On-line verification system for voltage and current transformers

Abstract

Provided in the invention is an on-line verification system for voltage and current transformers. The system is composed of a standard transformer, a verified transformer, and a PC machine. The standard transformer consists of a primary sensing unit, an acquisition transmission unit, and a main control module; the primary sensing unit is connected to the acquisition transmission unit connected tothe main control module; and the main control module is connected to the PC machine. A voltage or current signal outputted by the primary sensing unit is transmitted to the acquisition transmission unit at a low-voltage side by a shielding cable for signal processing; the outputted signal is transmitted to the main control module by a first fiber; after framing processing, the processed signal asa standard signal is transmitted to the PC machine. According to the on-line verification system, online verification the voltage and current transformers in operation is realized simultaneously by using one set of acquisition transmission unit and main control module, so that the equipment investment is saved substantially and the complexity of the system is reduced.

Description

technical field [0001] The invention relates to an online verification system of a voltage and current transformer, which is used for live verification of the accuracy of the voltage and current transformer in a high-voltage environment. Background technique [0002] The transformer is an important measuring device in the power system, and its measurement accuracy and stability are necessary guarantees for the safe and reliable operation of the power system. Especially with the development of digital substations and smart grids, electronic transformers have been widely used due to their advantages such as wide dynamic range, wide measurement frequency bandwidth, and digital output. However, because it is an emerging technology, the failure rate of electronic transformers in grid-connected operation is significantly higher than that of traditional transformers, which requires shortening the calibration cycle and further improving the accuracy of the calibration system. The t...

AI Technical Summary

Problems solved by technology

The traditional calibration of transformers mostly adopts the method of power outage calibration, which is not only complicated to operate, but also has a long calibration cycle, and will cause power outage losses, which has brought certain adverse effects on the development of the power grid

In addition, most of the traditional calibrators focus on the research of hardware circuits, which have low efficiency and poor versatility

[0003] In response to this problem, many literatures have proposed online transformer calibration methods and systems, but most of them use the FFT algorithm to calculate the electrical parameters of the signal. Due to the influence of harmonics, the traditional FFT algorithm has been unable to meet the accuracy requirements of the on-site live calibration system due to large calculation errors.

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