Wireless power supply system and power transmission device

• US 9,796,284 B2
• Filed: 02/25/2014
• Issued: 10/24/2017
• Est. Priority Date: 02/25/2014
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Okamoto, Tomofumi
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): SHIAO, DAVID A
• Application Number:
  US15/120,240
• Publication Number:
  US 20170203656A1
• Time in Patent Office: 1,337 Days
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: 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
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/62 in response to charging parameters, e.g. current, voltage or electrical charge
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A wireless power supply system includes a power transmission device having a power transmission coil and a power receiving device having a power receiving coil. The power transmission coil transmits electric power to the power receiving coil via a wireless connection, so as to supply the electric power to a battery installed in the power receiving device. The power transmission device controls electric power supplied to the power transmission coil according to a transmission power command value. The power receiving device calculates a power transmission efficiency based on the electric power supplied to the electrical load and the transmission power command value and stops supplying the electric power when the power transmission efficiency falls to a threshold efficiency or less. The power transmission device regulates the output power when a current flowing through the power transmission coil exceeds a threshold current.

Claims

1. A wireless power supply system comprising a power transmission device provided on a ground side and having a power transmission coil, and a power receiving device provided in a vehicle and having a power receiving coil, the power transmission coil transmitting electric power to the power receiving coil via a wireless connection, so as to supply the electric power to an electrical load installed in the power receiving device,

the power transmission device including a power controller configured to control electric power supplied to the power transmission coil according to a transmission power command value,

the power receiving device including an efficiency calculator configured to calculate a power transmission efficiency based on the electric power supplied to the electrical load and the transmission power command value, and a switching controller configured to stop supplying the electric power received by the power receiving coil to the electrical load when the power transmission efficiency falls to a predetermined threshold efficiency or less,

the power controller being configured to regulate the electric power supplied to the power transmission coil when the power controller determines a current flowing through the power transmission coil exceeds a threshold current when the electric power supplied to the electrical load is stopped by the switching controller.

2. The wireless power supply system according to claim 1, wherein the power controller controls the electric power supplied to the power transmission coil according to the power transmission efficiency.

3. The wireless power supply system according to claim 1, wherein the power controller controls the electric power supplied to the power transmission coil to remain constant regardless of the power transmission efficiency.