High precision voltage transient event detection and wave-recording method

Abstract

The invention discloses a high precision voltage transient event detecting and wave recording method, which comprises synchronizing a voltage signal collected by a digital signal processing (DSP) plate to a voltage signal of 50Hz via a software, and frequency doubling every frequency current voltage signal by four times; judging the voltage effective value deviation of sampled data, subsequently determining the effective value in a sequence of 1 frequency current, 1 / 2 frequency current, 1 / 4 frequency current, and 1 / 8 frequency current if the voltage effective value deviation exceeds 2%, recording voltage extreme value, accumulated duration time and corresponding voltage waveform of an event that the voltage effective value deviation exceeds 10% via an event recording program, making a time mark, and calculating event time; and writing the recorded event and corresponding waveform thereof into an event chain table, carrying out waveform recording via a micro control (MCU) plate, and storing in a hard disk memory. By adopting software synchronization and software frequency doubling technique, the high precision voltage transient event detecting and wave recording method can accurately the voltage transient event (not smaller than 5ms) and record wave, with event duration time precision up to 2.5ms.

Description

technical field The invention relates to a voltage transient event detection and wave recording technology, in particular to a high-precision detection and wave recording method of a voltage transient event in a power system and a power user distribution network. Background technique Voltage transient events in power systems and power user distribution networks refer to voltage swells, sags, and short-term interruption events. Detection and recording mainly record the event occurrence time, duration, voltage drop amplitude, and event waveform. Voltage sag means that the effective value of voltage drops to between 10% and 90% of the rated voltage, and lasts for 0.5 cycles to several seconds; voltage swell means that the effective value of voltage rises above 110% of the rated voltage, and lasts for 0.5 cycles to A few seconds; a short interruption means that the effective value of the voltage drops below 10% of the rated voltage, and the duration lasts from 0.5 cycles to 1 mi...

AI Technical Summary

Problems solved by technology

Most of the existing voltage transient event detection and wave recording methods use half-wave effective value for detection and wave recording, and the half-wave effective value algorithm for monitoring transient events mainly has the following shortcomings: For voltage transient events that last less than one cycle The duration of the event and the range of voltage rise and fall cannot be accurately calculated and detected, and the accuracy of monitoring the duration of transient events can only reach 20ms, which is difficult to meet the requirements of power system fault analysis

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