How to balance metering accuracy and EMC in concentrators?

The accuracy of concentrator metering is closely related to its EMC performance. Harsh electromagnetic environments can introduce noise and errors. EMC interference affects accuracy through multiple pathways: conducted noise is superimposed on the sampling signal; radiated fields induce error voltage in the sampling loop; and ground noise causes reference drift. Therefore, high-precision metering requires robust EMC design. This necessitates the use of low-noise, high-PSRR LDOs to power the metering chip; differential transmission of the sampling signal coupled with a high-CMRR amplifier; strict PCB layout with ground guard ring protection for the analog section; and the use of filtering and ESD protection (such as ESD5V0D3B) at the interface. Passing EMC testing (such as the IEC 61000-4 series) is essential for verifying the stability of metering accuracy under interference environments. Concentrators with high EMC ratings can maintain metering errors below 0.5% over long periods in complex power grids.