JP7003070B2 - Wireless power transmission device, wireless power transmission system, power receiving, wireless power transmission method, and power receiving method - Google Patents

Description

An embodiment of the present invention relates to a wireless power transmission device and a wireless power transmission system.

Radio waves of multiple antenna patterns are transmitted from the transmitter, the ID of the antenna pattern for which the maximum reception sensitivity is obtained by the receiver is notified from the receiver to the transmitter, and the radio waves of the notified antenna pattern are used for transmission. The technology to control the antenna is known.

Further, there is known a technique of optimizing the distribution of power transmission pulses to be transmitted to each power receiving machine according to the battery demand of a plurality of power receiving machines and transmitting the power transmission pulse to each power receiving machine.

However, even if the pulse is distributed to a specific target electric power receiver, the radio wave including the power transmission pulse is diffused and received by other electric power receivers, and the optimum power distribution method considering this is conventionally proposed. The reality is that it has not been done.

Special Table 2016-512677

An object to be solved by the present invention is to provide a wireless power transmission device and a wireless power transmission system capable of efficiently transmitting wireless power to a plurality of receiving electric powers by using a plurality of transmission patterns.

According to the present embodiment, it is a wireless power transmission device that transmits wireless power by radio waves to a plurality of receiving electric powers.
A power transmission condition calculation unit that calculates power transmission conditions including the power transmission period of each of two or more power transmission patterns among a plurality of different power transmission patterns based on the power reception power information and the required electric energy amount information from the plurality of power transmission patterns.
Provided is a wireless power transmission device including a power transmission unit that transmits radio waves while switching between the two or more power transmission patterns under the calculated power transmission conditions.

The block diagram which shows the schematic structure of the wireless power transmission system 2 provided with the wireless power transmission apparatus by 1st Embodiment. A block diagram showing an example of the internal configuration of a transmitter. The block diagram which shows an example of the internal structure of a receiving electric machine. FIG. 2 is a block diagram of a transmitter showing a modification of FIG. FIG. 3 is a block diagram of a receiving electric machine showing a modification of FIG. A flowchart showing an example of the processing procedure of the batch feedback method. Timing diagram of the batch feedback method. The flowchart which shows an example of the processing procedure of the sequential feedback method. Timing diagram of the sequential feedback method. The figure which shows an example of the received power table which summarized the received power information and required electric energy information from each electric power received by a transmitter. The figure which shows how to find the optimum solution of a linear programming problem. The figure which shows the received power characteristic and the received power amount characteristic of each electric receiving electric power. (A) is an example of transmitting radio waves in numerical order, and (b) is a diagram showing an example of transmitting radio waves in any order. The block diagram which shows the schematic structure of the wireless power transmission apparatus by 2nd Embodiment. The figure explaining the direction of the power transmission pattern, the beam width, and the arrangement place of the electric receiver. The flowchart which shows the processing procedure of the transmission according to 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings. In the present specification and the attached drawings, some components are omitted, changed or simplified for the sake of easy understanding and illustration, and the explanations and illustrations are shown, but the same functions can be expected. The technical content shall also be included in the present embodiment and interpreted. Further, in the drawings attached to the present specification, the scale and the aspect ratios are appropriately changed from the actual ones and exaggerated for the convenience of illustration and comprehension.

(First Embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a wireless power transmission system 2 including the wireless power transmission device 1 according to the first embodiment. The wireless power transmission system 2 of FIG. 1 includes one or more transmitters 3 and a plurality of power receiving 4s. When there are two or more power transmissions 3, each power transmission 3 transmits and receives information wirelessly or by wire, and generates a plurality of power transmission patterns 5 in cooperation with each other. Radio waves based on two or more transmission patterns 5 among the plurality of transmission patterns 5 generated by one or more power transmissions 3 are transmitted to the plurality of power receiving electric units 4. More specifically, the one or more power transmissions 3 transmit radio waves while sequentially switching two or more power transmission patterns 5 out of the plurality of power transmission patterns 5. Each power transmission pattern 5 is transmitted in a unique power transmission period. Each of the plurality of receiving electric power 4 receives the above-mentioned radio wave transmitted from one or more power transmissions 3 to generate DC power. The wireless power transmission device 1 in FIG. 1 is a general term for a power transmission device 3 and a power receiving device 4. In some cases, one or more power transmissions 3 may transmit radio waves based on only one power transmission pattern 5, but in the following, mainly, power transmission is performed while switching between two or more power transmission patterns 5. An example of doing so will be described.

FIG. 2 is a block diagram showing an example of the internal configuration of the transmitter 3. The power transmission 3 of FIG. 2 includes a power transmission antenna 11, a first communication antenna 12, a power transmission unit 13, a first communication unit 14, a first control unit 15, a first storage unit 16, and a first unit. It has a calculation unit 17.

The power transmission unit 13 performs trial power transmission and main power transmission. In the trial power transmission, the power transmission unit 13 transmits a plurality of radio waves including each of the plurality of power transmission patterns 5 at different timings. Further, in the main power transmission, the power transmission unit 13 transmits radio waves while switching two or more power transmission patterns 5 among the plurality of power transmission patterns 5 based on the power received power information and the required electric energy amount information from the plurality of power receiving electric power 4s. To transmit electricity.

The first communication unit 14 transmits and receives various information to and from a plurality of receiving electric power 4s, not for the purpose of transmitting wireless power. For example, the first communication unit 14 receives the received power information and the required electric energy amount information transmitted from the plurality of receiving electric powers 4.

The first calculation unit 17 calculates the power transmission condition including the power transmission period of each of two or more power transmission patterns 5 among the plurality of power transmission patterns 5 based on the power received power information and the required electric energy amount information from the plurality of power receiving electric power 4s. do. The power transmission condition calculated by the first calculation unit 17 includes not only the power transmission period of each power transmission pattern 5, but also at least one of the direction of each of the two or more power transmission patterns 5, the phase of the radio wave, and the amplitude of the radio wave. The parameters to be included may be included.

The first storage unit 16 stores the power transmission conditions and the like calculated by the first calculation unit 17. For example, the first storage unit 16 stores the power transmission period of each power transmission pattern 5, the above-mentioned parameters, and the like. Further, the received power information and the required electric energy amount information from the plurality of receiving electric powers 4 may be stored in the first storage unit 16.

The first control unit 15 controls each unit in the power transmission unit 13. For example, the first control unit 15 controls to transmit the received power information and the required electric energy amount information received by the first communication unit 14 to the first calculation unit 17, and the power transmission condition calculated by the first calculation unit 17. Controls transmission to the power transmission unit 13. Further, the first control unit 15 controls the writing of various information to the first storage unit 16 and controls the reading of various information from the first storage unit 16.

When a plurality of transmitters 3 are provided, the first communication antenna 12, the first communication unit 14, the first control unit 15, the first calculation unit 17, and a power signal source (not shown) are shared. You may. This makes it possible to simplify the internal configuration of each transmitter 3.

FIG. 3 is a block diagram showing an example of the internal configuration of the electric receiver 4. The electric receiving unit 4 of FIG. 3 includes a power receiving antenna 21, a communication second antenna 22, a power receiving unit 23, a measuring unit 24, a second communication unit 25, a second control unit 26, and a second storage unit. It has 27 and a second calculation unit 28.

The power receiving unit 23 receives radio waves from one or more transmitters 3 to generate DC power. The power receiving unit 23 has a rectifier 23a and a load 23b. The rectifier 23a converts the received AC power into DC power. The received power information defined by the amplitude of the DC power is measured by the measuring unit 24 through the load 23b. In addition, the power receiving unit 23 may have a matching unit or a DC-DC converter. The matching box performs impedance matching between the power receiving antenna 21 and the rectifier 23a. The DC-DC converter transforms the voltage after rectification.

The second communication unit 25 transmits and receives various information to and from one or more transmitters 3 via the second communication antenna 22. For example, the second communication unit 25 transmits the received power information and the required electric energy information of a plurality of radio waves based on the plurality of power transmission patterns 5 received during the trial power transmission to one or more power transmissions 3.

The second storage unit 27 calculates the required electric energy amount information required by the receiving electric power 4. The required electric energy amount information is calculated based on the charging status of the receiving electric power 4, the power consumption, and the like. The second storage unit 27 stores the received power information, the required power amount information, and the like. The second control unit 26 controls each unit in the power receiving unit 23.

FIG. 4 is a block diagram of a transmitter 3 showing a modified example of FIG. 2, and FIG. 5 is a block diagram of a receiving electric machine 4 showing a modified example of FIG. While the transmitter 3 of FIG. 2 and the receiver 4 of FIG. 3 described above show the internal configuration when the propagation path is not estimated, the transmitter 3 of FIG. 4 and the receiver 4 of FIG. 5 are shown. Shows the internal configuration when estimating the propagation path. Here, the propagation path refers to a propagation path between the transmitter 3 and each electric receiver 4.

The transmitter 3 of FIG. 4 includes a propagation path estimation unit 18 and a first transmission / reception switch 19 in addition to the internal configuration of the transmitter 3 of FIG. The propagation path estimation unit 18 receives the beacon signal transmitted from the electric receiver 4, and estimates the propagation path to and from the electric receiver 4 based on the received beacon signal. The first transmission / reception switch 19 switches between transmission / reception of radio waves depending on whether the radio waves are transmitted or the propagation path is estimated.

The electric receiving 4 of FIG. 5 has a beacon signal transmitting unit 29 and a second transmitting / receiving switching device 30 in addition to the internal configuration of the electric receiving 4 of FIG. The beacon signal transmission unit 29 transmits a beacon signal when estimating the propagation path. The second transmission / reception switch 30 switches between transmission / reception of radio waves depending on whether the radio waves from one or more transmitters 3 are received or the propagation path is estimated.

As described above, the power transmission 3 performs trial power transmission and main power transmission. There are a collective feedback method and a sequential feedback method as a method of trial power transmission. In the batch feedback method, a plurality of radio waves based on a plurality of power transmission patterns 5 are continuously transmitted, and then power received power information and required electric energy amount information from the plurality of power receiving electric power 4 are collectively received. On the other hand, in the sequential feedback method, each time a radio wave based on each transmission pattern 5 is transmitted, the received power information and the required electric energy amount information from a plurality of receiving electric powers 4 are received.

FIG. 6 is a flowchart showing an example of the processing procedure of the batch feedback method, and FIG. 7 is a timing diagram of the batch feedback method. The flowchart of FIG. 6 shows a processing procedure of one or more transmitters 3. In steps S1 to S4 of FIG. 6, trial transmission of a plurality of radio waves based on a plurality of power transmission patterns 5 is continuously performed. More specifically, first, the variable k representing the type of the power transmission pattern 5 is initialized to zero (step S1). Next, k is incremented by 1 (step S2). Next, the radio wave based on the k-th power transmission pattern 5 is trial-transmitted (step S3). Next, it is determined whether or not the variable k has reached the maximum value K (step S4), and if it has not yet been reached, the processes after step S2 are repeated. As a result, as shown at times t1 to t2 in FIG. 7, a plurality of radio waves based on the plurality of power transmission patterns 5 are continuously transmitted.
The transmission period of each transmission pattern 5 during the trial transmission may be arbitrary. Each receiving electric power 4 receives a radio wave based on each transmission pattern 5, and stores the received power information in the second storage unit 27.

When it is determined in step S4 that the variable k has reached K, each receiving electric power 4 transmits the received power information and the required electric energy amount information as shown at times t3 to t4 in FIG. Each transmitter 3 receives the received power information and the required electric energy amount information transmitted by each receiving electric power 4, and stores these information in the first storage unit 16 (step S5). The order in which the plurality of receiving electric power 4s transmit the received power information and the required electric energy amount information may be arbitrary. Further, the plurality of receiving electric power 4 may be transmitted after modulating the received power information and the required electric energy information in different frequency bands.

Next, based on the received power received power information and the required power amount information, the first calculation unit 17 calculates the power transmission period of each of the two or more power transmission patterns 5 (steps S6 and 7 in FIG. 6). Times t5 to t6). At this time, the first calculation unit 17 may calculate by combining various parameters other than the power transmission period.

Next, based on the calculation result of step S6, the main power transmission is performed while switching between two or more power transmission patterns 5 (step S7 in FIG. 6 and times t7 to t8 in FIG. 7). As a result, the power transmission pattern 5 included in the radio waves transmitted from the power transmission 3 is switched for each unique power transmission period (time t7 to t8 in FIG. 7). One or more power transmissions 3 transmit radio waves while switching the transmission period of each transmission pattern 5 based on the received power information and the required electric energy amount information of each receiving electric power 4. Each power receiving unit 4 may monitor whether or not the radio wave of the main power transmission has been received by the measuring unit 24, and periodically notify each power transmission unit 3 of information indicating the monitoring result.

FIG. 8 is a flowchart showing an example of the processing procedure of the sequential feedback method, and FIG. 9 is a timing diagram of the sequential feedback method. The flowchart of FIG. 8 shows a processing procedure of one or more transmitters 3. Steps S11 to S13 are the same as steps S1 to S3 in FIG. After the radio wave based on the k-th transmission pattern 5 is trial-transmitted in step S13, the received power information and the required electric energy amount information from each receiving electric power 4 that has received the radio wave are received (step S14). The received power received power information and the requested power amount information are stored in the first storage unit 16.
For example, times t11 to t12 in FIG. 9 are trial transmission periods of radio waves based on the first transmission pattern 5, and times t13 to t14 are power received power information and required electric energy amount information from each receiving electric wave 4 that received the radio waves. Is the period for receiving.

Next, it is determined whether or not the variable k has reached K (step S15), and if not, the processing after step S12 is repeated. When it is determined in step S15 that the variable k has reached K, the received power information and the required electric energy information corresponding to each power transmission pattern 5 stored in the first storage unit 16 are collectively read out and the first calculation is performed. In section 17, the transmission period of each of the two or more transmission patterns 5 is calculated (step S16 in FIG. 8, times t15 to t16 in FIG. 9). Next, based on the calculation result of step S6, the main power transmission is performed while switching between two or more power transmission patterns 5 (step S17 in FIG. 8, times t17 to t18 in FIG. 9).

As described above, in the batch feedback method, each receiving electric power 4 collectively transmits the received power information and the required electric energy amount information of a plurality of radio waves based on the plurality of transmission patterns 5 to each transmission device 3. Therefore, each power transmission 3 can collectively receive the received power information and the required electric energy amount information, and can calculate the power transmission period of each power transmission pattern 5 immediately after the reception. On the other hand, in the sequential feedback method, each receiving electric power 4 transmits the received power information and the required electric energy amount information of the radio wave based on each transmission pattern 5 to each transmission 3 at individual timings. Therefore, each power transmission 3 sequentially stores these information in the first storage unit 16 until all the received power information and the required electric energy information are received, and all the received power information and the required electric energy information. Is received, the transmission period and parameters of each transmission pattern 5 are calculated.

FIG. 10 is a diagram showing an example of a received power table 6 that summarizes the received power information and the required electric energy amount information from each of the received electric power 4 received by the transmitter 3. This table is stored in the first storage unit 16. The row direction of the received power table 6 in FIG. 10 indicates the identification number of each electric receiving electric power 4, the column direction indicates the identification number of the radio wave based on each power transmission pattern 5, and the corresponding power receiving is received in each cell of the row and the column. The power is recorded. Further, in each cell of the last row, the power transmission period of each power transmission pattern 5 calculated by the first calculation unit 17 is recorded. Further, the required electric energy of each receiving electric power 4 is recorded in each cell of the last column. The transmission period of the radio wave based on each transmission pattern 5 calculated by the first calculation unit 17 is also registered in the received power table 6.

The first control unit 15 and the power transmission unit 13 in each power transmission unit 3 perform the main power transmission with reference to the power reception power table 6 of FIG.

Next, a method of calculating the power transmission period of each power transmission pattern 5 to be calculated by the first calculation unit 17 will be described. When the power transmission period for main power transmission in the _kth power transmission pattern 5 is defined as tk, the total time T for power transmission for the total number of K power transmission patterns 5 is expressed by the following equation (1).

Here, since the time _tk is a positive real number,
_tk ≧ 0… (2)
Is.

Next, based on the received power table 6 of FIG. 10, if the received power of the nth receiving electric power 4 at the time of trial transmission of the kth transmission pattern 5 is defined as _{pn, k} , the kth transmission pattern 5 In order for the electric energy of the _nth receiving electric power 4 to satisfy the required electric energy Wn when the electric power is transmitted in the electric power transmission period _tk , it is necessary to determine the electric power transmission period _tk so as to satisfy the following equation (3). be.

In the equation (3), if _{pn and k} are non-zero, the required power amount W _n will be satisfied _eventually by setting the transmission period tk to a large value. However, from the viewpoint of power saving and shortening of the transmission period, it is desirable that the transmission period _tk , that is, the total time T is smaller. Therefore, in order to satisfy all the required electric energy of all the receiving electric powers 4 in the shortest time, it is sufficient to find the solution of the minimization problem of the following equation (4) regarding the transmission period _tk .

As can be seen from the equation (4), the minimization problem of the equation (4) is a linear programming problem in which both the objective function and the constraint condition can be expressed in a linear form. FIG. 11 is a diagram showing how to find the optimum solution of a linear programming problem. FIG. 11 shows an example in which the number of 5 transmission patterns is 2 and the number of 4 receiving electric powers is 2. The shaded area in the figure represents the feasible region that satisfies the constraint condition, and in the linear programming problem, the optimum solution exists at the apex of the polygon indicating the feasible region.

In the case of FIG. 11, the vertices (t ₁ ', t ₂ ') when the objective function of the total time T shown by the broken line is asymptotic to the origin and the total time T is minimized are the optimum solutions. When the number of power transmission patterns 5 is 2 and the number of electric power transmissions 4 is 2, the optimum solution can be easily searched by displaying the graph as shown in FIG. However, when the number of power transmission patterns is 5, that is, the variable is 3 or more, the feasible region is represented by a superpolyhedron, and it is extremely difficult to intuitively find the optimum solution. In this case, it is desirable to obtain global optimization by efficiently searching the vertices of the feasible region based on a specific rule, as in the simplex method.

FIG. 12 shows in the upper part the power received power characteristics of each electric power receiving electric power 4 with respect to time in each electric power receiving electric power system 4 when the main power transmission is performed based on the calculation result of the first calculation unit 17, and the power receiving power amount characteristic with respect to time. Is shown in the lower row.

Regarding the received power characteristics in the upper part of FIG. 12, if there is no change in the radio wave propagation environment and the position of the transmitting and receiving electric power, the received power during transmission of the radio wave based on the same transmission pattern 5 is constant. When the power transmission pattern 5 is switched, the received power changes to a value corresponding to the power transmission pattern 5.

Regarding the characteristics of the amount of received power in the lower part of FIG. 12, the slope of the graph of the amount of received power with respect to time is constant while transmitting radio waves based on the same power transmission pattern 5. When the power transmission pattern 5 is switched, the slope of the graph of the amount of power received changes. The broken line at the bottom of FIG. 12 shows the required electric energy. At the same time as transmitting the radio wave based on the last K-th power transmission pattern 5, the power transmission period of each power transmission pattern 5 is set so that the amount of power received by each power receiving electric power 4 reaches or exceeds the broken line. ..

Note that FIG. 12 shows an example in which radio waves based on each power transmission pattern 5 are transmitted in numerical order from the first power transmission pattern 5 to the Kth power transmission pattern 5, but the order of the power transmission patterns 5 to be transmitted is arbitrary. good. FIG. 13 (a) shows an example of transmitting radio waves based on the power transmission pattern 5 in numerical order, whereas FIG. 13 (b) shows an example of transmitting radio waves based on the power transmission pattern 5 in an arbitrary order. There is. Further, the radio waves based on each power transmission pattern 5 do not necessarily have to be collectively transmitted, and as shown in FIG. 13B, each power transmission pattern 5 is divided into a plurality of power transmission periods, and the divided power transmission pattern is divided. Every 5 may be transmitted in any transmission order.

(First modification)
When transmitting radio waves from one or more power transmissions 3 to a plurality of power receiving units 4, it is desirable that the power transmission time is as short as possible. That is, when transmitting radio waves from each power transmission 3 to a plurality of power receiving 4 while switching two or more power transmission patterns 5, it is possible to satisfy the required electric energy information of each power receiving 4 within a predetermined time. desirable. As a method of setting a predetermined time, there are the following first method and second method.

In the first method, when all K power transmission patterns 5 are used for equal power transmission periods and power transmission is performed, the minimum time T _{1, min} required to satisfy the required electric energy of all N power receiving electric power transmissions 4 is predetermined. It is time. When the total time is T1, the power transmission period equal allocated to all K power transmission patterns 5 is given by the following equation (5).

Here, when each power transmission pattern 5 is transmitted in equal transmission periods, the amount of power received by the nth power receiving electric power 4 is represented by the left side of the following equation (6) according to the above equation (3). To. The amount of received power must be equal to or greater than the required amount of power Wn of the _nth receiving electric power 4 represented by the right side of the equation (6).

なお、（７）式のmax( )は、( )内のベクトルのうち最大値を示す。 Therefore, the minimum time T _{1, min} for satisfying all the required electric energies of all N receiving electric power 4 is expressed by the following equation (7).

Note that max () in Eq. (7) indicates the maximum value among the vectors in ().

The second method for setting a predetermined period is a total of N pieces, assuming that only the received power information when applying the power transmission pattern 5 in which the maximum received power is obtained in each receiving power 4 is returned to the transmitter 3. The minimum time T2 _{and min} required to satisfy the required power amount of the electric receiving electric power 4 is set as a predetermined time.

When the maximum received power _{pn, k} is obtained by the k-th power transmission pattern 5 in the n-th receiving electric power 4, the time t _{n, k} that satisfies the required electric energy Wn of the _nth receiving electric power 4 in the shortest time. Is obtained by the following equation (8).

Here, when the maximum received power is obtained by the k-th power transmission pattern 5 in each of the plurality of receiving electric power 4, the minimum time that satisfies the required electric energy of each electric receiving electric power 4 calculated based on the equation (8). The largest of t _{n and k} is defined as the transmission period tk _{and min} of the kth transmission pattern 5.
For the power transmission pattern 5 that is not selected in any of the power receiving 4s, the time tk _{and min} are set to zero, and the power transmission pattern 5 at this time is not used during the main power transmission. According to the above-mentioned equation (3), the amount of power received by the n-th receiver 4 when the k-th transmission pattern 5 is transmitted in the transmission period tk, min is represented by the left side of the following equation (9). .. The amount of received power must be equal to or greater than the required amount of power Wn of the nth receiving electric power 4 represented by the right side of the equation (9).

Here, the transmission periods tk _{and min} of the k-th transmission pattern 5 are predefined so as to satisfy all the required electric energy W _n of all the receiving electric powers 4. Therefore, in reality, the left side of the equation (9) is equal to or larger than the right side of the equation (9). Here, the scale factor s _n , which is the value obtained by dividing the left side of the equation (9) by the right side, is expressed by the following equation (10).

The minimum value s _min of the scale factor s _n for all the receiving electric machines 4 is expressed by the following equation (11).
s _min = min (s ₁ , s ₂ , ..., s _N ) ... (11)

Min () in Eq. (11) indicates the minimum value of the vectors in (). That is, by dividing the power transmission period tk _{, min of the kth} power transmission pattern 5 by the minimum scale factor s _min , the total time T _{2, min} that satisfies all the required electric energy Wn of all the receiving electric power 4 at the minimum. Is required. From the above, the minimum time T _{2, min} is expressed by the following equation (12).

(Second modification)
The power transmission antenna 11 of the power transmission 3 may be a phased array antenna. The phased array antenna has a plurality of antenna elements and a variable phase device connected to these antenna elements. The variable phase detector can generate an arbitrary power transmission pattern 5 by controlling the phase of the radio wave input to each antenna element. Further, the phased array antenna may have a variable amplifier as well as a variable phase detector. By providing the variable amplifier, the amplitude of the radio wave can also be controlled, and it is possible to generate a power transmission pattern 5 having a higher degree of freedom, such as suppressing the radiation of electric power in an unnecessary direction.

(Third modification example)
The radio waves used for power transmission are preferably unmodulated continuous waves without information from the viewpoint of improving power transmission efficiency and reducing interference with other radio equipment. Further, it is desirable that the frequencies of the radio waves used for power transmission and communication are different so as not to interfere with the communication performed between the transmission and reception electric machines. As a result, the power transmission from the power transmission 3 and the transmission of the received power information from the electric power receiving 4 can be stably performed without interference.

(Fourth modification)
In the above, the control method of the power transmission period assigned to the plurality of power transmission patterns 5 prepared in advance has been described, but the power transmission pattern 5 may be variably controlled.

For example, as in the transmission 3 of FIG. 4 and the power receiving 4 of FIG. 5, the power transmission pattern 5 may be determined based on the propagation path information between the power transmission 3 and the power receiving 4. More specifically, the singular vector on the power transmission side obtained when the propagation path matrix between the plurality of power transmissions 3 and the plurality of power receiving units 4 is decomposed into singular values is the radio wave input to the power transmission antenna of each power transmission 3. The weights corresponding to the phase and amplitude information (hereinafter referred to as weights) of the above, and particularly corresponding to the maximum singular value, generate a power transmission pattern 5 that maximizes the total amount of AC power received by all the receiving electric machines 4. However, due to the non-linearity of the rectifying efficiency of the rectifier 23a of each receiving electric power 4, this weight does not always maximize the total DC power received by all the receiving electric powers 4. In addition, the weight corresponding to the non-zero singular value can supply electric power to the receiving electric power 4, but the weight corresponding to the zero singular value cannot supply electric power. Therefore, the weight corresponding to the singular value of zero is not used for the power transmission pattern 5, and one or more of the weights corresponding to the non-zero singular value can be used as the power transmission pattern 5.

Further, when power transmission is concentrated on one specific power receiving 4, weights having a complex conjugate relationship of the propagation path vector with the power receiving 4 can be used. This method is widely known as the retro directive method. The weight of the retro directive method can be assumed for the number of electric power receiving units 4, and one or more of the weights for the number of electric power receiving electric units 4 can be used as the power transmission pattern 5.

The above weight may not be reproduced exactly depending on the resolution of the variable phase detector and the variable amplifier and the dynamic range of the variable amplifier. In this case, it is possible to use a pseudo weight that is rounded to a configurable phase value / amplitude value close to the ideal weight, or the upper and lower limits of the amplitude are clipped or compressed so as to be within the dynamic range.

(Fifth variant)
When neither the transmitter 3 nor the receiver 4 has a propagation path estimation function as in the transmitter 3 of FIG. 2 and the receiver 4 of FIG. 3, power transmission is based on the propagation path information described in the fourth modification. It is difficult to find pattern 5. Instead of determining the power transmission pattern 5 from the propagation path estimation information, the power transmission pattern 5 can be determined based on the relative position or direction information of the receiving electric power 4 with respect to the transmitter 3. For example, in an indoor environment such as a commercial facility or a factory, a monitoring camera or the like (electric receiving electric receiving specifying unit) is arranged, and it is possible to obtain the position information of the electric receiving electric power 4 from the image information obtained by the camera or the like. Further, if it is outdoors, the approximate position of the receiving electric power 4 can be specified by GPS. In addition, the position information can be acquired by receiving the signal used for communication by the power receiving side by a radar or the like separately mounted on the power transmission side.

Here, in the case of a phased array consisting of power transmission antennas 11 arranged one-dimensionally or two-dimensionally at equal intervals, the radio waves are subjected to an appropriate phase difference by giving an appropriate phase difference to the radio waves input to each power transmission antenna 11. It is possible to control the traveling wave surface and concentrate power transmission in a specific direction. As described above, one or more power transmission patterns 5 based on position or direction information can be used for the power receiving electric power 4 that does not have the propagation path estimation function.

As described above, in the present embodiment, the power transmission period of each of the two or more power transmission patterns 5 is calculated based on the power reception power information and the required electric energy amount information from the plurality of power reception patterns 4, and these power transmission patterns 5 are used. Since power transmission is performed while switching within the calculated power transmission period, it is possible to transmit power that satisfies the required electric energy amount information of the plurality of receiving electric power 4. Further, the power transmission 3 in the present embodiment performs trial power transmission and main power transmission. In the trial power transmission, a plurality of radio waves based on the plurality of power transmission patterns 5 are continuously transmitted, and the plurality of power receiving electric power transmissions 4 that have received these radio power transmissions transmit the received power information and the required electric energy amount information. Can calculate the transmission period of two or more transmission patterns 5 used in the main transmission by receiving the received power information and the required electric energy amount information. By adjusting the power transmission period of each of the two or more power transmission patterns 5 in this way, it is possible to enable a plurality of power receiving electric power transmission units 4 to receive the required electric energy within a predetermined time.

(Second embodiment)
In the wireless power transmission device 1 according to the first embodiment, each receiving electric power 4 transmits the received power information for each trial transmission pattern to the transmission 3 for all the plurality of trial transmission patterns.
However, as the number of trial power transmission patterns increases, the number of times each power receiving 4 transmits the power received information to the power transmission 3 increases, so that the power consumption of the power receiving 4 increases. Originally, it is desirable to transmit the received power information to the transmitter only for the receiving electric power 4 having a high power feeding efficiency according to the trial power transmission pattern. Therefore, in the second embodiment, the power receiving electric power 4 having a low power feeding efficiency due to the trial power transmission pattern is prevented from transmitting the power receiving power information to the power transmission device 3.

FIG. 14 is a block diagram showing a schematic configuration of the wireless power transmission device 1 according to the second embodiment, and shows a block configuration of the transmitter 3. The transmitter 3 of FIG. 14 includes a determination unit 31 and a transmission request unit 32 in addition to the configuration of the transmitter 3 of FIG.

The determination unit 31 is based on at least one of the propagation path information of the plurality of power receiving 4 and the arrangement information of the plurality of power receiving 4 and the power transmission pattern information to the plurality of power receiving 4 and the plurality of power receiving 4 It is determined for each power receiving 4 whether or not it is necessary to transmit the power received power information from. The transmission requesting unit 32 requests the receiving electric power 4 determined by the determination unit 31 to transmit the received power information to transmit the received power information and the required electric energy amount information requested by the receiving electric power 4.

As a specific processing procedure of the determination unit 31, two types, a first processing procedure and a second processing procedure, can be considered.

In the first processing procedure, the received power information and the required power from the plurality of receiving electric powers 4 are based on the value obtained by multiplying the propagation path information of the plurality of receiving electric powers 4 and the power transmission pattern information to the plurality of receiving electric powers 4. It is determined for each power receiving 4 whether or not it is necessary to transmit the amount information.

The power transmission pattern information to the plurality of power receiving units 4 can be represented by the phase and amplitude information (weight) of the radio waves input to the plurality of power transmission antennas 11 included in the power transmission device 3. The power transmission antenna 11 of the power transmission 3 is a phased array antenna composed of a total of M elements, and of the total of N receiving electric machines 4, the mth of the propagation path vector with respect to the nth receiving electric machine (n = 1 ... N). The element (m = 1 ... M) is defined as h _{n, m} . This corresponds to the propagation path coefficient between the nth receiving electric machine 4 and the mth element of the phased array antenna. Further, the mth element of the weight corresponding to the kth transmission pattern is defined as w _{k, m} . This corresponds to the phase and amplitude information of the radio wave input to the mth element of the phased array antenna. The complex correlation coefficient ρ _{n, k} of the propagation path vector for the nth receiving electric machine 4 and the weight corresponding to the kth power transmission pattern is expressed by the following equation (13).

When evaluating the correlation, the square value of the absolute value of the complex correlation coefficients ρ _{n and k} expressed by Eq. (13) is often used. When | ρ _{n, k} | ² is equal to or greater than a predetermined value, it is determined that the received power information from the receiving electric power 4 needs to be transmitted. Generally, when | ρ _{n, k} | ² is a value of 0.5 or more, it is considered that the correlation is high. Therefore, 0.5 may be adopted as the predetermined value, or other values may be adopted.

In the second processing procedure, the determination unit 31 receives power information and required power from the plurality of power receiving 4s based on the arrangement information of the plurality of power receiving 4s and the power transmission pattern information to the plurality of power receiving 4s. It is determined for each power receiving 4 whether or not the quantity information is necessary. As described above, the arrangement information (relative position information) of the plurality of receiving electric power 4 can be acquired from the camera, GPS, radar and the like. The power transmission pattern information includes, for example, as shown in FIG. 15, information on the main beam (main lobe) direction and beam width of the power transmission pattern. The determination unit 31 compares the relative position information of the plurality of power receiving 4 with the main beam direction and the beam width of the power transmission pattern, and determines whether or not the plurality of power receiving 4 are located within the main beam range of the power transmission pattern. Is determined. For example, for the predetermined beam width, an angle width that is 3 dB lower than the maximum gain, that is, a so-called half-value angle may be adopted. It is determined that the receiving power information 4 needs to be transmitted to the receiving electric power 4 located within the main beam range of the power transmission pattern.

Here, the main beam direction and the beam width of the power transmission pattern can be obtained by measuring in advance, but it is practically impossible to measure all the assumed power transmission patterns. Therefore, the values calculated by simulation may be used for the main beam direction and the beam width of the power transmission pattern. It is not always necessary to use an electromagnetic field simulator for the simulation, and the directivity (also known as the element factor) of the antenna used for each element of the phased array antenna and the array coordinate information and weight information (array) of each element of the phased array antenna. It can be calculated by a general-purpose computer based on the factor).

In the above, the processing procedure for determining whether or not it is necessary to transmit the received power information from each receiving electric power 4 has been described, but the electric power receiving 4 group consisting of two or more specific receiving electric power 4 is a predetermined determination condition. A power transmission pattern that satisfies the above conditions may be determined, and the determined power transmission pattern may be transmitted to the four receiving electric power groups. Regarding the classification of the power receiver group, the complex correlation coefficient between the propagation path vectors of the two power receivers 4 obtained by Eq. (13) and the coordinate information of each power receiver 4 (for example, x, y, in the Cartesian coordinate system). By using various clustering methods with the z-coordinate as a variable, it is possible to classify the receivers into a plurality of receiver groups composed of the receivers 4 that are "highly correlated" or "physically close" to each other. Typical examples of the clustering method include Ward's method, which is a hierarchical method, and K-means method, which is a non-hierarchical method.

Then, for example, as described above, a power transmission pattern based on the weight (particularly the weight corresponding to the maximum singular value) obtained by singular value decomposition of the propagation path matrix for a plurality of power receiving 4s in each power receiving 4 group is used as a candidate. can do.

FIG. 16 is a flowchart showing a processing procedure of the transmitter 3 according to the second embodiment. This flowchart shows the processing procedure of the batch feedback method similar to that of FIG. First, the propagation path information of each receiving electric machine 4 is acquired (step S21). Here, for example, a beacon signal transmitted from each receiver 4 is received, and the propagation path estimation unit in the transmitter 3 receives a propagation path to and from each receiver 4 based on the received beacon signal. Estimate the information.

Next, the determination unit 31 determines whether or not it is necessary to transmit the received power information from each receiving electric power 4 (step S22). Here, in the first processing procedure or the second processing procedure described above, it is determined whether or not it is necessary to transmit the received power information from each receiving electric power 4.

Next, the receiving electric power 4 determined to need to transmit the received power information is notified to transmit the received power information and the required electric energy amount information (step S23). This notification is made, for example, via the first communication unit 14.

After that, as in steps S1 to S7 of FIG. 6, trial power transmission, reception of received power information and required electric energy amount information, and main power transmission are sequentially performed (steps S24 to S30). When the sequential feedback method is adopted, the processes of S11 to S17 of FIG. 8 may be performed in steps S24 to S30 of FIG.

As described above, in the second embodiment, based on at least one of the propagation path information of the plurality of power receiving 4 and the arrangement information of the plurality of power receiving 4 and the power transmission pattern information to the plurality of power receiving 4 , It is determined for each power receiving 4 whether or not it is necessary to transmit the power received power information from the plurality of power receiving 4s. As a result, for each transmission pattern, only the receiving power 4 having high power supply efficiency needs to transmit the received power information and the required electric energy amount information to the transmission 3, so that the power consumption of each receiving power 4 can be reduced and the transmission. Since the number of received power information and the like received by 3 can be reduced, the processing load of the power transmission 3 can also be reduced.

The processing of each part in the transmitter 3 according to each of the above-described embodiments can be performed by one or more signal processing processors. Further, the transmitter 3 may be configured by a SoC (System on Chip) in which a memory is mixedly mounted on a signal processing processor.

At least a part of the wireless power transmission device 1 and the wireless power transmission system 2 described in the above-described embodiment may be configured by hardware or software. When configured with software, a program that realizes at least a part of the functions of the wireless power transmission device 1 and the wireless power transmission system 2 is stored in a recording medium such as a flexible disk or a CD-ROM, read by a computer, and executed. You may let me. The recording medium is not limited to a removable one such as a magnetic disk or an optical disk, and may be a fixed recording medium such as a hard disk device or a memory.

Further, a program that realizes at least a part of the functions of the wireless power transmission device 1 and the wireless power transmission system 2 may be distributed via a communication line (including wireless communication) such as the Internet. Further, the program may be encrypted, modulated, compressed, and distributed via a wired line or a wireless line such as the Internet, or stored in a recording medium.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 wireless power transmission device, 2 wireless power transmission system, 3 transmitter, 4 receiver, 5 transmission pattern, 11 transmission antenna, 12 communication 1st antenna, 13 transmission unit, 14 1st communication unit, 15 1st control Unit, 16 1st storage unit, 17 1st calculation unit, 18 Propagation path estimation unit, 21 Power receiving antenna, 22 Communication 2nd antenna, 23 Power receiving unit, 24 Measuring unit, 25 2nd communication unit, 26 2nd control Unit, 27 2nd storage unit, 28 2nd calculation unit, 29 Beacon signal transmission unit, 30 2nd power transmission / reception switch

Claims (20)

It is a wireless power transmission device that transmits wireless power by radio waves to the first receiving electric power and the second receiving electric power by a plurality of transmission patterns .
The first information indicating the electric power received by the first electric power transmission pattern according to the plurality of power transmission patterns, the second information indicating the electric energy received by the second electric power transmission pattern according to the plurality of power transmission patterns, the first information. The first power transmission pattern and the first power transmission pattern included in the plurality of power transmission patterns are based on the third information indicating the amount of power required from the first power receiving machine and the fourth information indicating the amount of power required from the second power receiving machine. 2 A calculation unit that determines a power transmission pattern and calculates a first power transmission period according to the first power transmission pattern and a second power transmission period according to the second power transmission pattern.
A power transmission unit that transmits a first radio wave according to the first power transmission pattern during the first power transmission period and transmits a second radio wave according to the second power transmission pattern during the second power transmission period .
A control unit that controls trial transmission of a plurality of radio waves based on each of the plurality of power transmission patterns from the power transmission unit.
The first information and the third information transmitted from the first receiver that has received each of the plurality of radio waves are received, and the second receiver that has received each of the plurality of radio waves transmits the first information and the third information. A communication unit that receives the second information and the fourth information is provided.
The calculation unit determines the first power transmission pattern and the second power transmission pattern based on the first information and the fourth information received by the communication unit, and determines the first power transmission period and the second power transmission period. To calculate, wireless power transmission equipment. A wireless power transmission device that transmits radio power by radio waves to a first receiver and a second receiver in a plurality of transmission patterns .
The first propagation path information indicating the first propagation path between the first receiver and the wireless power transmission device and the second propagation path indicating the second propagation path between the second receiver and the wireless power transmission device. Based on the information, at least one of the first receiving electric power and the arrangement information of the second receiving electric power, and the transmission pattern information indicating the plurality of power transmission patterns, the first receiving electric power causes the plurality of power transmission patterns. It is determined whether or not the first information indicating the electric power received according to the above is necessary, and whether or not the second information indicating the electric power received by the second electric power receiving pattern according to the plurality of power transmission patterns is necessary. Judgment unit and
When it is determined that the first information is necessary, the first receiving electric power is requested to transmit the first information and the third information indicating the amount of electric power required from the first receiving electric power, and the first is said. (2) A transmission requesting unit that requests the second receiving electric power to transmit the second information and the fourth information indicating the amount of electric power required from the second receiving electric power when it is determined that the information is necessary .
Based on at least one of the first information and the third information, and the second information and the fourth information, the first power transmission pattern and the second power transmission pattern included in the plurality of power transmission patterns are determined, and the power transmission pattern is determined. A calculation unit that calculates the first power transmission period according to the first power transmission pattern and the second power transmission period according to the second power transmission pattern.
A wireless power transmission device comprising a transmission unit that transmits a first radio wave according to the first power transmission pattern during the first power transmission period and transmits a second radio wave according to the second power transmission pattern during the second power transmission period . The determination unit multiplies the first value obtained by multiplying the value indicating the first propagation path and the value indicating the plurality of transmission patterns, the value indicating the second propagation path, and the value indicating the plurality of transmission patterns. The wireless power transmission device according to claim 2, wherein it is determined whether or not the first information is necessary and whether or not the second information is necessary based on the second value. The determination unit determines whether or not the first information is necessary and whether or not the second information is necessary based on the arrangement information of the first receiving electric power and the second receiving electric power and the transmission pattern information. 2. The wireless power transmission device according to claim 2. A control unit that controls trial transmission of a plurality of radio waves based on each of the plurality of power transmission patterns from the power transmission unit.
The first information and the third information transmitted from the first receiver that has received each of the plurality of radio waves are received, and the second receiver that has received each of the plurality of radio waves transmits the first information and the third information. A communication unit that receives the second information and the fourth information is provided.
The calculation unit determines the first power transmission pattern and the second power transmission pattern based on the first information and the fourth information received by the communication unit, and determines the first power transmission period and the second power transmission period. The wireless power transmission device according to any one of claims 2 to 4 , wherein the wireless power transmission device is calculated. The calculation unit further includes the direction of the first radio wave, the phase of the first radio wave, the amplitude of the first radio wave, the direction of the second radio wave, the phase of the second radio wave, and the amplitude of the second radio wave. The radio power transmission device according to any one of claims 1 to 5 , wherein at least one is calculated . In the calculation unit, the wireless power satisfying the electric energy required from the first electric power receiving electric power and the electric electric power amount required from the second electric power receiving electric power can be generated within a predetermined time by the first electric power receiving electric power machine and the second electric power receiving electric power generation. The radio according to any one of claims 1 to 6, wherein the first power transmission pattern and the second power transmission pattern are determined, and the first power transmission period and the second power transmission period are calculated so as to be transmitted to the power transmission. Power transmission device. The power transmission unit divides the first power transmission period and the second power transmission period calculated by the power transmission unit into a plurality of power transmission division periods, and the first power transmission unit based on the first power transmission pattern according to the power transmission division period. The wireless power transmission device according to any one of claims 1 to 7, which transmits a radio wave and a second electric power transmission based on the second power transmission pattern. A plurality of antennas for transmitting and receiving radio waves between the first receiving electric wave and the second receiving electric wave, and the plurality of transmission patterns connected to the plurality of antennas and variably controlling the phase of a high frequency signal according to the radio waves. The radio power transmission device according to any one of claims 1 to 8, further comprising a variable phase device and a phased array antenna. The first radio wave and the second radio wave are unmodulated continuous waves with no information.
The frequencies of the first radio wave and the second radio wave are the frequencies of the radio waves to which the first receiving electric wave transmits the first information and the third information, and the second receiving electric wave has the second information and the fourth information. The wireless power transmission device according to any one of claims 1 to 9, which is different from the frequency of radio waves for transmitting information . A propagation path estimation unit that estimates a first propagation path between the first receiver and the wireless power transmission device and estimates a second propagation path between the second receiver and the wireless power transmission device. Further prepare,
The first transmission pattern and at least one of the second transmission patterns are according to any one of claims 1 to 10, which are generated based on the first propagation path and the second propagation path . Wireless power transmission device. Further , a power receiving identification unit for detecting at least one of the position and the direction of the first power receiving machine and the second power receiving machine is provided.
Claims 1 to 10, wherein at least one of the first power transmission pattern and the second power transmission pattern is generated based on at least one of the position and direction of the first power receiving machine and the second power receiving machine. The wireless power transmission device according to any one of the following items. In the calculation unit, wireless power satisfying the electric energy required from the first electric power receiving electric power and the electric electric power amount required from the second electric power receiving electric power is transmitted to the first electric power receiving electric power and the second electric power receiving electric power within a predetermined time. The wireless power transmission device according to any one of claims 1 to 12, wherein the first power transmission pattern and the second power transmission pattern are determined, and the first power transmission period and the second power transmission period are calculated. .. A wireless power transmission system comprising the wireless power transmission device according to any one of claims 1 to 13, the first receiving electric power, and the second receiving electric power. With a transmitter
A wireless power transmission system including a first receiving electric power and a second receiving electric power for receiving wireless power by radio waves transmitted from the transmitter.
The transmitter is
A control unit that controls the trial transmission of multiple radio waves based on each of multiple transmission patterns,
First information indicating the power received by the first power receiving machine according to the plurality of power transmission patterns transmitted from the first power receiving machine that has received each of the plurality of radio waves, and a request from the first power receiving machine. Receives second information indicating the amount of power to be generated,
A third piece of information indicating the power received by the second power receiving machine according to the plurality of power transmission patterns transmitted from the second power receiving machine that has received each of the plurality of radio waves, and a request from the second power receiving machine. The first communication unit that receives the fourth information indicating the amount of power to be generated , and
Based on the first to fourth information, the first power transmission pattern and the second power transmission pattern included in the plurality of power transmission patterns are determined, and the first power transmission period according to the first power transmission pattern and the second power transmission pattern according to the second power transmission pattern. 2 The first calculation unit that calculates the transmission period and
A power transmission unit that transmits a plurality of radio waves, transmits a first radio wave according to the first power transmission pattern during the first power transmission period, and transmits a second radio wave according to the second power transmission pattern during the second power transmission period. Have and
The first receiving electric machine is
The first power receiving unit that receives the radio waves transmitted from the power transmission unit and generates DC power,
A second calculation unit that generates the first information when the first power receiving unit receives the plurality of radio waves .
It has a second communication unit that transmits the first information and the first radio wave including the second information .
The second receiving electric machine is
A second power receiving unit that receives radio waves transmitted from the power transmission unit and generates DC power, and
A third calculation unit that generates the third information when the second power receiving unit receives the plurality of radio waves.
A wireless power transmission system including a third communication unit that transmits the third information and a second radio wave including the fourth information . At least one of the second communication unit and the third communication unit transmits a beacon signal before the power transmission transmits the plurality of radio waves .
The transmitter is
It further has a propagation path estimation unit that estimates propagation path information between the receiving electric machine that transmitted the beacon signal and the transmitter based on the beacon signal received by the first communication unit.
The wireless power transmission system according to claim 15 , wherein at least one of the first power transmission pattern and the second power transmission pattern is generated based on the propagation path information. A power receiving unit that receives radio waves transmitted from a power transmission and generates DC power,
When the power receiving unit receives a plurality of radio waves based on each of the plurality of power transmission patterns of trial power transmission from the power transmission device , the first information indicating the power received according to the plurality of power transmission patterns is generated. Power receiving power generation unit and
A communication unit for transmitting the first information and the second information indicating the amount of electric power required by the power receiving unit is provided.
The power receiving unit switches between the first power transmission pattern and the second power transmission pattern included in the plurality of power transmission patterns transmitted from the power transmission device that has received the first information and the second information in a unique power transmission period. A power receiving machine that generates the DC power based on radio waves. It is a method of transmitting wireless power by radio waves to the first receiving electric power and the second receiving electric power by a plurality of transmission patterns .
The first information indicating the electric power received by the first electric power transmission pattern according to the plurality of power transmission patterns, the second information indicating the electric energy received by the second electric power transmission pattern according to the plurality of power transmission patterns, the first information. The first power transmission pattern and the first power transmission pattern included in the plurality of power transmission patterns are based on the third information indicating the amount of power required from the first power receiving machine and the fourth information indicating the amount of power required from the second power receiving machine. 2 The power transmission pattern is determined, and the first power transmission period according to the first power transmission pattern and the second power transmission period according to the second power transmission pattern are calculated.
The first radio wave is transmitted by the first power transmission pattern during the first power transmission period, and the second radio wave is transmitted by the second power transmission pattern during the second power transmission period .
Control is performed to test-transmit a plurality of radio waves based on each of the plurality of power transmission patterns from the power transmission unit.
The first information and the third information transmitted from the first receiver that has received each of the plurality of radio waves are received, and the second receiver that has received each of the plurality of radio waves transmits the first information and the third information. Upon receiving the second information and the fourth information ,
A wireless power transmission method that determines the first power transmission pattern and the second power transmission pattern based on the received first information and the fourth information, and calculates the first power transmission period and the second power transmission period. .. It is a method of transmitting wireless power by radio waves to the first receiving electric power and the second receiving electric power by a plurality of transmission patterns .
First propagation path information indicating a first propagation path between the first receiver and the wireless power transmission device, and second propagation path information indicating a second propagation path between the second receiver and the wireless power transmission device. , And, based on at least one of the arrangement information of the first receiving electric power and the second receiving electric power, and the transmission pattern information indicating the plurality of power transmission patterns, the first receiving electric power makes the plurality of power transmission patterns. It is determined whether or not the first information indicating the electric power to be received is necessary, and whether or not the second information indicating the electric power to be received by the second electric power receiving pattern is necessary according to the plurality of power transmission patterns. death,
When it is determined that the first information is necessary, the first receiving electric power is requested to transmit the first information and the third information indicating the amount of electric power required from the first receiving electric power.
When it is determined that the second information is necessary, the second receiver is requested to transmit the second information and the fourth information indicating the amount of power required by the second receiver .
Based on the first information and the third information, and at least one of the second information and the fourth information, the first power transmission pattern and the second power transmission pattern included in the plurality of power transmission patterns are determined, and the first power transmission pattern is determined. Calculate the first power transmission period according to one power transmission pattern and the second power transmission period according to the second power transmission pattern.
A wireless power transmission method in which a first radio wave is transmitted by the first power transmission pattern during the first power transmission period, and a second radio wave is transmitted by the second power transmission pattern during the second power transmission period . The radio waves transmitted from the power transmission are received by the power receiving section to generate DC power.
When the power receiving unit receives a plurality of radio waves based on each of the plurality of power transmission patterns of trial power transmission from the power transmission device , the first information indicating the power received according to the plurality of power transmission patterns is generated. death,
The first information and the second information indicating the amount of electric power required by the power receiving unit are transmitted.
The power receiving unit switches between the first power transmission pattern and the second power transmission pattern included in the plurality of power transmission patterns transmitted from the power transmission device that has received the first information and the second information in a unique power transmission period. A power receiving method that generates the DC power based on radio waves.

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