Passive element-thyristor parallel connection for mitigating inrush current in static transfer switch
AssigneeABB Schweiz AG
InventorsHany Habib, Thomas Anthony Kendzia, III, Veerakumar Bose, Christopher Alan Belcastro
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Abstract
Disclosed herein is a static transfer switch and methods of operating the same. The static transfer switch includes a first switch between a first voltage source and a load, and a second switch between a second voltage source and the load. The first switch and the second switch are configured to alternate power to the load between the first voltage source or the second voltage source. The static transfer switch also includes a first parallel circuit branch coupled in parallel to the first switch, the first parallel circuit branch comprising a first passive element and a first auxiliary switch.
Claims16
A static transfer switch comprising:
- a first silicon-controlled-rectifier-based (SCR-based) switch between a first voltage source and a load;
- a second SCR-based switch between a second voltage source and the load, wherein the first SCR-based switch and the second SCR-based switch are configured to alternate power to the load between the first voltage source and the second voltage source;
- and
- a first parallel circuit branch coupled in parallel to the first SCR-based switch, the first parallel circuit branch comprising a first inductor and a first auxiliary SCR-based switch, the first auxiliary SCR-based switch connected in series with the first inductor in the first parallel circuit branch,
- wherein the first auxiliary SCR-based switch is configured to be closed while the first SCR-based switch is open during activation of the first voltage source.
A method of operating a static transfer switch, the method comprising:
- coupling a first silicon-controlled-rectifier-based (SCR-based) switch between a first voltage source and a load;
- coupling a second SCR-based switch between a second voltage source and the load, wherein the first SCR-based switch and the second SCR-based switch are configured to alternate power to the load between the first voltage source and the second voltage source;
- coupling a first parallel circuit branch in parallel to the first SCR-based switch, the first parallel circuit branch including a first inductor and a first auxiliary SCR-based switch, the first auxiliary SCR-based switch connected in series with the first inductor in the first parallel circuit branch;
- closing the first auxiliary SCR-based switch to conduct current through the first parallel circuit branch during activation of the first voltage source until the first voltage source is ON;
- and
- when the first voltage source is ON, closing the first SCR-based switch to conduct current through the first SCR-based switch to power the load using the first voltage source.
Dependencies are inferred from the claim text.