JP2019068681A - Power transmission device and wireless power transmission system - Google Patents

Abstract

To provide a transmission device and a wireless power transmission system, in which an electric field intensity of the circumference of a feeding line is reduced.SOLUTION: A power transmission device comprises: a power transmission electrode unit including a first power transmission electrode and a second power transmission electrode; a power transmission circuit part that supplies an electric power to the power transmission electrode unit; and a feeding line part having a first feeding line connecting the first power transmission electrode with the power transmission circuit part, and a second feeding line connecting the second power transmission electrode and the power transmission circuit part. The power transmission circuit part comprises a matching circuit that increases a voltage amplitude of an AC power. A voltage output from the matching circuit is applied to the power transmission electrode unit through the feeding line part, the first and second feeding lines are adjacently arranged. A voltage component of an inverse phase is applied to each of the first and second feeding lines. A distance between the first feeding line and the second feeding line is shorter than the maximum distance between the adjacent first power transmission electrode and the second power transmission electrode.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a power transmission device that wirelessly transmits power and a wireless power transmission system.

  In recent years, development of wireless (non-contact) power transmission technology for transmitting power wirelessly (non-contact) has been advanced for mobility involving mobility such as transport robots and electric vehicles. The wireless power transmission technology includes a plurality of methods such as a magnetic field coupling method and an electric field coupling method.

  For example, Patent Document 1 describes a wireless power transmission system of a magnetic field coupling system. In the case of the magnetic field coupling type wireless power transmission system, since power is supplied from the coil of the power transmission device to the coil of the power reception device, mobility must be stopped at a predetermined position in the charging region. The magnetic field coupling type wireless power transmission system has a problem that the alignment of mobility at the time of charging is strict, and it is difficult to supply power to the displacement of the mobility.

  On the other hand, in the case of an electric field coupling type wireless power transmission system, power can be supplied if the electrodes of the power receiving device are positioned in parallel on the electrodes of the power transmitting device. Therefore, by making the electrode of the power transmission device longer than the electrode of the power reception device, mobility at the time of charge can compensate for the positional deviation. Patent Document 2 describes an electric field coupling type wireless power transmission system.

Unexamined-Japanese-Patent No. 2016-119784 JP, 2017-70055, A

  In the electric field coupling type wireless power transmission, when DC power is converted to AC power by an inverter circuit, the power supply efficiency can be increased by lowering the frequency. However, lowering the frequency lowers the transmission efficiency between the power transmission device and the power reception device. Therefore, lowering the transmission efficiency can be compensated by increasing the voltage applied to the power transmission electrode unit.

  However, when the voltage is boosted in the matching circuit disposed in the power supply box, a high voltage is also applied to the feed line from the power supply box to the power transmission electrode unit. Thereby, the strength of the electric field generated from the feed line is increased. The high electric field may affect electronic devices in the vicinity of the feed line to cause the electronic devices to malfunction. Moreover, it is preferable to reduce the electric field strength distributed around the feed line to a low value for safety.

  Therefore, an object of the present disclosure is to solve the above-mentioned problems, and to provide a power transmission device and a wireless power transmission system in which the electric field strength around the feed line is reduced.

In order to achieve the above object, a power transmission device according to an aspect of the present disclosure,
An electric field coupling type power transmission device for wireless power transmission, comprising:
A power transmission electrode unit having a first power transmission electrode and a second power transmission electrode;
A power transmission circuit unit that supplies power to the power transmission electrode unit;
A feed line portion having a first feed line connecting the first power transmission electrode and the power transmission circuit portion, and a second feed line connecting the second power transmission electrode and the power transmission circuit portion;
Equipped with
The power transmission circuit unit includes an inverter circuit that outputs the input power as AC power of a predetermined frequency, and a matching circuit that increases the voltage amplitude of the AC power.
The voltage output from the matching circuit is applied to the power transmission electrode unit through the feed line portion,
The first feed line and the second feed line are disposed adjacent to each other,
A voltage component of opposite phase is applied to the first feed line and the second feed line, and the distance between the first feed line and the second feed line is the adjacent first power transmission electrode and the second feed line. Less than the maximum distance between the transmission electrodes.

Further, a wireless power transmission system according to an aspect of the present disclosure is:
An electric field coupling type wireless power transmission system,
A power transmission electrode unit having a first power transmission electrode and a second power transmission electrode, a power transmission circuit unit for supplying power to the power transmission electrode unit, and a first feed line for connecting the first power transmission electrode and the power transmission circuit unit; A power transmission line portion including a second power feed line connecting the second power transmission electrode and the power transmission circuit portion;
Mobility having a power receiving device for receiving power transmitted from the power transmitting device;
Equipped with
The power transmission circuit unit includes an inverter circuit that outputs the input power as AC power of a predetermined frequency, and a matching circuit that increases the voltage amplitude of the AC power.
The voltage output from the matching circuit is applied to the power transmission electrode unit through the feed line portion,
The first feed line and the second feed line are disposed adjacent to each other,
Applying voltage components of opposite phases to the first feed line and the second feed line,
The distance between the first feed line and the second feed line is shorter than the maximum distance between the adjacent first power transmission electrode and the second power transmission electrode.

  It is possible to provide a power transmission device and a wireless power transmission system in which the electric field strength around the feed line is reduced.

A diagram schematically showing an example of a wireless power system according to a first embodiment Block diagram showing a schematic configuration of the wireless power transmission system according to the first embodiment A circuit diagram showing a schematic configuration of a wireless power transmission system according to Embodiment 1. Diagram schematically showing a configuration example of an inverter circuit Diagram schematically showing a configuration example of a converter circuit A plan view schematically showing the arrangement of feed line portions connected to the power transmission electrode unit according to the first embodiment Sectional drawing which shows the feed-line part which concerns on Embodiment 1 typically Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Cross section showing electric field strength of feed line portion Graph showing the relationship between inter-electrode distance and electric field strength Table showing relationship between feed line width and electric field strength Table showing the relationship between shield and electric field strength Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion Sectional view showing a modification of the feed line portion A plan view showing a modification of the arrangement of feed line portions connected to the power transmission electrode unit

  According to an aspect of the present disclosure, there is provided an electric field coupling type power transmission device for wireless power transmission, which is a power transmission electrode unit having a first power transmission electrode and a second power transmission electrode, and power transmission to supply power to the power transmission electrode unit. A feed line portion having a circuit portion, a first feed line connecting the first power transmission electrode and the power transmission circuit portion, and a second feed line connecting the second power transmission electrode and the power transmission circuit portion , And the power transmission circuit unit includes: an inverter circuit that outputs the input power as AC power of a predetermined frequency; and a matching circuit that increases the voltage amplitude of the AC power; The output voltage is applied to the power transmission electrode unit through the feed line portion, and the first feed line and the second feed line are disposed adjacent to each other, and the first feed line and the second feed line are connected to each other. Each in reverse The voltage component is applied, the distance between the first feed line and the second feeder line is shorter than the maximum distance between the between adjacent said first transmission electrode second power electrode.

  Moreover, according to one aspect of the present disclosure, there is provided a wireless power transmission system of an electric field coupling type, comprising: a power transmission electrode unit having a first power transmission electrode and a second power transmission electrode; and a power transmission circuit for supplying power to the power transmission electrode unit. A feeder line portion having a part, a first feed line connecting the first power transmission electrode and the power transmission circuit portion, and a second feed line connecting the second power transmission electrode and the power transmission circuit portion; And a mobility having a power receiving device for receiving power transmitted from the power transmitting device, wherein the power transmitting circuit unit outputs the input power as AC power of a predetermined frequency. A circuit and a matching circuit for increasing the voltage amplitude of the AC power, and a voltage output from the matching circuit is applied to the power transmission electrode unit through the feed line portion, and the first feed line And the second feed line are disposed adjacent to each other, and voltage components of opposite phases are applied to the first feed line and the second feed line, respectively, and a distance between the first feed line and the second feed line Is shorter than the maximum distance between the adjacent first transmission electrode and the second transmission electrode.

  In the entire range of the feed line portion from the power transmission circuit unit to the power transmission electrode unit, the distance between the first feed line and the second feed line is the distance between the first power transmission electrode and the second power transmission electrode. It may be shorter than the maximum distance.

  Further, the feed line portion may extend outside the longitudinal extension area of the first power transmission electrode and the second power transmission electrode.

  The line widths of the first feed line and the second feed line may be shorter than the widths of the first power transmission electrode and the second power transmission electrode.

  In addition, an insulating resin may be disposed between the first feed line and the second feed line.

  The thickness of the insulating resin may be larger than the thickness of the feed line.

  The first feed line and the second feed line may be arranged in parallel in the width direction.

  The feed line portion may further include another second feed line adjacent to the first feed line.

  Further, the feed line portion includes a plurality of pairs of first feed lines disposed in parallel in the width direction, with the first feed line and the second feed line to which voltages of opposite phases are respectively applied as a pair. You may have the said 2nd feed line.

  Further, the feed line portion may include a conductor shield that shields at least a part of the periphery of the first feed line and the second feed line.

  In addition, the conductor shield may include a ground line disposed outside the arrangement direction of the first feed line and the second feed line.

  Also, the conductor shield may include a ground line disposed between the first feed line and the second feed line.

  Further, the conductor shield may include a ground layer arranged to face the first feed line and the second feed line in a direction in which the first feed line and the second feed line are arranged and in a direction in which the conductor shield extends.

  In addition, the conductor shield may include another ground layer disposed opposite to the ground layer and facing the first feed line and the second feed line.

  The conductor shield may surround the first feed line and the second feed line.

  The distance between the first power feed line and the second power transmission electrode to which a voltage having a phase opposite to the voltage applied to the first power feed line is applied is the distance between the first power transmission electrode and the second power transmission electrode. It may be shorter than the distance.

  In addition, even if the feed line portion includes a magnetic shield arranged to face the first feed line and the second feed line in the direction in which the first feed line and the second feed line are arranged and in the extending direction. Good.

  The feed line portion may further include another magnetic shield disposed to face the magnetic shield with the first feed line and the second feed line interposed therebetween.

  Further, the mobility may include a human detection sensor, and the feed line portion may be disposed at least in part outside the detection area of the human detection sensor.

(Embodiment 1)
Hereinafter, a power transmission device and a wireless power transmission system according to an embodiment of the present disclosure will be described. In the following drawings, the A direction is the direction in which the power transmission electrodes 131 and 133 extend (that is, the longitudinal direction), the B direction is the direction in which the power transmission electrodes 131 and 133 line up (that is, the lateral direction), and the C direction is the A It means a direction perpendicular to a plane including the direction and the B direction (that is, the height direction of the power transmission electrodes 131 and 133). Also, the X direction includes the direction in which the feed lines 141 and 143 line up (that is, the width direction), the Y direction includes the direction in which the feed lines 141 and 143 extend (that is, the longitudinal direction), and the Z direction includes the X direction and the Y direction It means the direction perpendicular to the plane (ie, the height direction of the feed lines 141, 143).

  FIG. 1 is a diagram schematically illustrating an example of a wireless power transmission system according to a first embodiment. In this example, power is wirelessly transmitted from the power transmission device including the power transmission electrode unit 130 provided on the floor surface 30 to the transport robot 10 including the power reception electrode unit. In the present system, wireless power transmission of the electric field coupling system is performed. The power transmission electrode unit 130 has a pair of power transmission electrodes 131 and 133. The power transmission electrodes 131 and 133 extend in parallel with each other along the floor surface 30, and voltages in opposite phase to each other are applied. The transfer robot 10 can transfer an object on the power transmission electrodes 131 and 133 while receiving power.

  The transfer robot 10 is provided with a proximity sensor 11 at the outer side, and can detect a person near the transfer robot 10. Examples of the proximity sensor 11 include an infrared sensor and a camera. The transport robot 10 also includes a communication device 13, and can communicate with the control unit via the communication device 13. When the proximity sensor 11 detects a person, the detection is transmitted to the control unit via the communication device 13. The control unit that has received human detection sends an instruction to the power transmission device to shut off or reduce the DC power supply that supplies power, or to stop the PWM signal that controls the inverter circuit in the power supply circuit, etc. Do. This reduces the emission of a high electric field from the power transmission electrode unit 130.

  FIG. 2 is a block diagram showing a schematic configuration of the wireless power transmission system according to the first embodiment. The wireless power transmission system 1 includes a power transmission device 100 and a transport robot 10. As an example, the power transmission device 100 transmits a DC power supplied from an external DC power source 310 to AC power, and a power transmission electrode unit 130 connected to the power transmission circuit portion 103 via the feed line portion 140. And AC power is transmitted from the power transmission electrode unit 130 to the transfer robot 10. The power transmission circuit unit 103 includes an inverter circuit 110 that converts DC power to AC power of a predetermined frequency, and a power transmission matching circuit 120 that boosts the voltage of AC power. As another example, a converter in which the DC power supply 310 in FIG. 2 is replaced with 50 Hz or 60 Hz AC power supply, and the inverter circuit 110 in the power transmission circuit unit 103 directly converts AC energy of different frequency from input AC energy. The circuit 110 may be substituted.

  The transfer robot 10 includes a power receiving device 200 and a load 320. The power receiving device 200 capacitively couples with the power transmission electrode unit 130, receives the transmitted AC power in a contactless manner, the power receiving side alignment circuit 220 connected to the power receiving electrode unit 210, and the received AC power. And a converter circuit 230 for converting DC power into DC power and outputting the DC power. Load 320 includes, for example, a secondary battery and a motor, and is charged or driven by the DC power output from converter circuit 230.

  FIG. 3 is a circuit diagram showing a schematic configuration of the wireless power transmission system according to the first embodiment. The power transmission side matching circuit 120 includes, for example, a power transmission side series resonant circuit 121 connected to the inverter circuit 110, and a power transmission side parallel resonant circuit 123 inductively coupled to the power transmission side series resonant circuit 121. In the power transmission side series resonant circuit 121, the first coil L1 and the first capacitor C1 are connected in series. In the power transmission side parallel resonant circuit 123, the second coil L2 and the second capacitor C2 are connected in parallel. The first coil L1 and the second coil L2 constitute a transformer coupled with a coupling coefficient k1. The turns ratio (1: N1) of the first coil L1 to the second coil L2 is set to a value that achieves a desired boost ratio. For example, the step-up ratio is set such that the amplitude increases from about 3 kV to about 5 kV.

  The power receiving side matching circuit 220 includes, for example, a power receiving side parallel resonant circuit 221 connected to the power receiving electrode unit 210, and a power receiving side series resonant circuit 223 inductively coupled to the power receiving side parallel resonant circuit 221. In the power receiving side parallel resonant circuit 221, the third coil L3 and the third capacitor C3 are connected in parallel. In the power receiving side series resonant circuit 223, the fourth coil L4 and the fourth capacitor C4 are connected in series. The third coil L3 and the fourth coil L4 constitute a transformer connected with a coupling coefficient k2. The turns ratio (N2: 1) of the third coil L3 to the fourth coil L4 is set to a value that achieves a desired step-down ratio.

  FIG. 4 is a view schematically showing a configuration example of the inverter circuit 110. As shown in FIG. The inverter circuit 110 converts direct current energy from the direct current power source 310 into alternating current energy. In this example, the inverter circuit 110 is a full bridge type inverter circuit including four switching elements, and also includes a control circuit 112 that performs on / off control of each switching element. The switching element is, for example, a transistor such as an IGBT or a MOSFET. The control circuit 112 includes a gate driver that outputs a control signal that controls the on (conductive) and off (nonconductive) states of each switching element, and a processor such as a microcontroller (microcomputer) that outputs the control signal to the gate driver. Have. Instead of the full bridge inverter circuit, a half bridge inverter circuit or another oscillation circuit such as class E may be used. The inverter circuit 110 may have a modulation / demodulation circuit for communication and various sensors for measuring voltage, current, and the like.

  FIG. 5 schematically shows a configuration example of converter circuit 230. Referring to FIG. Converter circuit 230 converts the received AC energy into DC energy available to load 320. In this example, converter circuit 230 is a full wave rectifier circuit including a diode bridge and a smoothing capacitor, but may have other rectifier configurations. The converter circuit 230 may include various circuits such as a constant voltage / constant current control circuit and a modulation / demodulation circuit for communication in addition to the rectification circuit. Various sensors for measuring the voltage and current output from the power receiving side series resonant circuit 223 may be included in the converter circuit 230. The converter circuit 230 may output AC energy of different frequency or different voltage with respect to AC addition.

  The DC power supply 310 is connected to, for example, a commercial power supply, a primary battery, a secondary battery, a solar battery, a fuel cell, a USB (Universal Serial Bus) power supply, a high-capacity capacitor (for example, an electric double layer capacitor), and a commercial power supply. It may be any power source such as a voltage converter.

  The resonance frequency f0 of the power transmission side series resonance circuit 121, the power transmission side parallel resonance circuit 123, the power reception side parallel resonance circuit 221, and the power reception side series resonance circuit 223 is set to coincide with the transmission frequency f at the time of power transmission. It does not have to match exactly. Each resonance frequency f0 may be set to, for example, a value within the range of about 50% to 150% of the transmission frequency. The transmission frequency f is at least 20 kHz and at most 13.56 MHz, preferably at least 20 kHz and at most 6.78 MHz. The 6.78 MHz band refers to the range of 6.765 to 6.795 MHz, and the 13.56 MHz band refers to the range of 13.553 to 13.567 MHz. In the first embodiment, the transmission frequency f is set to 500 kHz. As described above, when the transmission frequency f is a low frequency band equal to or lower than the 6.78 MHz band, the power transmission efficiency is lowered, but the power source efficiency for converting into AC power in the inverter circuit 110 is increased. Will rise.

  In the first embodiment, the space between the power transmission electrode unit 130 and the power reception electrode unit 210 is an air layer, and the distance between them is, for example, about 10 mm in length. Thereby, the capacitances Cm1 and Cm2 between the electrodes are very small, and the impedance between the power transmission electrode unit 130 and the power reception electrode unit 210 is very high, for example, several kΩ. On the other hand, the impedance of the inverter circuit 110 and the converter circuit 230 is as low as, for example, several ohms. For this reason, in the first embodiment, the power transmission side series resonant circuit 121 and the power transmission side parallel resonant circuit 123 are arranged in order from the inverter circuit 110. Further, by arranging the power receiving side series resonant circuit 223 and the power receiving side parallel resonant circuit 221 sequentially from the converter circuit 230, impedance matching can be easily performed, and power can be transmitted with high efficiency.

  FIG. 6 is a plan view schematically showing the arrangement of feed line portions connected to the power transmission electrode unit 130 according to the first embodiment. The power transmission side matching circuit 120 and the power transmission electrode unit 130 are connected via the feed line portion 140. The feed line portion 140 has a feed line 141 connecting the power transmission side parallel resonant circuit 123 and the power transmission electrode 131 and a feed line 143 connecting the power transmission side parallel resonant circuit 123 and the power transmission electrode 133. While the power transmission electrode unit 130 is two-dimensionally disposed on the floor surface 30, the feed line portion 140 is three-dimensional from the power supply box where the DC power supply 310 and the power transmission circuit portion 103 are disposed to the power transmission electrode unit 130. Are arranged. Therefore, compared to the transmission electrode unit 130, the feed line portion 140 can be disposed along a path that is not clear. In addition, the length of the feed line portion 140 may be several tens of meters. Even with such a length, since the applied voltage is high, the flowing current can be reduced, and the power loss in the feed line portion 140 can be reduced.

  The power transmission electrode 131 and the power transmission electrode 133 have, for example, a width of 150 mm and a length of 1000 mm. The power transmission electrode 131 and the power transmission electrode 133 have a rectangular shape, but may have, for example, a curved strip shape or a circular shape. The distance GT between power transmission electrodes which is the distance between the adjacent power transmission electrode 131 and the power transmission electrode 133 is, for example, 25 mm. An area obtained by combining the area of the power transmission electrodes 131 and 133 and the area between the power transmission electrodes 131 and 133 is referred to as a charging area CH. That is, the transport robot 10 moves immediately above the charging area CH. The charge area CH is also an area formed from the outer periphery of the power transmission electrodes 131 and 133. When the power transmission electrodes 131 and 133 are rectangular, the charge area CH is also an area formed by connecting the apexes of the power transmission electrodes 131 and 133. is there. The distance GS between feed lines, which is the distance between the feed line 141 and the feed line 143, is shorter than the maximum distance between the power transmission electrodes 131 and 133, and is, for example, 1 mm. The maximum distance between the power transmission electrodes 131 and 133 is the most distance between the power transmission electrodes 131 and 133 in the width direction (that is, the alignment direction) of the power transmission electrodes 131 and 133. When the power transmission electrodes 131 and 133 are disposed in parallel, the maximum distance is the distance GT between the power transmission electrodes.

  The feed line 143 is connected to the outer end in the opposite direction to the adjacent power transmission electrode 131 in the width direction of the power transmission electrode 133 in a direction intersecting the longitudinal direction of the power transmission electrode 133. The feed line 141 extends from the longitudinal end of the power transmission electrode 141 in the longitudinal direction of the power transmission electrode 131 and then extends in a direction intersecting the longitudinal direction. Therefore, the feed line portion 140 extends outside the longitudinal extension area of the power transmission electrodes 131 and 133. The longitudinal extension regions of the power transmission electrodes 131 and 133 are regions extending in the longitudinal direction from the longitudinal end portions of the power transmission electrodes 131 and 133.

  The inter-electrode wiring distance GL, which is the distance between the feed line 141 and the power transmission electrode 133 to which the voltage of the reverse phase component is applied, is the same as the feed line distance GS. That is, the inter-electrode wiring distance GL is shorter than the transmission electrode distance GT.

  Since the feed line portion 140 is a wire connecting the power transmission side matching circuit 120, which is a booster circuit, to the power transmission electrode unit 130, each feed line 141, 143 has a voltage value applied to the power transmission electrodes 131, 133 and The same voltage value is applied. Therefore, a high voltage of about 3 kV to 5 kV is applied to the feed lines 141, 143. Further, the voltage applied to the feed line 141 and the voltage applied to the feed line 143 are in reverse phase relationship.

  FIG. 7 is a cross-sectional view schematically showing the feed line portion according to the first embodiment. The feed line portion 140 includes feed lines 141 and 143 and a resin body 145 covering the circumference of the feed lines 141 and 143. The line width W of each of the feed line 141 and the feed line 143 is shorter than the width of each of the electrode 131 and the electrode 133. The line width W is, for example, 1 mm to 2 mm.

  The feed lines 141 and 143 are disposed parallel to each other in the width direction (i.e., the short direction). In FIG. 7, the cross sections of the feed lines 141 and 143 are square, but in the case of a rectangle, for example, the short sides of the feed lines are arranged to face each other. In the parallel arrangement, the arrangement in which the opposing surfaces of the feed lines 141 and 143 have the smallest area reduces the parasitic capacitance.

  An insulating resin is filled between the feed line 141 and the feed line 143. As a result, even though the distance GS between the feed lines 141 and 143 is short, generation of discharge can be prevented. In addition, the feed line 141 and the feed line 143 can be prevented from coming into contact and shorting. The resin body 145 is formed of an insulating resin, and examples thereof include a fluorine resin. Here, insulation means having a resistivity of 0.4 [MΩ · m] or more. Further, the thickness GB of the resin body 145 is larger than the thickness GH of the feed lines 141 and 143. Thereby, even if the feed line portion 140 is stepped by a person, the pressure can be dispersed by the resin body 145, so that the feed lines 141 and 143 can be prevented from being broken. The thickness GH of the feed lines 141 and 143 is, for example, 1 mm, and the thickness GB of the resin body 145 is, for example, 3 mm.

  FIG. 8 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 147 has a configuration in which the feed line portion 140 further includes a conductor shield 149 grounded. The feed line portion 147 is the same as the feed line portion 140 with respect to the configuration other than the configuration described below. The conductor shield reduces the electric field generated from the feed line by shielding at least a part of the periphery of the feed line. The conductor shield 149 is disposed on the top of the resin body 145. That is, the conductor shield 149 is a ground layer arranged to face the first feed line and the second feed line in the direction in which the feed line 141 and the feed line 143 are arranged (X direction) and the extending direction (Y direction). It is. The conductor shield 149 is, for example, a thin plate made of metal. Since the conductor shield 149 is provided on one surface of the feed line portion 147, leakage of the electric field from the feed lines 141 and 143 to the conductor shield 149 can be further reduced. When the conductor shield 149 is provided on the upper portion of the feed line portion 147, if the feed line portion 147 is laid on the floor surface 30, the electric field leakage to the upper side is reduced, the electronic device or the electronic device disposed above the feed line portion 147 The influence on the person walking on the floor 30 can be reduced.

  FIG. 9 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 151 further includes a conductor shield 153 grounded to the feed line portion 140. The feed line portion 151 is the same as the feed line portion 140 with respect to the configuration other than the configuration described below. The conductor shield 153 surrounds the entire circumference of the resin body 145. Therefore, the electric field strength generated from the feed lines 141 and 143 can be significantly reduced. The conductor shield 153 is, for example, a thin plate made of metal. Further, the strength of the feed line portion 151 can be increased by the metal conductor shield 153 surrounding the feed lines 141 and 143. Thus, the feed lines 141 and 143 can be further prevented from being disconnected due to pressure such as weight.

  Next, the electric field strength generated from the feed line portion will be described. FIG. 10 is a cross-sectional view showing the electric field strength generated from the feed line portion. The feed lines 141 ′ and 143 ′ each have a line width W, and the feed line 141 ′ and the feed line 143 ′ have a line interval G. In addition, electric field regions Es1, Es2 and Es3 are generated around the feed lines 141 'and 143', and the electric field strength becomes weaker as they are separated from the feed lines 141 'and 143'. That is, in the electric field areas Es1, Es2 and Es3, the electric field strength in the electric field area Es1 is the strongest, and the electric field strength in the electric field area Es3 is the weakest. Here, it is assumed that the electric field strength at the outer periphery of the electric field area Es3 exceeds the predetermined electric field strength reference. One of the predetermined field strength criteria is, for example, the exposure limit value of International Commission on Non-lonizing Radiation Protection (ICNIRP).

  The height Hr of the electric field area Es3 and the width Wr of the electric field area Es3 fluctuate with the line interval G of the feed lines 141 'and 143'. FIG. 11 is a graph showing the line spacing and the reduction rate of the electric field strength in the electric field region. When the line width W of the feed lines 141 ′ and 143 ′ is constant at 75 mm and power of 500 W is transmitted to the power receiving electrode unit 210, the reduction ratio of the half width Wv of the electric field region Es3 when the line interval G is changed The reduction rate of the half value height Hv is shown. As both the half width Wv and the half height Hv decrease, the reduction rate increases as the length of the line interval G decreases. As described above, when the line spacing G is shortened, the width Wr and the height Hr of the electric field area Es3 can be reduced. Therefore, the reduction of the range of the electric field region above the predetermined electric field strength around the feed line corresponds to the reduction of the electric field strength around the feed line. Generally, malfunction of the electronic device may occur outside the electric field region Es3, but the probability can be reduced by the configuration of the present application.

  FIG. 12 is a table showing the relationship between the line width and the half width and half height of the electric field region. It is a table | surface which shows half-value width Wv and half-value height Hv of electric field area | region Es3 on the conditions which make inter-line distance G constant with 2.5 mm, and line width W differs. The line width W is 75 mm in condition 1 and 2 mm in condition 2. When the line width W is 75 mm, the half value width Wv of the electric field area Es3 is 30.67 cm, and the half value height Hv of the electric field area Es3 is 22.25 cm. On the other hand, when the line width W is 2 mm, the half width Wv of the electric field area Es3 is 15.33 cm, and the half height Hv of the electric field area Es3 is 11.5 cm. As described above, even if the line width W is shortened, the range of the electric field region Es can be reduced.

  FIG. 13 is a table showing the relationship between the conductor shield and the size of the electric field area. In FIG. 13, the line width W is constant at 2 mm, and the distance G between lines is also constant at 2.5 mm. Condition 3 is a feed line portion which does not have a conductor shield like feed line portion 140, and condition 4 is a feed line portion which has conductor shield 149 only on one side like feed line portion 147, condition 5 In the case of the feed line portion 151, the feed line portion has the conductor shield 153 on the entire outer surface.

  The half value width and half value height of the electric field region Es3 are reduced in the feed line portion of the conditions 4 and 5 having the conductor shield as compared with the feed line portion of the condition 3 which does not have the conductor shield. In the condition 4, the half value height of the electric field region Es3 is reduced along with the shield side and the non-shield side, but is reduced more largely on the shield side. Further, the half value width of the electric field region Es3 of the condition 5 is largely reduced as compared with the half value width of the electric field region Es3 of the condition 4.

  As described above, by providing the conductor shields on one of the upper and lower sides of the feed lines 141 ′ and 143 ′ as in the feed line portion 147, the half value height of the electric field region Es3 on the shield side can be significantly reduced. . Further, by providing the conductor shield on the entire surface around the feed lines 141 'and 143' like the feed line portion 151, not only the half value height of the electric field region Es3 but also the half value width can be significantly reduced.

  As described above, the electric field coupling type power transmission apparatus 100 for wireless power transmission includes the power transmission electrode unit 130 having the power transmission electrode 131 and the power transmission electrode 133, the power transmission circuit unit 103 for supplying power to the power transmission electrode unit 130, and power transmission. A feed line portion 140 having a feed line 141 connecting the electrode 131 and the power transmission circuit portion 103 and a feed line 143 connecting the second power transmission electrode 133 and the power transmission circuit portion 103 is provided. The power transmission circuit unit 103 also includes an inverter circuit 110 that outputs the input power as AC power of a predetermined frequency, and a power transmission matching circuit 120 that increases the voltage amplitude of the AC power. The voltage output from the power transmission side matching circuit 120 is applied to the power transmission electrode unit 310 through the feed line portion 140, and the feed line 141 and the feed line 143 are disposed adjacent to each other. A voltage component of opposite phase is applied. The distance between the feed line 141 and the feed line 143 is shorter than the maximum distance between the adjacent transmission electrodes 131 and 133. With such a configuration, the parasitic capacitance between the feed lines increases under the condition that the distance GS between the feed lines 141 and 143 is short, but the strength of the electric field can be significantly reduced.

  In addition, when the feed line portion 147 includes the conductor shield 149 on the top, leakage of the electric field to the conductor shield 149 side can be reduced. Moreover, the feed line part 151 can reduce the leakage of the electric field not only in the height direction but also in the width direction by providing the conductor shield 153 on the entire surface of the periphery. In addition, since the space between the power transmission electrode unit 130 and the power reception electrode unit 210 is an air layer, laying of the wireless power transmission system 1 is easy.

  In addition, since the transport robot moves on the power transmission electrodes 131 and 133, in the longitudinal direction of the power transmission electrodes 131 and 133, the proximity sensor 11 of the transport robot 10 may detect a person approaching the power transmission electrodes 131 and 133. it can. Since the feed line 143 may be disposed in the non-longitudinal direction of the power transmission electrode 133, the feed line portion 140 may be disposed in at least a part of the non-detection area outside the detection area of the proximity sensor 11. Thus, even if the feed line portion 147 is disposed in a region where the proximity sensor 11 of the transport robot 10 can not detect the intrusion of a person into the feed region, the electric field leaked from the feed line portion 147 is reduced. It is possible to improve the countermeasure level against the electric field exposure risk.

Second Embodiment
The second embodiment has a configuration in which a magnetic shield is added in the first embodiment. The configuration other than the items described below is the same as that of the first embodiment.

  FIG. 14 is a cross-sectional view of a feed line portion according to a second embodiment. In the feed line portion 155, the magnetic shield 161 is disposed above the resin body 145 of the feed line portion 140, and the magnetic shield 163 is disposed below the resin body 145. That is, the magnetic shield 161 is disposed to face the feed line 141 and the feed line 143 in the alignment direction and the extending direction of the feed line 141 and the feed line 143. In addition, another magnetic shield 163 is disposed to face the magnetic shield 161 with the feed line 141 and the feed line 143 interposed therebetween. That is, the first feed line 141 and the feed line 143 are disposed between the magnetic shield 161 and the magnetic shield 163. Examples of the magnetic shields 161 and 163 include thin plates of permalloy. Since the magnetic shield 161 is located above the feed lines 141 and 143 and below the feed line 143, the impedance of the feed line portion 155 can be increased, and the voltage applied to the feed line portion 155 can be increased. Reflection can be reduced. In addition, although the feed line part 155 was provided with the two magnetic shields 161 and 163 in the upper part and the lower part, you may be provided with any one magnetic shield. Also in this configuration, the impedance of the feed line portion 155 can be increased.

  FIG. 15 is a cross-sectional view showing a modification of the feed line portion. In the feed line portion 165, the magnetic shield 161 is disposed on the resin body 145 of the feed line portion 140, and the conductor shield 149 grounded on the magnetic shield 161 is further disposed. The feed line portion 165 can increase the impedance of the feed line portion 165 by including the magnetic shield 161 and the conductor shield 149, and further reduces the leakage of the electric field from the feed line portion 165 to the conductor shield 149 side. can do.

  FIG. 16 is a cross-sectional view showing a modification of the feed line portion. In the feed line portion 166, the magnetic shield 163 is disposed below the resin body 145 of the feed line portion 165, and the conductor shield 167 grounded to the lower portion of the magnetic shield 163 is further disposed. The feed line portion 166 is provided with the magnetic shields 161 and 163 and the conductor shields 149 and 167 at the upper and lower portions, respectively, so that the impedance of the feed line portion 165 can be further increased, and the height from the feed line portion 165 Leakage of the electric field in the direction and width can be further reduced.

  The present disclosure is not limited to the above embodiment, and can be modified as follows.

  (1) In the first and second embodiments, the power transmission electrode unit 130 includes the two power transmission electrodes 131 and 133, but the present invention is not limited to this. The transmission electrode unit may comprise three or more transmission electrodes. When three or more power transmission electrodes are arranged in parallel, the respective power transmission electrodes may be arranged on the floor surface 30 so that voltages of opposite phases are applied to the adjacent power transmission electrodes. Also, in this case, feed lines corresponding to the number of transmission electrodes are arranged. By dividing the feed line into at least a part of three or more and arranging them in parallel, the electric field leakage intensity in the direction perpendicular to the feed line (that is, corresponding to ± Z direction in FIG. 10) around the transmission electrode is obtained. It can be effectively reduced. When at least two or more electrodes are fed with voltages of the same potential, the number of conductors in the feed line may be increased by the number of branches, or a conductor at the connection from the feed line to the transmission electrode May be branched. As an example, in the case of using four transmission electrodes, the feed line portion may be provided with four feed lines.

  FIG. 17 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 169 includes four feed lines 141, 143, 171, and 173. The feed line portion 169 further includes, on the feed line 143, an adjacent feed line 171 different from the feed line 141. The four feed lines 141, 143, 171, 173 are disposed in parallel in the X direction, and are connected to the corresponding power transmission electrodes. The voltages in opposite phase are applied to the feed line 143 and the feed line 171, and the voltages in reverse phase are applied to the feed line 171 and the feed line 173, respectively. Therefore, voltages of the same phase are applied to the feed lines 141 and 171, respectively. Also, voltages of the same phase are applied to the feed lines 143 and 173, respectively. In other words, the feed line portion 169 has a plurality of feed line lines 141 and feed line lines 143 arranged in parallel in the width direction, with the feed line line 141 and the feed line line 143 to which voltages of opposite phases are respectively applied as one pair. . Although FIG. 17 exemplifies a case where the feed line portion includes four feed lines, the present invention is not limited to this, and three feed lines may be provided, or five or more feed lines may be provided. good. In addition, the feed line portion may include three or more feed line pairs to which voltages of opposite phases are respectively applied.

  (2) In the first and second embodiments, the conductor shield provided in the feed line portion is a thin plate-like ground layer, but is not limited to this. A metal wire may be used as a conductor shield. FIG. 18 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 175 further includes conductor shields 177 and 179 in the feed line portion 140. Conductor shields 177 and 179 are grounded metal wires, ie, ground wires. The conductor shields 177 and 179 are disposed parallel to the outside in the direction in which the feed lines 141 and 143 are aligned (that is, in the width direction). Thereby, the electric field intensity leaking from the feed line portion 175 in the width direction can be reduced.

  FIG. 19 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 180 is provided with a thin plate-like conductor shield 149 in the upper portion of the resin body 145 in the feed line portion 175. Thereby, the electric field strength in which the conductor shields 177 and 179 which are ground lines leak in the width direction can be reduced, and the electric field strength in which the conductor shield 149 which is the ground layer leaks upward can be reduced.

  FIG. 20 is a cross-sectional view showing a modification of the feed line portion. The feed line portion 181 is provided with a conductor shield 183 of a metal wire in parallel to the feed line portion 141 and the feed line 143 in the feed line portion 175. Since the electric field strength between the feed lines 141 and 143 is reduced by the conductor shield 183 which is a ground line, the electric field strength leaking upward and downward from the feed line portion 181 can be reduced.

  (3) In the first embodiment, the feed line portion 147 is provided with the conductor shield 149 on the top, but the present invention is not limited to this. FIG. 21 is a cross-sectional view showing a modification of the feed line portion. As shown in FIG. 21, the feed line portion 185 further includes a thin plate-like conductor shield 167 in the lower portion of the resin body 145 in the feed line portion 147. That is, on the opposite side of the conductor shield 149 which is a ground layer, a conductor shield 167 which is another ground layer arranged to be opposed to the feed line 141 and the feed line 143 is disposed. By providing the conductor shield 167 below the feed line portion 185, for example, when the feed line portion 185 is installed on the floor 30, preventing electrical interference with reinforcing bars or steel frames of a building disposed under the floor it can. In addition, although the feed line part 185 is provided with the two conductor shields 149 and 167 in the upper part and the lower part, you may provide only the conductor shield 167. FIG.

  (4) In the first and second embodiments, the end portions of the power transmission electrodes 131 and 133 of the power transmission electrode unit 130 are arranged on the same straight line, but the present invention is not limited to this. One of the transmission electrodes may be shifted by the distance between the feed line width and the feed line interval. FIG. 22 is a plan view showing a modification of the arrangement of the power transmission electrode unit. The longitudinal end of the power transmission electrode 131 is shifted to the feed line 141 side more than the longitudinal end of the power transmission electrode 133. The amount of deviation corresponds to the width of the feed line 141 and the distance GS between the feed lines.

  (5) In the first and second embodiments, the range of the feed lines 141 and 143 between the adjacent feed lines 141 and 143 is shorter than the maximum distance between the adjacent power transmission electrodes 131 and 133. It may be a partial range or the entire range of the feed lines 141 and 143.

  (6) In the first and second embodiments, the power transmission electrode unit 130 has two power transmission electrodes 131 and 133, and the power reception electrode unit 210 has two power reception electrodes 211 and 213, but the present invention is not limited to this. Another electrode may be provided on the outer side in the arrangement direction of the power transmission electrodes 131 and 133. When another electrode is provided on the outer side in the arrangement direction of the power transmission electrodes 131 and 133, capacitive coupling occurs between the other electrode and the power transmission electrodes 131 and 133, and the other electrode has a reverse phase to the adjacent power transmission electrode. It takes a voltage. As a result, part of the electric field formed by the power transmission electrodes 131 and 133 is cancelled, and the strength of the leakage electric field is reduced. In addition, another electrode may be provided outside the direction in which the power receiving electrodes 211 and 213 are aligned.

  (7) In the present disclosure, use of the wireless power transmission system is not limited to the transfer robot 10. It may be an automated guided vehicle (AGV) or mobility such as an elevator or an electric wheelchair.

  The power transmission device and the wireless power transmission system according to the present disclosure are useful as a power transmission device and a wireless power transmission system for mobility power supply such as a carriage, an elevator, and an electric wheelchair.

DESCRIPTION OF SYMBOLS 1 wireless power transmission system 10 conveyance robot 11 proximity sensor 13 communication apparatus 30 floor 100 power transmission apparatus 103 power transmission circuit unit 110 inverter circuit 112 control circuit 120 power transmission side matching circuit 121 power transmission side series resonance circuit 123 power transmission side parallel resonance circuit 130 power transmission electrode Unit 131, 133 Power transmission electrode 140 Feed line portion 141, 143 Feed line 145 Resin body 147 Feed line portion 149 Conductor shield 151 Feed line portion 153 Conductor shield 155 Feed line portion 161, 163 Magnetic shield 165, 166 Feed line portion 167 Conductor shield 169 feed line portion 171, 173 feed line 175 feed line portion 177, 179 conductor shield 180, 181 feed line portion 183 conductor shield 185 feed line portion 200 power receiving device 210 power receiving electrode unit 211, 213 power reception Pole 220 Receiving side matching circuit 221 Receiving side parallel resonance circuit 223 Receiving side series resonance circuit 230 Converter circuit 310 DC power supply 320 Load 330 Charge area GT Transmission electrode distance GL Electrode wiring distance GS Feeding line distance GH Wiring thickness GB Resin body Thickness

Claims (20)

An electric field coupling type power transmission device for wireless power transmission, comprising:
A power transmission electrode unit having a first power transmission electrode and a second power transmission electrode;
A power transmission circuit unit that supplies power to the power transmission electrode unit;
A feed line portion having a first feed line connecting the first power transmission electrode and the power transmission circuit portion, and a second feed line connecting the second power transmission electrode and the power transmission circuit portion;
Equipped with
The power transmission circuit unit includes an inverter circuit that outputs the input power as AC power of a predetermined frequency, and a matching circuit that increases the voltage amplitude of the AC power.
The voltage output from the matching circuit is applied to the power transmission electrode unit through the feed line portion,
The first feed line and the second feed line are disposed adjacent to each other,
Applying voltage components of opposite phases to the first feed line and the second feed line,
The distance between the first feed line and the second feed line is shorter than the maximum distance between the adjacent first power transmission electrode and the second power transmission electrode.
Power transmission device. In the entire range of the feed line portion from the power transmission circuit unit to the power transmission electrode unit, the distance between the first feed line and the second feed line is the maximum distance between the first power transmission electrode and the second power transmission electrode Shorter than
The power transmission device according to claim 1. The feed line portion extends outside the longitudinal extension area of the first power transmission electrode and the second power transmission electrode.
The power transmission device according to claim 1. The line widths of the first feed line and the second feed line are shorter than the widths of the first transmission electrode and the second transmission electrode.
The power transmission device according to any one of claims 1 to 3. An insulating resin is disposed between the first feed line and the second feed line,
The power transmission device according to any one of claims 1 to 4. The thickness of the insulating resin is larger than the thickness of the feed line,
The power transmission device according to claim 5. The first feed line and the second feed line are disposed in parallel in the width direction.
The power transmission device according to any one of claims 1 to 6. The power transmission device according to any one of claims 1 to 6, wherein the feeding line portion further includes another second feeding line adjacent to the first feeding line. The feed line portion includes a plurality of pairs of the first feed line and the first feed line disposed in parallel in the width direction, wherein the first feed line and the second feed line to which voltages of opposite phases are respectively applied are paired. 2 with feed line,
The power transmission device according to any one of claims 1 to 6. The feed line portion includes a conductor shield that shields at least a part of the periphery of the first feed line and the second feed line.
The power transmission device according to any one of claims 1 to 9. The conductor shield includes a ground line disposed outside the alignment direction of the first feed line and the second feed line.
The power transmission device according to claim 10. The conductor shield includes a ground line disposed between the first feed line and the second feed line.
The power transmission device according to claim 10. The conductor shield includes a ground layer disposed to face the first feed line and the second feed line in a direction in which the first feed line and the second feed line are arranged and in a direction in which the conductive line extends.
The power transmission device according to any one of claims 10 to 12. The conductor shield includes another ground layer disposed opposite to the first feed line and the second feed line on the opposite side of the ground layer.
The power transmission device according to claim 13. The conductor shield surrounds a periphery of the first feed line and the second feed line,
The power transmission device according to claim 10. The distance between the first power feed line and the second power transmission electrode to which a voltage having a phase opposite to the voltage applied to the first power feed line is applied is the distance between the first power transmission electrode and the second power transmission electrode. The power transmission device according to any one of claims 1 to 15, wherein the power transmission device is shorter than the distance. The feed line portion includes a magnetic shield disposed to face the first feed line and the second feed line in a direction in which the first feed line and the second feed line are arranged and in a direction in which the feed line portion extends. The power transmission device according to any one of 16. The power transmission device according to claim 17, wherein the feed line portion includes another magnetic shield disposed to face the magnetic shield with the first feed line and the second feed line interposed therebetween. An electric field coupling type wireless power transmission system,
A power transmission electrode unit having a first power transmission electrode and a second power transmission electrode, a power transmission circuit unit for supplying power to the power transmission electrode unit, and a first feed line for connecting the first power transmission electrode and the power transmission circuit unit; A power transmission line portion including a second power feed line connecting the second power transmission electrode and the power transmission circuit portion;
Mobility having a power receiving device for receiving power transmitted from the power transmitting device;
Equipped with
The power transmission circuit unit includes an inverter circuit that outputs the input power as AC power of a predetermined frequency, and a matching circuit that increases the voltage amplitude of the AC power.
The voltage output from the matching circuit is applied to the power transmission electrode unit through the feed line portion,
The first feed line and the second feed line are disposed adjacent to each other,
Applying voltage components of opposite phases to the first feed line and the second feed line,
The distance between the first feed line and the second feed line is shorter than the maximum distance between the adjacent first power transmission electrode and the second power transmission electrode.
Wireless power transfer system. The mobility comprises a person detection sensor,
The wireless power transmission system according to claim 19, wherein the feed line portion is disposed at least in a part outside the detection area of the human detection sensor.

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