Detection method for secondary circuit disconnection of transformer used in conventional sampling instrument

Abstract

A method for detecting disconnection of a secondary circuit of a transformer used in a conventional sampling instrument in a substation. By adding pull-up and pull-down resistors with unequal resistance values ​​in the secondary sampling circuit of the transformer, the disconnection of the secondary circuit of the transformer can be quickly identified. When the secondary circuit is normal, the pull-up and pull-down resistance does not affect the normal output of the transformer, the potential offset caused by the pull-up and pull-down resistance does not reduce the input range of the acquisition device, and the output of the acquisition device truly reflects the external access. When the secondary circuit of a certain transformer is disconnected, the AD collects a stable offset potential, and the processor completes the abnormal identification of the corresponding channel, and the disconnected transformer of the secondary circuit does not affect the normal collection of other transformers. The invention eliminates sampling output error or device misoperation caused by disconnection of the secondary circuit of the transformer of the acquisition device, realizes self-inspection of the device and equipment, and can be directly applied to the engineering site.

Description

technical field [0001] The invention belongs to the technical field of power transmission and transformation, and in particular relates to a rapid detection method for secondary circuit disconnection of a transformer used in a conventional sampling instrument in a substation. Background technique [0002] The substation is an indispensable and important link in the power system. It is responsible for the heavy task of power conversion and power redistribution, and plays a decisive role in the safety and economic operation of the power grid. Instrument transformers are used to collect voltage and current data of substations, and are widely used in merging units or conventional protection, measurement and control. The requirement of on-site digital output of the merging unit requires the merging unit to withstand the test of the harsh electromagnetic environment, temperature and humidity on site. The reliability of the merging unit is very important. Once an abnormal situation...

AI Technical Summary

Problems solved by technology

[0003] However, in the prior art, there is no method for detecting the disconnection of the secondary circuit of the instrument transformer of the acquisition device of the substation, but such faults frequently occur in the field, and the identification of the fault should be taken as a necessary part of the self-check of the device status

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