Voltage transformer online verifying system based on SF6 parallel-plate capacitor

Abstract

The invention provides a voltage transformer online verifying system based on an SF6 parallel-plate capacitor. The system comprises a primary voltage sensing unit, a digitalization collecting unit, an optical signal processing unit and an intelligent processing unit. The system is characterized in that the primary voltage sensing unit adopts the SF6 parallel-plate capacitor as a voltage sensing unit and obtains primary voltage signals by detecting currents in capacitance; the primary voltage sensing unit is connected or disconnected with a primary wire through a lifting platform, so that online obtaining of high-voltage signals is achieved; output of the primary voltage sensing unit is connected with the digitalization collecting unit through a shield cable; output of the digitalization collecting unit is digital quantity optical signals transmitted to the intelligent processing unit of the lower-voltage side through the optical signal processing unit. The SF6 parallel-plate capacitor is adopted as a standard mutual inductor, so that online obtaining of the high-voltage signals is achieved. Along with increase of voltage classes, the size and the weight are not increased much, and the system is light due to gas insulation and suitable for a transformer substation site.

Description

technical field [0001] The invention relates to a SF-based 6 The parallel plate capacitor voltage transformer online calibration system is used for real-time accuracy calibration or operating status monitoring of electronic voltage transformers or traditional voltage transformers in substations without power failure. Background technique [0002] As one of the key measurement devices in the power system, the accuracy and stability of the transformer is the guarantee for the safe and stable operation of the power system. In order to ensure the accuracy of the transformer, it is necessary to calibrate the transformer. [0003] At present, whether it is for traditional transformers or electronic transformers, the calibration method mainly adopts the offline calibration method, that is, the line where the transformer to be calibrated is powered off, the transformer withdraws from the power grid, and then uses boost, The current raising device applies excitation to the transfor...

AI Technical Summary

Problems solved by technology

When the voltage level is high (above 220kv), the volume and weight of the electromagnetic voltage transformer increase sharply, so it is not conducive to field use, and the insulation cost rises sharply

In addition, as an inductive device, electromagnetic voltage transformers may generate resonant overvoltage when connected to live buses, which poses certain safety risks

Patents CN102401889A and CN102313879A propose online verification methods for electronic current transformers, but they can only be used for verification of current transformers, not voltage transformers

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