On-line monitoring method and system for error state of electronic voltage transformer

Abstract

The invention discloses an on-line monitoring method and system for an error state of an electronic voltage transformer. The method comprises: (1), collecting measurement data of a three-phase electronic voltage transformer in calibrated operation, establishing a residual model of the measurement data by using a principal component analysis method, and calculating a control limit of a measurement data statistical feature quantity under the residual model; (2), collecting measurement data of the three-phase electronic transformer in an operating state, calculating a statistical feature quantity based on the residual model established in step (1), and carrying out comparison of the statistical feature quantity with a statistical control limit to determine whether an error state of the electronic transformer is abnormal; and (3), diagnosing error abnormity of the electronic transformer by using a variable contribution rate method when the statistical feature quantity of the measurement data exceeds the statistical control limit. With the on-line monitoring method and system, the traditional periodic etalon detection way can be avoided; and real-time on-line monitoring of the error state of the electronic voltage transformer is realized.

Description

technical field [0001] The invention belongs to the field of electric power technology, and more specifically relates to an online monitoring method and system for the error state of an electronic voltage transformer. Background technique [0002] The electronic voltage transformer is a new type of voltage signal measurement equipment. Compared with the traditional electromagnetic voltage transformer, it has great advantages in terms of insulation, cost, and measurement bandwidth. The main problem at present is its measurement error. long-term stability. The measurement error evaluation of electronic voltage transformers has long followed the periodic inspection mode. The traditional performance evaluation methods are divided into two types: offline verification and online verification according to whether the operation is live or not. For electronic voltage transformers under high-voltage operation on the primary side, the off-line calibration must be powered off, which a...

AI Technical Summary

Problems solved by technology

For electronic voltage transformers under high-voltage operation on the primary side, the off-line calibration must be powered off, which affects the reliability of its power supply; live calibration is still in the process of technological development, and long-term continuous online calibration of transformers in operation is not Reality

In addition, live calibration is more suitable for fixed-point precise calibration in the case of definite error deterioration, but the number of power transformers in operation is huge, so live calibration is not suitable for long-term operation of electronic voltage transformers with large quantities and wide areas Evaluate

At present, there is no method for long-term effective monitoring of electronic voltage transformers. When a fault occurs, it is difficult to determine the location of the fault point in a timely and accurate manner, which affects the timeliness of fault elimination and the reliability of applications such as protection and metering.

[0003] On the other hand, the essence of the existing performance test, that is, the periodic test, is to conduct time-domain sampling evaluation of the electronic voltage transformer, and evaluate the operating state of the equipment based on the state at discrete time points, so the randomness is large and the effect is not ideal.

To sum up, the traditional regular maintenance is no longer suitable for the development requirements of smart substations. In order to achieve the purpose of long-term continuous monitoring of the operation status of electronic voltage transformers in smart substations, the electronic There is a demand for the error state method of type voltage transformer

Images