Optical fiber digitized remote phase-checking system and phase-checking method thereof

Abstract

The invention discloses an optical fiber digitized remote phase-checking system and a phase-checking method thereof. A digital phase meter is respectively connected with two analog-to-digital conversion modules or two intelligent substation merging units through optical fibers. Checked voltage and reference voltage are respectively inputted into the two analog-to-digital conversion modules, and voltage analog quantities are converted into digital sampling values, which are transmitted to the digital phase meter via the optical fibers; the digital phase meter receives and filters the digital sampling values, calculates the fundamental wave quantities of the sampling values, and compares the amplitudes and phases of the two voltages in order to determine the amplitude and phase relation between the two voltages, and thereby the phase, phase sequence and polarity of the checked voltage are checked. Since the invention utilizes the analog-to-digital conversion modules to convert the voltage analog quantities into the form of digital quantities before transmission and the digital phase meter to synchronize, filter, calculate and process the voltage digital quantities in other ways, the phases of the voltages are checked, the potential safety hazards of conventional phase checking are eliminated, the accuracy and efficiency of phase checking are increased, and the invention is compatible with intelligent substation phase-checking tests.

Description

technical field [0001] The invention relates to a remote phase nuclear phase technology based on digital sampling and optical fiber transmission, which is suitable for remote phase nuclear phase tests during commissioning tests of conventional substations, intelligent substations and DC converter stations, and belongs to the technical field of electric power automation. Background technique [0002] The nuclear phase is one of the necessary test items in the process of substation commissioning. It is used to verify the correctness of the primary wiring and voltage secondary circuit of the newly built or renovated substation. It is a necessary step to ensure the correct operation of functions such as relay protection, measurement and control, and measurement. It is also the premise to ensure the safe and reliable operation of the substation. [0003] The conventional phase verification method is: connect two voltage analog quantities that need phase verification to the volta...

AI Technical Summary

Problems solved by technology

This method of using long cables to check phases has brought certain safety hazards and measurement errors: when the cable is broken or the insulation is lowered, someone will accidentally touch the cable, which will cause certain personal injury; when the cable is broken or the insulation is lowered, It may cause a short circuit to the ground, which may cause the voltage circuit breaker to trip, and may also cause damage to the secondary cable or PT; when the insulation of the cable to the ground is reduced, it may cause the leakage of the cable to the ground, resulting in inaccurate measurement; A certain voltage drop, resulting in inaccurate measured pressure difference

In the DC converter station, there are a lot of harmonics, and the multimeter or voltmeter has no filtering function. When using the conventional method to check the phase, the result deviation is often due to the interference of the harmonics, which affects the judgment.

In smart substations, since the voltage and current sampling has been digitized, it is no longer possible to use a multimeter or voltage for testing, and the conventional phase verification method is no longer applicable

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