Abstract: An inductive power transfer (IPT) control method is disclosed for controlling the output of an IPT pick-up. The invention involves selectively shunting first and second diodes of a diode bridge to selectively rectify an AC current input for supply to a load, or recirculate the AC current to a resonant circuit coupled to the input of the controller. By controlling the proportion of each positive-negative cycle of the AC input which is rectified/recirculated, the output is regulated. Also disclosed is an IPT controller adapted to perform the method, an IPT pick-up incorporating the IPT controller, and an IPT system incorporating at least one such IPT pick-up.

Abstract: An inductive power transfer pickup circuit has a pickup coil (L2) and tuning capacitor (C2) connected in series to provide a series resonant circuit. A bi-directional switch (S1) is used to vary the phase angle between the open circuit pickup coil voltage (VOC) and the pickup coil inductor current (iL) to provide a controlled AC supply to an output of the pickup.

Abstract: A magnetic flux pad for generating or receiving magnetic flux has two pole areas (11, 12), a permeable core (14) and a coil (16) wound about the core. The pad allows useable flux to be generated at a significant height above a surface of the pad.

Abstract: The present application invention relates to the control of electromagnetic fields. It has particular relevance to magnetic flux coupling apparatus such as inductive power transfer pads for wireless power transfer systems. There is provided a magnetic flux coupling apparatus comprising a coil for generating or receiving magnetic coupling flux and a leakage flux element comprising material of a relatively high magnetic permeability. The leakage flux element is separated from the coil by a region of relatively low magnetic permeability and positioned to provide a controlled path for leakage flux independent of coupling flux. There is provided an electromagnetic wave absorber comprising a high permeability magnetic material arranged in a first layer; and a conductive or low permeability material arranged in a second layer.

Abstract: A magnetic flux pad for receiving or generating magnetic flux. The pad includes two pole areas (11, 12) associated with a magnetically permeable core 14. Coils 17 define the pole areas. The pad allows useable flux to be generated at a significant height above a surface of the pad.

Abstract: The present application relates to the detection of moving vehicles and other objects, in particular though not exclusively for the application of switching stationary charging pads for moving electric vehicle charging. There is provided an electric vehicle detecting apparatus for switching a charging pad for charging a vehicle transmitting a locating signal, the apparatus comprising two sensors separated in the direction of travel of the vehicle, and a detector arranged to detect the vehicle by comparing the locating signals received by each of the two sensors.

Abstract: The present invention provides a magnetic flux pad for generating or receiving magnetic flux, comprising at least three coils positioned such that the windings thereof are in substantially the same plane, and a power supply or pickup controller operable to selectively energise or receive power from two or more of the coils such that a magnetic field is produced or received by at least one of a plurality of pairs of the at least three coils. In preferred embodiments, the three or more coils are substantially mutually decoupled, overlapping, and/or equidistantly spaced from one another.

Abstract: A demand side electric power supply management system is disclosed. The system comprises an islanded power system having a point of coupling to a supply grid. The islanded power system supplies a plurality of electric loads, each of which is associated with a load controller to control the maximum power demanded by that load. A measuring means associated with the point of coupling measures the total power transfer between the grid and the islanded system, and a system controller monitors the measured power transfer relative to a set point and provides a control signal to a plurality of load controllers. Each load controller receives substantially the same control signal and determines the maximum power which the or each load associated with the load controller is allowed to draw from the islanded power system based on information contained in the control signal.

Abstract: A method of controlling power delivered to one or more loads in an inductive power transfer (IPT) system includes varying a frequency of a current in a primary conductive path (109), detecting the frequency in a pick-up inductively coupled with the primary conductive path (109), and controlling the power supplied to a load (207) associated with the pickup dependent on the detected frequency of the current in the primary conductive path (109). The frequency of the current is determined by is determined by either or both the load on a power supply (104) of the IPT system or the load on an electricity supply network supplying the power supply (104).

Abstract: A magnetic flux pad for receiving or generating magnetic flux. The pad includes two pole areas (11, 12) associated with a magnetically permeable core 14. Coils 17 define the pole areas. The pad allows useable flux to be generated at a significant height above a surface of the pad.

Abstract: This disclosure provides methods and apparatus for use in wireless power transfer and particularly wireless power transfer to remote system such as electric vehicles. In one aspect a wireless power transfer system comprises a wireless power transfer device comprising a first connector portion; an electrical device comprising a second connector portion; and a wiring harness comprising a cable, a first end connector portion at one end of the cable configured to be removably connected to the first connector portion, and a second end connector portion at the other end of the second connector portion. In another aspect the the cable configured to be removably connected to wiring harness comprises a plurality of cables, each comprising a plurality of conductive filaments; and a connector portion comprising a plurality of pins each comprising a recessed end, wherein an end of each cable is soldered into the respective recessed ends.

Abstract: Systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote systems such as electric vehicles are disclosed. In one aspect an induction coil is provided comprising a plurality of substantially co-planar coils formed from one or more lengths of conducting material, each length of conducting material being electrically connectable at each end to a power source or battery, and wherein at least one of the lengths of conducting material is continuously wound around two or more of the coils. In another aspect, a method is provided for forming such an induction coil. In yet another aspect, a switching device is operable to alter the configuration of the coils, for example in response to a detected characteristic of another induction coil or device coupled thereto.

Abstract: An ICPT system has a single phase power supply which energises a conductive path (13) and has an inverter (5) to provide an alternating current at an operating frequency greater than the single phase utility supply frequency in the conductive path. The inverter modulates the amplitude of the alternating current with respect to the utility supply frequency such that the amplitude of the alternating current varies. The pick-up has an energy storage element (26) to provide a continuous supply of power to a load (27) irrespective of the varying amplitude of the alternating current in the conductive path.

Abstract: Disclosed herein is an inductive power transfer (IPT) compensation circuit and method for reflecting a controlled reactance to a primary conductor at a selected operating frequency, compensating for reactive loads reflected to the primary conductor by one or more other pick-ups inductively coupled with the primary conductor in use. The compensation circuit comprises a first switch means coupled to a resonant circuit and operable to reflect a capacitive reactance to the primary conductor; a second switch means coupled to the resonant circuit and operable to reflect an inductive reactance to the primary conductor; and control means adapted to control operation of the first and second switch means to compensate for inductive and capacitive reactances, respectively, in the primary conductor.

Abstract: Foreign object detection apparatus for an IPT system, includes a control means adapted to detect the presence of a foreign object on or adjacent to an IPT primary pad of the system.

Abstract: An IPT pick-up circuit includes a resonant circuit including a pick-up inductor and a tuning capacitance in parallel with the pick-up inductor, a control system to control power transfer to the pick-up circuit and a power conditioning impedance provided in series between the resonant circuit and the control system, selected to provide a required power factor in the resonant circuit.

Abstract: An inductive power transfer pad for transmitting wireless power to a wireless power receiver separable from the inductive power transfer pad. The inductive power transfer pad includes a coil having at least one turn of a conductor in a first layer and a plurality of ferromagnetic slabs arranged in a second layer substantially parallel to that of the coil, the ferromagnetic slabs being arranged so as to be spaced apart from one another about the coil with their lengths extending across a longitudinal length of the coil.

Abstract: An IPT system magnetic flux device for generating or receiving a magnetic flux, has a magnetically permeable core and at least one coil magnetically associated with the core. A shield repels magnetic flux and is located on the opposite side of the core such that the shield includes an outer portion that extends beyond at least part of the perimeter of the core.

Abstract: An apparatus for generating and/or transmitting communications signals, the apparatus including a system for generating signals at a first frequency, a system for mixing the frequency of the generated signals from the first frequency down to a second frequency and a near field antenna for receiving the signals at the second frequency and being provided sufficiently near to a wire transmission line so as to wirelessly couple thereto.

Abstract: An apparatus is disclosed for charging a battery of an electric or a hybrid vehicle. The apparatus includes first means for selectively coupling the battery to a high power electrical supply and second means for selectively coupling the battery to a lower power electrical supply, wherein the second means for coupling comprises a pickup pad electrically coupled to the battery. Power is transferred to the pickup pad from a charging pad by inductive power transfer.