On-line monitoring and verification device for distributed capacitive equipment and on-site verification method based on the device

Abstract

The present invention relates to the field of power equipment online monitoring and specifically relates to a distributed capacitive equipment online monitoring and calibration device and a field calibration method based on the device. The device comprises a processor, an RF transceiver, a memory circuit, an analog to digital converter, a digital to analog converter, an input channel conditioning circuit, a conditioning circuit I, and a conditioning circuit II. The calibration method comprises the steps of (1) connecting the distributed capacitive equipment online monitoring and calibration device into a capacitive equipment online monitoring device, (2) obtaining the error data of a small current transformer, (3) generating a group of analog signals and loading the analog signals to a measurement motherboard so as to obtain the error data of the measurement motherboard, (4) carrying out error fitting on the error data of the small current transformer and the measurement motherboard and thus judging the reliability of the capacitive equipment online monitoring device. According to the invention, the field calibration accuracy and reliability of the capacitive equipment online monitoring device can be improved, the operation steps of field calibration are simplified, and the operation is safe.

Description

technical field [0001] The invention relates to the field of on-line monitoring of electric power equipment, in particular to an on-line monitoring and verification device for distributed capacitive equipment and an on-site verification method based on the device. Background technique [0002] At present, the online monitoring technology of capacitive equipment has been widely used in 220kV and above voltage level substations. The long-term operation shows that the online monitoring technology can effectively provide early warning for the failure of capacitive equipment. However, with the aging of the online monitoring device, the monitoring accuracy It will gradually decrease and often cause false alarms, so it is necessary to check the installed online monitoring devices. The on-site verification of online monitoring devices currently has the following problems: [0003] a) The current online monitoring device uses a distributed scheme. Since the leakage current sampling ...

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Problems solved by technology

[0003] a) At present, the online monitoring device uses a distributed scheme. Since the leakage current sampling unit and the reference voltage sampling unit are far apart, the existing on-site verification device of the online monitoring system cannot provide the reference voltage and reference current for the system at the same time

[0004] b) The small current current transformer used in the online monitoring device is connected in series to the grounding wire of the last screen, and its disassembly requires a lot of work, which is not suitable for the calibration work of the online monitoring device

Moreover, there are greater equipment risks and personal safety risks in live disconnection and bypass ground wires

[0005] c) The zero-flux current transformer used in the online monitoring device is connected in series to the grounding wire of the last screen, and the workload of disassembly is large during the calibration, which is not suitable for the calibration of the online monitoring device.

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