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US 11,146,067 B2Granted
Line control circuit configuration
AssigneeHatch Ltd.
InventorsMichael Morgan Campbell, Yan Elksnis, Dong Shen
Life of this patent
Estimating the term…
Abstract
A configuration of switches added to a line control circuit allows for switching back and forth between a configuration featuring a series-connected thyristor switch and reactor and a configuration featuring a parallel-connected thyristor switch and reactor. Connecting the reactor in series with the thyristor switch allows a controlled high-impedance circuit configuration that is particularly well adapted for cold furnace start-ups and furnace idling. In this manner, there is reduced need for such equipment as extra startup transformers, alternate low-voltage power supply configurations and temporary specialty electrical apparatus for cold furnace start-ups.
Claims19
A line control circuit comprising:
- a supply-side connection point for connecting to an electrical supply;
- a load-side connection point for connecting to a load;
- a thyristor switch;
- a first reactance;
- a second reactance;
- and
- a plurality of switches for providing electrical connection of the thyristor switch to the electrical supply and to the load, wherein each switch, independently, is configured for disposition in either a closed condition or an open condition;
- wherein the plurality of switches are configurable in and allow for switching between:
- a first configuration wherein the plurality of switches are disposed such that:
- the thyristor switch is disposed in a parallel combination with the first reactance;
- and
- the parallel combination of the thyristor switch and the first reactance is disposed in series with the second reactance;
- and
- a second configuration wherein the plurality of switches are disposed such that:
- the parallel combination of the thyristor switch and the first reactance is defeated;
- and
- the thyristor switch is disposed in series with a third reactance.
14 more elements
An adapted variable series reactor comprising:
- a supply bus connection point for connecting to a phase of a supply bus having a plurality of phases;
- a transformer connection point for connecting to a transformer for an electrical load;
- a fixed-value reactor connected, at a first fixed-value reactor end, to the supply bus connection point, the fixed-value reactor having a second fixed-value reactor end;
- a thyristor-path switch connected, at a first thyristor-path switch end, to the second fixed-value reactor end, the thyristor-path switch having a second thyristor-path switch end;
- a thyristor switch connected, at a first thyristor switch end, to the second thyristor-path switch end, the thyristor switch having a second thyristor switch end connected to the transformer connection point;
- a tapped reactor connected, at a first tapped reactor end, to the second fixed-value reactor end, the tapped reactor having a second tapped reactor end and a tapped reactor selector;
- a tapped-reactor-path switch connected between the second tapped reactor end and the transformer connection point;
- and
- a selector-path switch connected, at a first selector-path switch end, to the tapped reactor selector and, a second selector-path switch end, to the first thyristor switch end;
- the adapted variable series reactor having a first configuration defined by:
- the selector-path switch being an open state;
- the tapped-reactor-path switch being a closed state;
- and
- the thyristor-path switch being in a closed state;
- and
- the adapted variable series reactor having a second configuration defined by:
- the selector-path switch being a closed state;
- the tapped-reactor-path switch being an open state;
- and
- the thyristor-path switch being in an open state.
17 more elements
An adapted variable series reactor comprising:
- a supply bus connection point for connecting to a phase of a supply bus having a plurality of phases;
- a transformer connection point for connecting to a transformer for an electrical load;
- a fixed-value reactor connected, at a first fixed-value reactor end, to the supply bus connection point, the fixed-value reactor having a second fixed-value reactor end;
- a thyristor-path switch connected, at a first thyristor-path switch end, to the second fixed-value reactor end, the thyristor-path switch having a second thyristor-path switch end;
- a thyristor switch connected, at a first thyristor switch end, to the second thyristor-path switch end, the thyristor switch having a second thyristor switch end connected to the transformer connection point;
- a further reactor connected, at a first further reactor end, to the second fixed-value reactor end, the further reactor having a second further reactor end;
- a lower switch connected between the second further reactor end and the transformer connection point;
- and
- a middle switch connected, at a first middle switch end, to the second further reactor end and, at a second middle switch end, to the first thyristor switch end;
- the adapted variable series reactor having a first configuration defined by:
- the middle switch being an open state;
- the lower switch being a closed state;
- and
- the thyristor-path switch being in a closed state;
- and
- the adapted variable series reactor having a second configuration defined by:
- the middle switch being a closed state;
- the lower switch being an open state;
- and
- the thyristor-path switch being in an open state.
17 more elements
Dependencies are inferred from the claim text.