Cross-core current transformer disconnection and polarity inspection system and control method thereof

Abstract

The invention discloses a cross-core current transformer disconnection and polarity inspection system and a control method thereof. The cross-core current transformer disconnection and polarity inspection system comprises a plurality of controllable pulse generating circuits and a plurality of Hall sensors, and a secondary output terminal of a cross-core current transformer CT penetrates into the Hall sensors in the forward direction; the multipath change-over switch selects circuits SWA, SWB and SWC, the SWA and the SWB respectively control the frequencies and the amplitudes of the output pulses of all the controllable pulse generation circuits, and the SWC is responsible for gating one Hall sensor to output; the switching control circuit is used for controlling and selecting one of the controllable pulse generating circuits to output the pulse; the frequency control circuit and the amplitude control circuit are respectively used for controlling and shaping the frequency and the amplitude of the output pulse; the data acquisition and conversion circuit is connected with the multi-path change-over switch selection circuit and is responsible for signal processing and acquisition of stoping pulses; and a core control module. On the premise that normal monitoring of the straight-through mutual inductors is not affected, broken line detection and polarity detection of the multiple straight-through mutual inductors can be achieved, the detection efficiency is high, and the precision is high.

Description

【Technical field】 [0001] The invention belongs to the technical field of electric power systems, and in particular relates to a wire breakage and polarity inspection system and a control method for a feedthrough current transformer. 【Background technique】 [0002] In the power system, the feedthrough current transformer (CT) is widely used, such as detecting the zero-sequence current of the power system, the leakage current of the equipment, and the unbalanced current. In the above-mentioned application conditions, under the normal operation condition of the primary equipment, the synthetic magnetic flux of the primary current of the through-core current is zero, so the secondary current is also zero. The through-the-heart CT will have output current only when a device fails. However, when the through-the-heart CT has a secondary disconnection or internal coil disconnection due to some reasons, the secondary current is also zero, so it cannot be distinguished from the norma...

AI Technical Summary

Problems solved by technology

Although this method adopts the online method, the harmonics will interfere with other secondary equipment. At the same time, due to the different parameters of different CTs, it is impossible to realize multi-CT inspections. Only one CT can be equipped with an open circuit monitoring device, which is costly and inefficient.

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