Switched Reluctance Drives Limited Patent applications |
Patent application number | Title | Published |
20100231062 | Electrical Machine with Dual Radial Airgaps - A switched reluctance machine has an array of poles attached to a stationary holding member to form a stator. The stator has no back-iron. The machine has two arrays of rotor poles, positioned on either side of the stator poles, and circumferentially aligned with each other. When a pair of rotor poles is aligned with a stator pole, a small airgap is formed at each end of the stator pole, across which flux can be driven to produce torque in a rotary arrangement or force in a linear arrangement. When the poles are in the unaligned position, the phase inductance is very low. | 09-16-2010 |
20100211231 | Operating Electrical Machines from a DC Link - A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimized and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold. | 08-19-2010 |
20100079028 | Slot Wedges for Electrical Machines - A wound core assembly for an electrical machine comprising a stack of laminations defining a core having a plurality of poles, the wound core assembly further comprising at least one slot wedge, wherein the slot wedge comprises a first portion arranged between adjacent poles and at least one second portion protruding from the first portion and abutting an end face of the core in the region of at least one of the poles. The at least one second portion may apply axial pressure to the end face to reduce the tendency of the laminations to splay axially outwards. | 04-01-2010 |
20090134831 | Deriving Values of Parameters in Electrical Machines - An electrical drive system includes an electrical machine controlled by an electronic controller and requires control signals representing quantities associated with the operation of the electrical machine. These signals may represent, for example, rotor position and flux or current. A controller includes an estimation routine to use the known magnetic characteristics of the machine and a rotor position signal to provide an estimate of current or of supply voltage. | 05-28-2009 |
20080272721 | Control of a brushless electrical machine - A brushless electrical machine has at least one phase winding which produces magnetic flux in the machine. A controller controls the flux in the machine with reference to a demanded flux and a stabilisation signal which, in combination, enable the controller to operate in a stable manner in the presence of disturbances in the inputs or parameters of the controller. The controller is able to operate with either a hardware rotor position detector or with a sensorless position algorithm. | 11-06-2008 |
20080197793 | Control of an electrical machine - A switched reluctance machine has salient poles on the stator and rotor. The windings of the machine are supplied from a converter which provides energisation at a chosen rate. The windings of the machine may be energised at the rate at which the rotor poles pass the stator poles, or it may be operated at a fraction of that rate by energising the windings to cooperate with every second, third or fourth rotor pole. This can extend the output of the machine. | 08-21-2008 |