Power system voltage sag level evaluation method with consideration of phase jump

Abstract

The invention relates to a power system voltage sag level evaluation method with consideration of a phase jump. The method comprises: S1, a fault condition of Monte Carlo simulation is determined; S2, according to the fault condition determined at the S1, a sag amplitude and a phase jump angle are calculated based on a voltage sag voltage-dividing model; S3, a preliminary statistical table and subdivision statistical table for the sag amplitude and phase jump are formulated based on the calculation results obtained by the S2; and S4, the calculation results are processed and thus are expressed graphically with consideration of the amplitude and phase jump. According to the invention, uncertain factors of an impedance angle between the fault line impedance and the system impedance, a fault distance, a fault type, and a conversion effect on a sag type by a transformer are taken into consideration; multi-times short-circuit calculation is carried out based on a Monte Carlo simulation method and a sag amplitude and a phase jump of a concerned node are calculated; the statistical tables and statistic graphs that consider the sag amplitude and phase jump are introduced; and the results are expressed in graphs to realize direct observation and detailed comparison.

Description

technical field [0001] The invention relates to the field of power system power quality evaluation, in particular to a power system voltage sag level evaluation method considering phase jumps. Background technique [0002] Voltage sag is an inevitable power quality disturbance event in the power system, and is considered to be the most serious power quality problem. As more and more electrical equipment sensitive to voltage sags, and intermittent power sources such as wind power and solar power are connected to the grid, the economic losses and social impact caused by voltage sags are increasing, which has caused power supply companies and power users and extensive attention from academia. Evaluating the voltage sag level of the power system or concerned nodes can help power supply companies and power users to predict potential sag hazards and take necessary measures to avoid or mitigate the risks caused by voltage sags. [0003] The voltage sag assessment can be divided i...

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Problems solved by technology

This method also cannot rule out the individuality of a specific monitoring period, and the result only has amplitude and frequency information, which cannot reflect the phase jump

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