# US 2014/0197693 A1 · Contactless power transmission device

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- Number: US 2014/0197693 A1
- Document ID: US20140197693A1
- Status: Published application
- Kind: A1
- Application number: 14/198,944
- Filed: 2014-03-06
- Published: 2014-07-17
- Earliest claimed: 2011-10-28
- Assignees: Panasonic Corporation
- Applicants: Panasonic Corporation
- Inventors: Atsushi FUJITA; Yoshihiro SAKAMOTO; Yoshiharu OMORI; Hideki SADAKATA; Takashi KASHIMOTO; Hiroaki KURIHARA
- Web page: https://patentgrep.com/patent/US20140197693A1

## CPC

- B60L 53/124: Detection or removal of foreign bodies
- B60L 53/126: Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
- B60L 53/20: characterised by converters located in the vehicle
- H02J 7/02: for charging batteries from AC mains by converters
- H02J 7/65: against overtemperature
- H02J 7/80: including monitoring or indicating arrangements
- H02J 50/10: using inductive coupling
- H02J 50/60: responsive to the presence of foreign objects, e.g. detection of living beings
- H02J 50/80: involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
- H02J 50/90: involving detection or optimisation of position, e.g. alignment
- B60L 2270/147: electro magnetic [EMI]
- H02J 2105/37: exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV]
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- Y02T 10/7072: Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
- Y02T 90/12: Electric charging stations
- Y02T 90/14: Plug-in electric vehicles
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A contactless power transmission device includes a power receiver, a power feeder configured to contactlessly feed power to the power receiver, the power feeder including a primary coil configured to generate magnetic flux by an input alternating current voltage, and a cover configured to cover the primary coil, and a capacitive sensor configured to supply an alternating current voltage to an electrode to measure a capacitance occurring between the electrode and foreign matter present around the cover and thereby detect the foreign matter. The frequency of the alternating current voltage of the capacitive sensor is set to be higher than the frequency of the magnetic flux generated by the primary coil.

## Claims

### Claim 1

A contactless power transmission device comprising:
a power receiver;
a power feeder configured to contactlessly feed power to the power receiver, the power feeder including a primary coil configured to generate magnetic flux by an input alternating current voltage, and a cover configured to cover the primary coil; and
a capacitive sensor including an electrode and configured to supply an alternating current voltage to the electrode to measure a capacitance occurring between the electrode and foreign matter present around the cover and thereby detect the foreign matter, wherein
the frequency of the alternating current voltage of the capacitive sensor is set to be higher than the frequency of the magnetic flux generated by the primary coil.

### Claim 2 (depends on 1)

The contactless power transmission device of claim 1, wherein
the capacitive sensor includes
a voltage supply unit configured to supply the alternating current voltage to the electrode, and
a capacitance measurement unit configured to measure the capacitance occurring the electrode and the foreign matter.

### Claim 3 (depends on 1)

The contactless power transmission device of claim 1, wherein
when the intensity of the magnetic flux is low, the frequency of the alternating current voltage and the frequency of the magnetic flux are set to be close to each other.

### Claim 4 (depends on 1)

The contactless power transmission device of claim 1, wherein
the frequency of the alternating current voltage is set to be at least two as high as the frequency of the magnetic flux.