Abstract: An inductive power transfer apparatus suitable for producing a magnetic field for inductive power transfer is disclosed. The apparatus has three or more coils arranged such that when energised with a power source, magnetic fields produced by each coil augment each other on a first surface and substantially weaken each other on a second surface. The first and second surfaces have an obverse relationship to each other. Also disclosed is a roadway inductive power transfer module suitable for producing a magnetic field for inductive power transfer to a vehicle using the roadway, and an Inductive power transfer apparatus suitable for receiving a magnetic field for inductive power transfer.

Abstract: A pick-up circuit for an inductive power transfer (IPT) system includes a series-tuned pick-up coil and a plurality of parallel AC processing circuits provided between the series-tuned pick-up coil and an output, each processing circuit being adapted to produce an output signal based directly or indirectly at least in part on a voltage of the series-tuned pick-up coil and including a switch for selectively coupling the processing circuit to the output so as to selectively provide the respective output signal to the output of the pick-up circuit.

Abstract: An inductive power transfer (IPT) pad and system for the charging of electric and hybid electric vehicles. The batter of such a vehicle can be selectively coupled to a high power electrical supply for fast charging or a lower power electrical supply for charging using IPT. The batteries of the vehicles are used in a system to control the load demand in an electricity network through variations of the frequency of power supplied.

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 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: An inductive power transfer system (IPT) pick-up comprises: a pick-up coil capable of generating a voltage by magnetic induction from a primary conductive pathway, and a tuning capacitor associated with the pick-up coil to provide a first pick-up resonant circuit; a first output associated with a first control means to substantially control the voltage or current provided by the first output; a further resonant circuit connected in series or parallel with the first pick-up resonant circuit; and a second output associated with a second control means to control the voltage or current provided by the second output. A method of providing an additional independently controllable output from an IPT pick-up having a resonant pick-up circuit is also disclosed.

Abstract: A communication apparatus comprises a communication path capable of conveying communication signals, a communication device adapted to receive or generate VHF or UHF communication signals, and a near field antenna associated with the communication device. The near field antenna is provided sufficiently near to the communication path to couple VHF or UHF communication signals to or from the communication device to the communication path. A HID/IPT system and a communication method are also provided.

Abstract: An inductively coupled power transfer system has a power pick-up that uses an asymmetrical magnetically permeable core (103, 105, 106, 107). Such cores have been found to provide a significant increase in the output power for given losses and given core volume when transferring power from a primary conductive path (101) to a secondary coil (104) provided on the core.

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 IPT system magnetic flux pad includes two substantially planar coils (17) in close proximity to each other above a magnetically permeable core (14). The coils (17) each define a pole area (11, 12) and the distance between one or more adjacent turns of the coils (17) located in a region between the pole areas (11, 12) being different from the distance between one or more adjacent turns of the coils (17) located outside the region between the pole areas (11, 12).

Abstract: A multiphase IPT primary track conductor arrangement comprising a first phase conductor and a second phase conductor, the conductors being arranged substantially in a plane and so as to overlap each other and being arranged such that there is substantially balanced mutual coupling between the phase conductors.

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: 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 roadway powered electric vehicle system includes a power supply (101) which makes power available inductively to one or more modules (111) provided in or under a roadway. Modules (111) make a magnetic field selectively available to one or more vehicles travelling over the roadway corresponding to the location of the vehicle. The presence or strength of the magnetic field provided on the roadway may be dependent upon the vehicle type or category.

Abstract: A method is provided for controlling a resonant circuit (1) of an ICPT system. The resonant circuit has a controlled variable reactance (2), and a predetermined perturbation is introduced in the magnitude of variable reactance. The change in a property of the resonant circuit in response to the perturbation is sensed, and the variable reactance is varied to alter the resonant frequency of the circuit in response to the sensed change.

Abstract: The invention provides an electric autocycle support apparatus comprising an autocycle engagement device adapted to support an autocycle, the engagement device having a coil adapted to provide a magnetic field for inductively charging an autocycle supported by the apparatus. The invention also provides an electric autocycle stand and a charging system.

Abstract: An arrangement for supplying a load with electrical energy from a power source comprises a textile, woven floor covering (101) with longitudinally running warp threads and transversely running weft threads, three or more current conductors (106) that are spaced apart and substantially parallel to one another being woven in either as warp threads or as weft threads, the current conductors replacing part of a filling warp, a binding warp or the weft threads during the weaving operation. The arrangement also comprises a feed for the connection of the current conductors (106) to the power source and a coupling device (130) for picking up electrical energy from the current conductors (106) in the floor covering (101) and transporting it further to the load when the coupling device (130) is brought into a power pick-up area of the floor covering (101).

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: 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: An Inductive Power Transfer System pickup provides a controlled AC power supply by controlled variation of the phase angle between the pickup coil induced voltage (jwMI) and the tuning capacitor C voltage. The phase angle can be varied by maintaining the tuning capacitor C voltage substantially constant for a selected time period. Switches S1 and S2 may be used to clamp the tuning capacitor C voltage at substantially zero volts during the selected time period. Switch S1 can be operated to prevent a rise in positive voltage across the tuning capacitor, and switch S2 can be used to prevent the voltage across the tuning capacitor from going negative.

Abstract: An Inductive Power Transfer (IPT) pick-up apparatus includes a magnetically permeable core, a first coil, being wound about the core so as to be inductive coupled therewith such that a current induced in the first coil is most sensitive to a first directional component of magnetic flux and a second coil, being wound about the core so as to be inductively coupled therewith such that a current induced in the second coil is most sensitive to a second directional component of magnetic flux. The first directional component is substantially orthogonal to the second directional component.