Wireless power supply system

Abstract

Provided is a wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, wherein: the first transmitter and the second transmitter can wirelessly supply electric power to the receiver via power supply radio waves; the center frequency of power supply radio waves of the first transmitter differs from the center frequency of power supply radio waves of the second transmitter; and the power supply radio waves of the first transmitter and the second transmitter are wireless radio waves which can be regarded as substantially uninterrupted continuous waves.

Description

Wireless power supply system

[0001] The present disclosure relates to a wireless power supply system.

[0002] 2. Description of the Related Art Techniques for wirelessly transmitting power are known. Patent Document 1 discloses a technique for providing an electronic device and a power supply method that realize efficient power supply to a terminal.

[0003] Japanese Patent Application Laid-Open No. 2019-154195

[0004] In a wireless power supply system, there is a problem that a receiver may not be able to receive a stable supply of power from multiple transmitters. Therefore, the present disclosure has been made to solve the above problem, and its purpose is to provide a technology that enables a receiver to receive a stable supply of power from multiple transmitters.

[0005] A wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, wherein the first transmitter and the second transmitter are capable of wirelessly supplying power to the receiver via power supply radio waves, the center frequency of the power supply radio waves of the first transmitter is different from the center frequency of the power supply radio waves of the second transmitter, and the power supply radio waves of the first transmitter and the second transmitter are radio waves that can be regarded as approximately continuous waves.

[0006] According to the present disclosure, it is possible to provide a technique that enables a receiver to stably receive power supply from a plurality of transmitters in a wireless power supply system.

[0007] It is a diagram showing the overall configuration of a WPT system 1 according to this embodiment. It is a block diagram showing an example of the configuration of a first transmitter 100, a second transmitter 110, and a receiver 200. It is a block diagram showing the functional configuration of a control device C10.

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In all drawings describing the embodiments, common components are designated by the same reference numerals, and repeated explanations will be omitted. Note that the following embodiments do not unduly limit the content of the present disclosure described in the claims. Furthermore, not all components shown in the embodiments are necessarily essential components of the present disclosure. Furthermore, each drawing is a schematic diagram and is not necessarily a precise illustration.

[0009] <1. Overall System Configuration Diagram> FIG. 1 is a diagram showing the overall configuration of a WPT system 1 according to this embodiment.

[0010] The WPT system 1 shown in Fig. 1 includes, for example, a first transmitter 100, a second transmitter 110, a receiver 200, a first information processing device 300, and a second information processing device 400. The WPT system 1 shown in Fig. 1 is used, for example, in a building or a factory. Note that the connection between the first transmitter 100, the second transmitter 110, and the first information processing device 300, and the connection between the first information processing device 300 and the second information processing device 400 may be wired or wireless.

[0011] 1 shows an example in which the WPT system 1 includes three transmitters (first transmitter 100, second transmitter 110, and third transmitter 120), but the number of transmitters included in the WPT system 1 is not limited to three. The number of transmitters included in the WPT system 1 may be two or less, or may be four or more.

[0012] 1 shows an example in which the WPT system 1 includes seven receivers 200, but the number of receivers 200 included in the WPT system 1 is not limited to seven. The number of receivers 200 included in the WPT system 1 may be six or less, or eight or more.

[0013] The first transmitter 100 and the second transmitter 110 can wirelessly supply power to the plurality of receivers 200 via power supply radio waves. The first transmitter 100 and the second transmitter 110 can wirelessly communicate information with the plurality of receivers 200 via communication radio waves.

[0014] The power supply radio waves of the first transmitter 100 and the second transmitter 110 may be radio waves that can be regarded as substantially continuous waves. The power supply signals transmitted from the first transmitter 100 and the second transmitter 110 are radio frequency signals having a predetermined power. It is preferable to provide these radio frequency signals with pause periods of any period that are short compared to periods other than the pause periods, thereby making the radio frequency signals capable of being regarded as substantially continuous waves. Specifically, the power supply signals (power supply radio waves) transmitted from the first transmitter 100 and the second transmitter 110 may be, for example, continuous waves (CW) having a predetermined power. Furthermore, the frequency band of the power supply signal is, for example, the 920 MHz band, taking into account the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200. If the frequency band is higher than the exemplified frequency band, it may be impossible to supply a predetermined amount of power that enables the receiver 200 to operate unless the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200 is short, so an appropriate frequency band can be determined by taking into consideration a practical range (for example, the distance between the first transmitter 100 and the second transmitter 110 and the receiver 200 may be several meters). Note that in the present disclosure, the frequencies of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 differ from each other, with the 920 MHz band being the center.

[0015] In this case, the laws of the country in which the WPT system 1 is installed may impose restrictions on the intermittent transmission of a power feed signal having a predetermined power. For example, if the power feed signals from the first transmitter 100 and the second transmitter 110 fall under the radio station regulations stipulated in Japan's Radio Act (regardless of whether a license is granted), the Radio Act may require a certain pause period for the power feed signal. In this case, the power feed signal cannot be considered a continuous wave when considered over a certain time axis. However, it is essential to provide a pause period, and a short pause period is sufficient. Therefore, the power feed signals transmitted from the first transmitter 100 and the second transmitter 110 can be considered to be a substantially continuous wave. As described above, the ratio between the duration of the power feed signal and the duration of the pause period may be set to a value sufficient to allow the power feed signals transmitted from the first transmitter 100 and the second transmitter 110 to be considered to be a substantially continuous wave. For example, the duration of the pause period is approximately 1 / 50 to 1 / 100 of the duration of the power feed signal.

[0016] The power supply radio waves from the first transmitter 100 and the second transmitter 110 are preferably unmodulated, unmodulated, and uninformed. Specifically, there is a radio wave type that indicates the characteristics of radio waves generally used in communication systems. The radio wave type is expressed by a three-character string combining letters or numbers that indicate the modulation type of the main carrier wave, the nature of the signal modulating the main carrier wave, and the type of information transmitted. The modulation type of the main carrier wave can be one of the following: N: no modulation; A: amplitude modulation (double sideband); H: amplitude modulation (single sideband, full carrier); R: amplitude modulation (single sideband, reduced carrier); J: amplitude modulation (single sideband, suppressed carrier); B: amplitude modulation (independent sideband); C: amplitude modulation (independent sideband); F: angle modulation (frequency modulation); G: angle modulation (phase modulation); and D: amplitude modulation and angle modulation modulated simultaneously or in a fixed order. The nature of the signal modulating the primary carrier wave is one of: 0 (no modulated signal), 1 (a single channel of a digital signal without a subcarrier), 2 (a single channel of a digital signal with a subcarrier), 3 (a single channel of an analog signal), 7 (two or more channels of a digital signal), 8 (two or more channels of an analog signal), or 9 (a combination of one or more channels of an analog signal and one or more channels of a digital signal). The type of transmitted information is one of: N (no information), A (telegraph (audible reception)), B (telegraph (automatic reception)), C (facsimile), D (data transmission, telemetry, remote command), E (telephone (audio)), F (television (video)), or W (a combination of N to F). In this disclosure, the radio wave types of the power supply radio waves of the first transmitter 100 and the second transmitter 110 are N0N, with N (unmodulated), 0 (a single channel of a digital signal without a subcarrier), and N (no information). In this case, the power transmission radio wave indicates that the main carrier wave is not modulated (unmodulated), there is no digital signal (a single channel digital signal without a subcarrier), and there is no information being transmitted (no information). This allows for stable energy transmission by reducing interference with other surrounding communication systems due to the lack of modulation. Also, because it is unmodulated, the transmitted energy is concentrated on the carrier wave. This allows for efficient energy transmission between the transmitter and receiver.Because no information is transmitted, the system is simple and the transmitter and receiver can be designed and implemented simply.

[0017] In this specification, the first transmitter 100 and the second transmitter 110 are (power) first transmitter 100 and (power) second transmitter 110 in the sense of wirelessly transmitting power, and similarly, the receiver 200 is (power) receiver 200 in the sense of wirelessly receiving power. As described below, the receiver 200 may transmit, for example, information about the state of the receiver 200 or information about measurement results by a sensor to the first transmitter 100 and the second transmitter 110 as a data signal (communication radio wave), and the first transmitter 100 and the second transmitter 110 may receive such data signal. In this case, the first transmitter 100 and the second transmitter 110 are receivers that receive the data signal, and the receiver 200 functions as a transmitter that transmits the data signal.

[0018] 1 shows an example in which the WPT system 1 includes two first information processing devices 300, but the number of first information processing devices 300 included in the WPT system 1 is not limited to two. The number of first information processing devices 300 included in the WPT system 1 may be one, or three or more.

[0019] The following describes the relationship between the first transmitter 100 and the receiver 200, the first information processing device 300, the second information processing device 400, etc. Note that the second transmitter 110 is similar to the first transmitter 100, and therefore a detailed description thereof will be omitted.

[0020] The first transmitter 100 transmits, for example, a power supply signal or a data signal to the receiver 200. The first transmitter 100 transmits, for example, a power supply signal to the receiver 200 by radio waves in the 920 MHz band. The first transmitter 100 transmits, for example, a data signal to the receiver 200 by radio waves in the 2.4 GHz band. The first transmitter 100 may transmit a data signal by radio waves in the 920 MHz band.

[0021] The first transmitter 100 may, for example, supply power to one receiver 200, or may supply power to multiple receivers 200. The first transmitter 100 may, for example, transmit a data signal to one receiver 200, or may transmit a data signal to multiple receivers 200. The first transmitter 100 may, for example, transmit the same data signal as another first transmitter 100, or may transmit a data signal different from that of the other first transmitters 100. The first transmitter 100 may, for example, transmit a predetermined command signal as a data signal to the receiver 200, or may transmit a preset signal as a data signal to the receiver 200.

[0022] The first transmitter 100 receives, for example, a data signal transmitted from the receiver 200. The first transmitter 100 may receive, for example, a data signal transmitted from one receiver 200, or may receive data signals transmitted from a plurality of receivers 200. The first transmitter 100 transmits the data signal transmitted from the receiver 200 to the first information processing device 300. The first transmitter 100 transmits information related to the state of the first transmitter 100 to the first information processing device 300.

[0023] The receiver 200 receives, for example, a power supply signal or a data signal transmitted from the first transmitter 100. If the receiver 200 has, for example, a power storage unit, it converts the power supply signal transmitted from the first transmitter 100 into electric power and stores the converted electric power in the power storage unit. If the receiver 200 has, for example, a predetermined sensor, it converts the power supply signal transmitted from the first transmitter 100 into electric power and drives the sensor with the converted electric power.

[0024] The receiver 200 transmits, for example, information about the state of the receiver 200 or information about the measurement results of the sensor to the first transmitter 100 as a data signal.

[0025] The first information processing device 300 is an information processing device that monitors the operations of the first transmitter 100 and the receiver 200 housed in the WPT system 1. For example, the first information processing device 300 determines whether the first transmitter 100 or the receiver 200 is in a preset state based on information about the states of the first transmitter 100 and the receiver 200 transmitted from the first transmitter 100. If it is determined that the first information processing device 300 is in a preset state, the first information processing device 300 transmits predetermined information to the second information processing device 400.

[0026] Furthermore, the first information processing device 300 accumulates information about the first transmitter 100 and the receiver 200 accommodated in the WPT system 1. For example, the first information processing device 300 stores information about the states of the first transmitter 100 and the receiver 200, which is transmitted from the first transmitter 100, in a storage unit provided in the first information processing device 300.

[0027] Furthermore, the first information processing device 300 controls the operation of the first transmitter 100 housed in the WPT system 1. For example, the first information processing device 300 transmits predetermined instructions or information to the first transmitter 100.

[0028] The first information processing device 300 also controls the operation of the second information processing device 400 .

[0029] The second information processing device 400 is, for example, an information processing device operated by an administrator of the WPT system 1. When the second information processing device 400 receives a notification from the first information processing device 300 that the first transmitter 100, the receiver 200, or both of them housed in the WPT system 1 are in a predetermined state, the second information processing device 400 notifies the user that the first transmitter 100, the receiver 200, or both of them are in the predetermined state.

[0030] Furthermore, the second information processing device 400 analyzes information about the status of the first transmitter 100 and the receiver 200 stored in the first information processing device 300, and presents predetermined information to the user. The predetermined information is, for example, the following: Information about the location of the first transmitter 100 Information about the location of the receiver 200 Information about power consumption Information about the amount of power

[0031] <Configuration of Transmitter and Receiver> FIG. 2 is a block diagram showing an example configuration of the first transmitter 100 and the receiver 200 shown in FIG. 1 . As shown in FIG. 2 , the first transmitter 100 and the receiver 200 are, for example, spaced apart by a predetermined distance. For example, the first transmitter 100 and the receiver 200 are installed at a distance of approximately several meters. Specifically, for example, the first transmitter 100 is fixedly installed at a high location indoors, such as a predetermined high position on a ceiling or wall. The receiver 200 is installed in a predetermined device indoors or placed near a device requiring power supply. The receiver 200 may also be carried by a user. The first transmitter 100 transmits a power supply signal to the receiver 200 using radio waves at a predetermined frequency, for example, the 920 MHz band. The receiver 200 converts the power supply signal transmitted from the first transmitter 100 into power and uses the converted power to charge or supply the converted power to a predetermined device.

[0032] The first transmitter 100 includes, for example, an oscillator 101, a transmitting antenna 102, a microcomputer (controller) 103, a data transceiver 104, a data transmitting / receiving antenna 105, a capacitor, a PLL 107, a power amplifier 108, and a power supply 109. The oscillator 101, the microcomputer 103, the data transceiver 104, the data transmitting / receiving antenna 105, the capacitor, the PLL 107, the power amplifier 108, the power supply 109, or a combination of at least any of these may be mounted on, for example, a PCB (printed circuit board).

[0033] The oscillator 101 oscillates a signal in a predetermined frequency band, for example, the 920 MHz band. The oscillated signal may be amplified and unwanted frequency components may be removed, if necessary.

[0034] The transmitting antenna 102 is configured to be able to efficiently transmit radio waves in the 920 MHz band, for example, and emits a signal oscillated by the oscillator 101 as a power supply signal.

[0035] The microcomputer 103 controls the operation of the first transmitter 100. The microcomputer 103 is realized by, for example, a semiconductor device equipped with an ARM processor. The microcomputer 103 controls, for example, the transmission of radio waves by the transmitting antenna 102. The microcomputer 103 can control the transmission intensity of radio waves by the transmitting antenna 102 by controlling the current and voltage of power supplied to the power amplifier 108.

[0036] The data transceiver 104 performs processes such as converting digital data to analog and modulating analog data. The data transceiver 104 also performs processes such as demodulating a data signal received by the data transceiver antenna 105 and digitizing the demodulated data. For example, the data transceiver 104 extracts a predetermined signal from the data signal received by the data transceiver antenna 105, converts it into digital data, and transmits it to the microcomputer 103.

[0037] The data transmission / reception antenna 105 is configured to be able to efficiently transmit and receive radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 105 radiates data signals supplied from the data transceiver 104. The data transmission / reception antenna 105 also receives data signals transmitted from the receiver 200.

[0038] The capacitor is provided between the PLL 107, the power supply 109, and GND (ground, 0 V) ​​and serves as a bypass capacitor for generating a high-quality signal. The capacitor may also be connected to the PLL 107 and serve as a low-pass filter for generating a high-quality signal and removing unnecessary high-frequency components. The low-pass filter includes a resistor and a capacitor and has the function of passing high-frequency components through the capacitor and allowing low-frequency components to pass. By providing a low-pass filter between the oscillator 101 and the PLL 107, unnecessary high-frequency components can be removed, improving the quality of the output signal.

[0039] The PLL 107 is an electronic circuit called a Phase-Locked Loop for controlling frequency and phase. A capacitor is connected to the PLL, and the frequency of the radio waves transmitted by the transmitting antenna 102 changes depending on the capacitance of the capacitor. In this disclosure, the capacitor is provided between the oscillator 101 and the PLL 107.

[0040] The power amplifier 108 is an electronic circuit that amplifies the signal output from the PLL 107 based on the power from the microcomputer 103 and outputs the amplified signal to the transmitting antenna 102 .

[0041] The power supply 109 supplies power to the oscillator 101 and the microcomputer 103 .

[0042] The receiver 200 includes, for example, a receiving antenna 201, a rectifier 202, a power management unit 203, a power storage unit 204, a microcomputer 205, a data transceiver 206, and a data transmitting / receiving antenna 207. The receiving antenna 201, the rectifier 202, the power management unit 203, the power storage unit 204, the microcomputer 205, the data transceiver 206, and the data transmitting / receiving antenna 207, or a combination of at least any of these, may be mounted on, for example, a PCB or an FPC (flexible printed circuit board).

[0043] The receiving antenna 201 is configured to be able to efficiently receive radio waves in the 920 MHz band, for example. The receiving antenna 201 receives the power supply signal radiated from the transmitting antenna 102.

[0044] The rectifier 202 rectifies the radio waves received as the power supply signal and converts them into a DC voltage.

[0045] The power management unit 203 manages the DC voltage. For example, the power management unit 203 controls a charging voltage based on the DC voltage. The power management unit 203 charges the power storage unit 204 by controlling the charging voltage. Furthermore, for example, when the power storage unit 204 stores power equal to or greater than a predetermined capacity, the power management unit 203 supplies the DC voltage to a connected component.

[0046] Furthermore, the power management unit 203 discharges the power stored in the power storage unit 204 in response to control from the microcomputer 205 .

[0047] The power storage unit 204 stores power in response to an instruction from the power management unit 203. The power storage unit 204 is realized by, for example, a battery or a capacitor. The power storage unit 204 also discharges the stored power in response to an instruction from the power management unit 203.

[0048] The microcomputer 205 controls the operation of the receiver 200. The microcomputer 205 is driven by a DC voltage supplied from the power management unit 203 or by power stored in the power storage unit 204. The microcomputer 205 controls the power management unit 203 to cause the power storage unit 204 to release the power stored therein.

[0049] For example, various sensors can be connected to the receiver 200. For example, a heat sensor, a temperature sensor, a light sensor, a humidity sensor, a vibration sensor, etc. are connected to the receiver 200. The sensors connected to the receiver 200 are driven, for example, by a DC voltage supplied from the power management unit 203 or by power discharged from the power storage unit 204. The microcomputer 205 continuously or intermittently monitors the voltage values ​​at predetermined locations of the receiver 200, the status of the sensors connected to the receiver 200, information detected by the sensors, etc. The microcomputer 205 transmits the voltage values ​​at predetermined locations of the receiver 200, the status of the sensors connected to the receiver 200, information detected by the sensors, etc. as digital data to the data transceiver 206. Note that the sensors may be built into the receiver 200.

[0050] The data transceiver 206 performs processes such as converting digital data supplied from the microcomputer 205 into analog data and modulating the analog data. The data transceiver 206 also performs processes such as demodulating a data signal received by a data transmission / reception antenna 207 and digitizing the demodulated data. The data transceiver 206 is driven by, for example, a DC voltage supplied from the power management unit 203 or power discharged from the power storage unit 204.

[0051] The data transmission / reception antenna 207 is configured to be able to efficiently transmit and receive radio waves in the 2.4 GHz band, for example. The data transmission / reception antenna 207 radiates a data signal supplied from the data transceiver 206. The data transmission / reception antenna 207 also receives a data signal transmitted from the first transmitter 100. For example, the data transmission / reception antenna 207 is driven by a DC voltage supplied from the power management unit 203 or by power discharged from the power storage unit 204.

[0052] <Configuration of the control device C10> The control device C10 is an information processing device including a storage unit C101 and a control unit C104. In the present disclosure, the control device C10 is disclosed as an information processing device different from the first information processing device 300 and the second information processing device 400. However, the first information processing device 300 or the second information processing device 400 may have the functions of the control device C10. In other words, the control device C10 may be the first information processing device 300 or the second information processing device 400. Furthermore, the functions of the control device C10 may be included in at least one of the multiple first transmitters 100 and implemented as part of the functions of the first transmitter 100. In other words, the processing executable by the control device C10 may be executed by the first transmitter 100. In other words, the first transmitter 100 may include, as part of the hardware and software configuration of the control device C10. For example, any one of the multiple first transmitters 100 may function as a master (host) of the other first transmitters 100, fulfilling the functions of the control device C10 and executing various processes. In other words, the master first transmitter 100 may partially include hardware and software configurations for functioning as the control device C10. Note that all of the first transmitters 100 may partially include hardware and software configurations for functioning as the control device C10. In this case, a selected, predetermined first transmitter 100 may fulfill the functions of the control device C10 as a master. The master may be selected by an input operation by the user. FIG. 3 is a block diagram showing the functional configuration of the control device C10.

[0053] <Configuration of Storage Unit C101 of Control Device C10> The storage unit C101 of the control device C10 includes an application program C1011.

[0054] The application program C1011 is a program for causing the control unit C104 of the control device C 10 to function as each functional unit, and includes applications such as a web browser application.

[0055] <Configuration of the control unit C104 of the control device C10> The control unit C104 of the control device C10 executes the application program C1011 stored in the storage unit C101, thereby realizing each functional unit.

[0056] The control device C10 can control the plurality of transmitters via a wired connection. Specifically, the control device C10 may be wired to the plurality of first transmitters 100 based on any wired connection standard such as Ethernet, USB (Universal Serial Bus), or serial connection. The control unit C104 of the control device C10 can control the transmission of a power supply signal and the transmission and reception of a data signal by the first transmitters 100 by transmitting a control signal to the first transmitters 100 via the wired connection.

[0057] The control device C10 can control the multiple transmitters via a wireless connection. Specifically, the control device C10 may be wirelessly connected to the multiple first transmitters 100 based on any wireless connection standard such as Wi-Fi, Bluetooth (registered trademark), NFC (Near Field Communication), Zigbee (registered trademark), Z-Wave, or LTE. The control unit C104 of the control device C10 can control the transmission of a power supply signal and the transmission and reception of a data signal by the first transmitters 100 by transmitting a control signal to the first transmitters 100 via the wireless connection.

[0058] <Operation of WPT System 1> Features of the WPT system 1 in the present disclosure will be described below.

[0059] The center frequency of the power supply radio wave of the first transmitter 100 is different from the center frequency of the power supply radio wave of the second transmitter 110. Specifically, the center frequency refers to the frequency located in the center of the frequency band of the frequency range of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110. Note that in the present disclosure, the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 are assumed to be radio waves of the same channel (substantially the same frequency) as defined by the Radio Act. A predetermined reference frequency is assigned to each predetermined channel, and typically, radio waves having frequencies within a range of ±20 ppm (Parts Per Million) from the reference frequency (center frequency) are considered to be radio waves of the same channel. For example, if the reference frequency of a predetermined channel is f, then multiple radio waves having frequencies within a range of f × (1±20 / 1,000,000) [Hz] are considered to be radio waves of the same channel. In this disclosure, the definition of a co-channel based on the Japanese Radio Act has been described as an example, but is not limited to this. The range of a co-channel may be specifically determined based on the laws and regulations of the country of implementation, industry practices, etc. For example, any center frequency may be selected within the range of 902 MHz to 928 MHz in the Americas, and 865.0 to 865.6 MHz in the European countries. For example, the center frequency of the first transmitter may be 902 MHz, and the center frequency of the second transmitter may be 928 MHz. It may also be applied to other frequencies such as 24 GHz (millimeter waves).

[0060] In the present disclosure, the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 are unmodulated, unmodulated, and uninformed radio waves (radio wave type N0N). In such cases, the center frequency is the frequency of the power supply radio waves. In the present disclosure, the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 are radio wave type N0N. Radio waves of type N0N are known as unmodulated continuous waves (CW) and, in theory, should have a single frequency. However, it is difficult for an actual transmitter to maintain a perfectly constant frequency. For example, changes in the outside temperature in the environment in which the transmitter is installed affect the characteristics of the transmitter's components (especially the oscillator), which in turn affects the frequency of the power supply radio waves transmitted by the transmitter. Furthermore, subtle individual differences in the manufacturing process of electronic components such as oscillators, capacitors, and resistors included in the transmitter may affect the transmission frequency. Noise from the power supply supplied to the transmitter and instability of the power supply also affect the transmitter's frequency. In this disclosure, the center frequency will be described as an example where it is the average value of the minimum and maximum values ​​of the power supply radio waves transmitted over a specified period in a specified installation environment in which the first transmitter 100 and the second transmitter 110 are installed.

[0061] The center frequency f1 [Hz] of the power feeding radio wave of the first transmitter 100 is equal to or less than f2 × (1 + 100 / 1,000,000) [Hz] and equal to or greater than f2 × (1 - 100 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power feeding radio wave of the second transmitter 110. The center frequency f1 [Hz] of the power feeding radio wave of the first transmitter 100 is equal to or greater than f2 × (1 + 1 / 1,000,000) [Hz] and equal to or less than f2 × (1 - 1 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power feeding radio wave of the second transmitter 110. When the center frequency of the power supply wave of the second transmitter 110 is f2 [Hz], the center frequency f1 [Hz] of the power supply wave of the first transmitter 100 is equal to or greater than f2 × (1 + 1 / 1,000,000) [Hz], and it is preferable that the center frequency f1 of the first transmitter 100 and the center frequency f2 of the second transmitter 110 differ from each other in a range of equal to or less than f2 × (1 + 100 / 1,000,000) [Hz]. When the center frequency of the power supply wave of the second transmitter 110 is f2 [Hz], the center frequency f1 [Hz] of the power supply wave of the first transmitter 100 is equal to or less than f2 × (1-1 / 1,000,000) [Hz], and it is preferable that the center frequency f1 of the first transmitter 100 and the center frequency f2 of the second transmitter 110 differ in a range of equal to or more than f2 × (1-100 / 1,000,000) [Hz].

[0062] Specifically, it is preferable that the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 differ within the range specified by the Radio Act (±20 ppm, Parts Per Million) based on the reference frequency fc specified by the Radio Act for each specified channel.

[0063] The center frequency f1 [Hz] of the power feeding radio wave of the first transmitter 100 is preferably in the range of f2 × (1 + 20 / 1,000,000) [Hz] or less and f2 × (1 - 20 / 1,000,000) [Hz] or more, where f2 [Hz] is the center frequency of the power feeding radio wave of the second transmitter 110. The center frequency f1 [Hz] of the power feeding radio wave of the first transmitter 100 is preferably in the range of f2 × (1 + 1,000 / 1,000,000) [Hz] or less and f2 × (1 - 1,000 / 1,000,000) [Hz] or more, where f2 [Hz] is the center frequency of the power feeding radio wave of the second transmitter 110.

[0064] When the center frequency of the power feed radio wave of the first transmitter 100 is 920 MHz, the center frequency of the power feed radio wave of the second transmitter 110 is preferably approximately 920 MHz ± 9.2 kHz. Specifically, the center frequency of the power feed radio wave of the second transmitter 110 preferably differs from the center frequency of the power feed radio wave of the first transmitter 100 by approximately 920 MHz × (10 / 1,000,000) [Hz] = 9.2 kHz. When the above two waves with different frequencies overlap, the amplitude (received power) fluctuates at 9.2 kHz. The fluctuation refers to the occurrence of both increased and decreased power over time. The shorter the fluctuation between the increased and decreased power times, the more robust the behavior over time. When the center frequency f1 of the power transmission wave of the first transmitter 100 and the center frequency f2 of the power transmission wave of the second transmitter 110 differ by about 9.2 kHz, the temporal fluctuation of the supplied power is approximately 1 / 9.2 kHz = 100 μsec. In particular, when applied to wireless power transmission in sensors used in FA (Factory Automation) devices, beacons, etc., this level of temporal fluctuation of the supplied power is suitable because it does not affect the operation of the power transmission device.

[0065] When the center frequency of the power feeding radio wave of the second transmitter 110 is f2 [Hz], the center frequency f1 [Hz] of the power feeding radio wave of the first transmitter 100 is preferably equal to or greater than f2 × (1 + 0.001 / 1,000,000) [Hz] or equal to or less than f2 × (1 - 0.001 / 1,000,000) [Hz]. Specifically, when the center frequency of the power feeding radio wave of the first transmitter 100 is 920 MHz, the center frequency of the power feeding radio wave of the second transmitter 110 is preferably approximately 920 MHz ± 9.2 Hz. Specifically, the center frequency of the power feeding radio wave of the second transmitter 110 is preferably different from the center frequency of the power feeding radio wave of the first transmitter 100 by approximately 920 MHz × (0.001 / 1,000,000) [Hz] = 9.2 Hz. When the two waves with different frequencies overlap, the amplitude (received power) fluctuates by 9.2 Hz. The fluctuation refers to the occurrence of both increased and decreased power over time. The shorter the fluctuation between the increased and decreased power periods, the more robust the behavior over time. When the center frequency f1 of the power transmission wave from the first transmitter 100 and the center frequency f2 of the power transmission wave from the second transmitter 110 differ by approximately 9.2 Hz, the temporal fluctuation in the power supply is approximately 1 / 9.2 Hz, or 10 milliseconds. This is particularly suitable for environmental sensors, which are devices for detecting, measuring, and monitoring environmental conditions (temperature, humidity, air pressure, lighting conditions, acoustic conditions, radiation levels, vibrations, wind speed and direction, or other environmental factors) in the installation environment, as these sensors have a large storage capacity and thus such temporal fluctuations in the power supply do not affect the operation of the power supply device.

[0066] The center frequency of the powered radio wave of the first transmitter 100 and the center frequency of the powered radio wave of the second transmitter 110 can be made different based on the following conditions: The capacitances of the capacitors connected to the output terminals of the first transmitter 100 and the second transmitter 110 are different. Note that the capacitor referred to here is a capacitor included in a low-pass filter connected to the PLL 107 and used to suppress the effects of power supply noise on the transmitted radio wave signal. The capacitor is included in at least the first transmitter 100 or the second transmitter 110. The component characteristics of the first transmitter 100 and the second transmitter 110 differ due to differences in the outside temperatures of the installation environments of the first transmitter 100 and the second transmitter 110. This also includes cases where the temperature characteristics of the first transmitter 100 and the second transmitter 110 change due to differences in the components of the first transmitter 100 and the second transmitter 110. The power supply voltage or power supply current supplied to the first transmitter 100 and the second transmitter 110 are different. Specifically, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107. Specifically, in the first transmitter 100 and the second transmitter 110, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107, thereby making the center frequency of the powered radio wave of the first transmitter 100 and the center frequency of the powered radio wave of the second transmitter 110 different from each other.

[0067] The first transmitter 100 or the second transmitter 110 may make the center frequency of the power supply radio wave of the first transmitter 100 different from the center frequency of the power supply radio wave of the second transmitter 110 without receiving communication information from each other. Specifically, it is possible to set the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 to different frequencies in advance. Furthermore, by controlling the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 randomly at predetermined intervals according to a predetermined time-varying pattern, the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 can be made different from each other without receiving communication information from each other. This reduces the complexity of the wireless power supply system, reduces interference between transmitters, and improves the efficiency of power transmission. Furthermore, since communication is not required, security risks can be reduced.

[0068] <Operation of the control device C10> The control of the first transmitter 100 by the control unit C104 of the control device C10 will be described.

[0069] The wireless power feeding system (WPT system 1) includes a control device C10 capable of controlling the first transmitter 100 and the second transmitter 110, and the control device C10 controls the first transmitter 100 so that the center frequency of the power feeding radio wave differs from the center frequency of the power feeding radio wave of the second transmitter 110. The center frequencies of the first transmitter 100 and the second transmitter 110 are controlled to differ based on at least one of the following control means: a temperature control means for controlling the temperature of the first transmitter 100 and the second transmitter 110; a power supply voltage control means for controlling the power supply voltage of the first transmitter 100 and the second transmitter 110; and a power supply current control means for controlling the power supply current to the first transmitter 100 and the second transmitter 110.

[0070] The control device C10 controls the temperature of the components or the outside air temperature by sending a control signal to the microcomputer of the first transmitter 100 or the second transmitter. As a result, the center frequencies of the first transmitter 100 and the second transmitter 110 are controlled to be different. For example, the control device C10 may control the temperature by controlling the microcomputer 103 included in the first transmitter 100 or the second transmitter 110 to cause the components included in the transmitter to generate heat. Alternatively, the temperature of the transmitter may be controlled by separately controlling a heater (not shown) included in the transmitter. Furthermore, the temperature of the first transmitter 100 or the second transmitter 110 may be controlled by controlling an air conditioning device or the like in the installation environment where the first transmitter 100 or the second transmitter 110 is installed.

[0071] The control device C10 controls the power supply voltage or power supply current supplied to the PLL 107 by transmitting a control signal to the microcomputer of the first transmitter 100 or the second transmitter. As a result, the center frequencies of the first transmitter 100 and the second transmitter 110 are controlled to be different. Specifically, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107. Specifically, in the first transmitter 100 and the second transmitter 110, the microcomputer 103 controls the voltage and current of the power supplied to the PLL 107, thereby making the center frequency of the powered radio wave of the first transmitter 100 and the center frequency of the powered radio wave of the second transmitter 110 different from each other.

[0072] The first transmitter 100 or the second transmitter 110 may control the center frequency of the power supply radio wave of the first transmitter 100 so that it is different from the center frequency of the power supply radio wave of the second transmitter 110, without receiving communication information from each other. Specifically, the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be set to different frequencies in advance. Alternatively, the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be controlled randomly at predetermined intervals according to a predetermined time-varying pattern, thereby making the center frequencies of the power supply radio waves transmitted by the first transmitter 100 and the second transmitter 110 different without receiving communication information from each other. This reduces interference between the transmitters, enables each transmitter to transmit power efficiently, and improves the power transmission performance of the wireless power supply system.

[0073] The first transmitter 100 and the second transmitter 110 may include communication means for communicating with each other, and the first transmitter 100 or the second transmitter 110 may control the center frequency of the power feeding radio wave of the first transmitter 100 to be different from the center frequency of the power feeding radio wave of the second transmitter 110 based on communication information received via the communication means. Specifically, the first transmitter 100 may acquire information regarding the frequency of the power feeding radio wave transmitted by the second transmitter 110 via wireless or wired communication, and control the frequency of the power feeding radio wave transmitted by the first transmitter 100 to be different from the frequency of the power feeding radio wave transmitted by the second transmitter 110. Alternatively, the first transmitter 100 may control the frequency of the power feeding radio wave transmitted by the first transmitter 100 to be different from the frequency of the power feeding radio wave transmitted by the second transmitter 110 based on information regarding the frequency of the power feeding radio wave transmitted by the second transmitter 110 acquired via the control device C10.

[0074] When the receiver 200 is installed in a mobile object, the control device C10 may be configured to execute the power supply control according to the present disclosure when the receiver 200 enters the power supply space. Specifically, when the receiver 200 newly enters the space, the control device C10 may execute the power supply control according to the present disclosure for a predetermined period of time, and may not execute the power supply control according to the present disclosure after the predetermined period has elapsed. This allows stable power supply even when the position of the receiver 200 is not determined within the power supply space. Furthermore, if power supply radio waves can be transmitted so as to ensure stable power supply to the position of the receiver 200 after the predetermined period has elapsed, the control according to the present disclosure may not be executed.

[0075] The difference in frequency of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be changed depending on the distance between the first transmitter 100 and the second transmitter 110. For example, the frequencies of the radio waves of the first transmitter 100 and the second transmitter 110 may be controlled to be different depending on the positions within the power supply space where the first transmitter 100 and the second transmitter 110 are installed, so that power can be supplied stably throughout the power supply space. For example, the greater the distance between the first transmitter 100 and the second transmitter 110, the greater the difference in frequency of the power supply waves of the first transmitter 100 and the second transmitter 110. For example, the greater the distance between the first transmitter 100 and the second transmitter 110, the smaller the difference in frequency of the power supply waves of the first transmitter 100 and the second transmitter 110.

[0076] Alternatively, the difference in frequency of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be changed depending on the output power between the first transmitter 100 and the second transmitter 110. For example, the frequencies of the radio waves transmitted by the first transmitter 100 and the second transmitter 110 may be controlled to be different depending on the output power, the difference in output power, the ratio of output power, etc. of the power supply waves of the first transmitter 100 and the second transmitter 110 so as to stably supply power to the entire power supply space. For example, the greater the difference in output power of the power supply waves between the first transmitter 100 and the second transmitter 110, the greater the difference in frequency of the power supply waves between the first transmitter 100 and the second transmitter 110. For example, the smaller the difference in output power of the power supply waves between the first transmitter 100 and the second transmitter 110, the smaller the difference in frequency of the power supply waves between the first transmitter 100 and the second transmitter 110.

[0077] In the present disclosure, the first transmitter 100 and the second transmitter 110 are described as transmitting devices housed in separate housings. The first transmitter 100 and the second transmitter 110 may be configured as antenna elements of an array antenna composed of multiple antenna elements. Specifically, the first antenna element and the second antenna element included in multiple antenna elements housed in a single housing may be considered as the first transmitter 100 and the second transmitter 110. In such a case, when a single receiver receives power via radio waves from a single array antenna, the receiver can receive a stable power supply from the single array antenna regardless of the location in the space where the receiver is installed. Specifically, the occurrence of spatial locations (dead spots) where the receiver cannot receive sufficient power can be suppressed. This allows the single array antenna to supply power more uniformly throughout the entire power supply space.

[0078] <Additional Notes> The matters described in the above embodiments will be added below.

[0079] (Supplementary Note 1) In a wireless power supply system including a first transmitter, a second transmitter, and at least one receiver, the first transmitter (100) and the second transmitter (110) can wirelessly supply power to the receiver (200) via power supply radio waves, the center frequency of the power supply radio waves of the first transmitter is different from the center frequency of the power supply radio waves of the second transmitter, and the power supply radio waves of the first transmitter and the second transmitter are radio waves that can be considered to be substantially continuous waves. When one receiver receives power supply via radio waves from multiple transmitters, the receiver can receive stable power supply from the multiple transmitters regardless of its location in the space where the receiver is installed. Specifically, the occurrence of spatial locations (dead spots) where the receiver cannot receive sufficient power supply can be suppressed. This allows the transmitter to supply power more uniformly throughout the entire power supply space.

[0080] (Supplementary Note 2) The wireless power feeding system according to Supplementary Note 1, wherein the frequency of the power feeding radio waves of the first transmitter (100) is a radio wave belonging to the same channel as the frequency of the power feeding radio waves of the second transmitter (110). This allows the first transmitter and the second transmitter, which transmit power feeding radio waves belonging to channels in the same radio wave frequency band, to supply sufficient power to the receiver while suppressing the occurrence of spatial positions (dead spots) in the power feeding space where stable power supply is not possible. This allows the multiple transmitters to supply power to the receiver using power feeding radio waves in the same channel frequency band, while the transmitters can supply power more uniformly throughout the entire power feeding space.

[0081] (Supplementary Note 3) The wireless power feeding system according to Supplementary Note 1, wherein the first transmitter (100) and the second transmitter (110) are capable of wirelessly communicating information with the receiver (200) via communication radio waves, and the power feeding radio waves of the first transmitter and the second transmitter are unmodulated radio waves without a modulated signal and without information. This improves power transmission efficiency. It is possible to prevent the power feeding radio waves from including information unnecessary for communication.

[0082] (Supplementary Note 4) The wireless power transfer system according to Supplementary Note 1, wherein the center frequency f1 [Hz] of the power transmission wave from the first transmitter is equal to or less than f2 × (1 + 1000 / 1,000,000) [Hz] and equal to or greater than f2 × (1 - 1000 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power transmission wave from the second transmitter. When a single receiver receives power supply from multiple transmitters via wireless radio waves, the receiver can receive power supply from the multiple transmitters stably regardless of the location of the receiver in the space where it is installed. Specifically, the occurrence of dead spots can be particularly suppressed.

[0083] (Supplementary Note 5) The wireless power feeding system according to Supplementary Note 4, wherein the center frequency f1 [Hz] of the power feeding radio wave of the first transmitter is equal to or greater than f2 × (1 + 0.001 / 1,000,000) [Hz] or equal to or less than f2 × (1 - 0.001 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power feeding radio wave of the second transmitter. When one receiver is supplied with power by wireless radio waves from multiple transmitters, the receiver can stably receive power from the multiple transmitters regardless of the location of the receiver in the space where it is installed.

[0084] (Supplementary Note 6) The wireless power feeding system according to Supplementary Note 1, wherein the capacitances of the capacitors connected to the output terminals of the first transmitter and the second transmitter are different from each other, so that the center frequency of the power feeding radio wave of the first transmitter is different from the center frequency of the power feeding radio wave of the second transmitter. This allows the center frequencies of the first transmitter and the second transmitter to be different. A wireless power feeding system can be realized that can stably supply power from multiple transmitters to one receiver regardless of the location of the receiver in a space where it is installed.

[0085] (Supplementary Note 7) The wireless power feeding system according to Supplementary Note 1, wherein the center frequencies of the first transmitter and the second transmitter are controlled to be different based on at least one of a temperature control means for controlling temperatures of the first transmitter and the second transmitter, a power supply voltage control means for controlling a power supply voltage of the first transmitter and the second transmitter, and a power supply current control means for controlling a power supply current to the first transmitter and the second transmitter. A wireless power feeding system can be realized that can stably supply power from multiple transmitters to one receiver regardless of the location of the receiver in a space where it is installed.

[0086] (Supplementary Note 8) The wireless power feeding system according to Supplementary Note 1, further comprising a control device capable of controlling the first transmitter and the second transmitter, wherein the control device controls the first transmitter so that a center frequency of the power feeding radio wave differs from a center frequency of the power feeding radio wave of the second transmitter. A wireless power feeding system capable of stably supplying power from multiple transmitters to one receiver can be realized, regardless of the location of the receiver in a space where it is installed.

[0087] (Supplementary Note 9) The wireless power transfer system according to Supplementary Note 1, wherein the first transmitter and the second transmitter include a communication means for communicating with each other, and the first transmitter or the second transmitter controls the center frequency of the power transfer radio wave of the first transmitter so that it is different from the center frequency of the power transfer radio wave of the second transmitter, based on communication information received via the communication means. This makes it possible to realize a wireless power transfer system that can stably supply power from multiple transmitters to one receiver, regardless of the location of the receiver in a space where it is installed. This reduces interference between transmitters, allowing each transmitter to transfer power efficiently, thereby improving the power transfer performance of the system.

[0088] (Supplementary Note 10) The wireless power transfer system according to Supplementary Note 1, wherein the first transmitter or the second transmitter controls the center frequency of the power transfer wave of the first transmitter so that it is different from the center frequency of the power transfer wave of the second transmitter, without receiving communication information from each other. This makes it possible to realize a wireless power transfer system that can stably supply power from multiple transmitters to one receiver, regardless of the location of the receiver in the space where it is installed. This reduces system complexity, reduces interference between transmitters, and improves power transfer efficiency. Furthermore, since communication is not required, security risks can be reduced.

[0089] 1 WPT system, 300 first information processing device, 3001 memory unit, 3004 control unit, 3006 input device, 3008 output device, 400 second information processing device, 4001 memory unit, 4004 control unit, 4006 input device, 4008 output device, C10 control device, C101 memory unit, C104 control unit, C106 input device, C108 output device, 100 transmitter, 110 transmitter, 200 receiver

Claims

1. A wireless power supply system comprising a first transmitter, a second transmitter, and at least one receiver, wherein the first transmitter and the second transmitter are capable of wirelessly supplying power to the receiver via power supply radio waves, the center frequency of the power supply radio waves of the first transmitter is different from the center frequency of the power supply radio waves of the second transmitter, and the power supply radio waves of the first transmitter and the second transmitter are radio waves that can be regarded as approximately continuous waves.

2. The wireless power supply system according to claim 1, wherein the frequency of the power supply radio wave from the first transmitter is a radio wave belonging to the same channel as the frequency of the power supply radio wave from the second transmitter.

3. The wireless power supply system according to claim 1, wherein the first transmitter and the second transmitter are capable of wirelessly communicating information with the receiver via communication radio waves, and the power supply radio waves of the first transmitter and the second transmitter are unmodulated radio waves without a modulated signal and without information.

4. The wireless power supply system according to claim 1, wherein a center frequency f1 [Hz] of the power supply wave of the first transmitter is equal to or less than f2 × (1 + 1000 / 1,000,000) [Hz] and equal to or greater than f2 × (1 - 1000 / 1,000,000) [Hz], where f2 [Hz] is the center frequency of the power supply wave of the second transmitter.

5. The wireless power supply system according to claim 4, wherein a center frequency f1 [Hz] of the power supply wave of the first transmitter is equal to or greater than f2 × (1 + 0.001 / 1,000,000) [Hz], or equal to or less than f2 × (1 - 0.001 / 1,000,000) [Hz], where f2 [Hz] is a center frequency of the power supply wave of the second transmitter.

6. The wireless power supply system according to claim 1, wherein the capacitances of capacitors connected to the output terminals of the first transmitter and the second transmitter are different from each other, so that the center frequency of the power supply wave of the first transmitter is different from the center frequency of the power supply wave of the second transmitter.

7. A wireless power supply system as described in claim 1, wherein the center frequencies of the first transmitter and the second transmitter are controlled to be different from each other based on at least one of the following control means: temperature control means for controlling the temperatures of the first transmitter and the second transmitter; power supply voltage control means for controlling the power supply voltage of the first transmitter and the second transmitter; and power supply current control means for controlling the power supply current to the first transmitter and the second transmitter.

8. The wireless power supply system according to claim 1, further comprising a control device capable of controlling the first transmitter and the second transmitter, the control device controlling the first transmitter so that a center frequency of the power supply radio wave is different from a center frequency of the power supply radio wave of the second transmitter.

9. A wireless power supply system as described in claim 1, wherein the first transmitter and the second transmitter are provided with a communication means for communicating with each other, and the first transmitter or the second transmitter controls the center frequency of the power supply radio wave of the first transmitter to be different from the center frequency of the power supply radio wave of the second transmitter based on communication information received via the communication means.

10. The wireless power supply system according to claim 1, wherein the first transmitter or the second transmitter controls the center frequency of the power supply wave of the first transmitter to be different from the center frequency of the power supply wave of the second transmitter without receiving communication information from each other.

Images