A centralized sampling device for three-phase split transformer insulation monitoring signals

Abstract

The invention discloses a three-phase split transformer insulation monitoring signal centralized sampling device. The device is composed of a centralized sleeve end screen current signal sampling unit, a centralized reference voltage signal sampling current, an intelligent sink control cabinet, three-phase split transformer sleeve current signals and three-phase split transformer sleeve voltage signals. The device has the advantages that online monitoring signals of sleeves of one transformer can be acquired in a centralized mode, the number of reference sensors is greatly reduced, and therefore measurement errors caused by the sensors are reduced; as is shown in detection, all technical indexes of the device meet the requirement for safe operation of the sleeves of the transformer; the configuration mode is simple, technicians can install, adjust, check and maintain the device conveniently, and the device is easy to apply and popularize.

Description

technical field [0001] The invention relates to the field of on-line monitoring of substation equipment, in particular to a signal sampling device for three-phase split type 500kV transformer capacitive bushing insulation monitoring, in particular to a three-phase split type transformer insulation monitoring signal centralized sampling device. Background technique [0002] The transformer bushing is the main insulation device outside the transformer box. There are usually 12 bushings on the high, medium and low voltage sides of a three-phase split 500kV transformer (3 on the high voltage side, 3 on the medium voltage side, and 6 on the low voltage side). The lead-out wires of the high, medium and low-voltage side windings of the transformer must pass through the corresponding insulating sleeves to insulate between the lead-out wires, between the lead-out wires and the transformer shell, and between the lead-out wires and the ground, and at the same time play the role of fixin...

AI Technical Summary

Problems solved by technology

[0003] At present, online monitoring of transformer bushing insulation in power companies has been widely carried out, and there are various sampling devices for transformer bushing insulation signals in the industry, especially the three-phase split 500kV transformer bushing insulation monitoring signal sampling The performance of the device is even more uneven. Not only is it difficult to guarantee the accuracy of the monitoring data, but also there are hidden dangers such as false positives and missed negatives due to inaccurate monitoring data, and even endanger the safe and stable operation of the transformer equipment.

[0004] At present, there are two main structures of 500kV transformer bushing insulation monitoring signal sampling devices in the industry. One is a dual-channel single-phase structure, that is, a sampling unit is installed for each bushing of a transformer, and each sampling unit contains One signal acquisition channel and one reference signal channel. This structure needs to install more signal sampling units. If it is necessary to monitor 12 bushings on the high, medium and low voltage sides of a 500kV transformer, at least 12 bushing end screens need to be installed Current signal sampling unit and 12 reference voltage signal sampling units; the structure of this scheme is complex, and each unit uses a reference signal channel, and the measurement error caused by the difference of the reference sensor will also increase

The other is a four-channel three-phase structure, that is, each phase transformer (one transformer is divided into ABC three-phase) needs to be installed with a sampling unit, and each sampling unit includes 4 bushing end screen current signal acquisition channels and 1 Reference signal channel, although this structure reduces the number of signal sampling units compared with the single-phase structure, it still needs to configure 4 bushing end screen current signal sampling units and 3 reference voltage signal sampling units in each transformer, which is not the most best solution

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