Switching circuit for an inductive load
AssigneeSwitched Reluctance Drives Limited
InventorPaul Donald Webster
Life of this patent
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Abstract
A switching circuit for an inductive load such as a switched reluctance machine comprises two separate switching circuits for separate portions of the inductive load. A supply voltage is applied across the two circuits which are connected together at a node between two dc link capacitors. Each separate circuit is exposed to only approximately half the supply voltage between a respective terminal and the central node so that conventional switching components can be used to handle higher voltages applied across the two connected circuits.
Claims13
A switched reluctance drive system comprising a reluctance machine having a rotor, a stator and at least one phase winding having at least first and second winding portions, and a switching circuit for controlling the current in the winding, the switching circuit comprising:
- a first switch arrangement having first and second junctions, the first switch arrangement being connected with the first winding portion for controlling current in the first winding portion;
- a second switch arrangement having first and second junctions, the second switch arrangement being connected with the second winding portion for controlling current in the second winding portion;
- and
- first and second capacitors respectively connected across the first and second junctions of each switch arrangement, the second junction of the first switch arrangement and the first junction of the second switch arrangement being connected at a node between the first and second capacitors, the switch arrangements being operable to share a full voltage applied between the first junction of the first switch arrangement and the second junction of the second switch arrangement such that each winding portion is free of exposure to said full voltage;
- wherein the at least one phase winding is subject to unipolar excitation.
A switched reluctance drive system comprising a reluctance machine having a rotor, a stator and at least two phase windings, each phase winding including at least one winding portion, and a switching circuit for controlling current in each of the windings, the switching circuit comprising:
- a first switch arrangement having first and second junctions, the first switch arrangement being connected with the at least one winding portion of one of the phase windings for controlling current in the one phase winding;
- a second switch arrangement having first and second junctions, the second switch arrangement being connected with the at least one winding portion of the other of the phase windings for controlling current in the other phase winding;
- and
- first and second capacitors respectively connected across the first and second junctions of each switch arrangement, the second junction of the first switch arrangement and the first junction of the second switch arrangement being connected at a node between the first and second capacitors, the switch arrangements being operable to share a full voltage applied between the first junction of the first switch arrangement and the second junction of the second switch arrangement such that each winding portion is free of exposure to said full voltage;
- wherein the at least two phase windings are subject to unipolar excitation.
Dependencies are inferred from the claim text.