Influence of Fast Fluctuation of Dynamic Load Current on Dynamic Error of Smart Electricity Meter

摘要

This paper is concerned with the influence of the dynamic error of smart electricity meter (here in after referred to as smart meter) in the condition of dynamic current. Firstly, the random fluctuation of the dynamic load current amplitude is analysed and two typical run lengths are found out. Secondly, dynamic models of every unit in the smart meter are established. These models reflect the dynamic transfer relationship between the input and output signals of every unit. Thirdly, the dynamic errors of smart meter are simulated and analysed in the condition of dynamic current with typical run lengths. Finally, we verify the simulation results by experiment with On-Off-Key (OOK) dynamic test current signal. The result shows that the gain feedback switching of programmable gain amplifier (PGA) unit leads to the dynamic current signal clipping in dynamic current conditions, and the signal clipping is the main source of the dynamic error of smart meter. Moreover, the dynamic error of the short-time run length of dynamic current is larger than the long-time run length.