Phase Angle Measurement System for Energy Meter Composed of Multiple Single-Phase Measuring Chips

Traditional three-phase electric energy meters adopt the current transformer sampling method, which is susceptible to constant magnetic field interference and easy DC saturation, while the manganese-copper sampling method can well solve the problem of anti-DC component of the electric energy meter. When disturbed by a magnetic field, the energy error jumps, Therefore the all-manganese-copper sampling scheme used on the three-phase electric energy meter mainly faces the problems of electrical isolation of the three-phase metering circuit and the problem of asynchronous sampling of the three-phase signal. This paper introduces a phase angle measurement system composed of multiple single-phase metering chips, including the structure and working principle. It uses the synchronous zero-crossing sampling method to achieve high-precision phase angle measurement, reverse phase sequence analysis and unbalance judgment under three-phase electricity, which has high industrial practical value. Experiments are carried out on the stereotype of the phase angle measurement system. The results have shown that the phase angle runout are all within 0.5°.