KR20170102454A - Wireless Power Transfer System and Operating method thereof - Google Patents

Abstract

The present invention relates to a wireless power transmission system capable of solving the instability of power transmission due to a sudden change in a coupling coefficient between a transmission device and a reception device due to shaking of the reception device being wirelessly charged, and a driving method thereof. A method for wirelessly transmitting power from a transmission device to a reception device comprises the steps of: transmitting a signal for detecting the reception device; receiving an identification packet from the reception device; resetting a range of driving frequency of the transmission device based on the identification packet of the reception device; and transmitting wireless power generated in the range of the reset driving frequency.

Description

An electrolone power transmission system and its driving method. {Wireless Power Transfer System and Operating Method}

The present invention relates to an electroluminescent transmission system and a driving method thereof.

Generally, various electronic apparatuses are equipped with a battery and are driven by using electric power charged in the battery. At this time, in the electronic device, the battery may be replaced and charged again. To this end, the electronic device has a contact terminal for contact with an external charging device. That is, the electronic device is electrically connected to the charging device through the contact terminal. However, as the contact terminal is exposed to the outside in the electronic device, it may be contaminated by foreign substances or short-circuited by moisture. In this case, there is a problem that a contact failure occurs between the contact terminal and the charging device, and the battery is not charged by the electronic device.

In order to solve the above-mentioned problem, a wireless power transfer (WPT) for charging an electronic device by wireless has been proposed.

The wireless power transmission system is a technology that transfers power without a line through space and maximizes the convenience of power supply to mobile devices and digital home appliances.

The wireless power transmission system has advantages such as saving energy through real-time power usage control, overcoming space limit of power supply, and reducing waste battery discharge by battery recharging.

As a method of implementing a wireless power transmission system, there are typically a magnetic induction type and a self resonance type. The magnetic induction method is a noncontact energy transmission technique in which two coils are brought close to each other, a current is supplied to one coil, and an electromotive force is generated in the other coil via the magnetic flux generated thereby. The self-resonance method is a magnetic resonance technique that uses only electric fields or magnetic fields without using electromagnetic waves or currents, and the distance capable of power transmission is several meters or more, and a band of several MHz can be used.

The wireless power transmission system includes a transmitting device that transmits power wirelessly and a receiving device that receives power to charge a load such as a battery. At this time, a transmitting apparatus capable of selecting a charging system of a receiving apparatus, that is, a charging system of either a magnetic induction system or a self-resonance system, and capable of transmitting power wirelessly corresponding to a charging system of a receiving apparatus has been developed.

In the meantime, when a receiving device disposed in a charging area of a transmitting device is shaken intentionally or a vibration phenomenon of a receiving device such as an automobile frequently occurs, a sudden change in coupling coefficient according to misalignment between the transmitting and receiving devices There has been a problem that the receiving apparatus is damaged due to a sudden change in the transmission power.

When excessive transmission power is transmitted in response to a rapid change in the transmission power, there is a problem in that an overvoltage is applied on the reception coil of the reception apparatus. The receiving apparatus has a function of providing a feedback to the transmission apparatus to reduce the transmission power to prevent the overvoltage or discharging the overcurrent according to the excessive transmission power by providing a clamp capacitor by itself, There is a limitation in responding to an overcurrent that is suddenly changed suddenly only by the receiving capacitor being damaged before the feedback device provides feedback or by the clamp capacitor alone.

Embodiments can provide an unshielded power transmission system and a method of driving the same that can solve the instability of power transmission due to a sudden change in the coupling coefficient between the transmitting apparatus and the receiving apparatus due to the shaking of the receiving apparatus being wirelessly charged.

A power transmission method according to an embodiment is a method of wirelessly transmitting power from a transmission device to a reception device, comprising: transmitting a signal for detection of the reception device; Receiving an identification packet from the receiving device; Resetting a range of the driving frequency of the transmitting apparatus based on the identification packet of the receiving apparatus; And transmitting the generated wireless power within the range of the reset frequency.

In the power transmission method according to the embodiment, the step of resetting the range of the driving frequency may provide a power transmission method for resetting the minimum frequency and the maximum frequency of the driving frequency.

In the power transmission method according to the embodiment, the range of the driving frequency may be reset based on a current threshold value of the receiving side coil part included in the identification packet.

In the power transmission method according to the embodiment, the range of the driving frequency may provide a power transmission method that is reset based on the identification packet after receiving the control error packet from the reception device.

In the power transmission method according to the embodiment, the minimum frequency of the reset driving frequency may be greater than the minimum frequency of the predetermined driving frequency of the transmitting apparatus.

In the power transmission method according to the embodiment, the maximum frequency of the reset driving frequency may be less than the maximum frequency of the predetermined driving frequency of the transmitting apparatus.

In the power transmission method according to the embodiment, receiving the control error packet from the receiving device; And generating wireless power based on the information on the amount of power required by the receiving apparatus of the control error packet.

In the power transmission method according to the embodiment, the step of generating the wireless power provides a power transmission method for generating wireless power based on proportional control, integral control, and proportional integral differential control (PID control) It is possible.

In the power transmission method according to the embodiment, the current control variable is set based on the difference between the current control error packet and the scaling factor multiplied by the current PID control amount according to the previous control error packet, May also provide a power transmission method for generating wireless power based on the received power.

In the power transmission method according to the embodiment, the scaling factor may provide a power transmission method that is changed based on the range of the reset drive frequency.

A power receiving method according to an embodiment includes: transmitting a response signal to a detection signal from the transmitting device, the method comprising: receiving a power from a transmitting device wirelessly; Transmitting an identification packet to the transmitting device; And receiving wireless power generated based on the range of the driving frequency that is reset based on the identification packet.

In the power receiving method according to the embodiment, the identification packet may include a current threshold value of the receiving apparatus, and the range of the driving frequency may be reset based on the current threshold value.

In the power receiving method according to the embodiment, the power receiving method may be provided in which the range of the driving frequency is reset by resetting the minimum frequency and the maximum frequency of the driving frequency.

In the power receiving method according to the embodiment, the minimum frequency of the reset driving frequency may be greater than the minimum frequency of the predetermined driving frequency of the transmitting apparatus.

In the power receiving method according to the embodiment, the maximum frequency of the reset driving frequency may be smaller than the maximum frequency of the predetermined driving frequency of the transmitting apparatus.

In the power receiving method according to the embodiment, comparing the received radio power with the required power; And transmitting the control error packet to the transmission apparatus according to the comparison result, wherein the control error value is any one of a positive value, a zero value, and a negative value, and the power increase request signal includes a positive control error value The power hold request signal corresponds to a control error value of zero and the power decrease request signal may provide a power reception method corresponding to a negative control error value.

A transmitting apparatus according to an embodiment includes: a transmitting coil for wireless power transmission; A power converter for outputting power to the transmission coil; A control unit for controlling the power conversion unit to control an amount of power output to the transmission coil; The control unit may provide a transmitting apparatus for resetting the driving frequency range of the power converting unit based on the identification packet of the receiving apparatus that receives the wireless power.

In a transmitting apparatus according to an embodiment, the identification packet may include a current threshold value of the receiving apparatus, and the transmitting apparatus may reset the range of the driving frequency based on the current threshold value.

In the transmitting apparatus according to the embodiment, the power converting unit may provide a transmitting apparatus that operates either as a half bridge inverter or a full bridge inverter based on the identification packet.

In the transmission apparatus according to the embodiment, the control unit may control the amount of the radio power by controlling any one of a driving frequency, an input voltage, a duty cycle, and a phase shift of the power conversion unit, Device may be provided.

In the transmitting apparatus according to the embodiment, the control unit may include: a first calculating unit that determines a second current based on a power increase request signal from the receiving apparatus and a first current of the transmitting coil; A PID controller for determining a control amount based on proportional control, integral control, and proportional integral differential control (PID control); And a second calculation unit for determining a current control variable based on the control amount and the previous control variable, wherein the control unit controls the power conversion unit based on the current control variable.

In the transmission apparatus according to the embodiment, the second calculation unit may provide a transmission apparatus for determining the current time control variable based on a value obtained by multiplying the control amount by a scaling factor and a difference value between the previous control variable.

In the transmitting apparatus according to the embodiment, the scaling factor may be changed based on the range of the driving frequency that is reset.

A receiving apparatus according to an embodiment of the present invention includes: a control unit for communicating with the transmitting apparatus to transmit an identification packet; And a receiving coil for receiving the wireless power generated according to the range of the driving frequency that is reset based on the identification packet.

A receiving apparatus according to an embodiment may provide a receiving apparatus in which the identification packet includes a current threshold value of the receiving apparatus and the range of the driving frequency is reset based on the current threshold value.

The receiving apparatus according to the embodiment may provide a receiving apparatus in which the range of the driving frequency is reset by resetting the minimum frequency and the maximum frequency of the driving frequency.

The reception apparatus according to the embodiment is characterized in that the minimum frequency of the reset drive frequency is larger than the minimum frequency of the predetermined drive frequency of the transmission apparatus and the maximum frequency of the reset drive frequency is a maximum It is also possible to provide a receiving device smaller than the frequency.

Embodiments can prevent a problem of unstable power transmission, heat generation, and system damage of the receiving apparatus due to a sudden change in the coupling coefficient between the transmitting apparatus and the receiving apparatus due to the shaking of the receiving apparatus being wirelessly charged.

1 is a magnetic induction type equivalent circuit.
2 is a self-resonant-type equivalent circuit.
Figures 3a and 3b are block diagrams illustrating a transmitter as one of the subsystems that make up the wireless power transmission system.
3C is a specific circuit diagram of the transmission-side power conversion unit according to the embodiment;
4A and 4B are block diagrams illustrating a receiving unit as one of the sub-systems constituting the wireless power transmission system.
FIG. 5 is a flowchart illustrating an operation of a wireless power transmission system according to an embodiment of the present invention. FIG.
6 is a graph illustrating a driving state of a power conversion unit according to a load of a receiving apparatus;
7 is a flowchart related to a method for determining a required power of a receiving apparatus;
8 is a graph showing the magnitude of the coil current on the transmission side coil part according to the driving frequency.
9 and 10 are operational flowcharts of a transmitting apparatus including a driving frequency boundary value setting step.
11 is a detailed view of a control unit of a transmission apparatus for a power transmission control method.
12 is a timing diagram of a transmitting apparatus in a power transmission state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wireless power transmission system including a transmitting apparatus having a function of transmitting power wirelessly and a receiving apparatus receiving power wirelessly according to an embodiment of the present invention will be described in detail with reference to the drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Embodiments may include a communication system that selectively uses various types of frequency bands from a low frequency (50 kHz) to a high frequency (15 MHz) for wireless power transmission and can exchange data and control signals for system control .

The embodiments can be applied to various industrial fields such as a mobile terminal industry using a battery or an electronic device required, a smart clock industry, a computer and notebook industry, a household appliance industry, an electric car industry, a medical device industry, and a robot industry .

Embodiments may consider a system capable of power transmission to one or more multiple devices using one or more transmission coils.

According to the embodiment, it is possible to solve the battery shortage problem in a mobile device such as a smart phone and a notebook. For example, when a wireless charging pad is placed on a table and a smart phone or a notebook is used on the table, the battery is automatically charged and can be used for a long time . In addition, by installing wireless charging pads in public places such as cafes, airports, taxis, offices, restaurants, etc., mobile devices manufacturers can charge various mobile devices regardless of charging terminals. In addition, when wireless power transmission technology is applied to household electrical appliances such as cleaners, electric fans, etc., there is no need to look for power cables and complex wires can be eliminated in the home, which can reduce wiring in buildings and increase the space utilization. In addition, it takes a lot of time to charge the electric car with the current household power, but if the high power is transmitted through the wireless power transmission technology, the charging time can be reduced. If the wireless charging facility is installed at the bottom of the parking lot, It is possible to solve the inconvenience of having to prepare.

The terms and abbreviations used in the examples are as follows.

Wireless Power Transfer System: A system that provides wireless power transmission within a magnetic field region

Power Transmission Unit (PTU): A device that provides wireless power transmission to a power receiver within a magnetic field range and manages the entire system, which can be referred to as a transmitter or transmitter.

Wireless Power Receiver System (PRU): A device that receives a wireless power transmission from a power transmitter within a magnetic field region and may be referred to as a receiver or receiver.

Charging Area: A region where actual wireless power transmission occurs within the magnetic field region, and may vary depending on the size, required power, and operating frequency of the application product.

Scattering parameter: The S parameter is the ratio of the input port to the output port in terms of the input voltage to the output voltage on the frequency distribution (Transmission S21) or the self reflection value of each input / output port, Reflection (S11, S22) of the reflected output.

Quality factor Q: The value of Q in resonance means the quality of frequency selection. The higher the Q value, the better the resonance characteristics. The Q value is expressed as the ratio of the energy stored in the resonator to the energy lost.

The principles of wireless power transmission include magnetic induction and self-resonance.

The magnetic induction method is a noncontact energy transfer technique in which an electromotive force is generated in the load inductor Ll via a magnetic flux generated when the source inductor Ls and the load inductor Ll are brought close to each other and a current is supplied to one of the source inductors Ls. to be. The self-resonance method combines two resonators to generate self-resonance by the natural frequency between the two resonators. By resonating at the same frequency and using the resonance technique to form an electric field and a magnetic field in the same wavelength range, Technology.

1 is a magnetic induction equivalent circuit.

Referring to FIG. 1, in a magnetic induction equivalent circuit, a transmitter includes a source voltage Vs, a source resistance Rs, a source capacitor Cs for impedance matching, and a magnetic coupling with a receiving unit, And a load coil Rl for an impedance matching and a load coil Ll for magnetic coupling with a transmitting unit. The load coil Rl may be implemented as a source coil Ls for impedance matching, And the degree of magnetic coupling between the source coil Ls and the load coil Ll can be expressed by mutual inductance Msl.

In FIG. 1, the ratio S21 of the input voltage to the output voltage is obtained from the magnetic induction equivalent circuit consisting only of the coil without the source capacitor Cs and the load capacitor Cl for impedance matching, The power transmission condition satisfies Equation (1) below.

Equation 1

Ls / Rs = L1 / R1

The maximum power transmission is possible when the ratio of the inductance of the transmission coil Ls to the source resistance Rs and the ratio of the inductance of the load coil Ll to the load resistance Rl are equal to each other. Since there is no capacitor that can compensate for reactance in a system with only an inductance, the value of the self reflection value S11 of the input / output port can not be zero at the point where the maximum power transfer occurs, and the mutual inductance Msl), the power transmission efficiency may vary greatly. Thus, the source capacitor Cs may be added to the transmitter as a compensation capacitor for impedance matching, and the load capacitor Cl may be added to the receiver. The compensation capacitors Cs and Cl may be connected in series or in parallel to the receiving coil Ls and the load coil Ll, respectively. For impedance matching, a passive element such as an additional capacitor and an inductor may be added to each of the transmitter and the receiver as well as the compensation capacitor.

2 is a self-resonant-type equivalent circuit.

2, in the self-resonant type equivalent circuit, a transmitter includes a source coil constituting a closed circuit by a series connection of a source voltage Vs, a source resistor Rs and a source inductor Ls, Side resonant coil constituting a closed circuit by a series connection of the transmission line L1 and the transmission-side resonance capacitor C1, and the reception unit is realized by a series connection of the load resistance Rl and the load inductor Ll, Side resonance coil constituting a closed circuit by a series connection of a load coil constituting a receiving side resonance inductor L2 and a receiving side resonance capacitor C2 and a receiving side resonance coil constituting a closed circuit constituted by a source inductor Ls and a transmitting side inductor L1 are magnetically coupled to each other by a coupling coefficient of K01 and the load inductor L1 and the load side resonance inductor L2 are magnetically coupled to each other by a coupling coefficient of K23 and the transmission side resonance inductor L1 and the reception side resonance inductor L2, (L2) is the magnetic coupling coefficient of K12 . In the equivalent circuit of another embodiment, the source coil and / or the load coil may be omitted and only the transmission-side resonance coil and the reception-side resonance coil may be formed.

When the two resonators have the same resonance frequency, most of the energy of the resonator of the transmitter is transmitted to the resonator of the receiver so that the power transfer efficiency can be improved, and the efficiency in the self resonance method satisfies Equation When it gets better.

Equation 2

k / Γ >> 1 (k is the coupling coefficient, Γ attenuation factor)

In order to increase the efficiency in the self-resonant mode, an element for impedance matching can be added, and the impedance matching element can be a passive element such as an inductor and a capacitor.

Based on such a wireless power transmission principle, a wireless power transmission system for transmitting power by a magnetic induction method or a self resonance method will be described.

<Transmitter>

FIGS. 3A and 3B are block diagrams showing a transmitter as one of subsystems configuring a wireless power transmission system. 3C is a specific circuit diagram of the transmission-side power conversion unit according to the embodiment.

Referring to FIG. 3A, a wireless power transmission system according to an embodiment of the present invention may include a transmitter 1000 and a receiver 2000 that receives power wirelessly from the transmitter 1000. FIG. The transmission unit 1000 generates a magnetic field based on an AC signal output from the transmission-side power conversion unit 101 and outputs the AC signal as an AC signal, Side resonance circuit section 102 that provides power to the receiving section 2000 within the region and the transmission side power conversion section 101 and controls the power conversion of the transmission side power conversion section 101 to the amplitude of the output signal of the transmission side power conversion section 101 Frequency, impedance matching of the transmission-side resonance circuit unit 102, sensing impedance, voltage, and current information from the transmission-side power conversion unit 101 and the transmission-side resonance circuit unit 102, And a transmission side control unit 103 capable of wireless communication with the reception unit 2000. The transmission-side power conversion section 101 includes at least one of a power conversion section for converting an AC signal to DC, a power conversion section for varying the level of DC to output a DC, and a power conversion section for converting DC to AC . The transmission-side resonance circuit unit 102 may include a coil and an impedance matching unit capable of resonating with the coil. The transmission-side control unit 103 may include a sensing unit and a wireless communication unit for sensing impedance, voltage, and current information.

 3B, the transmitting unit 1000 includes a transmitting side AC / DC converting unit 1100, a transmitting side DC / AC converting unit 1200, a transmitting side impedance matching unit 1300, a transmitting coil unit 1400, And a transmission-side communication and control unit 1500.

The transmitting side AC / DC converting unit 1100 is a power converting unit for converting an AC signal provided from the outside under the control of the transmitting side communication and control unit 1500 to a DC signal. The transmitting side AC / DC converting unit 1100 includes: May include a rectifier 1110 and a transmission side DC / DC converter 1120 as a subsystem. The rectifier 1110 converts a supplied AC signal into a DC signal. The rectifier 1110 may be a diode rectifier having a relatively high efficiency in high-frequency operation, a synchronous rectifier capable of one-chip operation, And a hybrid rectifier capable of saving space and having a high degree of freedom in dead time. However, the present invention is not limited to this, and can be applied to a system that converts AC to DC. The transmitting side DC / DC converting unit 1120 adjusts the level of the DC signal provided from the rectifier 1110 under the control of the transmitting side communication and control unit 1500. As an example of implementing the DC signal, A buck converter, a boost converter that boosts the level of the input signal, a buck-boost converter or a Cuk converter that can raise or lower the level of the input signal. Also, the transmission side DC / DC converter 1120 includes a switch element that performs a power conversion control function, an inductor and a capacitor that perform a power conversion medium function or an output voltage smoothing function, a voltage gain control function or an electrical isolation function (insulation function) And may have a function of removing a ripple component or a ripple component (AC component included in the DC signal) included in the input DC signal. The error between the command value of the output signal of the transmitting side DC / DC converting unit 1120 and the actual output value can be adjusted through the feedback method and can be performed by the transmitting side communication and control unit 1500 .

The transmission side DC / AC conversion unit 1200 converts the DC signal output from the transmission side AC / DC conversion unit 1100 into an AC signal under the control of the transmission side communication and control unit 1500 and outputs the converted AC signal frequency A half bridge inverter or a full bridge inverter is an example of implementing this system. In the wireless power transmission system, various amplifiers for converting direct current to alternating current can be applied. For example, class A, class B, class AB, class C, class E class F amplifier. The transmission side DC / AC conversion unit 1200 may include an oscillator for generating a frequency of an output signal and a power amplifier for amplifying an output signal.

3B, the transmission side power conversion unit 101 of FIG. 3A or the transmission side DC / AC conversion unit 1200 of FIG. 3B is controlled by the first to fourth switching devices Q1 to Q4, Or a full bridge inverter.

For example, the first switching device Q1 maintains turn-off. The fourth switching device Q4 can be driven by the half bridge inverter as the second and third switching devices Q2 and Q3 are controlled to be turned on and off while the turn-on state is maintained. The full bridge inverter can be driven by turning on and off the switching elements Q12 and Q4.

A transmitter side DC according to an embodiment. The AC converting unit 1200 can alternately drive the second and third switching devices Q2 and Q3 in the half bridge inverter driving state and the first and fourth switching devices Q1 and Q4 And the second and third switching elements Q2 and Q3 can be alternately driven.

The first to fourth switching elements Q1 to Q4 may be transistors.

The configuration of the AC / DC converter 1100 and the transmission side DC / AC converter 1200 may be replaced with an AC power supply, or may be omitted or replaced with another configuration.

The transmission-side impedance matching unit 1300 minimizes the reflected waves at points having different impedances to improve the signal flow. Since the two coils of the transmitting unit 1000 and the receiving unit 2000 are spatially separated and the leakage of the magnetic field is large, the impedance difference between the two connecting ends of the transmitting unit 1000 and the receiving unit 2000 is corrected, . The impedance matching unit 1300 may include at least one of an inductor, a capacitor, and a resistance element. The impedance of the inductor, the capacitance of the inductor, and the resistance of the resistance may be varied under the control of the communication and control unit 1500, The impedance value for matching can be adjusted. When the wireless power transmission system transmits power in a self-induction manner, the transmission-side impedance matching unit 1300 may have a series resonance structure or a parallel resonance structure, and may have an inductive coupling between the transmission unit 1000 and the reception unit 2000 The energy loss can be minimized by increasing the coefficient. When the wireless power transmission system transmits power in a self-resonant manner, the transmission-side impedance matching unit 1300 may change the separation distance between the transmission unit 1000 and the reception unit 2000, or may change a foreign object (FO) It is possible to perform real-time correction of the impedance matching according to the change of the matching impedance on the energy transmission line due to the change of the characteristics of the coil due to the mutual influence by the device of the capacitor, A matching method, a method using a multi-loop, and the like.

The transmitting coil 1400 may be implemented as a plurality of coils or a plurality of coils. If a plurality of transmitting coils 1400 are provided, they may be spaced apart from each other, The overlapping area can be determined in consideration of the deviation of the magnetic flux density. Also, when the transmission coil 1400 is manufactured, it can be manufactured in consideration of the internal resistance and the radiation resistance. If the resistance component is small, the quality factor can be increased and the transmission efficiency can be increased.

The communication and control unit 1500 may include a transmission side control unit 1510 and a transmission side communication unit 1520. The transmission side control unit 1510 controls the transmission side AC control unit 1510 in consideration of at least one of a power requirement of the receiving unit 2000, a present charging amount, a voltage Vrect of a rectifier output terminal of the receiving unit, DC converter 1100 or the current (Itx_coil) flowing in the transmission coil of the transmission side DC / AC converter 1200. The transmission side DC / AC converter 1200 is driven in consideration of the maximum power transmission efficiency The control unit 230 may control the operation of the receiving unit 2000 by using an algorithm, a program, or an application required for control read from a storage unit (not shown) of the receiving unit 2000 The transmission side control unit 1510 may be a microprocessor, a microcontroller unit, or a microcomputer. The transmission side communication unit 1520 can perform communication with the reception side communication unit 2620 and can use a short distance communication scheme such as Bluetooth, NFC, Zigbee, etc. As an example of the communication scheme, And the receiving side communication unit 2620 can transmit and receive the charging status information and the charging control command to each other. The charging status information includes the number of the receiving units 2000, the remaining battery level, the number of charging cycles, The battery capacity, the battery ratio, and the transmission power amount of the transmission unit 1000. The transmission side communication unit 1520 can transmit a charging function control signal for controlling the charging function of the receiving unit 2000, The function control signal may be a control signal for controlling the receiver 2000 to enable or disable the charge function.

As described above, the transmitting-side communication unit 1520 may be communicated in an out-of-band format, which is a separate module, but the present invention is not limited thereto. A feedback signal to be transmitted to a transmitter may be used to perform communication in an in-band format in which a transmitter transmits a signal to a receiver using a frequency shift of a frequency of a power signal transmitted by the transmitter have. For example, the receiver may modulate the feedback signal to transmit information such as start of charge, end of charge, battery condition, etc. to the transmitter through a feedback signal. The transmission side communication unit 1520 may be configured separately from the transmission side control unit 1510 and the reception side communication unit 2620 may be included in the control unit 2610 of the reception device or separately have.

In addition, the transmitter 1000 of the wireless power transmission system according to the embodiment may further include a detector 1600.

The detecting unit 1600 detects an input signal of the transmitting side AC / DC converting unit 1100, an output signal of the transmitting side AC / DC converting unit 1100, an input signal of the transmitting side DC / AC converting unit 1200, The input signal of the transmission side impedance matching unit 1300, the output signal of the transmission side impedance matching unit 1300, the input signal of the transmission side coil 1400, or the transmission side coil 1400). &Lt; / RTI &gt; For example, the signal may include at least one of information on a current, information on a voltage, or information on an impedance. The detected signal is fed back to the communication and control unit 1500 and the communication and control unit 1500 controls the transmission side AC / DC conversion unit 1100, the transmission side DC / AC conversion unit 1200, the transmission side impedance matching The control unit 1300 can be controlled. Also, the communication and control unit 1500 can perform a foreign object detection (FOD) based on the detection result of the detection unit 1600. And the detected signal may be at least one of a voltage and a current. Meanwhile, the detection unit 1600 may be implemented by hardware different from the communication and control unit 1500, or may be implemented by one hardware.

<Receiver>

4A and 4B are block diagrams showing a receiving unit (or receiving apparatus) as one of the subsystems constituting the wireless power transmission system. Referring to FIG. 4A, a wireless power transmission system according to an embodiment of the present invention may include a transmitter 1000 and a receiver 2000 that receives power wirelessly from the transmitter 1000. FIG. The receiving apparatus 2000 includes a receiving-side resonant circuit unit 201 for receiving an AC signal transmitted from the transmitting apparatus 1000, an AC-to-AC converting circuit for converting AC power from the receiving- A load 2500 to receive a DC signal output from the receiving-side power converter 202 and the receiving-side power converter 202, a current voltage of the receiving-side resonator circuit 201, Side resonance circuit unit 201 or to control the power conversion of the reception side power conversion unit 202 and to adjust the level of the output signal of the reception side power conversion unit 202, It is possible to sense the input or output voltage or current of the power conversion section 202 or to control whether or not the output signal of the reception side power conversion section 202 is supplied to the load 2500, That can be It may include sincheuk control section 203. The receiving-side power converting section 202 may include a power converting section for converting the AC signal into DC, a power converting section for varying the level of the DC to output the DC, and a power converting section for converting the DC to AC. Referring to FIG. 4B, a wireless power transmission system according to an embodiment includes a transmitter (or a transmitter) 1000 and a receiver (or receiver) 2000 that receives power wirelessly from the transmitter 1000 The receiving unit 2000 includes a receiving-side resonant circuit unit 2120 including a receiving-side coil unit 2100 and a receiving-side impedance matching unit 2200, a receiving-side AC / DC converting unit 2300, a DC / A DC conversion unit 2400, a load 2500, and a reception side communication and control unit 2600. The receiving-side AC / DC converter 2300 may be referred to as a rectifier for rectifying the AC signal into a DC signal.

The receiving side coil part 2100 can receive power through a magnetic induction method or a self resonance method. As described above, at least one of the induction coil and the resonance coil may be included according to the power reception scheme.

In one embodiment, the receiving side coil part 2100 may be disposed in a portable terminal together with an antenna for near field communication (NFC). The receiving side coil part 2100 may be the same as the transmitting side coil part 1400 and the dimensions of the receiving antenna may be different according to the electrical characteristics of the receiving part 200. [

The receiving-side impedance matching unit 2200 performs impedance matching between the transmitter 1000 and the receiver 2000.

The receiving-side AC / DC converter 2300 rectifies the AC signal output from the receiving-side coil part 2100 to generate a DC signal. DC converter 2300 can be referred to as a rectified voltage Vrect and the receiving-side communication and control unit 2600 can be referred to as an output voltage of the receiving-side AC / DC converting unit 2300 (Or referred to as a minimum output voltage Vrect_min) which is the minimum value of the output voltage of the receiving AC / DC converter 2300 and a maximum rectified voltage Vrect_max (Or referred to as the maximum output voltage Vrect_max), the optimum rectified voltage Vrect_set (referred to as the optimum output voltage Vrect_set) having any one of the values between the minimum value and the maximum value, It is possible to transmit the same status parameter information to the transmission unit 1000.

The receiving-side DC / DC converting section 2400 can adjust the level of the DC signal output from the receiving-side AC / DC converting section 2300 to the capacity of the load 2500.

The load 2500 may include a battery, a display, a sound output circuit, a main processor, a battery management unit, and various sensors. The load 2500 may include at least a battery 2510 and a battery management unit 2520 as shown in FIG. 4A. The battery management unit 2520 senses the state of charge of the battery 2510 and can adjust the voltage and current applied to the battery 2510.

The receiving side communication and control unit 2600 can be activated by the wake-up power from the transmitting side communication and control unit 1500 and performs communication with the transmitting side communication and control unit 1500, The operation of the system can be controlled.

The receiving unit 2000 includes a single or a plurality of receiving units 2000, and can simultaneously receive energy from the transmitting unit 1000 wirelessly. That is, in the self-resonant wireless power transmission system, a plurality of target receivers 2000 can receive power from one transmitter 1000. At this time, the transmitter matching unit 1300 of the transmitter 1000 may adaptively perform impedance matching between the plurality of receivers 2000. This can be equally applied to a case where a plurality of reception side coil portions independent from each other in the magnetic induction system are provided.

When the receiving unit 2000 includes a plurality of units, the power receiving systems may be the same system or different types of systems. In this case, the transmitting unit 1000 may be a system for transmitting power by a magnetic induction system or a self-resonance system, or a system for mixing both systems.

Meanwhile, in the case of a wireless power transmission of a magnetic induction type, the transmission side AC / DC conversion unit 1100 in the transmission unit 1000 may transmit data of several tens or hundreds of V (for example, (For example, 10 V to 20 V) and can output a DC signal of several V to several tens V and several hundred V (for example, 10 V to 20 V) by receiving an AC signal of several tens or several hundred Hz Side DC / AC converting unit 1200 can receive an AC signal and output an AC signal of KHz band (for example, 125 KHz). The receiving AC / DC converting unit 2300 of the receiving unit 2000 receives AC signals of KHz band (for example, 125KHz) and receives DC signals of several V to several tens V, several hundred V (for example, 10V to 20V) And the receiving side DC / DC converting section 2400 can output a DC signal of, for example, 5V suitable for the load 2500 and transmit the DC signal to the load 2500. In the case of the wireless power transmission of the self-resonance type, the transmitting side AC / DC converting unit 1100 in the transmitting unit 1000 may transmit power of several tens or several hundreds Hz (for example, 110 V to 220 V) And the transmission side DC / AC conversion unit 1200 converts the DC signal into a DC signal of several V to several tens V and several hundred V (for example, 10V to 20V) And can output an AC signal of MHz band (for example, 6.78 MHz). The receiving AC / DC converting unit 2300 of the receiving unit 2000 receives AC signals of MHz (for example, 6.78 MHz) and receives AC signals of several V to several tens V, several hundred V (for example, 10 V to 20 V) DC converter 2400 can output a DC signal of, for example, 5V suitable for the load 2500 and transmit it to the load 2500. The DC /

&Lt; Operation state of transmitting apparatus >

5 is a flowchart illustrating an operation of the wireless power transmission system according to an embodiment of the present invention. 6 is a graph showing the driving state of the power conversion unit according to the load of the receiving apparatus.

5, a transmitting apparatus according to an embodiment may have at least 1) a selection state, 2) a detection state, 3) an identification and setting state, 4) a power delivery state, and 5) a charge end state.

[Selection Phase]

(1) In the selected state, the transmitting apparatus 1000 can perform a detecting process to select the receiving apparatus 200 existing in the sensing area or the charging area.

(2) The sensing area or the charging area may refer to an area where an object in the area may affect the characteristics of the power of the transmission-side power converter 101, as described above. The detection process for selecting the receiving apparatus 2000 in the selected state may be performed by the transmitting apparatus 1000 side instead of receiving the response from the receiving apparatus 2000 using the power control message The power conversion unit of the mobile communication terminal detects the change of the amount of power for forming the wireless power signal and checks whether an object exists within a certain range. The detection process in the selected state can be referred to as an analog detection process (analog ping) in that an object is detected using a wireless power signal without using a digital format packet in a detection state to be described later.

(3) In the selected state, the transmitting apparatus 1000 can detect that an object enters or exits the sensing area or the charging area. Also, the transmitting apparatus 1000 can distinguish the receiving apparatus 2000 and other objects (e.g., keys, coins, etc.) capable of wirelessly transmitting power among the objects in the sensing region or the charging region .

As described above, since the distance over which the electric power can be transmitted wirelessly differs according to the inductive coupling method and the resonant coupling method, the sensing area where the object is detected in the selected state may be different from each other.

(4) First, when power is transmitted according to the inductive coupling method, the transmitting apparatus 1000 in the selected state can monitor the interface surface (not shown) to detect the placement and removal of objects.

The transmitting apparatus 1000 may sense the position of the wireless power receiving apparatus 2000 placed on the interface surface.

(5) When the transmitting apparatus 1000 includes one or more transmission coils, the controller enters the detection state in the selected state, and transmits a response to the detection signal from the object using each coil in the detection state Or after entering the identification state, it is checked whether identification information is transmitted from the object.

The transmitting apparatus 1000 can determine a coil to be used for wireless power transmission based on the position of the receiving apparatus 2000 that is acquired through the above process.

(6) When power is transmitted in accordance with the resonance coupling method, the transmitting apparatus 1000 in the selected state changes the frequency, current, and voltage of the power conversion unit due to an object in the sensing area or the charging area to The object can be detected.

(7) On the other hand, the transmitting apparatus 1000 in the selected state can detect an object by at least one of the inductive coupling method and the resonant coupling method detecting method.

(8) The transmitting apparatus 1000 may perform an object detecting process according to each power transmission method, and then select a method of detecting the object among the combining methods for wireless power transmission in order to proceed to other states .

(9) On the other hand, in the transmitting apparatus 1000 in the selected state, a wireless power signal to be formed for detecting an object and a wireless power signal for digital detection, identification, setting, and power transmission in the following states, , Intensity, etc. may be different. This is because the selected state of the transmitting apparatus 1000 corresponds to an idle phase for detecting an object, and thus the transmitting apparatus 1000 can reduce the power consumption in the air or generate a specialized signal for efficient object detection So that it can be used.

[Detection state (Ping Phase)]

(1) In the detection state, the transmitting apparatus 1000 can detect the receiving apparatus 2000 existing in the sensing area or the charging area through the power control message. In comparison with the detection process of the receiving apparatus 2000 using the characteristics of the wireless power signal in the selected state, the detection process in the detection state can be referred to as digital ping.

(2) The transmitting apparatus 1000 forms a radio power signal for detecting the receiving apparatus 2000, demodulates the radio power signal modulated by the receiving apparatus 2000, A power control message in the form of digital data corresponding to a response to the detection signal can be obtained.

(3) The transmitting apparatus 1000 can recognize the receiving apparatus 2000 that is a target of power transmission by receiving a power control message corresponding to a response to the detection signal.

(4) The detection signal formed by the transmitting apparatus 1000 in the detecting state to perform the digital detecting process may be a wireless power signal formed by applying a power signal of a specific operating point for a predetermined time.

The operating point herein may refer to the frequency, duty cycle and amplitude of the voltage applied to the transmitting coil section 1400.

The transmitting apparatus 1000 may generate the detecting signal generated by applying the power signal of the specific operating point for a predetermined time and attempt to receive the power control message from the receiving apparatus 2000. [

(5) Meanwhile, the power control message corresponding to the response to the detection signal may be a message indicating the strength of the wireless power signal received by the receiving apparatus 2000. For example, the receiving apparatus 2000 may transmit a signal strength packet including a message indicating the strength of the received wireless power signal in response to the detection signal. The packet may include a header indicating that the packet is a signal indicating the signal strength and a message indicating the strength of the power signal received by the receiving apparatus 2000. The strength of the power signal in the message may be a value indicating the degree of coupling of inductive coupling or resonant coupling for power transmission between the transmitting device 1000 and the receiving device 2000.

(6) After receiving the response message to the detection signal and finding the receiving apparatus 2000, the transmitting apparatus 1000 may extend the digital detecting process to enter the identification and detection state. That is, the transmitting apparatus 1000 can receive the power control message required in the identifying and detecting state by maintaining the power signal of the specific operating point after finding the receiving apparatus 2000.

However, if the transmitting apparatus 1000 does not find the receiving apparatus 2000 capable of transmitting the power, the operating state of the transmitting apparatus 1000 may be returned to the selected state.

[Identification and Configuration Phase]

(1) In the identification and setting state, the transmitting apparatus 1000 can receive the identification information and / or the setting information transmitted by the receiving apparatus 2000 and control the power transmission to be efficiently performed.

(2) In the identification and setting state, the receiving apparatus 2000 can transmit a power control message including its own identification information. For this purpose, the receiving apparatus 2000 may transmit an identification packet including a message indicating identification information of the receiving apparatus 2000, for example. The packet may be configured to include a header indicating that it is a packet indicating identification information and a message including identification information of the reception apparatus 2000. The message may be configured to include information indicating a version of a protocol for wireless power transmission, information identifying a manufacturer of the receiving device 2000, information indicating the presence or absence of an extension device identifier, and a basic device identifier. Also, in the case where the extension device identifier is present in the information indicating the presence or absence of the extension device identifier, an Extended Identification Packet including the extension device identifier may be separately transmitted. The packet may be configured to include a message including a header indicating an extension device identifier and an extension device identifier. In the case where the extension apparatus identifier is used, information based on the identification information of the manufacturer, the base apparatus identifier, and the extension apparatus identifier may be used to identify the receiving apparatus 2000.

(3) In the identifying and setting state, the receiving apparatus 2000 may transmit a power control message including information on the estimated maximum power. To this end, the receiving apparatus 2000 can transmit, for example, a configuration packet (Configuration Packet). The packet may be configured to include a header indicating that the packet is a configuration packet and a message including information on the estimated maximum power.

The message may be configured to include a power class, information about the expected maximum power, an indicator that indicates how to determine the current of the primary cell on the side of the wireless power transmission device 1000, and the number of optional configuration packets. The indicator may indicate whether or not the current of the main cell of the transmitting apparatus 1000 side is determined as specified in the protocol for the wireless power transmission.

(4) On the other hand, the transmitting apparatus 1000 may generate a power transfer contract to be used for power charging with the receiving apparatus 2000 based on the identification information and / or the setting information. The power transfer protocol may include limits of parameters that determine the power transfer characteristics in the power transfer state.

(5) The transmitting apparatus 1000 may terminate the identification and setting state before entering the power transmission state, and return to the selected state. For example, the transmitting apparatus 1000 may terminate the identifying and setting state to search for another receiving apparatus 2000 capable of receiving power wirelessly.

[Power Transfer Phase]

(1) The transmitting apparatus 1000 in the power transmission state transmits power to the receiving apparatus 2000.

(2) In this case, the transmitting apparatus 1000 can transmit the wireless power by controlling the power converting unit 101 according to the version of the receiving apparatus 2000, based on the received identification packet. Specifically, if the receiving apparatus 2000 checks the version of the receiving apparatus 2000 and the receiving apparatus 2000 corresponds to a low power level, the power converting unit 101 may be driven by the half bridge inverter to transmit the wireless power If the receiving apparatus 2000 corresponds to the middle power class, the power conversion unit 101 may be driven by a full bridge inverter to transmit wireless power.

More specifically, referring to FIG. 6, it can be seen that the load of the receiving apparatus 2000 becomes larger as the version of the receiving apparatus 2000 goes from the low power level to the middle power level. In this case, the power conversion unit 101 of the transmission apparatus 1000 can transmit wireless power to the receiving apparatus 2000 corresponding to a small load, that is, a low power class, as it is driven by the half bridge inverter.

The power consumption of the low power class receiving apparatus 2000 having a load smaller than that of the second load Load2 can be reduced by at least one of the duty ratio of the switching elements Q2 and Q3 and the switching frequency change. Can be adjusted. The switching frequency of the switching elements Q2 and Q3 of the power conversion section 101 is fixed to the third driving frequency f3 with respect to the receiving apparatus 2000 having a load smaller than that of the first load Load1, The amount of wireless power can be adjusted by adjusting the duty ratio and the switching frequency can be adjusted, that is, the third drive (for example, the second drive), for a receiving apparatus 2000 having a load larger than one load The amount of wireless power can be adjusted according to the frequency change between the frequency f3 and the second driving frequency f2. However, the present invention is not limited to that shown in the drawing, and it is possible to adjust the amount of wireless power according to the switching frequency change for the receiving apparatus 2000 having a load smaller than that of the first load (Load1) For the receiving apparatus 2000 having a larger load, the amount of wireless power may be adjusted according to the duty ratio change, the switching frequency and the duty ratio may be changed at the same time, and the amount of wireless power may be adjusted.

The power conversion section 101 is driven by the full bridge inverter for the middle power-class receiving apparatus 2000 having the load larger than the second load Load2 and the switching frequency of the switching elements Q1 to Q4 is the second The amount of wireless power can be adjusted through a phase shift or a switching frequency change while the driving frequency f2 is fixed. Specifically, the driving frequency of the switching elements Q1 to Q4 of the power conversion section 101 is fixed to the second driving frequency f2 with respect to the receiving apparatus 2000 having a load smaller than that of the third load (Load3) Change of the switching frequency of the switching elements Q1 to Q4 of the power conversion section 101 with respect to the receiving apparatus 2000 having a load larger than that of the third load (Load3) That is, the amount of wireless power can be adjusted according to the change of the driving frequency between the second driving frequency f2 and the first driving frequency f1. However, the present invention is not limited to that shown in the drawing, and the amount of wireless power can be adjusted according to the switching frequency change for the receiving apparatus 2000 having a load smaller than that of the third load (Load3) For the receiving apparatus 2000 having a larger load, the amount of the wireless power may be adjusted according to the phase shift, and the amount of the wireless power may be adjusted by simultaneously performing the switching frequency change and the phase shift.

(3) The transmitting apparatus 1000 receives a power control message from the receiving apparatus 2000 during the transmission of the power, and determines a characteristic of the power applied to the transmitting coil unit 1400 according to the received power control message Can be adjusted. For example, a power control message used to control the power characteristic of the transmission coil may be included in a control error packet. The packet may be configured to include a header indicating a control error packet and a message including a control error value. The transmission apparatus 1000 can adjust the power applied to the transmission coil according to the control error value. That is, when the control error value is 0, since the desired control point requested by the receiving apparatus 2000 and the actual control point of the receiving apparatus 2000 are substantially equal to each other, The applied current can be maintained, reduced in the case of a negative value, and adjusted in the case of a positive value.

(4) Further, at the initial driving time of the power transfer state, the transmitting apparatus 1000 is driven by the half bridge inverter in the power conversion unit 101, and the first control error packet (1 ^st Control Error Packet) And determines the version of the receiving apparatus 2000 on the basis of the identification packet already received after the receiving apparatus 2000 receives the identification packet. If the receiving apparatus 2000 corresponds to the low power class, the half bridge inverter of the power converting section 101 And if it corresponds to the middle power class, it may be changed to full bridge inverter drive.

(5) In the power transmission state, the transmission apparatus 1000 may monitor parameters in a power transfer contract generated based on the identification information and / or the setting information. As a result of monitoring the parameters, when the power transmission to the receiving apparatus 2000 violates the limitations contained in the power transfer protocol, the transmitting apparatus 1000 cancels the power transmission and returns to the selected state I can go.

(6) Also, the power transfer protocol is related to the threshold current value of the current induced on the receiving coil part 2100 of the receiving apparatus 2000 and the characteristics of the power transmitted from the transmitting apparatus 1000 to the receiving apparatus 2000 And may include boundary conditions. (5) The transmitting apparatus 1000 may terminate the power transmission state based on the power control message transmitted from the receiving apparatus 2000. [

For example, if the charging of the battery is completed while the receiving apparatus 2000 is charging the battery using the transmitted power, a power control message requesting the transmitting apparatus 1000 to suspend the wireless power transmission . In this case, the transmitting apparatus 1000 may terminate the wireless power transmission and return to the selected state after receiving the message requesting the suspension of the power transmission.

As another example, the receiving apparatus 2000 may transmit a power control message requesting renegotiation or reconfiguration to update the already generated power transfer protocol. The receiving apparatus 2000 may transmit a message requesting renegotiation of the power transfer protocol when a power amount that is more or less than the currently transmitted power amount is required. In this case, the transmitting apparatus 1000 may terminate the wireless power transmission and return to the identification and setting state after receiving the message requesting renegotiation of the power transfer protocol.

To this end, the message transmitted by the receiving apparatus 2000 may be, for example, an End Power Transfer Packet as shown in FIG. The packet may be configured to include a header indicating a power transmission interruption packet and a power transmission interruption code indicating a reason for the interruption. The power transmission interruption code may be generated by a plurality of power transmission interruption codes such as Charge Complete, Internal Fault, Over Temperature, Over Voltage, Over Current, Battery Failure, Reconfigure, No Response, and Unknown Error.

<Power transmission control>

A method for determining a required power of a receiving device.

7 is a flowchart related to a method for determining a required power of a receiving apparatus.

Referring to FIG. 7, the receiving apparatus 2000 includes the steps of 1) determining a desired control point S210, 2) detecting an actual control point S230, 3) ) Control error value (S250) to determine the power to be received, i.e., the required power.

In step S210 of determining a desired desired control point, the receiving apparatus 2000 may determine a required control point related to voltage, current, temperature, and the like. And, in step S230 of detecting an actual control point, the receiving apparatus 2000 can determine an actual control point related to an actual voltage, a current, a temperature, and the like. When the receiving apparatus 2000 determines the actual control point, various methods such as voltage or current detection, temperature sensing, and the like can be applied, and such a process can be performed at any time during the power transmission state. In the control error value generating step S250, the receiving apparatus 2000 may generate a control error value based on, for example, the difference between the required control voltage value and the actual control voltage value. The control error value may be a parameter indicating a positive value and a negative value. When the actual power amount is smaller than the required power amount, the control error value may indicate a positive value, and the actual power amount The control error value may refer to a negative value and may have a value of zero when the required power amount is equal to the actual power amount. In this way, in the power control process, the coupling coefficient can be drastically lowered according to the alignment between the transmitting apparatus 1000 and the receiving apparatus 2000, and accordingly, the required power amount of the receiving apparatus 2000 can be instantaneously increased. Also, the receiving apparatus 2000 can request the transmitting apparatus 1000 to request the amount of power required for the current to be induced in the receiving-side coil unit 2100 to exceed the threshold value. However, The problem of damaging the receiving apparatus 2000 is prevented because the generated radio power is transmitted within the range of the driving frequency that is reset based on the threshold value of the current induced in the part 2100. [

Meanwhile, the control error value may be transmitted to the transmission apparatus 1000 in the form of a control error packet.

When the new transmission power is received from the transmission apparatus that has received the control error value, it can be determined through the steps described above whether the new transmission power satisfies the requested power.

<Power Control Method>

8 is a graph showing the magnitude of the coil current on the transmitting side coil part according to the driving frequency. 9 and 10 are operational flowcharts of a transmitting apparatus including a driving frequency boundary value setting step.

Referring to FIG. 8, the power conversion unit 101 converts the version of the receiving apparatus 2000 included in the identification packet received in the identification and setting state, that is, according to whether the receiving apparatus 2000 is a low power or a middle power A half bridge inverter or a full bridge inverter and the switching frequency of the power conversion section 101 may be any one of driving frequency values in the range of the first driving frequency f1 to the third driving frequency f3 .

The frequency of the first driving frequency f1 which is the minimum frequency and the frequency of the third driving frequency f3 which is the maximum frequency may be preset according to the capacity or type of the transmitting apparatus 1000.

If the coupling coefficient between the transmitting apparatus 1000 and the receiving apparatus 2000 is larger than 0.5, the switching frequency may be formed at the second driving frequency f2. At this time, the transmission coil current on the transmission side coil part 1400 can be the first current A1. At this time, in order to increase the amount of radio power, the driving frequency can be changed. That is, in the half-bridge inverter driving state, the amount of radio power can be increased as the driving frequency is increased, and in the full bridge inverter driving state, the amount of radio power can be increased as the driving frequency is lowered. In order to keep the amount of power to be received by the receiving apparatus 2000 constant, corresponding to the coupling coefficient becoming smaller than 0.5 according to the misalignment of the receiving apparatus 2000, the half bridge inverter driving state The amount of radio power can be increased as the driving frequency is increased and the amount of radio power can be increased as the driving frequency is lowered in the full bridge inverter driving state.

However, if the coupling coefficient is abruptly changed or the coupling coefficient is significantly lowered, there may be a variation to the first driving frequency f1, which is the lowest driving frequency, or a variation to the third driving frequency f3, which is the maximum driving frequency have. In this case, the current applied on the transmission side coil part 1400 can reach the second current A2 and the third current A3. In this case, as shown in FIG. 9, the amount of current induced in the receiving-side coil part 2100 of the receiving apparatus 2000 also rapidly increases, which may damage the receiving apparatus 2000, This can be prevented. The boundary value of the driving frequency may be reset before the power transmission state rushes based on the information on the current threshold value of the receiving apparatus 2000 included in the identification packet, May be reset based on the information on the current threshold value of the receiving apparatus 2000 included in the identification packet after receiving the error packet. For example, when the current applied to the transmitting side coil part 1400 corresponds to the fourth current A4 and the amount of current induced in the receiving side coil part 2100 corresponds to the threshold value, the transmitting device 1000 May be determined to be within the range of the fourth to fifth driving frequencies f4 and f5 matching the fourth current A4.

Further, in a state where the driving frequency is fixed, the magnitude of the transmission coil current on the transmission side coil part 1400 is changed through the duty ratio or the phase transition of the switching device, and the amount of current induced in the reception side coil part 2100 can be adjusted accordingly have. Even in this case, since the magnitude of the transmission coil current on the transmission side coil part 1400 is limited in consideration of the threshold value of the amount of current induced in the reception side coil part 2100, the problem of damage to the reception device 2000 is prevented .

<Power Transmission Control Method>

11 is a detailed block diagram of a control unit of a transmission apparatus for a power transmission control method. And Fig. 12 is a timing chart of the transmitting apparatus in the power transmission state.

11, in the power transmission control method, the control unit 103 of the transmission apparatus 1000 can control the current of the transmission coil unit 1400 to obtain a new transmission coil current. This power transfer control can be performed based on a proportional integral differential (PID) algorithm.

The transmitting apparatus 1000 may include a first operator 11 and a second operator 15 and a proportional controller 12a, an integral controller 12b and a differential controller 12c in order to execute the PDI algorithm, And may include first to fifth amplifiers 13a to 13e and first and second summing amplifiers 14a and 14b and may perform the following operation to convert the power conversion unit 101 Can be controlled.

The following j = 1, 2, 3, .. may refer to the order of control error packets received by the transmitting apparatus 1000. [ Each of the first to fifth amplifiers 13a, 13b, 13c, 13d, and 13e may have at least one of an amplifier, a buffer, and a delay.

(1) a new transmit coil current calculation step.

1) When the first operator 11 of the transmitting apparatus 1000 receives j (th) Control Error Packet, a new transmit coil current td (j) can be calculated according to Equation (3).

Equation 3

2) where ta (j-1) refers to an actual primary cell current determined according to the previous control error packet c (j-1), c (j) May refer to a control error value included in a control error packet. Further, ta (0) may mean the current of the transmitting coil part 1400 at the start of the power transmission state.

A magnetic field may be generated in the transmission coil section 1400 based on the transmission coil current to generate output power.

3) The first operator 11 receives the actual transmission coil current ta (j-1) through the jth control error packet and the first amplifier 13a, And then calculates and outputs a new transmit coil current td (j).

4) If the control error value c (j) is not 0 (non-zero), the transmitting apparatus 1000 can adjust the transmission coil current for a predetermined time (t_active in FIG. 13) . To this end, the transmitting apparatus 1000 can execute a loop including steps to be described later.

Where i = 1, 2, 3, ... max can refer to the number of iterations of the loop.

 (2) Error calculation step.

1) The transmitting apparatus 1000 calculates i (i, j) according to the difference between the new transmission coil current td (j) and the actual transmission coil current ta (j, i-1) Th loop can be calculated.

Equation 4

Where ta (j, i-1) may refer to the transmit coil current determined by the (i-1) th loop. Where ta (j, 0) may refer to the actual transmitted coil current at the beginning of the loop.

2) The first adder 14a adds up the new transmit coil current td (j) and the actual transmit coil current ta (j, i-1) determined by the i-1th loop from the second amplifier 13a And can output the calculated error to the PID controller 12. [0034] FIG.

(3) the control amount calculation step.

1) The PID controller 12 of the transmission apparatus 1000 determines a proportional control (P) for changing the control amount in proportion to the error, an integral control (I) for integrating and controlling the error, and a control amount The differential control (D) can be executed.

The PID controller 12 may calculate a proportional term, an integral term and a derivative term as expressed in Equation (5). Specifically, the proportional controller 12a calculates the proportional element P (j, i) based on the error, the integral controller 12b calculates the integral element I (j, i) based on the cumulative value of the error, The controller 12c can calculate the differential element D (j, i) based on the amount of error change.

Equation 5

2) where Kp is the proportional gain, Ki is the integral gain, and Kd is the differential gain. And t_inner is the time required for a loop to iterate. Then, the integral term I (j, 0) = 0 and the error e (j, 0) = 0. The transmission device 1000 can limit the integral term I (j, i) to within the range of -M_I .. + M_I, and can change the calculated integral element I (j, i) . Where M_I is an integral term limit parameter.

3) The output signal of the integral controller 12b may be fed back to its input via the fourth amplifier 13d, where the feedback output signal is an integral term of the (i-1) th loop of the previous (j, i-1)). Also, the input signal of the differential controller 12c can be input to the differential controller 12c via the third amplifier 13c, where the input signal is the error of the previous (i-1) , i-1)).

4) The second summer 14b of the transmitting apparatus 1000 calculates the proportional element P (j, i) output from the proportional controller 12a, the integral element I (j, i) output from the integral controller 12b, (i, j) by summing the differential elements D (j, i) output from the derivative controller 12 (j, i) and the differential controller 12c.

Equation 6

(I) the control amount PID (j, i) is within the range of -M_PID .. + M_PID (i, j) Can be limited. Here, M_PID is a PID output limit parameter.

(4) a new control variable value calculation step.

1) The transmitting apparatus 1000 may calculate a new controlled variable value based on Equation (7).

Equation 7

2) where Sv may refer to a scaling factor based on a control variable.

Also, the control variable v (i, 0) = v (j-1, i_max) and v (0,0) denotes the actual value of the controlled variable at the start of the power transmission state can do. The control variable may be an operating frequency, a duty cycle of the DC / AC converter 1200, or a variation amount of an input voltage or a phase shift of the DC / AC converter 1200 It can be one.

If the calculated v (j, i) exceeds the preset range, the transmitting apparatus 1000 may change the calculated v (j, i) to an appropriate threshold value.

3) The second calculator 15 calculates the control variable PID (j, i) of the previous (i-1) th loop, which is fed back via the fifth amplifier 13e, The new control variable value v (j, i) can be calculated according to Equation (7) above.

4) It is also possible to adjust at least one of the scaling factor Sv and the new control variable value v (j, i) to properly limit the current induced in the receiving side coil part 2100 to within the current threshold value range.

Specifically, the scaling factor Sv may vary according to the range of the driving frequency as shown in Table 1, for example.

[Table 1]

Also, even if the driving frequency of the transmitting apparatus 1000 is in the range of 110 kHz to 205 kHz as shown in Table 1, the current threshold value induced on the receiving side coil section 2100 of the receiving apparatus 2000, , The minimum scaling factor Sv of the scaling factor Sv may be changed to a value larger than 1.5, and the maximum scaling factor Sz (Sv) may be changed to a value larger than 1.5 when the driving frequency needs to be limited to a value larger than 110 kHz and smaller than 205 kHz ) Can be changed to a value smaller than 5. Thus, the frequency range of the driving frequency can be reset by changing the minimum and maximum values of the driving frequency. This scaling factor Sv may be reset before entering the power delivery state as described in FIG. 9 or after receiving the primary control error packet as described in FIG.

As another example, when the control variable is the operating frequency, the power conversion section 101, in the half-bridge inverter driven state of the power conversion section 101 at 160 kHz in Table 1, And can change the new control variable value v (j, i) so that the drive frequency does not exceed the limit maximum value (for example, the fourth drive frequency f4 in FIG. 7). Similarly, The power conversion section 101 can be driven at a driving frequency lower than 160 kHz and the driving frequency can be reduced to a minimum limit value (for example, the fifth driving frequency f5 in FIG. 7) (J, i) so as not to exceed the new control variable value v (j, i).

(5) controlling the power converter based on the new control variable.

1) The transmitting apparatus 1000 can apply a new value of the control variable v (j, i) to the DC / AC converter 1200 and the new control variable v (j, i) 2100 does not exceed the current threshold value, the receiving apparatus 2000 is not damaged even if the coupling coefficient is abruptly changed.

2) The transmitting apparatus 1000 can generate a new power according to the transmission coil current ta (j, i) determined by the first calculating section 11 based on the control variable v (j, i) have.

(6) On the other hand, referring to FIG. 12, the transmitting apparatus 1000 can determine the transmission coil current ta (j) for a time t_delay + t_active + t_settle after the reception end point of the control error packet j (th).

Here, t_delay may be a delay time for performing power control according to the previous control error packet after receiving the previous control error packet, t_active may be a power control according to the previous control error packet Power increase), and t_settle may mean the settling time of the target power value.

On the other hand, when the gains Ki, Ki and Kd of the PID controller 12, the integral term restriction parameter M_I, the PID output restriction parameters M_PID and v (j, i) The predetermined range and the scaling factor Sv at the time of determination are determined based on a transmission power characteristic of a power transfer contract, a specification of the transmission apparatus 1000, a specification and a capacity of the transmission coil unit 1400, The current threshold value of the power supply 2000, and the like.

Thus, the transmitting apparatus 1000 receiving the control error packet can determine a new transmit coil current and determine a new transmit power based on the new transmit coil current. According to the new transmission power amount, the wireless power transmission can be stopped without generating the new transmission power, or the new transmission power can be generated to continue the wireless power transmission.

According to the embodiment, when the coupling coefficient is low due to misalignment between the transmitting apparatus 1000 and the receiving apparatus 2000, the receiving power of the receiving apparatus 2000 is lower than the power output from the transmitting apparatus 1000 , The receiving apparatus 2000 may request more power and the transmission power amount of the transmitting apparatus 1000 may increase. At this time, since the wireless power is generated and transmitted within the re-set driving frequency range in consideration of the current threshold value of the receiving apparatus 2000, the receiving apparatus 2000 is damaged due to heat generation due to excessive transmission power and excessive transmission power I can solve the problem.

Particularly, when the transmission apparatus 1000 and the reception apparatus 2000 occur instantaneously and repeatedly due to the vehicle shaking or the like, as in the vehicle wireless charging system, the transmission power of the transmission apparatus 1000 changes momentarily The induction current on the receiving side coil part 2100 does not exceed the threshold value, so that the receiving device 2000 can be prevented from being damaged in advance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

11 First operator
12 PID controller
12a proportional controller
12b integral controller
12c differential controller
13a first amplifier
13b second amplifier
13c third amplifier
13d fourth amplifier
13e fifth amplifier
14a First summing unit
14b &lt; / RTI &gt;
15 second operator
101 power conversion unit
102 Transmission-side resonance circuit section
103 control unit
1100 transmitting side AC / DC converting section 1600
1110 Rectifier
1120 Transmission side DC / DC converter unit
1200 transmission side DC / AC conversion unit
1300 transmitting side impedance matching unit
1400 transmit coil part
1500 Transmitting side communication and control unit
1510 Transmission side control section
1520 transmission side communication unit
1600 detector
2000 receiver
2100 Receiver side coil part
201, 2120 receiving side resonance circuit section
2200 receiving impedance matching unit
202 receiving side power conversion unit
2300 receiving AC / DC converter
2400 receiving side DC / DC converting section
2500 Load section
2510 battery
2520 battery management section
2600 Receive side communication and control unit
203 and 2610,
2620 Receiving side communication unit

Claims (27)

A method for wirelessly transmitting power from a transmitting device to a receiving device,
Transmitting an analog ping for detection of the receiving device;
Receiving a signal strength packet from the receiving device;
Receiving an identification packet from the receiving device;
Resetting the range of the driving frequency of the transmitting apparatus based on the current threshold value of the receiving side coil part included in the identification packet of the receiving apparatus such that the minimum frequency is larger than the minimum frequency of the predetermined driving frequency of the transmitting apparatus; And
And transmitting the generated wireless power within the range of the re-set driving frequency. The method according to claim 1,
Wherein the step of transmitting the generated wireless power within the range of the re-set driving frequency is performed such that when the transmitting device and the receiving device become misaligned, Transmission method. 3. The method of claim 2,
Wherein the misalignment is a case where a coupling coefficient between the transmitting apparatus and the receiving apparatus is less than 0.5. The method according to claim 1,
The range of the driving frequency is,
After receiving the control error packet from the receiving device, is reset based on the identification packet. 3. The method of claim 2,
Wherein the power conversion unit of the transmission apparatus operates as a half bridge inverter or a full bridge inverter. 6. The method of claim 5,
Wherein the transmitting device increases the amount of radio power as the driving frequency increases when the half bridge inverter operates, and increases the amount of radio power as the driving frequency decreases when the inverter operates as a full bridge inverter. The method according to claim 1,
Receiving a control error packet from the receiving apparatus; And
And generating wireless power based on information on the amount of power required by the receiving apparatus of the control error packet. 8. The method of claim 7,
Wherein generating the wireless power comprises:
A power transmission method for generating wireless power based on proportional control, integral control, and proportional integral differential control (PID control). 9. The method of claim 8,
The present time control variable is set based on the difference value of the product of the current PID control amount and the scaling factor according to the current control error packet to the previous control variable according to the previous control error packet
And generating wireless power based on the current time control variable. 10. The method of claim 9,
Wherein the scaling factor is changed based on a range of the reset drive frequency. A method of receiving power wirelessly from a transmitting device,
Receiving an analog ping for detection from the transmitting device;
Transmitting a signal strength packet in response to the analog ping;
Transmitting an identification packet to the transmitting device; And
Receiving a radio power generated based on a range of a driving frequency that is reset so that the minimum frequency is greater than a minimum frequency of a predetermined driving frequency of the transmitting apparatus based on a current threshold value of a receiving side coil part included in the identification packet &Lt; / RTI &gt; 12. The method of claim 11,
Wherein the step of receiving the generated wireless power according to the range of the re-set driving frequency includes a step of, when the transmitting device and the receiving device become misaligned, Receiving method. 13. The method of claim 12,
Wherein the misalignment is a case where a coupling coefficient between the transmitting apparatus and the receiving apparatus is less than 0.5. 13. The method of claim 12,
Wherein the power conversion unit of the transmission apparatus operates as a half bridge inverter or a full bridge inverter. 15. The method of claim 14,
Wherein the power conversion unit of the transmission apparatus increases the amount of radio power as the driving frequency increases when the inverter operates as the half bridge inverter and increases the amount of radio power as the driving frequency decreases when the inverter operates as a full bridge inverter. 12. The method of claim 11,
Comparing the received radio power with the required power; And
And transmitting the control error packet to the transmission apparatus according to the comparison result,
Wherein the control error value is any one of a positive number, a zero number, and a negative number,
The power increase request signal corresponds to a positive control error value,
The power-hold request signal corresponds to a control error value of zero,
Wherein the power reduction request signal corresponds to a negative control error value. A controller for communicating with a receiving device to transmit an analog ping;
A transmit coil for wireless power transmission;
A power converter for outputting power to the transmission coil;
A control unit for controlling the power conversion unit to control an amount of power output to the transmission coil;
Wherein,
Wherein the minimum frequency of the range of the driving frequency of the power conversion unit based on the current threshold value of the receiving side coil part included in the identification packet of the receiving apparatus that receives the wireless power is smaller than the minimum frequency of the predetermined driving frequency of the transmitting apparatus To be larger. 18. The method of claim 17,
Wherein the power conversion unit operates either as a half bridge inverter or a full bridge inverter based on the identification packet. 19. The method of claim 18,
Wherein the power conversion unit increases the amount of radio power as the driving frequency is increased when the inverter operates as the half bridge inverter and increases as the driving frequency decreases when the inverter operates as a full bridge inverter. 18. The method of claim 17,
Wherein,
And controls the amount of the wireless power by adjusting any one of a driving frequency, an input voltage, a duty cycle, and a phase shift of the power conversion unit. 18. The method of claim 17,
Wherein,
A first calculation unit for determining a second current based on a power increase request signal from the reception apparatus and a first current of the transmission coil;
A PID controller for determining a control amount based on proportional control, integral control, and proportional integral differential control (PID control); And
And a second calculation unit for determining a current control variable based on the control amount and the previous control variable,
And controls the power conversion section based on the current time control variable. 22. The method of claim 21,
Wherein the second calculation unit comprises:
And determines the current time control variable based on a value obtained by multiplying the control amount by a scaling factor and a difference value between the previous control variable. 23. The method of claim 22,
Wherein the scaling factor is changed based on a range of the drive frequency that is reset. A control unit communicating with the transmitting apparatus to transmit a signal strength packet and an identification packet; And
Receiving a radio power generated based on a range of a driving frequency that is reset so that a minimum frequency is greater than a minimum frequency of a predetermined driving frequency of the transmitting apparatus based on a current threshold value of a receiving side coil part included in the identification packet; And a coil. 25. The method of claim 24,
Wherein the receiving coil receives radio power generated within the range of the re-set driving frequency when the transmitting device and the receiving device become misaligned. 26. The method of claim 25,
Wherein the reception coil receives the generated radio power by operating the power conversion unit of the transmission apparatus as a half bridge inverter or a full bridge inverter. 27. The method of claim 26,
The receiving coil receives the generated radio power by increasing the amount of radio power when the power conversion unit of the transmission apparatus operates as the half bridge inverter, And operates to increase the amount of radio power as the driving frequency is lowered to receive the generated radio power.

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