electrical engineering and is intended to provide guaranteed wireless power and charge various devices. The utility model can be used for wireless charging of low-power electrical appliances: telephones, cameras, cameras, toys, souvenirs in an apartment, office, public building.

The prior art wireless charging system (patent RU 2306654 C1, H02J 17/00; HB04 1/38, publication date 09/20/2007), containing a narrow-band frequency generator with a radiating antenna. This system constantly generates a high-frequency signal, which is fed to the antenna and transmitted through the oscillations of the electromagnetic field into space. The amplitude of the oscillations decreases in proportion to the square of the distance. For this reason, the schemes known for many years have not found wide application, since the energy supplied from the generator in constant mode is wasted by 99%. The system on the receiving side includes an antenna, a voltage inverter, a charge / discharge controller. The disadvantage of this solution is the inefficiency of energy transfer due to the inefficient mode of receiving oscillations without resonance phenomena.

The prior art device for wireless transmission of electrical energy (see RF patent No. 2411142, B60L 9/00, publication date 08/10/2010), which provides for the supply of electrical energy from a resonant power supply system through a high-voltage high-frequency converter at a resonant frequency, a single-wire line and air gap to individual consumer current collectors. The disadvantage of this device is the need for a single-wire line to each consumer.

The prior art device and method for wireless transmission of energy and / or data between a source device and at least one target device (see patent RU 2419945, H02J 17/00; H01F 38/14, publication date 05/27/2011) . Wireless transmission of energy and / or data is carried out using at least one primary coil located on the side of the source device of the primary coil in at least one secondary coil of the at least one secondary current circuit located on the side of the target device , and a voltage is induced in at least one coil of the at least one resonant circuit. The resonant circuit is electrically isolated from the primary current circuit and the secondary current circuit. The disadvantage of a wireless charger is its low efficiency, since the generator on the source side regularly supplies energy to the oscillating system. In this case, the primary coil, the secondary coil, and the coil forming the inductor of the resonant circuit are located around the magnetic core forming the magnetic circuit. A disadvantage of the known installation is also a decrease in the radius of action (power supply) and a decrease in the number of consumers.

From the patent of the Russian Federation No. 2408476 (B60L 9/08, publication date January 10, 2011), an invention is known aimed at creating a wireless method for powering electric vehicles and a device for its implementation, providing high power and speed of movement of electric vehicles in multi-lane (multi-lane) traffic . The device provides for the supply of electrical energy from a resonant power supply system through a high-voltage high-frequency converter, a single-conductor line and an air gap to individual consumer current collectors. The disadvantage of this solution is the need for a single-wire line to each consumer.

The prior art invention is known "Method and device for the transmission of electrical energy" (RU 2341860, publication date 12/20/2008) according to which the method of transmitting electrical energy includes generating high-frequency electromagnetic waves and transmitting them through a conductive channel between the source and the receiver of electrical energy. The conductive channel forms using microwave radiation at a frequency much higher than the resonant frequency. The disadvantage of this solution is the need to form a conductive channel to each consumer using a microwave source.

The main problem of the power systems discussed above is that the generator, which works continuously on the antenna, the oscillating circuit, all the time gives energy to the electric circuit. In the antenna, the oscillatory circuit, it is converted into electromagnetic waves that propagate in space. The amplitude of the oscillations decreases in proportion to the square of the distance from the source. Therefore, a very small part of the generator energy reaches the consumer and is used. Therefore, a number of patents necessarily propose to form at least a single-conductor channel for energy transfer.

A known group of devices "Wireless energy transfer converters" WO 2011112795 A1 and "Method and Systems for wireless power transmission" US 2011241618 A1, operating due to resonance in a magnetic field with weak radiation of electromagnetic waves. This solution allows you to transfer up to 60% of the initial energy with minimal dispersion. The device comprises a charging station with a radiator and a receiver of a consumer of electrical energy, made with coils operating using feedback. The disadvantage of this system is the ability to achieve high efficiency only when combining the axes of the transmitting and receiving coils. Based on the set of essential features, this decision was taken as a prototype.

The technical result of the utility model is to increase the efficiency of the system by charging low-power devices without direct contact with the charging station at a distance of more than 10 cm with little dependence on the relative orientation of the charging station and receiver. The proposed system allows to increase the radius of work up to 30-50 cm with the absence of a constant charging direction and with a transmission efficiency of up to 55%.

The specified technical result is achieved by the fact that in a wireless charging system for low-power consumers of electric energy, comprising a charging station with a radiator and a receiver of a consumer of electric energy, made with coils operating using feedback, the radiator coil is made with two windings, the wire length of which is a multiple of λ / 4, where λ is the wavelength used, while the receiver consists of an oscillating circuit, including a parallel connected spiral flat coil with lengths a multiple of λ / 4 or λ / 2 wires and a tuning capacitor, through a controlled rectifier connected in series with a storage capacitor, with a pulse-width modulator and a controller that is connected to a pulse generator and a battery.

The length of the primary winding of the emitter coil can be equal to λ / 4, and the length of the secondary winding can be λ.

The charging station may be configured with an amplifier receiving a signal arriving at the antenna of the charging station from the receiver antenna.

For the operation of the charging system, a radiation range from 100 kHz to 40 MHz is used.

The controlled rectifier can be made in the form of an RF dinistor with a predetermined threshold voltage.

To provide a stimulating effect on the human body and prevent negative effects, the resonant frequency of the emitter is modulated with a low frequency from 10 to 30 Hz, and to provide a bactericidal effect on food and drinks located on the table, the resonant frequency of the emitter is modulated with a low frequency from 0 to 10 Hz.

When using two or more consumers, the power consumption and the energy required to charge each consumer is transmitted in the form of code signals.

The charging station can be made with two emitters switched in antiphase and creating counter magnetic fields and with three or more coils with a phase shift of the supplied signal, located at the vertices of the regular polygon.

The primary winding of the coils can be made of stranded wire with a core diameter of less than 0.5 mm with a total cross section of more than 2 square meters. mm

Transmitting and receiving coils can be wound on a ferromagnetic core with a minimum hysteresis loop, operating in the range of 500 kHz - 100 MHz.

For the relative orientation of the emitter and the receiver, the emitter is made movable with automatic direction to the receiver.

The receiving antenna, capacitors, control circuit, rectifiers, are made with a thickness of less than 3 mm, and are assembled in the form of a flat sticker attached to the battery of the mobile device and to the contacts of the battery.

The emitter can be made in the form of a table lamp, while the light from the lamp outlines with a precision of 7-10 cm the charging zone or with a flat antenna and flat electronic components.

The essence of the utility model is illustrated by drawings.

Figure 1 shows a block diagram of a charging system in General;

figure 2 - pulses along the vertices of the half-waves, amplitude modulation of the pulses, the growth of oscillations during pumping;

figure 3 - counter inclusion of coils, where a b - the direction of propagation of the field;

figure 4 - system with a movable axis of several coils, radiation pattern;

5 is a phase offset coil;

6 is a diagram of a generator with direct feedback on the base of the transistor and recovery protection;

7 is a diagram of a generator with a PLL on a CD4046 chip.

The charging station consists of a radiator 1, a generator 2 with phase-locked loop (PLL), a power switch 3, an amplifier 4, a power source 5. A power supply 5 supplies the required voltage to an amplifier 4, a generator 2 with a PLL, a power switch 3. Generator 2 supplies the signal to the key 3, feeding vibrations resonant with the natural vibrations of the emitter coil 1.

The receiving side is a quarter-wave antenna 6, rolled into a spiral, in parallel with which a capacitor with a variable capacitance is connected 7. The capacitor and the four-wave antenna are an oscillatory circuit.

The use of the energy of the circuit occurs in time with the oscillations. The controlled rectifier 8 opens with frequencies 4, 8, 16 times less than the frequency in the circuit, after which the energy enters the pulse-width modulator (PWM) 9 through the storage capacitor 10. With the PWM 9, the energy is supplied to the charge controller 11. The receiver contains a signal generator 12 supplying a signal through a switching system 13. The charge from the charge controller 11 is supplied to the battery 14.

PWM 9 uses a frequency between pulses of 1 to 10 kHz. As a controlled rectifier, bipolar or field effect transistors are used in series with a limiting diode. In voltage resonance, a dynistor with a certain threshold voltage, which opens at the maximum resonance, is used as a controlled rectifier. When resonant currents, an additional winding is used, in which there are maxima that control the thyristor or transistor.

The coil of the emitter 1 in its simplest form is a resonator with a standing wave in the form of a Tesla resonant transformer of a complicated design, consists of a primary winding 15, a secondary winding 16, a feedback winding 17, a matching winding 18 can be connected to the secondary winding, the secondary winding is provided with a solitary with a capacity of 19. Radiation diverges radially and bounded by shielding walls. The windings are made in a flattened form - cylindrical, conical, spiral.

The primary winding (inductor) is made of stranded wire with a core diameter of less than 0.5 mm with a total cross section of more than 2 square meters. mm, so that in the current resonance mode the winding could pass currents of 10-30 A through itself, while the induction of the external field can reach 1.5 T.

The pulse on the primary winding 15 generates a pulse on the secondary winding 16, which propagates through the wire, reaches the end of the winding and is reflected, returns to the beginning of the winding. When the secondary winding 16 is 4, 2 times shorter than the wavelength of the signal used, the return signal returns at the same time (in phase) as the incoming pulse from the primary winding, which leads to wave addition and forms a constant re-radiation of the generated standing wave between the windings and the formation of a more powerful field. In this case, the radiated power is concentrated inside the coil.

The secondary and primary winding is a multiple of λ / 4 (λ / 4, λ / 2, 3λ / 4, λ, 5λ / 4, 3λ / 2, 2λ), where λ is the wavelength used. The best result with a secondary winding length λ, primary λ / 4.

Matching winding 17 is connected to adjust the length and achieve resonance conditions. The emitter coil transmits magnetic field pulses into space, and in the intervals between pulses it operates in the reception mode. In the transmission mode, the signal from the feedback winding 17 is supplied to the generator 2 with a PLL, in the reception mode, to the amplifier 4.

Generator 2 delivers pulses to the primary winding along the vertices of the half-waves of sinusoidal oscillations with an adjustable pulse width and filling from 5 to 35% (figure 2) and with possible modulation. By adjusting the pulse width, the transmitted power is changed. Generator 2 operates in a phase locked loop, i.e. adjusts its frequency when changing temperature, humidity, etc.

The system of the emitter and receiver is in standby mode and in charging mode (figure 1). In standby mode, the generator 2 through the key system 3 of the device delivers rare pulses with a duty cycle of the order of 1000-5000 in the form of a series of high-frequency pulses with a frequency from 100 kHz to 5 MHz for 15-30 pulses in a series of times every 0.5-2 seconds, which leads to consumed power from the mains supply 5 less than 1 watt. During the intervals between pulses, the emitter switches to the receiving antenna mode, while the signal is received at the receiver amplifier. When a mobile device (6-14) is introduced into the zone of the charging system of the mobile device with the receiver, the radiation enters the helical antenna 6 of the receiver, which generates a weak current, feeding the signal generator 12, which supplies a signal through the switching system 13 to the same receiving antenna 6, which emits the signal perceived by the antenna of the emitter 1 and the amplifier 4 of the charging station and reduces the duty cycle to 4-10, which leads to charging the battery of the mobile device. The amplifier 4 of the emitter is tuned to a frequency two times higher than that emitted by this device. A series of pulses charges the capacitor, which feeds the signal generator 12, the receiving antenna 6 switches to the emitter mode. The signal is emitted at a frequency 2 times higher than the main one. The signal received by the charging station leads to a decrease in duty cycle and an increase in the radiation power sufficient to charge the mobile device. At the end of charging, the receiving part emits a signal that causes a decrease in the radiation power of the charging system.

When using two or more consumers with a full charge of one mobile device, the width of the pulses along the tops of half-waves decreases. In this case, the power consumption and the energy required to charge each consumer is transmitted in the form of code signals. In the source device, the total power and power required for radiation are calculated.

In an isolated oscillatory circuit, made in the form of an inductor and capacitance, oscillation begins at the natural resonance frequency. The oscillation flow time in the oscillatory circuit before the oscillation amplitude drops exceeds the pulse supply time from the source 2-10 times. The amplitude of the emitted electromagnetic waves also decreases in proportion to the square of the distance, but the source of 90% of the operating time does not send its own energy to the circuit. Most of the time, charging with electric energy on the receiving side is due to the natural oscillations of the circuit with high inductance on the generator side.

Modulation is performed in the range of 10-30 Hz to neutralize the inhibitory effect of electromagnetic waves. At the same time, small deviations and frequency changes are introduced with a frequency of 10-20 seconds. It is also possible to modulate with frequencies and to provide a stimulating effect on some body systems.

In a more complex version, two Tesla coils are used, connected in phase and creating a counter field (Fig. 3). Due to this, the radiation is concentrated in a plane of a certain width, for example, in the plane of a table. The radiation outside the plane decreases nonlinearly, so that at a distance of more than 30 cm the radiation tends to zero. The width of the plane is regulated by precision phase deviations from 180 degrees of the supplied signals. The coils are made spiral and flat.

Several coils allow you to form a biased charging zone, tunable when you change the position of the receiver on a mobile device (figure 4).

When using three or more coils with a phase shift, it is possible to form an interference zone with a uniform signal amplitude in a certain radius and fast further attenuation due to subtraction of the waves. Three or more coils with a phase shift of the supplied signal are located at the vertices of the regular polygon. When forming a toroidal charging zone, the phase angle of the signals on the coils is determined by α = 360 / N, where N is the number of coils and vertices of the polygon. This allows you to limit the charging zone and ensure the stability of the charge parameters in it. To form a dedicated charging zone, the phase shift is distributed α = 360 / N + β, where β = 360 / 2N + k, k <= β. K ~ β, for the coils that are in the direction of the allocated charging zone, k> = 0 for the coils on the opposite side of the charging zone

The phase offset is digitally generated using a typical circuit. It is also possible to use RF three-phase drivers. Figure 5 shows the manufacturing options for coils with phase displacement made toroidal on one winding casing.

Several coils are also used as receiving antennas to determine the location of mobile devices. At the same time, several coils send a test signal every 0.5-2 seconds. When a mobile device with a receiver is introduced into the operating station of the charging station, as in the case of a single coil, the radiator antennas receive a signal from the receiving part. Those coils on which the signal will be maximum indicate the direction to the mobile device.

When using 2x, 3x or more coils with a controlled phase shift, it becomes possible to form one or more radiation beams of a certain width. When adjusting the phase displacement of the coils according to the signal of the receiving system, it is possible to form a beam in the direction of the mobile device.

It is also possible to wind the transmitter and receiver coils on a ferromagnetic core operating in the range of 500 kHz - 100 MHz using nano-permalloys, microwave ferrites, etc. In this case, the core is selected from materials with a minimum hysteresis loop.

The wireless charger system is not in continuous generation mode. This ensures a high level of the output signal due to the natural oscillations of the inductive system on the generator side.

The power unit can work with direct feedback (OS), or with the generator OS.

With a direct OS (Fig. 6), when voltage is applied to the transistor Q 1 less than necessary for full opening, it works as a key with a large resistance (of the order of tens of kOhm), supplying current to T2, resulting in a backward wave (Back EMF) from the winding T2 closes the transistor Q1. After that, the backward wave opens the transistor again. Thus, a cyclic mode is created.

The frequency is calculated as:

,

,

Where L22 is the length of the wire of the high-voltage winding L2.

This will be the maximum of the spectrum, for the frequency of the first main resonance (quarter wave), at the base of the coil U _min , and at the point H (above) U _max . For the next mode (frequency), based on the coil, U _min , and U _max appears at 1/3 N, then the next U _min at 2/3 N, and finally, U _max at the very top (coil height 3/4 wavelength ) Everything happens as for the Fourier series:

In the next resonant mode, the nodes (minima) of the voltage base, 2/5 N and 4/5 N, and accordingly U _max appears at 1/5 N, 3/5 N, and at the very top (the height is 5/4 wavelength ) To clearly see the nodes, you must be at the resonant frequencies. (The impedance changes cyclically around the Smith diagram and the voltage changes accordingly). The modes (frequencies) will be numbered by the number of ¼ waves that fit into the height:

A flat spiral - the case of a resonator with frequency dispersion - speed is not a linear function of frequency and, therefore, the resonator overtones are not integral multiples of the fundamental. For the next harmonic, the nodes (minima) of the voltage are at the base, 2/7 N, 4/7 N, and 6/7 N. And the maxima U _max appear at 1/7 N, 3/7 N, 5/7 N and on top. For all odd resonant overtones, always on top of U _max , and U _min at base.

In this case, in order to achieve the best conditions of standing waves, the wire length in L2 must be a multiple of an even, or better quadratic, value of the length of the wire of the primary coil L1. Usually used here 2-4-8 times longer. In addition, the scheme uses the scheme "nesting dolls".

In this case, for different cylinders it is necessary to use the ratio of wavelengths, so that in all cylinders there is either an equal wire length or 2 or 4 times less, then there will be no antiphase waves in the windings.

Since the diameters of the concentric windings of the nesting dolls are different, in order to satisfy the conditions of equal length, it is possible to wind the windings with different wire thicknesses, respectively, the outer ones are thicker, the inner ones are thin.

OS from the generator is used either from the induced field or from the taps of the secondary coil, which then falls into the phase-locked loop of the generator frequency, which adjusts the frequency when changing the parameters of the circuit or line. Thus, the resonant mode is maintained regardless of external conditions. An example of a PLL generator circuit on a CD4046 chip is shown in FIG. 7

PLL driver - PLL driver on CD4046 chip. In the master oscillator, the standard CD4046 frequency synthesizer switching circuit was used to use the feedback operation mode, and the IR2104 microcircuit, which generates pulses with a fixed dead-time - pauses between control pulses with a duration of 120ns, necessary for the correct operation of the circuits. The low and high out conclusions are further drawn to power cascades as a full- and half-bridge circuit based on high-speed field-effect or bipolar transistors with a relaxation time of less than 300 ns.

Also, in the power unit, regenerative protection is used, it returns the self-induction energy to the supply circuit, but does not dissipate it, i.e. practically does not degrade the efficiency of the converter.

Figure 4 shows the protection circuit. In parallel with the power winding of the converter, a recovery transformer is connected through a diode. The diode is connected in such a way that a self-induction current flows through it. The secondary winding of this transformer through a second diode is connected to the supply circuit.

As soon as the self-induction voltage becomes more than the supply voltage, this diode will open and the "excess" current will go to the power capacitor.

The recovery transformer must have a winding inductance of 10 ... 100 μH. It is wound in a ferrite "cup" of high-current ferrite. Windings are laid in a cup in two wires, approximately 40 ... 60 turns of wire. The thickness of the wire and the operating currents of the diodes are selected based on their equality to the working currents of the power winding of the converter.

Claims (16)

1. A wireless charging system for low-power consumers of electric energy, comprising a charging station with a radiator and a receiver of a consumer of electric energy, made with coils operating using feedback, characterized in that the radiator coil is made with two windings, the wire length of which is a multiple of λ / 4 , where λ is the wavelength used, while the receiver consists of an oscillatory circuit, including a parallel connected spiral flat coil with a wire length that is a multiple of λ / 4 or λ / 2, and n an adjustment capacitor, through a controlled rectifier, connected in series with a storage capacitor and a generator with a pulse-width modulator and a controller, which is connected to a pulse generator and a battery. 2. The system according to claim 1, characterized in that the length of the primary winding of the emitter coil is λ / 4, and the secondary winding is λ. 3. The system according to claim 1, characterized in that the charging station is made with an amplifier that receives a signal coming to the antenna of the charging station from the antenna of the receiver. 4. The system according to claim 1, characterized in that the radiation range from 100 kHz to 40 MHz is used. 5. The system according to claim 1, characterized in that the controlled rectifier is made in the form of an RF dynistor with a predetermined threshold voltage. 6. The system according to claim 1, characterized in that the resonant frequency of the emitter is modulated by a low frequency from 10 Hz to 30 Hz to provide a stimulating effect on the human body and prevent negative effects. 7. The system according to claim 1, characterized in that the resonant frequency of the emitter is modulated with a low frequency from 0 Hz to 10 Hz to provide bactericidal effects on food and drinks on the table. 8. The system of claim 1, characterized in that when using two or more consumers, the power consumption and the energy required to charge each consumer are transmitted in the form of code signals. 9. The system according to claim 1, characterized in that the charging station is made with two emitters included in antiphase and creating counter magnetic fields. 10. The system according to claim 1, characterized in that the charging station is made with three or more coils with a phase shift of the supplied signal, located at the centers at the vertices of the regular polygon. 11. The system according to claim 1, characterized in that the primary winding is made of stranded wire with a core diameter of less than 0.5 mm with a total cross section of more than 2 mm ² , 12. The system according to claim 1, characterized in that the transmitting and receiving coils are wound on a ferromagnetic core with a minimum hysteresis loop, operating in the range of 500 kHz-100 MHz. 13. The system according to claim 1, characterized in that the emitter is made movable, with automatic direction to the receiver. 14. The system according to claim 1, characterized in that the receiving antenna, capacitors, control circuit, rectifiers are made with a thickness of less than 3 mm and are assembled in the form of a flat sticker attached to the battery of the mobile device and to the contacts of the battery. 15. The system according to claim 1, characterized in that the emitter is made in the form of a table lamp, while the light from the lamp outlines the charging zone with an accuracy of 7-10 cm. 16. The system according to claim 2, characterized in that the emitter is made with a flat antenna and flat electronic components.

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