Detection method for voltage fluctuation of electric energy quality

Abstract

The invention discloses a detection method for voltage fluctuation of the electric energy quality. The method comprises: a sensor device is used for converting a primary voltage of a system into a voltage signal suitable for AD conversion; after the AD conversion on the signal, voltage root-mean-square value calculation is carried out by using a cycle of a power frequency, thereby obtaining a voltage effective value; continuous voltage effective values are compared to obtain a peak value U (peak) and a valley value (valley); a microcomputer device calculates duration time, a time mark, and a voltage fluctuation value, starts storage data, processes data, and displays a fluctuation situation to complete a voltage disturbance analysis. Therefore, the high requirement on the microcomputer device hardware by the electric energy quality monitoring is reduced substantially; and the effect of controlling the cost of the electric energy quality monitoring device is good.

Description

technical field [0001] The invention relates to the field of electrical equipment, in particular to a detection method for power quality and voltage fluctuations. Background technique [0002] As a large number of computer-based control equipment and highly automated electrical equipment have been put into use, industrial users have higher and higher requirements for power quality, and even a fraction of a second of abnormality can cause huge damage. loss. According to statistics, industrial users with a high degree of automation generally suffer from 10 to 50 disturbances related to power quality problems every year, and the number of accidents caused by dynamic voltage quality problems including voltage fluctuations accounts for the majority of the total number of accidents. Voltage fluctuation has become one of the main reasons that threaten the reliability of power supply for many important users, and it must be effectively monitored. [0003] To control the power qual...

AI Technical Summary

Problems solved by technology

After a 0.05-30HZ band-pass filter, the DC component and the double power frequency component can be filtered out, so that the detected amplitude modulation wave is the voltage fluctuation component; the full-wave rectification demodulation detection method, the basic principle of the full-wave rectification detection method is The input AC voltage u(t) is full-wave rectified, that is, the absolute value operation is performed and then the fluctuating signal is obtained after the demodulation band-pass filter; the half-wave effective value detection method, the half-wave effective value method uses RMS / DC conversion The converter converts the fluctuating input AC voltage into a pulsating DC voltage, and then obtains the fluctuating signal after demodulating the band-pass filter; there are also wavelet transform methods, etc. These methods have their own advantages and disadvantages, but due to the large amount of software calculations in the above methods The computing speed of the microcomputer device is required to be fast, so there are high requirements for the hardware of the microcomputer device

Furthermore, the DC component and other components can be filtered out through a band-pass filter of 0.05-30HZ, which cannot reflect the real situation of voltage fluctuations.

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