Wireless power transmission device and wireless power transmission system

Abstract

A wireless power transmission device that transmits wireless power by a radio wave to a plurality of power receivers, has a power transmission condition calculator that calculates power transmission conditions including power transmission periods of two or more of a plurality of different power transmission patterns based on receiving power information and required electric energy information from the plurality of power receivers, and power transmission circuitry that transmits a radio wave while switching between the two or more power transmission patterns under the calculated power transmission conditions.

1 . A wireless power transmission device that transmits wireless power by a radio wave to a plurality of power receivers, comprising:
 a power transmission condition calculator that calculates power transmission conditions including power transmission periods of two or more of a plurality of different power transmission patterns based on receiving power information and required electric energy information from the plurality of power receivers; and   power transmission circuitry that transmits a radio wave while switching between the two or more power transmission patterns under the calculated power transmission conditions.   
     
     
         2 . The wireless power transmission device according to  claim 1 , wherein
 the power transmission conditions include the power transmission periods of the two or more power transmission patterns and at least one of directions of the two or more power transmission patterns, phase of the radio wave, and amplitude of the radio wave.   
     
     
         3 . The wireless power transmission device according to  claim 1 , further comprising:
 a first controller that controls trial power transmission of radio waves based on the plurality of power transmission patterns in sequence from the power transmission circuitry; and   a first communicator that receives the receiving power information and the required electric energy information transmitted from the plurality of power receivers having received the radio waves, wherein   the power transmission condition calculator calculates the power transmission conditions based on the receiving power information and the required electric energy information received by the first communicator.   
     
     
         4 . The wireless power transmission device according to  claim 1 , wherein
 the power transmission condition calculator calculates the power transmission conditions such that wireless power meeting required electric energies of the plurality of power receivers is transmitted to the plurality of power receivers within a predetermined time.   
     
     
         5 . The wireless power transmission device according to  claim 1 , wherein
 the power transmission circuitry divides the power transmission periods of the plurality of power transmission patterns calculated by the power transmission condition calculator into a plurality of power transmission division periods and transmits power while switching between the kinds of the power transmission patterns in the individual power transmission division periods.   
     
     
         6 . The wireless power transmission device according to  claim 1 , further comprising
 a phased array antenna that has a plurality of antennas that transmits or receives a radio wave to or from the plurality of power receivers and a variable phase shifter that is connected to the plurality of antennas to control variably phase of the radio wave to generate the plurality of power transmission patterns.   
     
     
         7 . The wireless power transmission device according to  claim 1 , wherein
 the radio wave transmitted by the power transmission circuitry under the calculated power transmission conditions is a non-modulated continuous wave, and   frequency of the radio wave transmitted by the power transmission circuitry under the calculated power transmission conditions is different from frequency of a radio wave for the plurality of power receivers to transmit the receiving power information and the required electric energy information.   
     
     
         8 . The wireless power transmission device according to  claim 1 , further comprising
 a propagation path estimator that estimates a propagation path between each of the plurality of power receivers and the wireless power transmission device, wherein   at least one of the two or more power transmission patterns for which the power transmission conditions are calculated by the power transmission condition calculator is generated based on the propagation path estimated by the propagation path estimator.   
     
     
         9 . The wireless power transmission device according to  claim 1 , further comprising
 power receiver localization circuitry that detects at least one of locations and directions of the plurality of power receivers, wherein   at least one of the two or more power transmission patterns for which the power transmission conditions are calculated by the power transmission condition calculator is generated based on at least one of the locations and directions of the plurality of power receivers.   
     
     
         10 . A wireless power transmission device that transmits wireless power by a radio wave to a plurality of power receivers, comprising:
 a determination unit that determines whether receiving power information from the plurality of power receivers is required based on at least one of propagation path information of the plurality of power receivers and arrangement information of the plurality of power receivers, and power transmission pattern information to the plurality of power receivers;   a transmission request unit that requests a power receiver for which the receiving power information is determined as required by the determination unit to transmit the receiving power information and required electric energy information required by the power receiver;   a power transmission condition calculator that calculates power transmission conditions including power transmission periods of two or more of a plurality of different power transmission patterns based on the receiving power information and the required electric energy information from a power receiver having accepted a request from the transmission request unit; and   power transmission circuitry that transmits a radio wave while switching between the two or more power transmission patterns under the calculated power transmission conditions.   
     
     
         11 . The wireless power transmission device according to  claim 10 , wherein
 the determination unit determines per power receiver whether the receiving power information and the required electric energy information from the plurality of power receivers are required based on a value obtained by multiplying the propagation path information from the plurality of power receivers and the power transmission pattern information to the plurality of power receivers.   
     
     
         12 . The wireless power transmission device according to  claim 10 , wherein
 the determination unit determines per power receiver whether the receiving power information and the required electric energy information from the plurality of power receivers are required based on the arrangement information of the plurality of power receivers and the power transmission pattern information to the plurality of power receivers.   
     
     
         13 . The wireless power transmission device according to  claim 10 , wherein
 the power transmission conditions include the power transmission periods of the two or more power transmission patterns and at least one of directions of the two or more power transmission patterns, phase of the radio wave, and amplitude of the radio wave.   
     
     
         14 . The wireless power transmission device according to  claim 10 , further comprising:
 a first controller that controls trial power transmission of radio waves based on the plurality of power transmission patterns in sequence from the power transmission circuitry; and   a first communicator that receives the receiving power information and the required electric energy information transmitted from at least one of the plurality of power receivers having received the radio waves,   wherein the power transmission condition calculator calculates the power transmission conditions based on the receiving power information and the required electric energy information received by the first communicator.   
     
     
         15 . The wireless power transmission device according to  claim 10 , wherein
 the power transmission condition calculator calculates the power transmission conditions such that wireless power meeting required electric energies required by each power receiver is transmitted to a corresponding power receiver within a predetermined time.   
     
     
         16 . The wireless power transmission device according to  claim 10 , wherein
 the power transmission circuitry divides each power transmission period of the two or more power transmission patterns calculated by the power transmission condition calculator into a plurality of power transmission division periods and transmits power while switching between the kinds of the power transmission patterns in the individual power transmission division periods.   
     
     
         17 . The wireless power transmission device according to  claim 10 , further comprising
 a phased array antenna that has a plurality of antennas that transmits or receives a radio wave to or from the plurality of power receivers and a variable phase shifter that is connected to the plurality of antennas to control variably phase of the radio wave to generate the plurality of power transmission patterns.   
     
     
         18 . A wireless power transmission system comprising:
 one or more power transmitters; and   a plurality of power receivers that receives wireless power by a radio wave transmitted from the one or more power transmitters, wherein   each of the one or more power transmitters comprises:   a power transmission controller that controls for performing trial power transmission of a plurality of radio waves based on a plurality of power transmission patterns in sequence from the power transmitter;   first communicator that receives receiving power information and required electric energy information transmitted from the plurality of power receivers having received the plurality of radio waves;   a first calculator that calculates power transmission conditions including power transmission periods of two or more of a plurality of different power transmission patterns based on the receiving power information and the required electric energy information from the plurality of power receivers; and   power transmission circuitry that transmits the radio wave while switching between the two or more power transmission patterns under the calculated power transmission conditions, wherein   each of the plurality of power receivers comprises:   power reception circuitry that receives the radio wave transmitted from the power transmission circuitry and generates direct-current power;   a second calculator that, when the power reception circuitry receives the radio waves based on the plurality of power transmission patterns transmitted in trial power transmission from any of the one or more power transmitters, calculates receiving power information of the received radio waves; and   a second communicator that transmits a radio wave including the receiving power information and the required electric energy information.   
     
     
         19 . The wireless power transmission system according to  claim 18 , wherein
 the second communicator in at least one of the plurality of power receivers transmits a beacon signal before the one or more power transmitters perform the trial power transmission,   at least one of the one or more power transmitters comprises a propagation path estimator that, based on the beacon signal received by the first communicator, estimates propagation path information with the power receiver having transmitted the beacon signal, and   at least one of the two or more power transmission patterns for which the power transmission conditions are calculated by the power transmission condition calculator is generated based on the propagation path information.   
     
     
         20 . A wireless power transmission device comprising:
 a power reception circuitry that receives a radio wave from one or more power transmitters and generates direct-current power;   a receiving power generator that, when radio waves based on a plurality of power transmission patterns transmitted in trial power transmission from any of the one or more power transmitters is received by the power reception circuitry, generates receiving power information of the received radio waves; and   a communicator that transmits the receiving power information and required electric energy information, wherein   the power reception circuitry generates the direct-current power based on a radio wave while switching between two or more of the plurality of power transmission patterns transmitted from the power transmitter having received the receiving power information and the required electric energy information and received by the power reception circuitry, in respective specific power transmission periods.