Power transfer system with capacitive coupling

Patent metadata

Field	Value
Publication number	US-10069335-B2
Application number	US-201615252652-A
Country	US
Kind code	B2
Filing date	Aug 31, 2016
Priority date	Jun 3, 2014
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A power transfer system that transfers electric power from a power transmission device to a power reception device through electrical coupling. The power transmission device and the power reception device structurally designed such that the power transfer system is able to stabilize reference potentials of the power transmission device and the power reception device when the power reception device is placed on the power transmission device.

First claim

The invention claimed is:

1. A power transfer system comprising:
a power transmission device including:
first and second power-transmission electrodes,
a power-transmission reference potential electrode,
a power source configured to apply a voltage to the first and second power-transmission electrodes, and
first and second power-transmission capacitors connected in series between the first and second power-transmission electrodes, wherein a connection point P5 between the first and second power-transmission capacitors is connected to the power-transmission reference potential electrode, and the first and second power-transmission capacitors have capacitances of C 15 and C 35 , respectively; and

a power reception device including:
first and second power-reception electrodes,
a power-reception reference potential electrode,
a load circuit configured to supply a voltage generated in the first and second power-reception electrodes to a load, and
first and second power-reception capacitors connected in series between the first and second power-reception electrodes, wherein a connection point P6 between the first and second power-reception capacitors is connected to the power-reception reference potential electrode, and the first and second power-reception capacitors have capacitances of C 26 and C 46 , respectively,

wherein electric power is transferred from the power transmission device to the power reception device through electrical coupling when the power reception device is placed on the power transmission device such that the respective first, second, and reference potential electrodes of the respective devices oppose each other,
wherein:
a connection point P1 is between the first power-transmission electrode and the first power-transmission capacitor,
a connection point P2 is between the first power-reception electrode and the first power-reception capacitor,
a connection point P3 is between the second power-transmission electrode and the second power-transmission capacitor,
a connection point P4 is between the second power-reception electrode and the second power-reception capacitor,

wherein, when electric power is transferred from the power transmission device to the power reception device:
a parasitic capacitance C 14 occurs between P1 and P4,
a parasitic capacitance C 16 occurs between P1 and P6,
a parasitic capacitance C 23 occurs between P2 and P3,
a parasitic capacitance C 25 occurs between P2 and P5,
a parasitic capacitance C 36 occurs between P3 and P6,
a parasitic capacitance C 45 occurs between P4 and P5,
a capacitance C A occurs between the first power-transmission electrode and the first power-reception electrode, and
a capacitance C P occurs between second power-transmission electrode and the second power-reception electrode, and

wherein the power transmission device and the power reception device have a structural configuration such that formulas (1) and (2) are satisfied as follows:

1
+

C
35

C
25

+

C
45

·

Σ
⁢

⁢
G

C
P

+

C
23

1
+

C
15

C
25

+

C
45

·

Σ
⁢

⁢
G

C
A

+

C
14

=

1
+

C
36

C
26

+

C
46

·

Σ
⁢

⁢
G

C
P

+

C
23

1
+

C
16

C
26

Assignees

• Murata Manufacturing Co

Inventors

• Ichikawa Keiichi
• Suesada Tsuyoshi
• Bondar Henri

Classifications

• H02M7/06

  using discharge tubes without control electrode or semiconductor devices without control electrode · CPC title

• H02J50/05 Primary

  using capacitive coupling · CPC title

• H02M7/5383

  in a self-oscillating arrangement (H02M7/538 takes precedence) · CPC title

• H02J50/10

  using inductive coupling · CPC title

• H02M7/537

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title