在Power quality monitoringdeviceDuring the operation of the system, the increasing impact of power quality issues has brought significant harm to the stability of the power grid operation. In the case of rapid changes in the effective value of voltage, voltage fluctuations occur. The waveform of voltage fluctuations belongs to the amplitude modulation wave of power frequency voltage, so it is necessary to extract the fluctuation signal in order to accurately measure voltage fluctuations and flicker. At present, the commonly used detection methods for voltage fluctuations are synchronous detection, rectification detection, and effective value detection.

When applying synchronous detection and rectification detection, it is necessary to retain the amplitude modulation wave through bandpass filtering, but compared to synchronous detection, rectification detection has certain errors. The detection of voltage flicker is mainly divided into three parts, which need to be adjusted for voltage input adaptation; Simulating the visual system requires a model; The statistical analysis of the instantaneous flicker visual sensitivity measured by power quality monitoring. The quality of electrical energy supplied to users through the public power grid refers to the quality of AC power in the power grid line.

Power quality issues are mainly caused by the terminal load side. For example, impulsive reactive loads can cause severe fluctuations in the voltage of the power grid, reducing the quality of power supply. The number of rectifiers, variable frequency speed control equipment, electric arc furnaces, electrified railways, and various power electronic equipment used in the distribution network of various user terminals in the power grid system is constantly increasing. The impact on the electricity network, or in other words, electricity pollution. Formation of voltage instability, overvoltage, harmonic generation, etc. Harmonics reduce the power required for the production, transmission, and use of electrical energy, causing overheating, vibration, and noise in electrical equipment, aging insulation, shortening lifespan, and even causing malfunctions or burning.

Harmonics can also cause parallel resonance or series resonance in some parts of the power system, expanding the harmonic content and causing equipment such as capacitors to burn out. The non-linear, impulsive, and unbalanced electricity consumption characteristics of these loads pose a serious pollution to the quality of power supply. Therefore, eliminating the problem of high-order harmonics in the power supply and distribution system has a very active meaning for improving power quality monitoring and ensuring stable and economic operation of the power system.