Control of line harmonics
AssigneeSwitched Reluctance Drives Limited
InventorsPatricia Mary Elliott, Howard James Slater
Life of this patent
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Abstract
A switched reluctance drive is supplied from a supply. The excitation applied to the phase winding(s) has one or more gaps inserted so that, when the phase currents are summed, the resulting supply current has a reduced harmonic content. The supply may be alternating or direct.
Claims18
A method of reducing harmonics of a supply current in a given bandwidth in the operation of a switched reluctance machine having at least one energizable phase winding and means for applying an excitation voltage to the at least one phase winding to energize it, the method comprising:
- removing the excitation voltage to create at least one gap in the energization of the at least one phase winding, the at least one gap having a predetermined duration and a predetermined position within the phase conduction period, such that the magnitude otherwise associated with the harmonics in the given bandwidth is reduced.
A switched reluctance machine having a supply current, the machine comprising:
- at least one energizable phase winding;
- means for applying an excitation voltage to the at least one phase winding to energize it;
- and
- means for removing the excitation voltage to create at least one gap in the energization of the at least one phase winding, the at least one gap having a predetermined duration and a predetermined position within the phase conduction period, such that the magnitude otherwise associated with harmonics in a given bandwidth of the supply current is reduced.
A switched reluctance machine having a supply current, the machine comprising:
- at least one energizable phase winding;
- and
- a switching arrangement for applying an excitation voltage to the at least one phase winding to energize it;
- wherein excitation voltage is removed to create at least one gap in the energization of the at least one phase winding, the at least one gap having a predetermined duration and a predetermined position within the phase conduction period, such that the magnitude otherwise associated with harmonics in a given bandwidth of the supply current is reduced.
Dependencies are inferred from the claim text.