Measuring method and measuring apparatus of subsynchronous and supersynchronous harmonic phasors

Abstract

The invention discloses a measuring method and measuring apparatus of subsynchronous and supersynchronous harmonic phasors. The method comprises the following steps: acquiring electrical signals so as to generate digital signals; performing filtering processing on the digital signals so as to obtain initial subsynchronous harmonic waves and/or supersynchronous harmonic waves; performing harmonic wave adaptive detection through DFT or FFT so as to obtain an initial frequency; according to the initial frequency, designing a filter so as to extract each subsynchronous harmonic wave and/or each supersynchronous harmonic wave; carrying out correction calculation by use of the phasor correction measuring algorithm so as to obtain the frequency, the amplitude and the phase of corresponding harmonic waves; and according to the gain and phase shift of the filter, performing amplitude compensation and phase compensation on the phasors so as to obtain a three-phase phasor of each subsynchronous harmonic wave and/or each supersynchronous harmonic wave. The measuring method provided by one embodiment of the invention can accurately measure the phasors of the subsynchronous and supersynchronous harmonic waves, thereby being applied to wide-area dynamic monitoring, analyzing, control and protection of subsynchrono resonance/oscillation of a power system.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to a method and device for measuring sub-synchronous and super-synchronous harmonic phasors. Background technique [0002] In related technologies, existing synchrophasor-based power system dynamic monitoring devices and systems, such as PMU (phasormeasurement unit, phasor measurement unit) and WAMS (wide-area measurement system, wide-area measurement system) cannot meet sub-synchronous and super-synchronous The monitoring of harmonics is required because: [0003] 1) The existing PMU aims to measure the fundamental phasor, but does not specifically consider the influence of subsynchronous and supersynchronous harmonics, and in order to improve the measurement accuracy of the fundamental phasor, usually other fractional and integer harmonics need to Filtering, resulting in the inability to accurately reflect the dynamics of sub-synchronous and super-synchronous harmo...

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Problems solved by technology

[0002] In related technologies, existing synchrophasor-based power system dynamic monitoring devices and systems, such as PMU (phasormeasurement unit, phasor measurement unit) and WAMS (wide-area measurement system, wide-area measurement system) cannot meet sub-synchronous and super-synchronous The monitoring of harmonics is required because:

[0003] 1) The existing PMU aims to measure the fundamental phasor, but does not specifically consider the influence of subsynchronous and supersynchronous harmonics, and in order to improve the measurement accuracy of the fundamental phasor, usually other fractional and integer harmonics need to Filtering, resulting in the inability to accurately reflect the dynamics of sub-synchronous and super-synchronous harmonics;

[0004] 2) When there are sub-synchronous and super-synchronous harmonics in addition to the fundamental component in the signal, the fundamental phasor obtained by the existing PMU will be modulated by the complementary frequencies corresponding to the sub-synchronous and super-synchronous, although it can be obtained from the fundamental The presence of sub-synchronous and super-synchronous harmonics can be observed in wave phasors, but due to the characteristics of the fundamental wave phasor algorithm and the frequency at which the fundamental wave phasor is uploaded to the monitoring center (WAMS master station) is limited (usually 50Hz in China , 100Hz for a few systems), resulting in attenuation or aliasing of sub-synchronous and super-synchronous harmonics, resulting in inaccurate information

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