摘要 |
A power system controller design for controlling fault current or load flow current by applying a variable inductive impedance. The device comprising multiple stages of transformers connected such that their primary coils are in series and carry the primary power. Their secondary circuits containing a device for interruption of secondary current. The secondary circuit of each stage having a small part of the primary energy flowing through them. Under normal conditions the interrupter allows secondary current to flow, producing no impedance on primary side. Upon operation of interrupter, inductive impedance appears across primary. Operation of single stages producing low inductive impedance on primary circuit. Operation of multiple stages producing higher inductive impedance on primary circuit. In a preferred embodiment, the transformers have saturating cores such that operation of single stages saturates their cores, producing low inductive impedance on primary circuit. Operation of multiple stages brings the individual cores back out of saturation, producing higher inductive impedance across primary. Also in a preferred embodiment, to form a stage the secondary circuits of an identical transformer pair are connected in parallel via an interrupting device. Normally, current flowing in the secondary of the first transformer is re-introduced into the primary via the second transformer. Upon operation of interrupter, inductive impedance appears across primary coils of both transformers.
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