Wireless power transmission system and control method for wireless power transmission system

Abstract

To reduce occupied area of a power transmission device in a wireless power transmission system.SOLUTION: A wireless power transmission system comprises: a first power transmission circuit which outputs first power for transmitting power; a second power transmission circuit which outputs second power for transmitting power; three or more power transmission coils for wirelessly transmitting the first power or the second power; a first power reception coil relatively movable to the power transmission coils to wirelessly receive the first power from any of the power transmission coils; a second power reception coil relatively movable to the power transmission coils to wirelessly receive the second power from any of the power transmission coils; and a first switch which connects the power transmission coil facing the first power reception coil among the power transmission coils with the first power transmission circuit and connects the power transmission coil facing the second power reception coil with the second power transmission circuit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wireless power transmission system and a control method for the wireless power transmission system. [Background technology]

[0002] In recent years, there has been an increasing demand for wireless power supply to moving parts. For example, in semiconductor exposure equipment, a stage that moves the wafer to the exposure position is equipped with multiple motors that perform fine movements to form a wafer pattern. Each motor has its own driver that controls the drive of the motor, which is located outside the stage. The driver output is connected to the motor on the stage by a cable. Because this cable moves in accordance with the movement of the stage, tension is generated in the cable, which degrades the stage positioning accuracy.

[0003] Therefore, it has been considered to make the connection between the driver and the motor wireless.As described above, in order to individually connect the driver and the motor to control each individual motor, a wireless power transmission system is required for each driver-motor pair.

[0004] Patent Document 1 describes a wireless power feeding system having a power transmitting device and a power receiving device. The power transmitting device has a power feeding circuit and a transmission line. The power receiving device has a power receiving antenna and an impedance conversion circuit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-99190 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when wirelessly supplying power from a driver output to a load such as a motor, a number of power transmitting devices and power receiving devices corresponding to the number of loads is required. Here, when multiple power transmitting devices each having a transmission line are arranged side by side, the occupied area becomes large.

[0007] Furthermore, when multiple power transmission devices with transmission lines are arranged side by side, power interference occurs. To suppress this interference, it is necessary to increase the distance between the multiple power transmission devices or to cover the power transmission devices with a shielding material, which further increases the occupied area.

[0008] An object of the present disclosure is to enable a reduction in the area occupied by a power transmitting device in a wireless power transmission system. [Means for solving the problem]

[0009] The wireless power transmission system includes a first power transmitting circuit that outputs a first power to be transmitted, a second power transmitting circuit that outputs a second power to be transmitted, three or more power transmitting coils that wirelessly transmit the first power or the second power, a first power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the first power from any of the plurality of power transmitting coils, a second power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the second power from any of the plurality of power transmitting coils, and a first switch that connects a power transmitting coil that faces the first power receiving coil to the first power transmitting circuit and connects a power transmitting coil that faces the second power receiving coil to the second power transmitting circuit. The first switch is connected so that each of the plurality of power transmitting coils can select either the first power or the second power and transmit the power wirelessly. do. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to reduce the area occupied by a power transmitting device in a wireless power transmission system. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 2] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 3] FIG. 10 is a diagram illustrating an example of a gate signal. [Figure 4] 10A and 10B are diagrams illustrating the interference suppression effect achieved by synchronous rectification in a power receiving circuit. [Figure 5] FIG. 10 is a diagram illustrating an example of a gate signal. [Figure 6] 10A and 10B are diagrams illustrating the interference suppression effect achieved by synchronous rectification in a power receiving circuit. [Figure 7] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 8] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. [Figure 9] FIG. 1 is a diagram illustrating a configuration example of a wireless power transmission system. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) 1 is a diagram showing an example of the configuration of a wireless power transmission system 700 according to the first embodiment. The wireless power transmission system 700 employs a method called electromagnetic induction or magnetic resonance, which transmits power using a magnetic field, an electric field, or both an electric field and a magnetic field.

[0013] The wireless power transmission system 700 will be described as being applied to a semiconductor exposure apparatus as an example, but is not limited thereto. For example, the wireless power transmission system 700 can be applied to equipment that drives multiple motors, etc., or to equipment in general that requires wireless transmission of power not only for driving the motors but also for driving control circuits. For example, the wireless power transmission system 700 can be applied to equipment that requires multiple power supplies, such as inkjet printers, robotic devices used in factories, and automated guided vehicles (AGVs). In particular, the wireless power transmission system 700 is suitable for use when multiple wireless power transmission systems 700 are arranged in a small area within a device.

[0014] The wireless power transmission system 700 includes power transmitting circuits 201 and 202, a power transmitting coil array 300, switches SW1 to SW12, power receiving coils 401 and 402, and power receiving circuits 501 and 502. The power transmitting coil array 300 includes power transmitting coils 301 to 312.

[0015] The semiconductor exposure apparatus includes a main body 800 and a moving stage 900. The main body 800 is a power transmitting device and includes drivers 101 and 102, power transmitting circuits 201 and 202, a power transmitting coil array 300, and switches SW1 to SW12. The moving stage 900 is a power receiving device and includes power receiving coils 401 and 402, power receiving circuits 501 and 502, and motors 601 and 602. The moving stage 900 is movable relative to the main body 800 in the direction of the arrow in FIG.

[0016] The driver 101 is connected to the power transmitting circuit 201. The driver 102 is connected to the power transmitting circuit 202. The switch SW1 connects or disconnects the power transmitting circuit 201 and the power transmitting coil 301. The switch SW2 connects or disconnects the power transmitting circuit 201 and the power transmitting coil 302.

[0017] The switch SW3 connects the power transmitting circuit 201 and the power transmitting coil 303, or connects the power transmitting circuit 202 and the power transmitting coil 303, or puts the power transmitting coil 303 in a non-connected state. The switch SW4 connects the power transmitting circuit 201 and the power transmitting coil 304, or connects the power transmitting circuit 202 and the power transmitting coil 304, or puts the power transmitting coil 304 in a non-connected state. Similarly, the switches SW5 to SW10 connect the power transmitting circuit 201 and the power transmitting coils 305 to 310, or connect the power transmitting circuit 202 and the power transmitting coils 305 to 310, or puts the power transmitting coils 305 to 310 in a non-connected state, respectively.

[0018] The switch SW11 connects or disconnects the power transmitting circuit 202 and the power transmitting coil 311. The switch SW12 connects or disconnects the power transmitting circuit 202 and the power transmitting coil 312.

[0019] The power receiving coil 401 is connected to a motor 601 via a power receiving circuit 501. The power receiving coil 402 is connected to a motor 602 via a power receiving circuit 502.

[0020] When the wireless power transmission system 700 is applied to a semiconductor exposure apparatus, three or more motors are required, but only two motors 601 and 602 are shown in FIG. 1. The wireless power transmission system 700 transmits power wirelessly between a main body 800 and a moving stage 900. The power transmitting coil array 300 has a plurality of power transmitting coils 301 to 312 arranged in the direction of movement of the moving stage 900. Switches SW1 to SW12 are connected to the power transmitting coils 301 to 312, respectively. Here, the power transmitting coil array 300 has 12 power transmitting coils 301 to 312, but the number of power transmitting coils is not limited to 12 because it is determined by the movable range of the moving stage 900 and the size of each power transmitting coil.

[0021] 1, the power transmitting coil 304 faces the power receiving coil 401, and therefore the power transmitting coil 304 is connected to the power transmitting circuit 201 by the switch SW4. Similarly, the power transmitting coil 306 faces the power receiving coil 402, and therefore the power transmitting coil 306 is connected to the power transmitting circuit 202 by the switch SW6. The other switches SW1 to SW3, SW5, and SW7 to SW12 disconnect the power transmitting coils 301 to 303, 305, and 307 to 312 from the power transmitting circuits 201 and 202, respectively. A control method for the wireless power transmission system 700 will now be described.

[0022] The driver 101 of the motor 601 outputs a voltage to be supplied to the motor 601 to the power transmitting circuit 201. The power transmitting circuit 201 switches the output voltage of the driver 101 at a high frequency suitable for wireless power transmission. The power transmitting circuit 201 then outputs the switched high-frequency voltage (power) to the power transmitting coil 304 via the switch SW4. The power transmitting coil 304 wirelessly transmits the high-frequency power to the power receiving coil 401. The power receiving coil 401 receives the high-frequency power (voltage) from the power transmitting coil 304 and outputs the received high-frequency voltage to the power receiving circuit 501. The power receiving circuit 501 rectifies the high-frequency voltage received by the power receiving coil 401 and restores the output voltage of the driver 101. The power receiving circuit 501 then outputs the restored voltage to the motor 601. The motor 601 is driven according to the voltage input from the power receiving circuit 501. Here, the driver 101 can appropriately control the motor 601 by outputting extra power to compensate for the power loss caused by wireless power transmission.

[0023] Similarly, the driver 102 of the motor 602 outputs a voltage to be supplied to the motor 602 to the power transmitting circuit 202. The power transmitting circuit 202 switches the output voltage of the driver 102 at a high frequency suitable for wireless power transmission. The power transmitting circuit 202 then outputs the switched high-frequency voltage (power) to the power transmitting coil 306 via the switch SW6. The power transmitting coil 306 wirelessly transmits the high-frequency power to the power receiving coil 402. The power receiving coil 402 receives the high-frequency power (voltage) from the power transmitting coil 306 and outputs the received high-frequency voltage to the power receiving circuit 502. The power receiving circuit 502 rectifies the high-frequency voltage received by the power receiving coil 402 and restores the output voltage of the driver 102. The power receiving circuit 502 then outputs the restored voltage to the motor 602. The motor 602 is driven according to the voltage input from the power receiving circuit 502. Here, the driver 102 can appropriately control the motor 602 by outputting extra power to compensate for the power loss caused by wireless power transmission.

[0024] 1 , when the moving stage 900 moves to the leftmost position, the power receiving coil 401 faces the power transmitting coil 301, and the power receiving coil 402 faces the power transmitting coil 303. Therefore, the power transmitting coils 301 and 302 do not face the power receiving coil 402. Therefore, the switches SW1 and SW2 do not have terminals for connecting the power transmitting coils 301 and 302 to the power transmitting circuit 202, respectively.

[0025] 1, when the movable stage 900 is moved to the rightmost position, the power receiving coil 401 faces the power transmitting coil 310, and the power receiving coil 402 faces the power transmitting coil 312. Therefore, the power transmitting coils 311 and 312 do not face the power receiving coil 401. Therefore, the switches SW11 and SW12 do not have terminals for connecting the power transmitting coils 311 and 312 to the power transmitting circuit 201, respectively. In this way, the number of terminals of the switches connected to the power transmitting coils can be varied depending on the power receiving coils that can face each other.

[0026] Here, the position of the moving stage 900 may be detected using a sensor (not shown) such as an optical sensor, or may be detected using control information of the moving stage 900. The wireless power transmission system 700 detects the positions of the power receiving coils 401 and 402 based on the position of the moving stage 900, and switches the switches SW1 to SW12 connected to the power transmitting coils 301 to 312.

[0027] Power transmitting coils 301 and 302 are power transmitting coils for transmitting power to power receiving coil 401. Power transmitting coils 311 and 312 are power transmitting coils for transmitting power to power receiving coil 402. Power transmitting coils 303 to 310 are power transmitting coils for transmitting power to power receiving coil 401 or 402. Since power receiving coils 401 and 402 share power transmitting coils 303 to 310, the area occupied by power transmitting coils 301 to 312 can be reduced, and the area occupied by wireless power transmission system 700 and main body 800 can also be reduced.

[0028] Furthermore, power is supplied only to the power transmitting coils 304 and 306 from the power transmitting circuits 201 and 202. Because the switch SW5 is in the off state, power is not supplied to the power transmitting coil 305. Because the power transmitting coil 305, which does not receive power, is disposed between the power transmitting coils 304 and 306, power interference between the power transmitting coils 304 and 306 can be suppressed. This allows the distance between the power transmitting coils 301 to 312 to be shortened. Furthermore, shielding members between the power transmitting coils 301 to 312 can be omitted. This reduces the area occupied by the power transmitting coils 301 to 312, and therefore the area occupied by the wireless power transmission system 700 and the main body 800.

[0029] (Second embodiment) Fig. 2 is a diagram showing an example of the configuration of a wireless power transmission system 700 according to the second embodiment. Similar to Fig. 1, the wireless power transmission system 700 includes power transmitting circuits 201 and 202, switches SW1 to SW5, power transmitting coils 301 to 305, power receiving coils 401 and 402, and power receiving circuits 501 and 502. A driver 101 is connected to the power transmitting circuit 201. A driver 102 is connected to the power transmitting circuit 202. A motor 601 is connected to the power receiving circuit 501. A motor 602 is connected to the power receiving circuit 502.

[0030] The power transmitting circuit 201 has field effect transistors (FETs) U1 and U2 and a capacitor C1. The field effect transistors U1 and U2 are switches that alternately switch the output of the driver (power supply) 101. A gate signal S1 of frequency f1 is input to the gate of the field effect transistor U1. The drain of the field effect transistor U1 is connected to the driver 101, and the source is connected to the drain of the field effect transistor U2. A gate signal S2 of frequency f1 is input to the gate of the field effect transistor U2. The source of the field effect transistor U2 is connected to a reference potential node (e.g., a ground potential node). The capacitor C1 is connected between the source of the field effect transistor U1 and first terminals of the switches SW1 to SW5.

[0031] The power transmitting circuit 202 includes field effect transistors U3 and U4 and a capacitor C2. The field effect transistors U3 and U4 are bidirectional switches. A gate signal S3 having a frequency f2 is input to the gate of the field effect transistor U3. The drain of the field effect transistor U3 is connected to the driver 102, and the source is connected to the drain of the field effect transistor U4. A gate signal S4 having a frequency f2 is input to the gate of the field effect transistor U4. The source of the field effect transistor U4 is connected to the reference potential node. The capacitor C2 is connected between the source of the field effect transistor U3 and the second terminals of the switches SW1 to SW5.

[0032] The switch SW1 connects or disconnects the power transmitting coil 301 and the power transmitting circuit 201, and also connects or disconnects the power transmitting coil 301 and the power transmitting circuit 202. The switch SW2 connects or disconnects the power transmitting coil 302 and the power transmitting circuit 201, and also connects or disconnects the power transmitting coil 302 and the power transmitting circuit 202. Similarly, the switches SW3 to SW5 connect or disconnect the power transmitting coils 303 to 305 and the power transmitting circuit 201, and also connect or disconnect the power transmitting coils 303 to 305 and the power transmitting circuit 202, respectively. The power transmitting coils 301 to 305 are capable of wirelessly transmitting power to the power receiving coil 401 or 402, respectively.

[0033] Here, for simplicity of explanation, the power transmitting circuits 201, 202 are configured as class D half-bridge circuits connected to only one of the power transmitting coils 301-305, but they may be class DE or class E. They may also be configured as full-bridge circuits that control the voltage across the power transmitting coils 301-305. Furthermore, the switches formed by the field-effect transistors U1-U4 are configured to be compatible only when the output of the drivers 101, 102 is positive, but this is not limiting. They may also be configured as bidirectional switches using two field-effect transistors with their sources connected to each other so that the output of the drivers 101, 102 can also be negative.

[0034] The power receiving coil 401 can receive power wirelessly from any of the power transmitting coils 301 to 305. The power receiving coil 402 can receive power wirelessly from any of the power transmitting coils 301 to 305.

[0035] The power receiving circuit 501 has field effect transistors U5 to U8 and capacitors C3 to C5. The field effect transistors U5 and U6 are switches that are turned on and off by gate signals S5 and S6 that are switched in response to the voltage applied to the power receiving coil 401. The field effect transistors U7 and U8 are also switches that are turned on and off by gate signals S7 and S8.

[0036] A gate signal S5 having a frequency f1 is input to the gate of the field-effect transistor U5. The drain of the field-effect transistor U5 is connected to a first terminal of the power receiving coil 401 via a capacitor C3. The source of the field-effect transistor U5 is connected to a first terminal of the motor 601.

[0037] A gate signal S6 having a frequency f1 is input to the gate of the field-effect transistor U6. The drain of the field-effect transistor U6 is connected to a first terminal of the motor 601. The source of the field-effect transistor U5 is connected to a second terminal of the power receiving coil 401 via a capacitor C4.

[0038] A gate signal S7 having a frequency f1 is input to the gate of the field-effect transistor U7. The drain of the field-effect transistor U7 is connected to a first terminal of the receiving coil 401 via a capacitor C3. The source of the field-effect transistor U7 is connected to a second terminal of the motor 601.

[0039] A gate signal S8 of frequency f1 is input to the gate of the field effect transistor U8. The drain of the field effect transistor U8 is connected to a second terminal of the motor 601. The source of the field effect transistor U8 is connected to a second terminal of the power receiving coil 401 via a capacitor C4. A capacitor C5 is connected between the source of the field effect transistor U5 and the source of the field effect transistor U7.

[0040] The power receiving circuit 502 has field effect transistors U9 to U12 and capacitors C6 to C8. The field effect transistors U9 and U10 are switches that are turned on and off by gate signals S5 and S6, which are switched in response to the voltage applied to the power receiving coil 401. The field effect transistors U11 and U12 are also switches that are turned on and off by gate signals S7 and S8.

[0041] A gate signal S9 having a frequency f2 is input to the gate of the field-effect transistor U9. The drain of the field-effect transistor U9 is connected to a first terminal of the receiving coil 402 via a capacitor C6. The source of the field-effect transistor U9 is connected to a first terminal of the motor 602.

[0042] A gate signal S10 having a frequency f2 is input to the gate of the field-effect transistor U10. The drain of the field-effect transistor U10 is connected to a first terminal of the motor 602. The source of the field-effect transistor U10 is connected to a second terminal of the power receiving coil 402 via a capacitor C7.

[0043] A gate signal S11 having a frequency f2 is input to the gate of the field-effect transistor U11. The drain of the field-effect transistor U11 is connected to a first terminal of the power receiving coil 402 via a capacitor C6. The source of the field-effect transistor U11 is connected to a second terminal of the motor 602.

[0044] A gate signal S12 of frequency f2 is input to the gate of the field effect transistor U12. The drain of the field effect transistor U12 is connected to a second terminal of the motor 602. The source of the field effect transistor U12 is connected to a second terminal of the power receiving coil 402 via a capacitor C7. A capacitor C8 is connected between the source of the field effect transistor U9 and the source of the field effect transistor U11.

[0045] Here, for simplicity of explanation, the receiving circuits 501 and 502 are configured as class D full-bridge rectifiers, but they may also be configured as half-bridge circuits with the midpoint of the receiving coils 401 and 402 as the reference potential. They may also be configured as class DE or class E switching circuits. Furthermore, each of the field-effect transistors U5 to U8 and U9 to U12 may be in the form of a bidirectional switch using two field-effect transistors with their sources connected to each other.

[0046] Note that the motors 601 and 602 are each a load, and there may be three or more motors. Also, since there are two motors 601 and 602, there are two drivers 101 and 102, two power transmitting circuits 201 and 202, two power receiving coils 401 and 402, and two power receiving circuits 501 and 502, but this can be changed according to the number of motors.

[0047] Furthermore, the number of switches SW1 to SW5 and the number of power transmitting coils 301 to 305 are five, but are not limited to five. The number of switches and the number of power transmitting coils can be changed depending on the movement distance of moving stage 900 in FIG. 1 and the size of power transmitting coils 301 to 305.

[0048] FIG. 3 is a timing chart showing an example of the gate signals S1 to S4 in FIG. 2. The gate signals S1 and S2 go high and low with a period T1, which is the reciprocal of the frequency f1. The phases of the gate signals S1 and S2 are shifted from each other by half the period T1 (=T1 / 2). The field-effect transistor U1 operates during the high-level period t of the gate signal S1. on1 and during the low level period t off1 The field effect transistor U2 is turned off during the high level period t on1 and during the low level period t off1 In addition, to prevent the field effect transistors U1 and U2 from being turned on at the same time, the high level periods t on1 is the low level period t of the gate signals S1 and S2. off1Therefore, the time is shorter by 2×Δt1. Capacitor C1 operates as a series resonant circuit when connected to any of power transmitting coils 301 to 305, and is set so that the resonant frequency is f1.

[0049] The gate signals S3 and S4 go high and low with a period T2, which is the reciprocal of the frequency f2. The phases of the gate signals S3 and S4 are shifted from each other by half the period T2 (=T2 / 2). The field-effect transistor U3 operates during the high-level period t on2 and during the low level period t off2 The field effect transistor U4 is turned off during the high level period t on2 and during the low level period t off2 In order to prevent the field effect transistors U3 and U4 from being turned on at the same time, the high level periods t on2 is the low level period t of the gate signals S3 and S4. off2 Therefore, the time is shorter by 2×Δt2. When the capacitor C2 is connected to any of the power transmitting coils 301 to 305, it operates as a series resonant circuit and is set so that the resonant frequency is f2. The frequency f2 is different from the frequency f1.

[0050] Next, the operation of the power receiving circuit 501 will be described. The power receiving circuit 501 is a synchronous rectifier circuit that receives the voltage of the motor 601, which has been converted to a frequency f1, from the power receiving coil 401. For simplicity, the voltage of the motor 601 is assumed to be a positive voltage always equal to or greater than 0 V. Voltage A1 in FIG. 2 is the drain voltage of the field-effect transistor U5. Voltage B1 in FIG. 2 is the source voltage of the field-effect transistor U6. When the power receiving coil 401 is not receiving an interference signal or the like, during a period when voltage A1 is higher than voltage B1, gate signals S5 and S8 turn on the field-effect transistors U5 and U8. This causes current to flow from the field-effect transistor U5 through the motor 601 to the field-effect transistor U8. The voltage R1 at the source of the field-effect transistor U5 becomes a positive voltage.

[0051] The gate signals S5 and S8 turn on / off the field-effect transistors U5 and U8 at the same frequency f1 as the power transmitting circuit 201. The phases of the gate signals S6 and S7 are shifted by 180° from the phase of the gate signals S5 and S8. The gate signals S6 and S7 turn on / off the field-effect transistors U6 and U7 at the same frequency f1 and in opposite phase to the gate signals S5 and S8. That is, the gate signals S6 and S7 turn on the field-effect transistors U6 and U7 during the period when the voltage B1 is higher than the voltage A1. This causes current to flow from the field-effect transistor U6 to the field-effect transistor U7 via the motor 601. The voltage R1 at the drain of the field-effect transistor U6 becomes positive. The operation of the power receiving circuit 502 is similar to that of the power receiving circuit 501.

[0052] Fig. 4 is a diagram showing the interference suppression effect achieved by synchronous rectification in the power receiving circuit 501. In Fig. 4, the vertical axis represents amplitude and the horizontal axis represents time. Signals 411 to 415 are signals for explaining the principle by which the power receiving circuit 501 suppresses the influence of an interference signal of frequency f2, which is different from frequency f1, and are not intended to limit the signals. Furthermore, for the purpose of explaining the principle, the amplitudes of signals 411 to 415 are calculated values ​​assuming no loss due to wireless power transmission.

[0053] The power transmitting circuit 201 switches the output signal of the driver 101 at a frequency f1. The power transmitting coil 301 wirelessly transmits the output signal of the power transmitting circuit 201 at a frequency f1 to the power receiving coil 401. The power transmitting circuit 202 switches the output signal of the driver 102 at a frequency f2. The power transmitting coil 304 wirelessly transmits the output signal of the power transmitting circuit 202 at a frequency f2 to the power receiving coil 402. The power receiving coil 401 receives the output signal of the power transmitting circuit 201 at a frequency f1 from the power transmitting coil 301, and also receives an interference signal at a frequency f2 from the power transmitting coil 304.

[0054] Signal 411 is an output signal of driver 101. Power transmitting circuit 201 switches output signal 411 of driver 101. Signal 412 is a signal that power receiving coil 401 receives as an output signal of power transmitting circuit 201 via power transmitting coil 301, and has a frequency of f1. Signal 413 is an interference signal that power receiving coil 401 receives as an output signal of power transmitting circuit 202 via power transmitting coil 304, and has a smaller amplitude than signal 412 and a frequency of f2. Signal 414 is a signal that field effect transistors U5 to U8 of power receiving circuit 501 rectify a composite signal of signals 412 and 413, and is the signal before smoothing by capacitor C5. Signal 415 is a signal that capacitor C5 of power receiving circuit 501 smoothes signal 414. For ease of understanding, signal 415 is shown as a signal when capacitor C5 is replaced with a high-order low-pass filter.

[0055] The smoothed signal 415 is a signal restored by the power receiving circuit 501. The smoothed signal 415 is substantially the same as the output signal 411 of the driver 101. Therefore, even if an interference signal 413 is mixed into the received signal 412 of the power receiving coil 401, it can be seen that the influence of the interference signal 413 is suppressed. Even if the interference signal 413 is mixed in, the power receiving circuit 501 can restore the signal 415 that is substantially the same as the output signal 411 of the driver 101.

[0056] Here, field effect transistors U5 to U8 rectify the signal received by power receiving coil 401 at frequency f1 and output signal 414. Signal 414 includes a beat frequency component due to interference between signal 412 of frequency f1 and interference signal 413 of frequency f2. Capacitor C5 is required to remove the beat frequency component from signal 414 and generate smoothed signal 415. For this reason, capacitor C5 may be replaced with a high-order low-pass filter.

[0057] If the motor 601 is almost insensitive to frequency f1 and the beat frequency of frequencies f1 and f2, the capacitance of the capacitor C5 should be such that leakage of frequency f1 and the beat frequency does not affect other devices. The operation of the power receiving circuit 502 in Figure 2 is similar to that of the power receiving circuit 501 described above.

[0058] (Third embodiment) A wireless power transmission system 700 according to the third embodiment has the same configuration as that shown in Fig. 2. Below, differences between this embodiment and the second embodiment will be described.

[0059] FIG. 5 is a diagram showing an example of gate signals S1 to S4 according to the third embodiment. The gate signals S1 and S2 in FIG. 5 are the same as the gate signals S1 and S2 in FIG. 3, respectively. The gate signals S1 and S2 go high / low with a period T1, which is the reciprocal of the frequency f1. The phases of the gate signals S1 and S2 are shifted from each other by half the period T1 (=T1 / 2). The high-level period t of the gate signals S1 and S2 on1 is the low level period t of the gate signals S1 and S2. off1 The field effect transistor U1 is turned on during the high level period t on1 and during the low level period t off1 The field effect transistor U2 is turned off during the high level period t on1 and during the low level period t off1 It will turn off.

[0060] The gate signals S3 and S4 also go high / low with a period T1, which is the reciprocal of the frequency f1. The phases of the gate signals S3 and S4 are shifted from each other by half the period T1 (=T1 / 2). The high-level period t on1 is the low level period t of the gate signals S3 and S4. off1 It is shorter by 2×δt1.

[0061] The phase of the gate signal S3 is shifted from the phase of the gate signal S1 by ¼ of the period T1 (=T1 / 4). The phase of the gate signal S4 is shifted from the phase of the gate signal S2 by ¼ of the period T1 (=T1 / 4). The field effect transistor U3 is turned on during the high level period t on1 and during the low level period toff1 The field effect transistor U4 is turned off during the high level period t on1 and during the low level period t off1 It will turn off.

[0062] Capacitors C1 and C2 in FIG. 2 have the same capacitance value and resonate with one of power transmitting coils 301 to 305 at frequency f1.

[0063] The field-effect transistors U1 and U2 of the power transmitting circuit 201 are switched at a frequency f1 based on gate signals S1 and S2, respectively. The field-effect transistors U3 and U4 of the power transmitting circuit 202 are switched at a frequency f1 based on gate signals S3 and S4, respectively. The gate signals S3 and S4 are 90° out of phase with the gate signals S1 and S2. Therefore, the switching timing of the power transmitting circuit 202 is shifted by 90° with respect to the switching timing of the power transmitting circuit 201.

[0064] Gate signals S5 to S8 in Fig. 2 correspond to gate signals S1 and S2, and have a frequency of f1 and a period of T1 (=1 / f1). Gate signals S9 to S12 in Fig. 2 correspond to gate signals S3 and S4, and have a frequency of f1 and a period of T1 (=1 / f1). The phases of gate signals S9 to S12 are shifted by ¼ of the period T1 (=T1 / 4) from the phases of gate signals S5 to S8, respectively.

[0065] The field effect transistors U5 to U8 of the power receiving circuit 501 are switched at a frequency f1. The switching timing is the same as in the second embodiment, and when suitable rectification is performed, the phase shift is α° with respect to the switching timing of the power transmitting circuit 201.

[0066] The field effect transistors U9 to U12 of the power receiving circuit 502 are switched at a frequency f1. When suitable rectification is performed, the timing of the switching is shifted in phase by (α+90)° with respect to the timing of the switching of the power transmitting circuit 201.

[0067] Fig. 6 is a diagram showing the interference suppression effect achieved by synchronous rectification in the power receiving circuit 501. In Fig. 6, the vertical axis represents amplitude, and the horizontal axis represents time. Signals 611 to 615 are signals for explaining the principle by which the power receiving circuit 501 suppresses the influence of interference signals when the phases of gate signals S1 and S2 and gate signals S3 and S4 are different from each other, and are not intended to limit the signals. Furthermore, for the purpose of explaining the principle, the amplitudes of signals 611 to 615 are calculated values ​​assuming no loss due to wireless power transmission.

[0068] The power transmitting circuit 201 switches the output signal of the driver 101 at the timing of the 0° gate signals S1 and S2. The power transmitting coil 301 wirelessly transmits the output signal of the power transmitting circuit 201 to the power receiving coil 401. The power transmitting circuit 202 switches the output signal of the driver 102 at the timing of the 90° gate signals S3 and S4. The power transmitting coil 304 wirelessly transmits the output signal of the power transmitting circuit 202 to the power receiving coil 402. The power receiving coil 401 receives the output signal of the power transmitting circuit 201 from the power transmitting coil 301 and also receives an interference signal from the power transmitting coil 304.

[0069] Signal 611 is an output signal of driver 101. Power transmitting circuit 201 switches output signal 611 of driver 101 at the timing of gate signals S1 and S2 at 0°. Signal 612 is a signal obtained by receiving the output signal of power transmitting circuit 201 via power transmitting coil 301 at power receiving coil 401, and has a phase of 0°. Signal 613 is an interference signal obtained by receiving the output signal of power transmitting circuit 202 via power transmitting coil 304 at power receiving coil 401, and has a smaller amplitude than signal 612 and a phase of 90°. Signal 614 is a signal obtained by rectifying a composite signal of signals 612 and 613 by field effect transistors U5 to U8 of power receiving circuit 501, and is the signal before being smoothed by capacitor C5. Signal 615 is a signal obtained after capacitor C5 of power receiving circuit 501 smoothes signal 614. For ease of understanding, signal 615 shows a signal when capacitor C5 is replaced with a high-order low-pass filter.

[0070] The smoothed signal 615 is a signal restored by the power receiving circuit 501. The smoothed signal 615 is substantially the same as the output signal 611 of the driver 101. Therefore, even if an interference signal 613 is mixed into the received signal 612 of the power receiving coil 401, it can be seen that the influence of the interference signal 613 is suppressed. Even if the interference signal 613 is mixed in, the power receiving circuit 501 can restore the signal 615 that is substantially the same as the output signal 611 of the driver 101.

[0071] Here, field effect transistors U5 to U8 rectify the signal received by power receiving coil 401 and output signal 614. Signal 614 contains noise components due to interference between signal 612, which has a phase of 0°, and interference signal 613, which has a phase of 90°. Capacitor C5 is required to remove the noise components from signal 614 and generate smoothed signal 615. For this reason, capacitor C5 may be replaced with a high-order low-pass filter.

[0072] If the motor 601 is hardly sensitive to the noise components, the capacitor C5 only needs to have a capacitance that prevents leakage of the noise components from affecting other devices. The operation of the power receiving circuit 502 in Figure 2 is similar to the operation of the power receiving circuit 501 described above.

[0073] (Fourth embodiment) 7 is a diagram showing an example of the configuration of a wireless power transmission system 700 according to the fourth embodiment. The wireless power transmission system 700 is an example applied to automated guided vehicles (AGVs) 711 to 713, and includes power transmitting coils 301 to 329 and three automated guided vehicles 711 to 713. The automated guided vehicle 711 includes a power receiving coil 401, the automated guided vehicle 712 includes a power receiving coil 402, and the automated guided vehicle 713 includes a power receiving coil 403. The power transmitting coil array 300 including the power transmitting coils 301 to 329 is placed on the floor. The three automated guided vehicles 711 to 713 move over the power transmitting coils 301 to 329. Each of the automated guided vehicles 711 to 713 includes a load such as a motor 601.

[0074] 7 shows an example of three automatic guided vehicles 711 to 713, but the number is not limited to this. Furthermore, the power transmitting coil array 300 is not limited to the number of power transmitting coils 301 to 329 or the way they are branched.

[0075] According to this embodiment, even when the automated guided vehicles 711 to 713 move over the branched power transmitting coil array 300, the wireless power transmission system 700 can wirelessly transmit power from any of the power transmitting coils 301 to 329 to the power receiving coils 401 to 403.

[0076] Fig. 8 is a diagram showing an example of the configuration of a wireless power transmission system 700 according to the fourth embodiment. The wireless power transmission system 700 includes drivers 101 to 103, power transmission circuits 201 to 203, switches SW1 to SW29, a power transmission coil array 300, and automated guided vehicles 711 to 713. The power transmission coil array 300 includes power transmission coils 301 to 329. The automated guided vehicle 711 includes a power receiving coil 401, a power receiving circuit 501, and a motor 601. The automated guided vehicle 712 includes a power receiving coil 402, a power receiving circuit 502, and a motor 602. The automated guided vehicle 713 includes a power receiving coil 403, a power receiving circuit 503, and a motor 603. The automated guided vehicles 711 to 713 are each movable in the directions of the arrows in Fig. 8.

[0077] The switch SW1 connects one of the power transmitting circuits 201 to 203 to the power transmitting coil 301, or disconnects the power transmitting coil 301. Similarly, the switches SW2 to SW29 connect one of the power transmitting circuits 201 to 203 to the power transmitting coils 302 to 329, or disconnects the power transmitting coils 302 to 329, respectively.

[0078] The receiving coil 401 can wirelessly receive the output voltage of the power transmitting circuit 201 from any of the transmitting coils 301 to 329. The receiving coil 402 can wirelessly receive the output voltage of the power transmitting circuit 202 from any of the transmitting coils 301 to 329. The receiving coil 403 can wirelessly receive the output voltage of the power transmitting circuit 203 from any of the transmitting coils 301 to 329.

[0079] The driver 101 of the motor 601 outputs a voltage to be supplied to the motor 601 to the power transmitting circuit 201. The power transmitting circuit 201 switches the output voltage of the driver 101 at a high frequency suitable for wireless power transmission. The power transmitting circuit 201 then outputs the switched high-frequency voltage (power) to the power transmitting coil 302 via the switch SW2. The power transmitting coil 302 wirelessly transmits the high-frequency power to the power receiving coil 401. The power receiving coil 401 receives the high-frequency power (voltage) from the power transmitting coil 302 and outputs the received high-frequency voltage to the power receiving circuit 501. The power receiving circuit 501 rectifies the high-frequency voltage received by the power receiving coil 401 and restores the output voltage of the driver 101. The power receiving circuit 501 then outputs the restored voltage to the motor 601. The motor 601 is driven according to the voltage input from the power receiving circuit 501.

[0080] The driver 102 of the motor 602 outputs a voltage to be supplied to the motor 602 to the power transmitting circuit 202. The power transmitting circuit 202 switches the output voltage of the driver 102 at a high frequency suitable for wireless power transmission. The power transmitting circuit 202 then outputs the switched high-frequency voltage (power) to the power transmitting coil 310 via the switch SW10. The power transmitting coil 310 wirelessly transmits the high-frequency power to the power receiving coil 402. The power receiving coil 402 receives the high-frequency power (voltage) from the power transmitting coil 310 and outputs the received high-frequency voltage to the power receiving circuit 502. The power receiving circuit 502 rectifies the high-frequency voltage received by the power receiving coil 402 and restores the output voltage of the driver 102. The power receiving circuit 502 then outputs the restored voltage to the motor 602. The motor 602 is driven according to the voltage input from the power receiving circuit 502.

[0081] The driver 103 of the motor 603 outputs a voltage to be supplied to the motor 603 to the power transmitting circuit 203. The power transmitting circuit 203 switches the output voltage of the driver 103 at a high frequency suitable for wireless power transmission. The power transmitting circuit 203 then outputs the switched high-frequency voltage (power) to the power transmitting coil 322 via the switch SW22. The power transmitting coil 322 wirelessly transmits the high-frequency power to the power receiving coil 403. The power receiving coil 403 receives the high-frequency power (voltage) from the power transmitting coil 322 and outputs the received high-frequency voltage to the power receiving circuit 503. The power receiving circuit 503 rectifies the high-frequency voltage received by the power receiving coil 403 and restores the output voltage of the driver 103. The power receiving circuit 503 then outputs the restored voltage to the motor 603. The motor 603 is driven according to the voltage input from the power receiving circuit 503.

[0082] As described above, the automated guided vehicles 711-713 are movable relative to the power transmitting coils 301-329. The power receiving coils 401-403 receive power wirelessly from the power transmitting coils 302, 310, and 322 that are located opposite the power receiving coils 401-403 among the power transmitting coils 301-329. Here, because the power transmitting coil array 300 is branched, the positions of the automated guided vehicles 711-713 can be interchanged. The positions of the automated guided vehicles 711-713 may be obtained from position control information of the automated guided vehicles 711-713, or may be obtained from an optical sensor (not shown), an on-site camera (not shown), or the like.

[0083] (Fifth embodiment) Fig. 9 is a diagram showing an example of the configuration of a wireless power transmission system 700 according to the fifth embodiment. The wireless power transmission system 700 in Fig. 9 differs from the wireless power transmission system 700 in Fig. 2 in that it has power transmitting circuits 201 and 202. The differences between Fig. 9 and Fig. 2 will be described below. In Fig. 2, the power transmitting circuit 201 has a pair of field effect transistors U1 and U2 and a capacitor C1, and the power transmitting circuit 202 has a pair of field effect transistors U3 and U4 and a capacitor C2.

[0084] 9, the power transmitting circuit 201 has five pairs of field effect transistors U1, U2 and a capacitor C1. The five pairs of field effect transistors U1, U2 and capacitor C1 are connected to five power transmitting coils 301-305 via five switches SW1-SW5, respectively. As in FIG. 2, the five pairs of field effect transistors U1 and U2 switch the output voltage of the driver 101 in response to gate signals S1 and S2, respectively, and output the switched voltage to the power transmitting coils 301-305 via the switches SW1-SW5.

[0085] 9, the power transmitting circuit 202 has five pairs of field effect transistors U3, U4 and a capacitor C2. The five pairs of field effect transistors U3, U4 and capacitor C2 are connected to five power transmitting coils 301-305 via five switches SW1-SW5, respectively. As in FIG. 2, the five pairs of field effect transistors U3 and U4 switch the output voltage of the driver 102 in response to gate signals S3 and S4, respectively, and output the switched voltage to the power transmitting coils 301-305 via the switches SW1-SW5.

[0086] In addition, when the power receiving coil is larger than the power transmitting coil and multiple power transmitting coils face one power receiving coil, the multiple power transmitting coils may wirelessly transmit power to one power receiving coil.

[0087] Furthermore, a magnetic sheet or a metal plate may be placed on the side of each power transmitting coil that does not face the power receiving coil, thereby preventing leakage of unwanted radiation. For example, a magnetic sheet may be placed on the side of the power transmitting coil that does not face the power receiving coil, and a metal plate may be placed on the magnetic sheet on the opposite side of the power transmitting coil.

[0088] Furthermore, a magnetic sheet or metal plate may be placed on the side of each receiving coil that does not face the power transmitting coil, making it difficult for unwanted radiation to leak. For example, a magnetic sheet may be placed on the side of the receiving coil that does not face the power transmitting coil, and a metal plate may be placed on the magnetic sheet on the opposite side of the receiving coil.

[0089] As described above, according to the first to fifth embodiments, the power transmitting circuit 201 outputs a first power for power transmission. The power transmitting circuit 202 outputs a second power for power transmission. The multiple power transmitting coils 301 to 312 are three or more power transmitting coils for wirelessly transmitting the first power of the power transmitting circuit 201 or the second power of the power transmitting circuit 202.

[0090] The power receiving coil 401 is movable relative to the power transmitting coils 301 to 312 and is a power receiving coil for wirelessly receiving the first power of the power transmitting circuit 201 from any of the power transmitting coils 301 to 312. The power receiving coil 402 is movable relative to the power transmitting coils 301 to 312 and is a power receiving coil for wirelessly receiving the second power of the power transmitting circuit 202 from any of the power transmitting coils 301 to 312.

[0091] The switches SW1 to SW12 connect the power transmitting coil 304, which faces the power receiving coil 401, among the multiple power transmitting coils 301 to 312, to the power transmitting circuit 201, and connect the power transmitting coil 306, which faces the power receiving coil 402, to the power transmitting circuit 202. Specifically, the switches SW1 to SW12 connect one or more power transmitting coils which face the power receiving coil 401 to the power transmitting circuit 201, and connect one or more other power transmitting coils which face the power receiving coil 402 to the power transmitting circuit 202.

[0092] 1, wireless power transmission system 700 includes a main body 800 and a movable stage 900. Main body 800 is a power transmitting device and includes a power transmitting circuit 201, a power transmitting circuit 202, power transmitting coils 301 to 312, and switches SW1 to SW12. Movable stage 900 is a power receiving device that is movable relative to main body 800 and includes a power receiving coil 401, a power receiving coil 402, a power receiving circuit 501, and a power receiving circuit 502.

[0093] 8, a wireless power transmission system 700 includes automated guided vehicles 711-713 and a main body (power transmitting device) 800 similar to that in FIG. 1. The automated guided vehicles 711-713 are each a power receiving device and are movable relative to the main body 800. The main body 800 includes power transmitting circuits 201-203, power transmitting coils 301-329, and switches SW1-SW29. The automated guided vehicle 711 includes a power receiving coil 401, a power receiving circuit 501, and a motor 601. The automated guided vehicle 712 includes a power receiving coil 402, a power receiving circuit 502, and a motor 602.

[0094] 2 and 9, the power transmitting circuit 201 has field effect transistors U1 and U2 for switching the input power from the driver 101. The power transmitting circuit 202 has field effect transistors U3 and U4 for switching the input power from the driver 102. The field effect transistors U1 to U4 are examples of switches.

[0095] The field effect transistors U1 and U2 are switched on and off based on gate signals S1 and S2, respectively. The field effect transistors U3 and U4 are switched on and off based on gate signals S3 and S4, respectively. The gate signals S1 to S4 are examples of control signals.

[0096] The power receiving circuit 501 has field effect transistors U5 to U8 for synchronously rectifying the power wirelessly received by the power receiving coil 401, and a capacitor C5 or a low-pass filter. The power receiving circuit 502 has field effect transistors U9 to U12 for synchronously rectifying the power wirelessly received by the power receiving coil 402, and a capacitor C8 or a low-pass filter. The field effect transistors U5 to U12 are an example of switches.

[0097] The field effect transistors U5 to U8 are switched on and off based on gate signals S5 to S8, respectively. The field effect transistors U9 to U12 are switched on and off based on gate signals S9 to S12, respectively. The gate signals S5 to S12 are an example of control signals.

[0098] 3, the frequency of gate signals S1 and S2 is f1. The frequency of gate signals S3 and S4 is f2. The gate signals S1 and S2 and the gate signals S3 and S4 have different frequencies.

[0099] The frequency of gate signals S5 to S8 is f1. The frequency of gate signals S9 to S12 is f2. The gate signals S5 to S8 and the gate signals S9 to S12 have different frequencies. The gate signals S1, S2 and the gate signals S5 to S8 have the same frequency. The gate signals S3, S4 and the gate signals S9 to S12 have the same frequency.

[0100] 5, gate signals S1, S2 and gate signals S3, S4 have different phases. Gate signals S5 to S8 and gate signals S9 to S12 also have different frequencies. The phase difference between gate signals S1, S2 and gate signals S3, S4 and the phase difference between gate signals S5 to S8 and gate signals S9 to S12 are the same, for example, 90°.

[0101] The power receiving circuit 501 restores the output power of the driver 101 through synchronous rectification and supplies the restored output power to the motor 601. The power receiving circuit 502 restores the output power of the driver 102 through synchronous rectification and supplies the restored output power to the motor 602. The motors 601 and 602 are examples of loads.

[0102] The wireless power transmission system 700 may include a detection unit that detects the relative position of the power receiving coil 401 with respect to the multiple power transmitting coils 301 to 312 and the relative position of the power receiving coil 402 with respect to the multiple power transmitting coils 301 to 312. The detection unit is, for example, an optical sensor or a camera.

[0103] A magnetic sheet or a metal plate is disposed on the sides of the multiple power transmitting coils 301-312 that do not face the power receiving coil 401 or 402. In addition, a magnetic sheet or a metal plate is disposed on the sides of the power receiving coils 401 and 402 that do not face the multiple power transmitting coils 301-312.

[0104] According to the first to fifth embodiments, the power receiving coils 401 and 402 are movable relative to the multiple power transmitting coils 301 to 312. The power receiving coils 401 and 402 share the multiple power transmitting coils 301 to 312. This allows for space saving for the placement of the multiple power transmitting coils 301 to 312. Furthermore, the power receiving coils 401 and 402 each receive power wirelessly only from the power transmitting coil that faces the power receiving coils 401 and 402. This eliminates the need to cover the entire power transmitting coil with a shielding member to suppress interference, and allows for a simpler mechanism for suppressing interference compared to a power transmitting coil that has the same length as the entire movement distance of the power receiving coil or when power is transmitted from the transmission line of Patent Document 1.

[0105] It should be noted that the above-described embodiments merely illustrate specific examples of implementing the present disclosure, and the technical scope of the present disclosure should not be construed as being limited by these embodiments. In other words, the present disclosure can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0106] 101, 102, 103 Driver, 201, 202, 203 Power transmission circuit, 300 Power transmission coil array, 301 to 329 Power transmission coil, 401, 402 Power receiving coil, 501, 502 Power receiving circuit, 601, 602 Motor, 700 Wireless power transmission system, 800 Main body of semiconductor exposure apparatus, 900 Moving stage of semiconductor exposure apparatus

Claims

1. a first power transmission circuit that outputs a first power to be transmitted; a second power transmission circuit that outputs a second power to be transmitted; a plurality of power transmitting coils, each of which includes three or more power transmitting coils, for wirelessly transmitting the first power or the second power; a first power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the first power from any one of the plurality of power transmitting coils; a second power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the second power from any one of the plurality of power transmitting coils; a first switch that connects, among the plurality of power transmitting coils, a power transmitting coil that faces the first power receiving coil to the first power transmitting circuit and a power transmitting coil that faces the second power receiving coil to the second power transmitting circuit; a first switch that connects the plurality of power transmitting coils so that each of the plurality of power transmitting coils can select either the first power or the second power and transmit the power wirelessly;

2. The wireless power transmission system includes: a power transmission device; a power receiving device that is movable relative to the power transmitting device, the power transmitting device includes the first power transmitting circuit, the second power transmitting circuit, the plurality of power transmitting coils, and the first switch; The wireless power transmission system according to claim 1 , wherein the power receiving device includes the first power receiving coil and the second power receiving coil.

3. The wireless power transmission system includes: a power transmission device; a first power receiving device that is movable relative to the power transmitting device; a second power receiving device that is movable relative to the power transmitting device; the power transmitting device includes the first power transmitting circuit, the second power transmitting circuit, the plurality of power transmitting coils, and the first switch; the first power receiving device has the first power receiving coil, The wireless power transmission system according to claim 1 , wherein the second power receiving device includes the second power receiving coil.

4. the first power transmitting circuit has a second switch for switching the first input power; 4. The wireless power transmission system according to claim 1, wherein the second power transmitting circuit has a third switch for switching the second input power.

5. the second switch is switched on the basis of a first control signal; the third switch is switched on the basis of a second control signal; The wireless power transmission system according to claim 4 , wherein the first control signal and the second control signal have different frequencies.

6. the second switch is switched on the basis of a first control signal; the third switch is switched on the basis of a second control signal; The wireless power transmission system according to claim 4 , wherein the first control signal and the second control signal are out of phase with each other.

7. a first power receiving circuit that rectifies the first power wirelessly received by the first power receiving coil; 4. The wireless power transmission system according to claim 1, further comprising a second power receiving circuit that rectifies the second power wirelessly received by the second power receiving coil.

8. the first power transmitting circuit has a second switch for switching the first input power; the second power transmitting circuit has a third switch for switching the second input power; the first power receiving circuit has a fourth switch for rectifying the first power wirelessly received by the first power receiving coil; 8. The wireless power transmission system according to claim 7, wherein the second power receiving circuit has a fifth switch for rectifying the second power wirelessly received by the second power receiving coil.

9. the second switch is switched on the basis of a first control signal; the third switch is switched on the basis of a second control signal; the fourth switch is switched on the basis of a third control signal; the fifth switch is switched on the basis of a fourth control signal; the first control signal and the second control signal have different frequencies from each other, the third control signal and the fourth control signal have different frequencies from each other, the first control signal and the third control signal have the same frequency; The wireless power transmission system according to claim 8 , wherein the second control signal and the fourth control signal have the same frequency.

10. the second switch is switched on the basis of a first control signal; the third switch is switched on the basis of a second control signal; the fourth switch is switched on the basis of a third control signal; the fifth switch is switched on the basis of a fourth control signal; the first control signal and the second control signal are out of phase with each other; the third control signal and the fourth control signal are out of phase with each other; 9. The wireless power transmission system according to claim 8, wherein a phase difference between the first control signal and the second control signal and a phase difference between the third control signal and the fourth control signal are the same.

11. the first power receiving circuit supplies power to a first load; The wireless power transmission system according to claim 7 , wherein the second power receiving circuit supplies power to a second load.

12. 12. The wireless power transmission system according to claim 7, wherein the first power receiving circuit and the second power receiving circuit each include a capacitor or a low-pass filter.

13. The wireless power transmission system according to any one of claims 1 to 12, characterized in that the first switch connects one or more transmitting coils opposite the first receiving coil to the first transmitting circuit, and connects one or more other transmitting coils opposite the second receiving coil to the second transmitting circuit.

14. The wireless power transmission system according to any one of claims 1 to 13, further comprising a detection unit that detects the relative position of the first receiving coil with respect to the plurality of transmitting coils and the relative position of the second receiving coil with respect to the plurality of transmitting coils.

15. The wireless power transmission system according to any one of claims 1 to 14, characterized in that a magnetic sheet or a metal plate is arranged on the side of the plurality of transmitting coils that does not face the first receiving coil or the second receiving coil.

16. The wireless power transmission system according to any one of claims 1 to 15, characterized in that a magnetic sheet or a metal plate is arranged on the side of the first receiving coil and the second receiving coil that does not face the multiple transmitting coils.

17. a first power transmission circuit that outputs a first power to be transmitted; a second power transmission circuit that outputs a second power to be transmitted; a plurality of power transmitting coils, each of which includes three or more power transmitting coils, for wirelessly transmitting the first power or the second power; a first power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the first power from any one of the plurality of power transmitting coils; a second power receiving coil that is movable relative to the plurality of power transmitting coils and that wirelessly receives the second power from any one of the plurality of power transmitting coils; a control method for a wireless power transmission system, wherein each of the plurality of power transmitting coils has a first switch that selects either the first power or the second power and connects the power transmitting coils so as to be able to wirelessly transmit power, connecting a power transmitting coil, among the plurality of power transmitting coils, that faces the first power receiving coil to the first power transmitting circuit; connecting a power transmitting coil that faces the second power receiving coil among the plurality of power transmitting coils to the second power transmitting circuit; A control method for a wireless power transmission system, comprising:

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