Capacitive power equipment medium loss on-line monitoring method and device

Abstract

The invention discloses a method and device for on-line monitoring of the dielectric loss of capacitive power equipment. A high-precision micro-current sensor is socketed on the grounding wire of the equipment, and a resistance voltage divider is installed on the low-voltage output of the voltage transformer of the substation. Analyze and process and display results to realize online monitoring of leakage current signals of power equipment; the device is composed of high-precision micro-current sensors, resistor dividers, signal cables, signal conditioners, data acquisition cards, digital IO cards, computers, etc. The method and device of the present invention can calibrate the phase offset caused by the hardware according to the leakage current value of the equipment, can eliminate the abnormal value of the measurement, and use the spectrum analysis method and the correlation method to calculate the dielectric loss. The above method ensures the accuracy of the measurement , the device also calculates the mean square value of the leakage current of the power equipment. The device implements data management through ORACLE, has the function of historical query, and also has functions such as report printing, threshold alarm, and remote query.

Description

technical field [0001] The invention belongs to the technical field of on-line monitoring of electric power equipment, and relates to a method and a device for on-line monitoring of dielectric loss of capacitive electric equipment. Background technique [0002] With the rapid development of the national economy, the requirements for the reliability of power system operation have been further improved, and the online monitoring technology of power equipment is an important way to improve the reliability of power operation. Capacitive power equipment occupies a large proportion in the power transmission and transformation system, such as transformers, cables, bushings, etc. These power equipment are aging due to factors such as electricity, heat, machinery, and the environment during operation. fall, becoming a potential accident hazard. Dielectric loss is an important insulation index that reflects the insulation status of capacitive power equipment. On-line monitoring of di...

AI Technical Summary

Problems solved by technology

Existing electric equipment dielectric loss electrification measurement devices use single-chip microcomputers as the core of calculation and processing, such as Chinese Patent Publication No. 1185585 and Chinese Patent Publication No. 2200823, which are limited by the functions of single-chip microcomputers, resulting in relatively simple functions of the devices without advanced data management capabilities and Remote data query function, while the digital signal processing ability is poor, it is difficult to filter out strong electromagnetic interference signals on site

Chinese Patent Publication No. 1188237 discloses a method and device for measuring the dielectric loss of capacitive electrical equipment with electricity. The device adopts the principle of balanced bridge and combined sampling of capacitance and resistance, which can improve the measurement accuracy, but the device needs to be adjusted manually. Suitable for real-time automatic monitoring

[0004] With the rapid development of the national economy, there is an urgent need to improve the reliability of power operation. In the past, the detection device with single-chip microcomputer as the processing core has simple functions and low automation level, so it is difficult to meet the increasing requirements of the power operation department for equipment automation.

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