JP2021072670A - Radio equipment - Google Patents

Abstract

To achieve high accuracy of voltage application to a load on the basis of electric power radio-transmitted.SOLUTION: The radio equipment includes: a power transmission coil (101) for radio-transmitting electric power; a power reception coil (201) for radio-receiving the electric power of the power transmission coil; a switch circuit (106) for applying a voltage to the power transmission coil on the basis of a first switching signal; a rectifier circuit (206) for rectifying the voltage output from the power reception coil and applying the rectified voltage to a load on the basis of a second switching signal; and a first phase shift circuit (102) for giving a phase difference to the first switching signal and the second switching signal.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wireless device.

There is a system that supplies electric power to a motor to drive it. For example, in a semiconductor exposure apparatus, a motor for finely moving a wafer to form a pattern on the wafer is mounted on a stage for moving the wafer to an exposure position, and power is supplied to drive the motor. The power supply cable is connected on the stage. Since this cable moves as the stage moves, the tension of the cable affects the positioning accuracy of the stage. Therefore, it is considered to make the power transmission for driving the motor wireless.

Patent Document 1 describes a configuration of a motor that wirelessly drives wheels. In order to drive a motor wirelessly, it is necessary to send not only power transmission but also control signals of a motor drive circuit and a rectifier circuit wirelessly, so wireless communication using radio waves is performed. By sending a control signal to the motor drive circuit on the movable side using this communication, the control of the motor drive circuit is realized.

Japanese Patent No. 6219495

In recent years, it has been required to control the voltage applied to a load unit such as a motor with high accuracy. For example, in a semiconductor exposure apparatus, high-speed motor control is required in order to move the stage at high speed and with high accuracy. Since the method described in Patent Document 1 causes a delay of several hundred μs to several ms in wireless communication using radio waves, a control signal to the motor drive circuit is sent at a cycle of several hundred μs or less to speed up motor control. It's difficult to do.

An object of the present invention is to improve the accuracy of voltage application to a load based on wirelessly transmitted power.

The wireless device of the present invention includes a power transmission coil that wirelessly transmits power, a power reception coil that wirelessly receives power from the power transmission coil, and a switch circuit that applies a voltage to the power transmission coil based on a first switching signal. Based on the second switching signal, a rectifying circuit that rectifies the voltage output from the power receiving coil and applies the rectified voltage to the load, and the first switching signal and the second switching signal. It has a first phase shift circuit that gives a phase difference.

According to the present invention, it is possible to improve the accuracy of applying a voltage to a load based on wirelessly transmitted electric power.

It is a system configuration diagram when a wireless device is applied to a movable stage. It is a figure which shows the configuration example of a wireless device. It is a figure which shows the structural example of a rectifier circuit. It is a figure which shows the actual measurement example of the input / output voltage. It is a figure which shows the configuration example of a wireless device. It is a figure which shows the configuration example of a wireless device. It is a figure which shows the configuration example of a wireless device.

(First Embodiment)
FIG. 1 is a diagram showing a configuration example of a wireless device applied to a movable stage such as a semiconductor exposure apparatus according to the first embodiment. The wireless device includes a power transmission unit 100, a power reception unit 200, a power transmission coil 101, and a power reception coil 201.

The power receiving unit 200 is arranged on the movable stage 401 and physically moves with respect to the power transmitting unit 100. The power transmission unit 100 is arranged not on the movable stage 401 but on the fixed side where the movable stage power source 402 for moving the movable stage 401 is arranged, and does not move itself.

Between the power transmission unit 100 and the power reception unit 200, there are a power transmission coil 101 and a power reception coil 201 for wirelessly feeding and communicating. The power transmission coil 101 and the power reception coil 201 are not in contact with each other. The power receiving coil 201 is also arranged on the movable stage 401 and moves together with the movable stage 401. By making the power transmission coil 101 long so as to cover the moving range of the movable stage 401, even if the movable stage 401 moves to an arbitrary position, power can be supplied to the motor in the power receiving unit 200 in a non-contact manner. ..

The shape of the power transmission coil 101 is, for example, a horizontally long elliptical coil, and the power reception coil 201 is a shorter coil than the power transmission coil 101. The power receiving coil 201 may be long and the power transmitting coil 101 may be short.

FIG. 2 is a block diagram showing a configuration example of the wireless device 300 according to the first embodiment. The wireless device 300 includes a power transmission unit 100, a power reception unit 200, a power transmission coil 101, and a power reception coil 201. The power transmission coil 101 and the power reception coil 201 are not physically connected, and power is transmitted from the power transmission coil 101 to the power reception coil 201 in a non-contact manner. The power transmission unit 100 and the power reception unit 200 are also not physically connected.

The power transmission unit 100 includes a phase-locked loop 102, a controller 103, a power supply 104, a reference frequency source 105, and a switch circuit 106. The power receiving unit 200 includes a reference frequency source 202, a power receiving circuit 204, a gate drive circuit 205, a rectifier circuit 206, and a motor 400.

The power source 104 is a power source that drives the motor 400. The switch circuit 106 drives a switching element by a switching control signal in which the reference frequency signal generated by the reference frequency source 105 is phase-shifted by the phase shift circuit 102, high-frequency switching the power supplied from the power supply 104, and wireless power transmission is possible. Converts to high frequency power. At this time, the switching frequency is higher than the cycle of the command signal of the controller 103, that is, the motor control frequency.

The controller 103 issues a command for the next position based on the current position information of the motor 400 obtained from an optical sensor or the like. Specifically, the controller 103 outputs the output voltage amplitude value of the power supply 104 that determines the thrust of the motor 400 and the motor applied voltage code information that determines the direction in which the motor moves. The output voltage amplitude value is changed from the output voltage amplitude value to the commanded value by the power supply 104 by sending a command signal from the controller 103 to the power supply 104. The motor applied voltage code information is output from the controller 103 to the phase shifting circuit 102. The reference frequency source 105 outputs a reference frequency signal to the phase-locked loop 102. The phase shift circuit 102 outputs a signal obtained by shifting the reference frequency signal output by the reference frequency source 105 to the switch circuit 106 as a first switching signal based on the motor applied voltage code information output by the controller 103.

The switch circuit 106 supplies (applies) a power transmission voltage (current) including information necessary for motor control to the power transmission coil 101 based on the first switching signal (voltage F3). The power transmission coil 101 wirelessly transmits electric power. The power receiving coil 201, which is not in contact with the power transmission coil 101 and is electromagnetically coupled, is excited by the electromagnetic field of the power transmission coil 101 to generate high-frequency power. The power receiving coil 201 wirelessly receives the electric power of the power transmitting coil 101.

The power receiving circuit 204 is provided between the power receiving coil 201 and the rectifier circuit 206. The power receiving circuit 204 is formed of a resonance circuit including an inductor and a capacitor, and its resonance frequency is substantially equal to the switching operating frequency of the switch circuit 106. The output of the power receiving circuit 204 is connected to the rectifier circuit 206.

The rectifier circuit 206 rectifies the output voltage of the power receiving circuit 204 based on the second switching signal (voltage F6) of the gate drive circuit 205, and applies the rectified voltage to the motor 400. Here, the second switching signal is a signal frequency-synchronized with the reference frequency source 202. The reference frequency source 202 synchronizes with the reference frequency source 105 and outputs a reference frequency signal to the gate drive circuit 205. The gate drive circuit 205 drives the rectifier circuit 206 with a second switching signal based on the reference frequency signal of the reference frequency source 202. If the reference frequency source 105 and the reference frequency source 202 are frequency-synchronized, the output voltage (electric power) of the rectifier circuit 206 can be controlled by the phase shift amount of the phase shift circuit 102. The motor 400 is a load and is rotated by the output voltage of the rectifier circuit 206.

The reference frequency source 202 can be replaced by means for non-contact transmission of the reference frequency signal of the reference frequency source 105 by electromagnetic field coupling communication or optical coupling communication. For example, a laser or a light emitting diode with sharp directivity is placed on a reference frequency source 105 on the fixed side, light is emitted along the moving direction of the stage, and a light receiving surface such as a photodiode is positioned on the light path. The element may be arranged at the reference frequency source 202 on the movable side. The electromagnetic field coupling in the present embodiment includes both an electric field coupling and a magnetic field coupling. That is, the non-contact transmission of the signal may be performed by electric field coupling, magnetic field coupling, or both electric field coupling and magnetic field coupling.

Further, the rectifier circuit 206 can rectify even a small voltage of several mV, which cannot be rectified by a diode, by performing synchronous rectification using an active switching element, and a minute voltage can be applied to the motor 400, so that the motor 400 is made high. It becomes possible to control with precision.

The power transmission coil 101 and the power reception coil 201 may be formed by wiring on a printed circuit board. A magnetic sheet may be attached to the printed circuit board to reduce the loss during magnetic field coupling. Further, the power transmission coil 101 and the power reception coil 201 may be a winding transformer using a magnetic material such as ferrite and windings such as litz wire.

Next, the operating principle of the wireless device 300 will be described from a mathematical point of view. The voltages F1 to F7 in FIG. 2 are represented by a function of the voltage waveform of each part. The voltage F1 is the output voltage of the power supply 104, is an absolute value of the voltage required to drive the motor, and can be represented by [Equation 1].

The voltage F4 is the output voltage of the reference frequency source 105 and is represented by [Equation 2]. A rectangular wave may be used as the voltage F4.

The voltage F3 is a control signal of the switch circuit 106 whose phase difference φ is shifted by the phase shifting circuit 102 according to the command of the controller 103, and is represented by [Equation 3].

The switch circuit 106 can be thought of as a multiplier that multiplies the voltages F1 and F3 on the time axis, and the output voltage F2 is given by [Equation 4].

This voltage F2 propagates from the power transmission coil 101 to the power reception coil 201 via electromagnetic field coupling, and is input to the rectifier circuit 206 after the power factor is adjusted by the power reception circuit 204. For convenience, it is assumed here that the power transmission coil 101 and the power reception coil 201 are ideally coupled at a voltage ratio of 1: 1. The input voltage F5 of the rectifier circuit 206 is given by [Equation 5].

Here, θ is the sum of the phase differences due to the propagation delay from the power transmission coil 101 to just before the rectifier circuit 206 and the resonance shift of the power reception circuit 204. The voltage F6 is a drive signal of the rectifier circuit 206 and can be represented by [Equation 6]. The voltage F6 does not necessarily have to be synchronized with the phase of the voltage F4, but here, the phase difference is set to 0 for the sake of simplicity. The phase-locked loop 102 gives a phase difference φ to the voltage F3 and the voltage F6. The voltage F3 and the voltage F6 have the same period.

Since the rectifier circuit 206 can be considered as a multiplier like the switch circuit 106, its output voltage F7 is given by [Equation 7].

Here, regarding [Equation 7], the first item means a harmonic component generated by multiplication. Since a smoothing capacitor showing an impedance sufficiently low with respect to the power transmission frequency is mounted on the output of the rectifier circuit 206, the harmonic component is attenuated to a negligible degree. As a result, the drive voltage of the motor 400 is represented by the second item. Therefore, the drive voltage F7 of the motor 400 is given by [Equation 8].

[Equation 8] indicates that the motor control voltage F7 can be sinusically controlled by the phase shift amount φ of the phase shift circuit 102. The maximum value of [Equation 8] can be read as 1/2 of the power supply 104, but this is the result when the switch circuit 106 is driven by a sine wave, and it is said that the switch circuit 106 is driven by an ideal square wave with a duty ratio of 50%. Assuming, the maximum value of [Equation 8] is the same as that of the power supply 104. Therefore, the motor drive voltage F7'in that case is rewritten as [Equation 9].

With the above, the operation of the wireless device 300 can be expressed mathematically although it is simple. A specific example of performing forward / reverse control of the motor 400 is shown below. When the phase shift amount φ is alternately switched between 0 and π, the voltage F7'is given by [Equation 10].

From [Equation 10], it can be seen that in order to perform forward rotation / reverse rotation control, the phase shift amount φ should be switched between 0 and π regardless of the value of the input voltage of the power supply 104 and the propagation delay θ. For example, when the phase shift amount is 0 and the motor drive voltage F7'is 1 V, when the phase shift amount changes to π, the motor drive voltage F7'changes to -1V.

In other words, as long as the reference frequency source 105 and the reference frequency source 202 are frequency-synchronized, it is possible to control the thrust, forward rotation, and reverse rotation of the motor 400 without transmitting the control signal in a non-contact manner. It becomes. In order to drive the motor 400 with high accuracy, it is desirable that the change of the motor drive voltage F7'with respect to the output voltage of the power supply 104 has a proportional relationship at a constant ratio regardless of the voltage value. When there is a condition in which this proportional relationship is broken for some reason, the proportional relationship can be improved by finely adjusting the phase shift amount in the phase-locked loop 102.

Further, in [Equation 10], when θ is 0, the absolute value of the motor drive voltage F7'is equal to the output voltage A of the power supply 104, which is the most ideal. In order to satisfy this condition, it is preferable to measure the correspondence between the output voltage of the rectifier circuit 206 and the output voltage of the power supply 104 in advance and adjust the initial phase of the phase shifting circuit 102 so that the correspondence becomes the most suitable state.

FIG. 3 is a diagram showing a configuration example of the rectifier circuit 206. A general synchronous rectifier circuit is realized by using four switching elements, but in the case of this configuration, it is not possible to output a rectified output that changes in both positive and negative directions. This is because a body diode or an equivalent parasitic element exists in the switch element, and if a reverse bias is applied between the drain and source of the transistor, the drain and source become conductive regardless of the drive state of the gate. Because. Therefore, the rectifier circuit 206 has a plurality of bidirectional switches composed of two switching elements for one gate drive circuit. With this configuration, unless the gate drive circuit performs on-control, the switching element does not conduct, and it is possible to output a rectified output that changes both positively and negatively. The drive power supply between the source and the gate is configured by an insulated power supply or the like, and can be realized by supplying a voltage of about 5 to 10 V from a floating power supply capable of supplying a voltage based on each source potential.

Next, the operation of the rectifier circuit 206 will be described. Basically, regardless of whether the output voltage of the rectifier circuit 206 is large or small, if the gate drive circuit 205 controls each bidirectional switch at the same frequency as the reference frequency source 105, the functional requirement can be achieved. Specifically, at the same frequency as the reference frequency source 105, for a certain half cycle, the upper left and lower right of the four bidirectional switches of the rectifier circuit 206 are turned on, the lower left and upper right are turned off, and the next half cycle. During that time, the operation may be switched to the reverse operation described above. As described above, if the phase shift amount φ of the phase shift circuit 102 changes while this operation is repeated, the rectified output voltage F7'corresponding to the phase shift amount φ can be obtained.

In this gate drive sequence, for example, when the upper right and lower right bidirectional switches are turned on at the same time, a through current flows and a large loss occurs. In some cases, this loss can damage the bidirectional switch, which is not desirable. Therefore, it is necessary to insert a so-called dead time in the gate drive signal at the switching timing of the bidirectional switch to avoid a through current. The drive signals of the plurality of bidirectional switches are provided with a dead time to prevent a through current. Since the insertion of the dead time has no effect on the frequency synchronization, it does not interfere with the rectification operation. Although the rectifier circuit 206 has been described as a full bridge type, it may be a center tap type. In that case, it is necessary to make the power receiving coil 201 a center tap type, which complicates the wiring, but the number of switching elements of the rectifier circuit 206 can be reduced to four.

Realizing a rectifier circuit 206 capable of outputting positive and negative voltages with such a simple circuit configuration is extremely advantageous from the viewpoint of miniaturization of the wireless device 300. In addition, the only condition required to satisfy the functional requirements of the rectifier circuit 206 is that it is driven by a control signal frequency-synchronized with the reference frequency source 105, which can be realized relatively easily. On the other hand, a general motor control signal is a PWM signal. In order to perform non-contact transmission of information necessary for realizing high-precision and high-speed PWM drive with low delay, the transmission system becomes complicated and becomes a main factor that determines the upper limit of high-speed speed.

FIG. 4 is a measurement result of the input / output voltage obtained by measuring the voltage applied to the motor 400 with respect to the output voltage of the power supply 104. The horizontal axis is the output voltage of the power supply 104, that is, the input voltage, and the vertical axis is the voltage applied to the motor 400, that is, the output voltage. The output voltage was switched between a positive voltage and a negative voltage by the phase shifting function of the phase shifting circuit 102, and measurements were performed for both potentials. FIG. 4 also draws an ideal curve when the input / output voltages match. The switching frequency is 4 MHz, and a 3 mH inductor is connected instead of the motor 400 as a pseudo load. Any voltage from 0V to 30V can be supplied wirelessly. There is a part where the output voltage is lower than the ideal curve. In that part, based on the measurement result of FIG. 4, the command value of the output voltage amplitude from the controller 103 to the power supply 104 is corrected so as to raise the output voltage of the power supply 104 by the amount of the voltage drop, or the phase shift circuit 102 is used. The ideal curve can be approached by adjusting the amount of phase shift. This result showed the practicality of the wireless device 300.

The wireless device 300 can realize high-speed motor control and small size and light weight of the movable side circuit in the motor drive circuit that supplies power wirelessly.

(Second Embodiment)
The second embodiment describes the wireless device 300 for satisfying the operating principle of the first embodiment while arbitrarily setting the switching frequency and the frequency of the reference frequency source used for wireless power transmission.

FIG. 5A is a diagram showing a configuration example of the wireless device 300 according to the second embodiment. In FIG. 5A, the reference frequency source 202 is deleted and the PLL (Phase Locked Loop) circuits 107 and 207 and the phase shifting circuit 208 are added to FIG. F1 to f3 in FIG. 5A show the frequency of the signal in each part.

The switching frequency used for wireless power transmission can take various values depending on the shape of the antenna, the transmitted power, and the input voltage. Further, the switching frequency needs to be adjusted with an accuracy of 10 to 100 kHz. A crystal oscillator, a MEMS oscillator, or the like is used as the reference frequency source 105, but these devices are commercialized at discrete frequencies and are not suitable for applications in which the output frequency is varied with fine precision. In order to solve such a problem, PLL (Phase Locked Loop) circuits 107 and 207 are used.

In the second embodiment, a crystal oscillator or the like is used as the reference frequency source 105. The PLL circuit 107 in the power transmission unit 100 and the PLL circuit 207 in the power reception unit 200 share the output signal of the reference frequency source 105. By commonly setting the set values of the output frequencies f2 of the two PLL circuits 107 and 207 as values suitable for wireless power transmission, flexible design according to the environment becomes possible. The output signal of the PLL circuit 107 is input to the phase shifting circuit 102, and the output signal of the PLL circuit 207 is input to the phase shifting circuit 208.

In FIG. 5A, a phase-locked loop 208 is also added to the power receiving unit 200 with respect to FIG. The phase-locked loop 208 of the power receiving unit 200 performs the same processing as the phase-locked circuit 102 of the power transmission unit 100. The output signal of the phase-locked loop 208 is input to the gate drive circuit 205. The phase-locked loop 208 is useful when acquiring the voltage or current waveform received by the power receiving unit 200, detecting θ in [Equation 5], and adjusting this to a desired value.

The reference frequency source 105 outputs a reference frequency signal. The PLL circuit 107 inputs a reference frequency signal and outputs the signal to the phase shifting circuit 102. The PLL circuit 207 inputs a reference frequency signal. The phase shift circuit 208 shifts the output signal of the PLL circuit 207. The gate drive circuit 205 outputs a second switching signal to the rectifier circuit 206 based on the output signal of the phase shift circuit 208.

The phase-locked circuit 102 and the phase-locked circuit 208 can be realized by an analog circuit system that combines a CR low-pass filter and a waveform shaping circuit, or change the output tap position of a shift register driven by a high-speed clock. It can also be realized. When the phase-locked circuit 102 and the phase-locked circuit 208 use a shift register, there is a concern about jitter in the output signal. Therefore, in the phase-locked circuit 102 and the phase-locked circuit 208, the drive clock of the shift register is sufficiently faster than the power transmission frequency (several tens of MHz to several GHz), or is an integral multiple of the power transmission frequency and is phase-locked. It is desirable to be.

As the circuit topology of the switch circuit 106, a full bridge type, a half bridge type, or a push-pull type is adopted. The output signal of the phase-locked loop 102 needs to be appropriately changed to a form suitable for driving each of the above circuit topologies. For example, when driving a half-bridge type, it is necessary to insert a dead time. FIG. 5B shows the relationship between the output signal of the phase-locked loop 102 and the drive signal in which the dead time is inserted for driving the half-bridge type switch circuit 106. As can be seen from FIG. 5B, even if the dead time is inserted, the cycle of the drive signal of the switch circuit 106 is stored in accordance with the cycle of the phase-locked loop 102, so that the drive signal of the switch circuit 106 is stored. And the drive signal of the rectifying circuit 206 are frequency-locked. The switch circuit 106 may be designed so that the switch circuit 106 operates in ZCS (Zero Current Switching) operation or ZVS (Zero Voltage Switching) operation for the purpose of improving the power conversion efficiency.

(Third Embodiment)
FIG. 6 is a diagram showing a configuration example of the wireless device 300 according to the third embodiment. In the third embodiment, the functions are further expanded with respect to the configuration shown in FIG. 5A to further improve the design flexibility, and the built-in functions of general integrated circuits (microcontroller and FPGA) are added. Describe the method suitable for use. Specifically, FIG. 6 adds frequency division / phase-locked loops 108, 109, 203 and 209 to FIG. 5A, and divides the frequency suitable for each part in consideration of cost constraints and circuit scale. Set the ratio or phase shift amount.

The frequency dividing / phase-locked loops 108 and 209 are provided in place of the phase-locked loops 102 and 208 of FIG. 5 (a), respectively. The output signal of the reference frequency source 105 is output to the PLL circuit 107 via the frequency dividing / phase shifting circuit 109. Further, the output signal of the reference frequency source 105 is output to the PLL circuit 207 via the frequency dividing / phase shifting circuit 203.

The reference frequency source 202 outputs a reference frequency signal. The frequency dividing / phase shifting circuit 109 divides and shifts the reference frequency signal. The frequency dividing / phase shifting circuit 203 divides and shifts the reference frequency signal. The PLL circuit 107 inputs the output signal of the frequency dividing / phase shifting circuit 109. The PLL circuit 207 inputs the output signal of the frequency dividing / phase shifting circuit 203. The frequency dividing / phase shifting circuit 209 divides and shifts the output signal of the PLL circuit 207. The gate drive circuit 205 outputs a second switching signal to the rectifier circuit 206 based on the output signal of the frequency dividing / phase shifting circuit 209. The frequency dividing / phase shifting circuit 108 outputs the frequency dividing and phase shifting signal of the output signal of the PLL circuit 107 to the switch circuit 106 as a first switching signal.

The operating condition of the third embodiment is that the switching signal of the switch circuit 106 and the gate drive signal of the rectifier circuit 206 are frequency-synchronized as in the first embodiment. Therefore, it is sufficient that the sum of the frequency multiplication ratio by the PLL circuit and the frequency division ratio by the frequency dividing circuit is the same in the power transmitting unit 100 and the power receiving unit 200. The frequency dividing / phase shifting circuits 203 and 209 and the PLL circuit 207 do not necessarily have to be physically arranged in the power receiving unit 200, and there are merits such as being easily controlled by arranging them in the power transmission unit 100. If there is, it may be arranged in the power transmission unit 100. Alternatively, vice versa, the frequency dividing circuit and the PLL circuit may be integrated in the power receiving unit 200.

The practical frequency relationship of FIG. 6 is shown. The output frequency f3 of the reference frequency source 105 is preferably several tens of kHz to several tens of MHz. The signal of the frequency f3 is appropriately divided by the frequency dividing / phase shifting circuits 109 and 203 according to the specifications of the PLL circuits 107 and 207, and is input to the PLL circuits 107 and 207.

The PLL circuits 107 and 207 generate reference frequency signals (f2t and f2r in FIG. 6) of several tens to several GHzs based on the previously divided reference signals. This reference frequency signal is divided and phase-shifted by the frequency-dividing / phase-locked circuits 108 and 209, and a frequency-synchronized switching signal f1 is obtained. The switching signal f1 is input to the switch circuit 106 and the rectifier circuit 206. The frequencies f2t and f2r are several tens to several GHz, and by passing through the process of dividing them, the concern of jitter generation described in the second embodiment can be eliminated. The above functions are provided as built-in functions of a general microcontroller or FPGA. By using these, it is possible to reduce the number of parts used, reduce the size and cost, and enjoy the expandability that the parameters can be flexibly changed by the program.

The PLL circuit and the phase shift circuit can be configured by the timer function of the microcontroller or the FPGA. Further, the PLL circuit and the phase shift circuit can be configured by a counter logic circuit or a frequency dividing circuit.

(Fourth Embodiment)
In the fourth embodiment, an example in which the PLL circuit is arranged only in either the power transmission unit 100 or the power reception unit 200 will be shown. FIG. 7 is a configuration diagram when the PLL circuit 107 is arranged only in the power transmission unit 100. FIG. 7 shows that the frequency dividing / phase shifting circuits 203 and 209 of the power receiving unit 200 and the PLL circuit 207 are deleted from FIG. 6, and the frequency dividing / phase shifting circuit 110 is added to the power transmission unit 100. The frequency dividing / phase shifting circuit 110 inputs the output signal of the PLL circuit 107, and outputs the frequency dividing / phase shifting signal to the gate drive circuit 205.

The reference frequency source 105 outputs a reference frequency signal. The frequency dividing / phase shifting circuit 109 divides and shifts the reference frequency signal. The PLL circuit 107 inputs the output signal of the frequency dividing / phase shifting circuit 109. The frequency dividing / phase shifting circuit 110 divides and shifts the output signal of the PLL circuit 107. The gate drive circuit 205 outputs a second switching signal to the rectifier circuit 206 based on the output signal of the frequency dividing / phase shifting circuit 110. The frequency dividing / phase shifting circuit 108 outputs the frequency dividing and phase shifting signal of the output signal of the PLL circuit 107 to the switch circuit 106 as a first switching signal.

The operating condition of the fourth embodiment is that the switching signal of the switch circuit 106 and the gate drive signal of the rectifier circuit 206 are frequency-synchronized as in the first embodiment. The fourth embodiment has the advantage of facilitating design (control software design) because the generation of control signals can be unified into one integrated circuit. On the other hand, when it is desired to change the phase shift amount of the power receiving unit 200, it is necessary to feed back the state of the power receiving unit 200 to the power transmission unit 100 and then request the change of the phase shift amount. It is useful when this feedback delay is not a problem or when it is easy to provide a means for feedback.

According to the first to fourth embodiments, the wireless device 300 can wirelessly supply power and drive the motor 400. Since the wireless device 300 does not require transmission of a control signal, it is possible to realize high speed control of the motor 400 and reduction in size and weight of the movable side circuit. The wireless device 300 can eliminate the influence of the transmission delay of the control signal, which has been a factor hindering the high speed, and can realize the high speed of the control of the motor 400.

It should be noted that all of the above embodiments merely show examples of embodiment in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner by these. That is, the present invention can be implemented in various forms without departing from the technical idea or its main features.

101 power transmission coil, 102 phase shift circuit, 103 controller, 104 power supply, 105 reference frequency source, 106 switch circuit, 201 power receiving coil, 202 reference frequency source, 204 power receiving circuit, 205 gate drive circuit, 206 rectifier circuit, 400 motor

Claims (13)

A power transmission coil that wirelessly transmits electric power,
A power receiving coil that wirelessly receives the power of the power transmission coil and
A switch circuit that applies a voltage to the power transmission coil based on the first switching signal,
A rectifier circuit that rectifies the voltage output from the power receiving coil based on the second switching signal and applies the rectified voltage to the load.
A wireless device comprising the first switching signal and a first phase-locked loop that gives a phase difference to the second switching signal. The wireless device according to claim 1, wherein the first switching signal and the second switching signal have the same period. The wireless device according to claim 1 or 2, wherein the rectifier circuit has a plurality of bidirectional switches. The wireless device according to claim 3, wherein the drive signals of the plurality of bidirectional switches are provided with a dead time for preventing a through current. The wireless device according to any one of claims 1 to 4, wherein the switch circuit is a full bridge type, a half bridge type, or a push-pull type. The wireless device according to any one of claims 1 to 5, wherein the switch circuit operates in ZCS (Zero Current Switching) operation or ZVS (Zero Voltage Switching) operation. The wireless device according to any one of claims 1 to 6, further comprising a resonance circuit provided between the power receiving coil and the rectifier circuit. The wireless device according to any one of claims 1 to 7, wherein the first phase-locked loop outputs a signal obtained by shifting a reference frequency signal as the first switching signal. A first reference frequency source that outputs a reference frequency signal to the first phase-locked loop, and
A drive circuit that drives the rectifier circuit by the second switching signal, and
The wireless device according to claim 8, further comprising a second reference frequency source that is frequency-synchronized with the first reference frequency source and outputs a reference frequency signal to the drive circuit. A reference frequency source that outputs a reference frequency signal and
A first PLL circuit that inputs the reference frequency signal and outputs a signal to the first phase shifting circuit, and a first PLL circuit.
A second PLL circuit for inputting the reference frequency signal and
A second phase-locked loop that shifts the output signal of the second PLL circuit, and
The wireless device according to claim 8, further comprising a drive circuit for outputting the second switching signal to the rectifier circuit based on the output signal of the second phase-locked loop. A reference frequency source that outputs a reference frequency signal and
A first frequency dividing / phase shifting circuit that divides and shifts the reference frequency signal, and
A second frequency dividing / phase shifting circuit that divides and shifts the reference frequency signal, and
The first PLL circuit that inputs the output signal of the first frequency division / phase shift circuit and
The second PLL circuit that inputs the output signal of the second frequency division / phase shift circuit and
A third frequency dividing / phase shifting circuit that divides and shifts the output signal of the second PLL circuit, and
Based on the output signal of the third frequency dividing / phase shifting circuit, the rectifier circuit further includes a drive circuit that outputs the second switching signal.
Any one of claims 1 to 7, wherein the first phase-locked loop outputs a signal obtained by dividing and phase-shifting the output signal of the first PLL circuit as the first switching signal. The wireless device described in the section. A reference frequency source that outputs a reference frequency signal and
A first frequency dividing / phase shifting circuit that divides and shifts the reference frequency signal, and
The first PLL circuit that inputs the output signal of the first frequency division / phase shift circuit and
A second frequency dividing / phase shifting circuit that divides and shifts the output signal of the first PLL circuit, and
Based on the output signal of the second frequency dividing / phase shifting circuit, the rectifier circuit further includes a drive circuit that outputs the second switching signal.
Any one of claims 1 to 7, wherein the first phase-locked loop outputs a signal obtained by dividing and phase-shifting the output signal of the first PLL circuit as the first switching signal. The wireless device described in the section. The wireless device according to any one of claims 1 to 12, wherein the load is a motor.

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