INDUCTIVE POWER SUPPLY

• US 20120007437A1
• Filed: 08/28/2008
• Published: 01/12/2012
• Est. Priority Date: 08/28/2007
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Fells, Julian Andrew John, Pooley, David Martin
• Granted Patent: US 8,587,154 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

There is disclosed an inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising: determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the field generators is inactive so that fewer than all of the field generators are active simultaneously.

Claims

1. An inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising:

determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the field generators is inactive so that fewer than all of the field generators are active simultaneously.

118. A system as defined in claim 1 further comprising means for enabling communication between the or each secondary device and the primary unit.

121. A system as defined in claim 1:

further comprising a current generator for generating an alternating current; and

the controlling means including switching means responsive to the determining means for supplying current from the current generator to the at least one first field generator in one sense and to the at least one second field generator in the opposite sense such that a magnetic flux flows through the secondary coil.

2-14. -14. (canceled)

15. A primary unit for use in an inductive power transfer system, the system comprising the primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the primary unit further comprising:

determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling means for controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the field generators is inactive so that fewer than all of the field generators are active simultaneously.

119. A primary unit as defined in claim 15 wherein the field generators comprise coils.

122. A primary unit as defined in claim 15 wherein:

the system further comprises a current generator for generating an alternating current; and

the controlling means further comprises switching means responsive to the determining means for supplying current from the current generator to the at least one field generator in one sense and to the at least one field generator in the opposite sense such that a magnetic flux flows through the secondary coil, supplying power to the secondary device, the switching means further being for deactivating a third field generator so that fewer than all of the field generators are activated simultaneously.

123. A primary unit as defined in claim 15 further comprising means for enabling communication between the secondary device and the primary unit.

16. A method for use in an inductive power transfer system, the system comprising a primary unit and a secondary device separable from the primary unit, the primary unit comprising a power transfer surface and more than two field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the method comprising:

determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling the field generators such that at least one first field generator and at least one second field generator, selected in dependence upon such determination, are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, and further such that a third one of the field generators is inactive so that fewer than all of the field generators are active simultaneously.

120. A method as defined in claim 16 wherein:

the system comprises a current generator for generating an alternating current; and

the method further comprises, responsive to such determination, supplying current from the current generator to the at least one first field generator in one sense and to the at least one second generator in the opposite sense such that a magnetic flux flows through the secondary coil, thereby supplying power to the secondary device, and deactivating a third primary filed generator so that fewer than all of the field generators are activated simultaneously.

124. A method as defined in claim 16 further comprising communicating between the secondary device and the primary unit to assist in at least one of the determination and the controlling.

17-101. -101. (canceled)

102. An inductive power transfer system comprising:

a primary unit including a power transfer surface and a plurality of field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface;

first and second secondary devices separable from the primary unit, the first secondary device including a power receiver having a coil having an axis that is generally parallel to the power transfer surface when the first secondary device is in an operative position with respect to the power transfer surface, the second secondary device including a power receiver having a coil having an axis that is generally perpendicular to the power transfer surface when the second secondary device is in an operative position with respect to the power transfer surface;

means for determining the presence and the type of at least one secondary device in an operative position with respect to the power transfer surface; and

means for at least one of (a) controlling the field generators such that first and second ones of the field generators, selected in dependence upon the determination, are active in an opposite sense to one another when one of the at least one secondary devices is the first secondary device so as to direct magnetic flux through the first secondary device coil thereby supplying power to the first secondary device and (b) controlling the field generators such that a plurality of third field generators, selected in dependence upon the determination, are active in the same sense to one another when another of the at least one secondary devices is the second secondary device so as to direct magnetic flux through the second secondary device coil thereby supplying power to the second secondary device.

103-112. -112. (canceled)

113. An inductive power transfer system comprising a primary unit and a secondary device separable from the primary unit, the primary unit including a power transfer surface and a plurality of field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the system further comprising:

determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling means for controlling the number of field generators that are active based on such determination so that for different positions and/or orientations different numbers of said field generators are active simultaneously.

125. An inductive power transfer system as defined in claim 113 further comprising:

a plurality of the secondary devices of first and second types;

the first type of secondary device comprises a power receiver having a coil whose axis is generally parallel to the power transfer surface when that secondary device is in its working disposition with respect to the power transfer surface;

the second type of secondary device comprises a power receiver having a coil whose axis is generally perpendicular to the power transfer surface when that secondary device is in its working disposition with respect to the power transfer surface; and

the controlling means comprises detection means for detecting the presence and the type of at least one secondary device in proximity to the power transfer surface, the control means further for controlling the field generators in dependence upon the detection so as to supply power to one or more detected said secondary devices.

128. An inductive power transfer system as defined in claim 113 wherein at least one first one of the field generators and at least one second one of the field generators are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, the number of the first field generators and the number of the second field generators selected in dependence upon such determination.

114-115. -115. (canceled)

116. A primary unit for use in an inductive power transfer system, the system comprising a primary unit and a secondary device separable from the primary unit, the primary unit including a power transfer surface and a plurality of field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the primary unit further comprising:

determining means for determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling means for controlling the number of field generators that are active based on such determination so that for different positions and/or orientations different numbers of said field generators are active simultaneously.

126. A primary unit as defined in claim 116 wherein:

the system further comprises a plurality of the secondary devices each of first and second types, the first type of secondary device including a power receiver having a coil whose axis is generally parallel to a power transfer surface when that secondary device is in an operative position with respect to the power transfer surface, the second type of secondary device including a power receiver having a coil whose axis is generally perpendicular to the power transfer surface when that secondary device is in an operative position with respect to the power transfer surface;

the primary unit further comprises means for receiving a communication from one or more said secondary devices, the or each communication specifying the type of the secondary device concerned and indicating the presence of that secondary device in its operative position with respect to the power transfer surface; and

the controlling means further for controlling the field generators such that their respective phases are configured in a predetermined pattern selected in dependence upon the communicated type of the secondary device concerned.

129. A primary unit as defined in claim 116 wherein the controlling means is further for controlling the field generators such that at least one first one of the field generators and at least one second one of the field generators are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, the number of the first field generators and the number of the second field generators being selected in dependence upon such determination.

117. A method for use in an inductive power transfer system, the system comprising a primary unit and a secondary device separable from the primary unit, the primary unit including a power transfer surface and a plurality of field generators each operable to generate an electromagnetic field, the field generators being located at different positions relative to the power transfer surface, the secondary device comprising a power receiver having a secondary coil, the method comprising:

determining at least one of the position and the orientation of the power receiver relative to the power transfer surface; and

controlling the number of field generators that are active based on such determination so that for different positions and/or orientations different numbers of said field generators are active simultaneously.

127. A method as defined in claim 117 wherein:

the system includes a plurality of the secondary devices each of first and second types, the first type of secondary device including a power receiver having a coil whose axis is generally parallel to a power transfer surface when that secondary device is in an operative position with respect to the power transfer surface, and the second type of secondary device including a power receiver having a coil whose axis is generally perpendicular to the power transfer surface when that secondary device is in an operative position with respect to the power transfer surface;

the method further comprises receiving a communication from one or more said secondary devices, the communication specifying the type of the secondary device concerned and indicating the presence of that secondary device in its operative position with respect to the power transfer surface; and

the controlling step, for the or each present secondary device, includes controlling the field generators such that their respective phases are configured in a predetermined pattern selected in dependence upon the communicated type of the secondary device concerned.

130. A method as defined in claim 117 wherein at least one first one of the field generators and at least one second one of the field generators are active in a substantially opposite sense to one another so as to direct magnetic flux through the secondary coil thereby supplying power to the secondary device, the number of the first field generators and the number of the second field generators being selected in dependence upon such determination.