Abstract:

Resistance capacitor series rectification is a common circuit used to provide DC power supply.When the circuit is used as the working power supply of single-phase electronic watt hour meter (WHM for short),the resistance is burned out frequently in operation.Through the analysis of theoretical and measured data,it is identified that the high-order harmonic current generated by nonlinear load flows through the working power supply of the electric energy meter,which causes the fundamental voltage distortion,and changes the operating parameters of the capacitor element,so as to increase the loop current,which is the main reason for the resistance burnout.In order to solve this problem,a high-order harmonic wave trap is connected in series in the power supply circuit of the WHM to ensure the safe and reliable operation of the WHM.

Key words: working power supply, harmonic source, resistance burnout, wave trap