Multi-Channel On-Line Power Quality Monitoring Instrument Design And Implementation

In recent years, with rapid development of high-technology industry, Precision electronic equipments basing MCU and PC get more and more application in our daily life. They are more sensitive than other normal control equipment. As the same time, the persistent growth of non-linear, asymmetrical loads accessing in the power system. The accidents of power are increasing as the power quality. The development of economy and industry have high requirement to the power system. Building perfect power quality monitoring system has Very Important Significance for power management and improvement.This dissertation introduces characteristics and parameters of the power quality and gives out computing method for those parameters firstly. Then design a power quality monitoring instrument with the kernel of DSP+ARM according to IEC and national standard. This instrument implements real-time on-line measuring and recording to the power system, implements accurate measuring for the parameters of power system such as long-term changes of the voltage and current RMS values, THD factor, harmonics contents, asymmetry factor for 3 phase voltages.This power quality monitoring instrument adopts module-design method. Design ARM-control sub-system, current monitoring sub-system, voltage monitoring sub-system and power supply sub-system as different cards. Those cards could be inserted to a union bottom card. The bottom card has multichannel for current and voltage sub-system. So the power quality monitoring instrument could monitor multichannel current and voltage agilely by the user need.