Controller for wireless power transmission system

Abstract

The purpose of the present invention is to provide a controller for a wireless power transmission system including at least one communication device and at least one power receiver, wherein either the number of communication devices or the number of power receivers is greater than one.　The communication device has a plurality of channels having different frequencies and transmits radio waves through any one of the channels. The power receiver has a unique resonance frequency, receives the radio waves, and converts the radio waves into electric power. The controller according to the present invention is characterized by having a power supply policy that defines the channels for transmitting the radio waves from the communication device on the basis of the number of the communication devices 10 and the number of the power receivers 20 of the wireless power transmission system as well as the resonance frequency of each power receiver, wherein input information is compared with the power supply policy and the channels for transmitting the radio waves are indicated to the communication device.

Description

Controller for wireless power transmission systems

[0001] This disclosure relates to wireless power transmission technology and energy harvesting technology using communication radio waves.

[0002] Consider a wireless power transmission system consisting of one communication device (e.g., an access point (AP)) that emits radio waves, and one receiver that receives those radio waves and converts them into power. In this system, by considering the frequency characteristics of the receiver and using radio waves with a frequency close to the most efficient resonant frequency, the power generated by the receiver can be maximized (see, for example, Non-Patent Document 1). For example, as shown in Figure 1, wireless LANs such as Wi-Fi (registered trademark) have channels 1 to 13, and by using channel 13, which is closest to the resonant frequency, the power generated by the receiver can be maximized.

[0003] A. Imae, S. Tamaki and S. Narikawa, “Dynamic Wi-Fi Channel Switching Based On Frequency Characteristics For Wireless Power Transfer”, 2024 IEEE Wireless Power Technology Conference and Expo (WPTCE), doi: 10.1109 / WPTCE59894.2024.10557415.

[0004] In the case of wireless power transmission technology such as that described in Non-Patent Document 1, when multiple access points (APs) are used, the channel frequencies from each AP may interfere with each other, potentially reducing the power reception efficiency of the receivers. Furthermore, when multiple receivers exist, each has a different resonant frequency. Therefore, using a radio wave close to the resonant frequency of one receiver maximizes its power reception efficiency, but reduces the power reception efficiency of the other receivers. In other words, wireless power transmission technology like that described in Non-Patent Document 1 presents challenges in maximizing the power obtained by a single receiver, ensuring fair power supply, and providing flexible power supply to multiple receivers in systems where at least one of the communication devices or receivers is multiple.

[0005] Therefore, the present invention aims to provide a controller for a wireless power transmission system in which at least one of the communication device and the power receiver is a plurality of units, in order to solve the above-mentioned problems.

[0006] To achieve the above objective, the controller of the wireless power transmission system according to the present invention is provided with a power supply policy for when at least one of the communication devices and power receivers is multiple. This power supply policy determines the allocation of power supply based on the number of power receivers and communication devices and the resonant frequency of each power receiver.

[0007] Specifically, the controller according to the present invention is a controller for a wireless power transmission system comprising: a communication device having a plurality of channels with different frequencies and transmitting radio waves on any one of the channels; and a power receiver having a unique resonant frequency and receiving the radio waves and converting them into power, wherein the controller has a power supply policy that defines the channel on which the communication device transmits the radio waves based on the number of communication devices, the number of power receivers, and the resonant frequency, and instructs the communication device on the channel on which to transmit the radio waves based on the input information in light of the power supply policy.

[0008] (Control 1) The power supply policy is characterized in that, when there are multiple communication devices and one power receiver, the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver is set to one of the communication devices, and one or more channels other than that channel, which do not interfere with that channel, are set to the other communication devices. (Control 2) The power supply policy is characterized in that, when there is one communication device and multiple power receivers, the channel of the radio wave with the frequency closest to the average resonant frequency obtained by averaging the resonant frequencies of the power receivers is set to the communication device; when there are multiple communication devices and multiple power receivers, and the number of power receivers is less than or equal to the number of communication devices, each of the channels of the radio wave with the frequency closest to the resonant frequency of the power receivers is set to the communication device; and when there are multiple communication devices and multiple power receivers, and the number of power receivers is greater than the number of communication devices, the frequency band covering all the channels is divided by the number of communication devices, and for each divided frequency band, the channel of the radio wave with the frequency closest to the average resonant frequency obtained by averaging the resonant frequencies of the power receivers included in that frequency band is set to the communication device responsible for that frequency band. (Control 3) The power supply policy is characterized in that, when there is one communication device and multiple power receivers, the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver with the highest priority is set for the communication device, and when there are multiple communication devices and multiple power receivers, the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver is set for each of the communication devices, in order of priority, up to the number of communication devices.

[0009] By applying these policies, even in systems where at least one of the communication devices or power receivers is multiple, it becomes possible to maximize the power available to the power receivers, distribute power fairly to each power receiver, and distribute power according to the priority of the power receivers, or a combination of these.

[0010] Therefore, the present invention can provide a wireless power transmission system controller in which at least one of the communication device and the power receiver is a plurality.

[0011] Furthermore, the above inventions can be combined as much as possible.

[0012] The present invention can provide a controller for a wireless power transmission system in which at least one of the communication devices and power receivers is a plurality.

[0013] This is a diagram illustrating the frequency characteristics of the power receiver. This is a diagram illustrating the configuration of the wireless power transmission system according to the present invention. This is a diagram illustrating the configuration of the wireless power transmission system according to the present invention. This is a table illustrating the control pattern of the wireless power transmission system. This is a diagram illustrating the channels used when four APs are used simultaneously with Wi-Fi. This is a diagram illustrating Embodiment A of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment B (fair power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating the average resonant frequency. This is a diagram illustrating Embodiment B (fair power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment B (priority power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating the frequency (channel) set for the AP in priority power supply. This is a diagram illustrating Embodiment B (priority power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 1; fair power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 2; fair power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 3; fair power supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 4; Fair Power Supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 5; Fair Power Supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Pattern 6; Fair Power Supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating Embodiment C (Priority Power Supply) of the wireless power transmission system according to the present invention. This is a diagram illustrating the control performed by the power supply controller of the wireless power transmission system according to the present invention. This is a diagram illustrating intermittent operation.

[0014] Embodiments of the present invention will be described with reference to the attached drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to these embodiments. In this specification and in the drawings, components with the same reference numerals refer to the same components.

[0015] [Embodiment 1] In this embodiment, a channel (frequency) control method for maximizing or smoothing the amount of power obtained by a power receiver in a use case using one or more communication devices (in this example, Wi-Fi APs) in wireless power transmission utilizing communication radio waves is described.

[0016] Figures 2 and 3 illustrate the wireless power transmission system of this embodiment. This wireless power transmission system comprises: a communication device 10 having multiple channels with different frequencies and transmitting radio waves RF on one or more of the channels; a receiver 20 having a unique resonant frequency and receiving radio waves RF and converting them into power; and a power supply policy (Figure 4) that defines the channels on which the communication device 10 transmits radio waves RF based on the number of communication devices 10, the number of receivers 20, and the resonant frequency, and a power supply controller 30 that instructs the communication device 10 on the channels on which to transmit radio waves RF based on the input information in accordance with the power supply policy.

[0017] The communication device 10 is intended for use individually or in groups, and is a device that enables communication with a group of terminals located within the coverage area 50. For example, a Wi-Fi access point is one such device.

[0018] A group of terminals consists of general communication terminals and power receivers that convert communication radio waves into electricity and use it as a power source. General communication terminals refer to terminals that communicate via communication devices, such as fixed or mobile terminals like PCs and smartphones.

[0019] As shown in Figure 3, the power receiver 20 refers to a device equipped with an RF-DC converter 22 that converts radio waves (RF) to electrical power (DC), and at least a power storage unit (capacitor) 23 and a power consumption unit (sensor 26, microcontroller 27, external communication module 24). The power consumption unit is, for example, an IoT sensor terminal. The power receiver 20 may use other energy harvesting (EH) 21 in addition to the RF-DC converter 22. The sensor can be any type of sensor, such as a device that senses temperature, illuminance, or humidity.

[0020] The microcontroller 27 monitors the amount of electricity stored in the capacitor 23 and controls the use of the power by turning on the sensor 26 and the communication module 24 when the amount of electricity exceeds a certain level, or at fixed time intervals.

[0021] The external communication module 24 is a functional unit that communicates with the external access point (AP) 41 in order to transmit sensing data to the database 42. The external communication module 24 may use radio waves different from the radio waves RF converted by the RF-DC converter 22, or the communication device 10 and the external AP 41 may be the same and use radio waves RF to transmit sensing data.

[0022] The external AP 41 is a communication device that acts as an intermediary to store sensing data in the database 42. The external AP 41 is a device that employs a low-power communication method, such as BLE or LPWA.

[0023] The database 42 is a device for storing sensing data and utilizing it for various services. The database 42 may reside in the cloud, or it may be the same hardware as the power supply controller 30.

[0024] The power supply controller 30 controls the communication frequency of the communication device 10, specifically the channel of the Wi-Fi access point, using information regarding the update frequency of sensing data and priority information of the power receiver.

[0025] As shown in the table in Figure 4, for a single AP and single power receiver, the control for maximizing generated power disclosed in Non-Patent Literature 1 is applied as a comparative example. However, Non-Patent Literature 1 does not disclose the optimal channel combination control when multiple APs are used or when multiple power receivers exist. In this disclosure, we will describe control methods 1 to 3 according to use cases when at least one of the communication devices 10 and power receivers 20 is multiple, as shown in Examples A to C in the table in Figure 4.

[0026] In the case of Wi-Fi, up to four access points (APs) can be used simultaneously. Therefore, when using one to three APs simultaneously, any combination of channels that do not interfere with each other is possible (for example, channels 1, 5, 9; channels 5, 9, 13; or channels 1, 6, 12). However, when using four APs simultaneously, the combination of channels 1, 5, 9, and 13 will always be used (see Figure 5). Thus, depending on the specifications of the wireless section, there may be no room for channel selection.

[0027] The following describes a specific channel control method for a Wi-Fi access point using the power supply controller 30.

[0028] (Example A) The power supply policy of Example A is that when there are multiple communication devices 10 and one power receiver 20, the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver 20 is set to one of the communication devices 10, and one or more channels other than that channel that do not interfere with that channel are set to the other communication devices 10. In this example, the power generation maximization method, which is control 1, is adopted. The power generation maximization method has the following policy: - Utilize the channel with the frequency closest to the resonant frequency of the power receiver 20 (referred to as the "optimal channel" in this example). - Furthermore, from the remaining channels, utilize the channel that is close to the resonant frequency and does not interfere with the optimal channel.

[0029] Figure 6 illustrates control 1 performed in Embodiment A. There are two Wi-Fi APs 10. The resonant frequency of the power receiver 20 in this embodiment is 2440 MHz. Therefore, the power supply controller 30 instructs one AP 10-1 to supply power using channel 7 (center 2442 MHz), which is closest to the resonant frequency of the power receiver 20. Channels that do not interfere with channel 7 are channels 1-3 and 11-13, but channel 3 (2422 MHz) is closer to the resonant frequency than channel 11 (2462 MHz). For this reason, the power supply controller 30 instructs the other AP 10-2 to supply power using channel 3.

[0030] Figure 7 illustrates control 1 performed in Embodiment A. There are three Wi-Fi APs 10. The resonant frequency of the power receiver 20 in this embodiment is 2450 MHz. Therefore, the power supply controller 30 instructs AP 10-2 to supply power using channel 9 (center 2452 MHz), which is closest to the resonant frequency of the power receiver 20. Channels 1 to 5 and 13 do not interfere with channel 9, but channel 5 (2432 MHz) and channel 13 (2472 MHz) are close to the resonant frequency. For this reason, the power supply controller 30 instructs AP 10-1 to supply power using channel 5 and AP 10-3 to supply power using channel 13.

[0031] (Example B) In Example B, the power supply policy of control 2 is to set the channel of the radio wave with the frequency closest to the average resonant frequency obtained by averaging the resonant frequencies of the power receivers 20 to the communication device 10 when there is one communication device 10 and multiple power receivers 20. In this example, a fair power supply method, which is control 2, is adopted. The fair power supply method has the following policies: - To supply power fairly to multiple power receivers 20. - To supply power as efficiently as possible.

[0032] Figure 8 illustrates control 2 performed in Example B. There is one Wi-Fi AP10 and two power receivers 20. Note that the resonant frequencies of each power receiver 20 are different. The average resonant frequency is calculated based on the formula below, and the channel closest to that average resonant frequency is set.

[0033] In the case of Figure 8, the average resonant frequency is (2440 + 2460) / 2 = 2450 MHz (see Figure 9). Therefore, the power supply controller 30 can supply power fairly to receivers 20-1 and 20-2 by instructing AP10 to supply power on channel 9. Although Figure 8 shows the case where N = 2, fair power supply is possible in the same way even if N is 3 or more.

[0034] Figure 10 is a diagram for explaining Control 2 performed in Example B. There is one Wi-Fi AP 10 and three power receivers 20. The resonance frequencies of power receivers 20-2 and 20-3 are the same. Power receivers with the same resonance frequency are treated as one unit. Calculate the average resonance frequency based on the following formula and set it to the channel closest to the average resonance frequency.

[0035] In the case of Figure 10, N = 3 and K = 2. Power receivers 10-2 and 10-3 with the same resonance frequency are regarded as one unit, and the average resonance frequency is (2440 + 2460) / 2 = 2450 MHz. Therefore, the power supply controller 30 can supply power fairly to power receivers 10-1 to 10-3 by instructing the AP 10 to supply power on channel 9.

[0036] The power supply policy of Control 3 in Example B is to set the channel of the radio wave at the frequency closest to the resonance frequency of the power receiver 20 with the highest priority for the communication device 10 when there is one communication device 10 and multiple power receivers 20. In this example, the priority power supply method of Control 3 is adopted. The priority power supply method is the following policy. - Focus on power receivers with high priority among multiple power receivers 20 and supply power. - The priority is set directly by the user to the power supply controller 30, the power supply controller 30 sets the priority based on arbitrary information, or a combination of both is set.

[0037] Figure 11 is a diagram for explaining Control 3 (Case 1) performed in Example B. There is one Wi-Fi AP 10 and two power receivers 20. The resonance frequencies of each power receiver 20 are different. In this case, the user sets the priority of the power receivers in advance. That is, determine the priority of each power receiver 20 in advance and set the priorities 1 to 255 of each power receiver to the power supply controller 30 by the administrator. Note that 1 to 255 of the priority is just an example, and the setting format of the priority can be any. The numerical value of the priority may be set according to the user's charging amount.

[0038] For example, assume a policy that prioritizes the power receiver with the lowest priority value. Therefore, the power receiver 20-1 is prioritized, and the power supply controller 30 is set to supply power to the AP10 on channel 7, which is closest to the frequency of 2440 MHz (see Fig. 12). Note that Fig. 11 shows the case where the number of power receivers is 2, but even when the number of power receivers is 3 or more, priority power supply is similarly possible.

[0039] Fig. 13 is a diagram for explaining Control 3 (Case 2) performed in Example B. There is one Wi-Fi AP10 and three power receivers 20. The resonance frequencies of the respective power receivers 20 are different. In this case, the intermittent operation period required for the power receiver is used as the priority (for intermittent operation, refer to the appendix materials). Each power receiver has an intermittent operation period T １ , ｉ , ｉ , ｉ , ,

[0042] , ２ , , ３ ,

[0041] , ,

[0040] which is determined by the use case (i is the power receiver number). For example, the temperature data is determined to be once an hour, and the position data is determined to be once every three hours. Therefore, the time within which the power receiver needs to operate varies depending on the power receiver, and this "within ○○ minutes" is used as the priority index P ｉ Let it be. [Equation 3] P ｉ = T ｉ - S ｉ P ｉ : Priority (minutes) of power receiver i T ｉ : Intermittent operation period (minutes) of power receiver i S ｉ : Time elapsed (minutes) since the previous intermittent operation

[0040] In the case of Fig. 13, P １ = 50, P ２ = 30, P ３ = 75. Therefore, the power supply controller 30 instructs the AP10 to supply power on channel 8, which is closest to the resonance frequency of 2450 MHz of the power receiver 20-2 with the lowest priority.

[0041] Note that the priority may be calculated by combining the priority values of Case 1 and the priority of Case 2. For example, the product of the respective priorities is used as the true priority.

[0042] (Example C) The power supply policy of control 2 in Example C is as follows: When there are multiple communication devices 10 and multiple power receivers 20, and the number of power receivers 20 is less than or equal to the number of communication devices 10, each channel of the radio wave with the frequency closest to the resonant frequency of the power receiver 20 is set to the communication device 10; when there are multiple communication devices 10 and multiple power receivers 20, and the number of power receivers 20 is greater than the number of communication devices 10, the frequency band covering all the channels is divided by the number of communication devices 10, and for each divided frequency band, the channel of the radio wave with the frequency closest to the average frequency obtained by averaging the resonant frequencies of the power receivers 20 included in that frequency band is set to the communication device 10 responsible for that frequency band. In this embodiment, the fair power supply method, which is control 2, is adopted. The fair power supply method has the following policy: - When the number of power receivers 20 is equal to or less than the number of APs 10, channels close to the resonant frequency of the power receivers are adopted. - When the number of power receivers 20 is greater than the number of APs 10, channels close to the average resonant frequency are used.

[0043] First, let's explain the case where the number of power receivers 20 is equal to the number of APs 10. Figure 14 is a diagram illustrating control 2 (Case 1) performed in Embodiment C. There are three Wi-Fi APs 10 and three power receivers 20, so the number of both is equal. Note that the resonant frequencies of each power receiver 20 are different: 2420 MHz, 2440 MHz, and 2460 MHz. In this case, the power supply controller 30 assigns one power receiver 20 to each AP 10. Specifically, AP 10-1, which is responsible for power receiver 20-1, is set to channel 3, which is close to 2420 MHz; AP 10-2, which is responsible for power receiver 20-2, is set to channel 7, which is close to 2440 MHz; and AP 10-3, which is responsible for power receiver 20-3, is set to channel 11, which is close to 2460 MHz.

[0044] Figure 15 illustrates control 2 (Case 2) performed in Embodiment C. There are three Wi-Fi APs 10 and three power receivers 20, so the number of both is equal. Note that the resonant frequencies of each power receiver 20 are different: 2420 MHz, 2430 MHz, and 2460 MHz. In this case as well, the power supply controller 30 assigns one power receiver 20 to each AP 10. In this case, the channels closest to the respective resonant frequencies are 3, 5, and 11. However, channels 3 and 5 interfere with each other. Therefore, the power supply controller 30 makes power receivers 20-1 and 20-2 yield one channel each to each other, and adopts channels 2, 6, and 11, which do not interfere with each other. Specifically, AP10-1, which is responsible for receiver 20-1, is assigned channel 3 at 2415 MHz; AP10-2, which is responsible for receiver 20-2, is assigned channel 5 at 2432 MHz; and AP10-3, which is responsible for receiver 20-3, is assigned channel 11 at 2462 MHz.

[0045] Next, we will explain the case where the number of power receivers 20 is less than or equal to the number of APs 10. Figure 16 is a diagram illustrating control 2 (case 3) performed in embodiment C. There are three Wi-Fi APs 10 and two power receivers 20. Note that the resonant frequencies of each power receiver 20 are different, at 2420 MHz and 2460 MHz. In this case, the power supply controller 30 sets channels 3 and 11, which are close to the resonant frequencies, for each AP 10. Specifically, channel 3, which is close to 2420 MHz, is set for AP 10-1, which is responsible for power receiver 20-1, and channel 11, which is close to 2460 MHz, is set for AP 10-3, which is responsible for power receiver 20-2. Note that channel 7, which does not interfere with channels 3 and 11, may be set for AP 10-2. Alternatively, AP 10-2 may be set not to emit radio waves, or channel 3 or 11 may be set.

[0046] Figure 17 illustrates control 2 (Case 4) performed in Embodiment C. There are three Wi-Fi APs 10 and two power receivers 20. Note that the resonant frequencies of each power receiver 20 are different, at 2430 MHz and 2440 MHz. Channels 5 and 7 are closest to these resonant frequencies but interfere with each other. Therefore, the power supply controller 30 makes power receivers 20-1 and 20-2 each yield one channel, and adopts channels 4 and 8 which do not interfere with each other. Specifically, AP 10-1, which is responsible for power receiver 20-1, is set to channel 4 at 2427 MHz, and AP 10-2, which is responsible for power receiver 20-2, is set to channel 8 at 2447 MHz. AP 10-3 may be set to channel 12 which does not interfere with channels 2 and 8. Alternatively, AP 10-3 may be set not to emit radio waves, or to channel 2 or 8. On the other hand, the power supply controller 30 may perform control that combines the control of Embodiment A (Figure 7) and the control of Embodiment B (Figure 8). Specifically, as in Embodiment B (Figure 8), it is considered as one power receiver with an average resonant frequency (2435 MHz), and the control of Embodiment A (Figure 7) is applied (AP10-1 is set to channel 6 which is close to 2435 MHz, and AP10-2 and AP10-3 are set to channels 2 and 10 which do not interfere with channel 6 and have the closest frequencies).

[0047] Next, we will explain the case where the number of power receivers 20 is greater than the number of APs 10. Figure 18 is a diagram illustrating control 2 (case 5) performed in embodiment C. There are two Wi-Fi APs 10 and four power receivers 20. Note that the resonant frequencies of each power receiver 20 are different: 2410 MHz, 2430 MHz, 2450 MHz, and 2470 MHz. In this case, the power supply controller 30 divides the Wi-Fi channel frequency of 2412 MHz to 2472 MHz into a front half and a back half, and assigns power receivers to each half. Specifically, channel 3, which is closest to the average resonant frequency (2420 MHz) of the receivers (20-1, 20-2) whose resonant frequency is within the first half of the frequency range (2412 MHz to 2442 MHz), is set to AP10-1, and channel 11, which is closest to the average resonant frequency (2460 MHz) of the receivers (20-3, 20-4) whose resonant frequency is within the second half of the frequency range (2442 MHz to 2472 MHz), is set to AP10-2.

[0048] Figure 19 illustrates control 2 (Case 6) performed in Example C. There are three Wi-Fi APs 10 and six power receivers 20. Note that the resonant frequencies of each power receiver 20 are different: 2415 MHz, 2430 MHz, 2440 MHz, 2450 MHz, 2455 MHz, and 2475 MHz. In this case, the power supply controller 30 divides the Wi-Fi channel frequency of 2412 MHz to 2472 MHz into three parts ([i] 2412 MHz to 2432 MHz, [ii] 2432 MHz to 2452 MHz, [iii] 2452 MHz to 2472 MHz) and assigns a power receiver to each part. Specifically, channel 3, which is closest to the average resonant frequency (2422.5 MHz) of receivers (20-1, 20-2) whose resonant frequency is within frequency range [i], is set to AP10-1; channel 7, which is closest to the average resonant frequency (2445 MHz) of receivers (20-3, 20-4) whose resonant frequency is within frequency range [ii], is set to AP10-2; and channel 12, which is closest to the average resonant frequency (2467.5 MHz) of receivers (20-5, 20-6) whose resonant frequency is within frequency range [iii], is set to AP10-3.

[0049] (Example C) In Example C, the power supply policy of control 3 is to set the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver 20 for each communication device 10, in order of priority, for the number of communication devices 10. In this embodiment, the priority power supply method of control 3 is adopted. The priority power supply method has the following policy: - Power is supplied to the power receiver with the highest priority among the multiple power receivers 20. - Priority is set by the user directly to the power supply controller 30, by the power supply controller 30 setting priority based on arbitrary information, or by a combination of both.

[0050] Figure 20 illustrates control 3 performed in Example C. There are three Wi-Fi APs 10 and four power receivers 20. Note that each power receiver 20 has a different resonant frequency. Control 3 uses a channel close to the resonant frequency (2430 MHz) of the highest priority power receiver 20-1. In this case, channel 5 is set to AP 10-1. It is checked whether the resonant frequency of the next priority power receiver is within ±10 MHz (2422 to 2442 MHz) of the center frequency 2432 MHz of channel 5. If it is, that power receiver will be powered on channel 5, and the next priority power receiver is considered. In this case, the second priority power receiver 20-2 (resonant frequency 2425 MHz) will be powered on channel 5. The resonant frequency of the next priority power receiver 20-3 is 2445 MHz, which is outside the range of channel 5. Here, we would like to use channel 8, which is closest to the resonant frequency in question, but it interferes with channel 5, so we compromise and use channel 9. The receiver 20-4, which has the lowest priority, has a resonant frequency of 2470 MHz, so we use channel 13.

[0051] [Embodiment 2] Figure 21 is a flowchart illustrating the control performed by the power supply controller 30. STEP S01: Determine whether or not to use the power supply controller to perform control. STEP S02: If the answer in step S01 is "No", the power supply controller 30 determines not to perform any control (do nothing). STEP S03: If the answer in step S01 is "Yes", check if there is one access point AP. STEP S04: If the answer in step S03 is "No" (multiple APs), check if there are two or three access point APs. STEP S05: If the answer in step S04 is "No", meaning four APs are used simultaneously, the channel is automatically determined, so no special control is performed. STEP S06: If the answer in step S05 is "YES", check if there is one power receiver 20. STEP S07: If the answer in step S06 is "YES" (one power receiver 20), the settings are changed to use the channel closest to the resonant frequency and a channel that does not interfere with that channel and is close to the resonant frequency (the control described in Example A is performed). STEP S08: If the answer in step S06 is "NO" (two to three power receivers 20), it is determined whether or not to use priority control.

[0052] STEP S09: If the answer in step S08 is "No" (fair power supply), determine if the number of power receivers 20 is greater than the number of APs 10. STEP S10: If the answer in step S09 is "No" (number of power receivers ≤ number of APs), use a channel close to the resonant frequency. If interference occurs, either compromise with each other, or avoid interference by combining the control methods of the aforementioned Examples A and B, or by changing the channel settings (Cases 1-4 of Example C). STEP S11: If the answer in step S09 is "Yes" (number of power receivers > number of APs), divide the channel frequency according to the number of APs, calculate the average resonant frequency of the power receivers within the division, and change the channel settings based on that (Cases 5 and 6 of Example C). STEP S12: If the answer in step S08 is "Yes" (priority control), calculate the priority of each power receiver. STEP S13: Change the channel settings based on priority (see Figure 20).

[0053] STEP S21: If the answer in step S03 is "Yes" (multiple APs), check if there is only one power receiver. STEP S22: If the answer in step S21 is "No" (multiple power receivers), determine whether or not to use priority control. STEP S23: If the answer in step S22 is "No" (fair power supply), calculate the average resonant frequency of the power receiver 20. STEP S24: Change the setting to a channel based on the average resonant frequency (see Figures 8 and 10). STEP S25: If the answer in step S22 is "Yes" (priority control), calculate the priority of each power receiver. STEP S26: Change the setting to a channel based on priority (see Figures 11 and 13). STEP S27: If the answer in step S21 is "Yes" (one power receiver), apply the control described in Non-Patent Literature 1.

[0054] [Supplementary Information] (1) The "information input" to the power supply controller 30 is the number of communication devices 10, the number of power receivers 20, and the resonant frequency of each power receiver 20. In addition, if there are multiple power receivers 20, the "information input" is whether to provide fair power supply as in control 2 or power supply according to the priority of control 3.

[0055] (2) The number of communication devices 10 is input to the power supply controller 30 by the user (system administrator). (3) The power supply controller 30 determines the number of power receivers 20 from the source information of the sensing data stored in the database 42. The number of power receivers 20 may also be input to the power supply controller 30 by the user (system administrator).

[0056] (4) The power supply controller 30 determines the resonant frequency of each power receiver 20 by referring to sensing data stored in the database 42 (cloud or local machine) (technology such as PCT / JP2023 / 032468). At this time, the power supply controller 30 also refers to the update frequency of the sensing data, so it can determine whether the power receiver 20 is being powered efficiently or whether the power supply efficiency is decreasing based on the update frequency. The resonant frequency of each power receiver 20 may also be input to the power supply controller 30 by the user (system administrator).

[0057] (5) The sensing data itself is used by the user to deploy / utilize IoT services. The power supply controller 30 collects information on "the time when the sensing data was updated". Since "the sensing data is updated" is synonymous with "the amount of power required by the IoT terminal (power receiver) has been supplied", the power supply efficiency (high efficiency / low efficiency) of the radio wave frequency (channel) set in the communication device 10 can be determined by referring to the update frequency.

[0058] (6) The power supply controller 30 provides fair power supply based solely on the resonant frequency of each power receiver 20. If fairness is to be strictly ensured based on the amount of power generated by each power receiver 20, calculations will be required on the power receiver controller side for overall optimization. It is also necessary to know the amount of power generated by each power receiver when performed on Wi-Fi channels 1-13. For this reason, ensuring strict fairness would require a significant amount of time and burden on the power receiver controller. On the other hand, the method of judging based solely on the resonant frequency as disclosed herein is a technology that ensures fairness from the perspective of power conversion efficiency, rather than the power generated by each power receiver. Furthermore, if the position or environment of the power receiver changes, the amount of power generated changes, but the resonant frequency does not. Therefore, the present invention has the advantage of being able to easily implement fair power supply by knowing the resonant frequency without tracking the amount of power generated.

[0059] (7) In the case of control 3 (Case 2, Figure 13) performed in Example B, the power supply controller 13 operates with the following intermittent cycle T ｉ (i) Take advantage of the fact that the power receiver 20 operates when the amount of power required for sensing and transmitting sensing data has been stored. In this case, the power supply controller 13 has an intermittent operation period T ｉ The intermittent period is determined from the update time of the sensing data. Also, if it is desired to operate a certain power receiver within a set time, such information is registered in the power supply controller 30, and the power supply controller 30 uses that information to change the frequency set in the communication device 10 (a frequency (channel) that can supply sufficient power to the power receiver 20 within a set time). (ii) Intermittent operation period T of the power receiver 20 ｉThe intermittent operation cycle T is set, and sensing and data transmission are performed at each of these cycles. In this case, when the power receiver is installed, the user also needs to set the intermittent operation cycle T in the power receiver controller 30. ｉ Set it.

[0060] [Appendix] Figure 22 illustrates an intermittent operation terminal. An intermittent operation terminal alternates between standby operation (sleep or power off) and normal operation (sensing and data transmission in very short periods). The duration of one standby operation and the duration of one normal operation constitute the intermittent operation cycle. Once the reference power and intermittent operation cycle are determined, the power required for the terminal is determined. The greater the power supplied by radio waves, the shorter the intermittent operation cycle can be, making it applicable to a wide range of use cases. SWIPT (Simultaneous Wireless Information and Power Transfer) is a frequency sharing technology that enables simultaneous power transmission and data communication in a single frequency band.

[0061] 10, 10-1, 10-2, ...: Communication devices (Wi-Fi AP) 20, 20-1, 20-2, ...: Power receivers 21: Energy harvesting (EH) 22: RF-DC converter 23: Capacitor 24: Communication module 26: Sensor 27: Microcontroller 30: Power supply controller 41: External communication terminal 42: Database 11: 12:

Claims

1. A controller for a wireless power transmission system comprising: a communication device having multiple channels with different frequencies and transmitting radio waves on any one of the channels; and a receiver having a unique resonant frequency and receiving the radio waves and converting them into power, wherein the controller has a power supply policy that defines the channel on which the communication device transmits the radio waves based on the number of communication devices, the number of receivers, and the resonant frequency, and instructs the communication device on the channel on which to transmit the radio waves based on the input information in light of the power supply policy.

2. The controller according to claim 1, characterized in that, when there are multiple communication devices and one power receiver, the power supply policy includes setting the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver to one of the communication devices, and setting one or more channels other than that channel, which do not interfere with that channel, to the other communication devices.

3. The controller according to claim 1, characterized in that the power supply policy includes, when there is one communication device and multiple power receivers, setting the channel of the radio wave with the frequency closest to the average resonant frequency obtained by averaging the resonant frequencies of the power receivers to the communication device; when there are multiple communication devices and multiple power receivers, and the number of power receivers is less than or equal to the number of communication devices, setting each of the channels of the radio wave with the frequency closest to the resonant frequency of the power receivers to the communication device; and when there are multiple communication devices and multiple power receivers, and the number of power receivers is greater than the number of communication devices, dividing the frequency band covering all the channels by the number of communication devices, and for each divided frequency band, setting the channel of the radio wave with the frequency closest to the average resonant frequency obtained by averaging the resonant frequencies of the power receivers included in that frequency band to the communication device responsible for that frequency band.

4. The controller according to claim 1, characterized in that the power supply policy includes, when there is one communication device and multiple power receivers, setting the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver with the highest priority to the communication device, and when there are multiple communication devices and multiple power receivers, setting the channel of the radio wave with the frequency closest to the resonant frequency of the power receiver to each of the communication devices, in order of priority, for each of the number of communication devices.

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