Method and device for compensating for harmonic voltage measurement error of capacitor voltage transformer (CVT)

Abstract

The invention provides a method and a device for compensating for a harmonic voltage measurement error of a capacitor voltage transformer (CVT). The method comprises the following steps of (1) establishing a CVT equivalent circuit model, and specifically converting the used CVT into the corresponding equivalent circuit model; (2) calculating a transfer function, specifically based on the CVT equivalent circuit model, calculating an equivalent impedance value of each port step by step, then calculating the transfer function, and obtaining frequency characteristics; and (3) compensating for themeasurement error, specifically according to the CVT frequency characteristics, correspondingly compensating for the harmonic measurement result of the CVT. The invention further provides the device for compensating for the harmonic voltage measurement error of the capacitor voltage transformer (CVT), in order to implement the above method and export the monitoring data after compensation. By adopting the method and the device provided by the invention, the problem of large measurement errors of the CVT is solved, and the accuracy of harmonic voltage measurement of the CVT is improved.

Description

technical field [0001] The invention relates to the technical field of power system monitoring, in particular to a method and device for compensating harmonic voltage measurement errors of a capacitive voltage transformer (CVT). Background technique [0002] In the power system, voltage measurement is an indispensable basic parameter measurement. According to the working principle, voltage transformers can be divided into two categories: electromagnetic type and capacitive type. The earliest 110~220kV level power plant step-up stations and step-down substation busbars mostly use electromagnetic voltage transformers (referred to as TV) as equipment for measuring voltage and power, but electromagnetic voltage transformers have inherent defects, such as easy contact with The distributed capacitance of the line produces ferromagnetic resonance, which can only be used for measuring voltage, power and power generation protection. Although it has been modified many times, the acci...

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Problems solved by technology

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a method and device for compensating the measurement error of the harmonic voltage of a capacitor voltage transformer (CVT), which realizes the compensation of the measurement error of the CVT harmonic voltage and solves the problem of the measurement error of the CVT harmonic voltage. The problem of large errors improves the accuracy of CVT harmonic voltage measurement

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