Polyphase Shunt Metrology with Isolated AFE Reference Design

1 января 2018

This reference design implements a class 0.5% three-phase energy measurement system with isolated shunt sensors by using metrology analog frontends( AFEs). The metrology AFEs sense the voltage and current for each phase, calculate the metrology parameters for the phase, and then send out the calculated parameters to a host microcontroller using a UART port that is digitally isolated. The capacitive isolation technology used to isolate the UART pins along with the cap-drop power supply used to power the metrology AFEs make this reference design a transformerless design that is immune to magnetic tampering. In addition, because metrology parameters are calculated locally at the metrology AFEs instead of at the Host microcontroller, less CPU bandwidth is needed from the Host for performing metrology calculations.

Особенности

Class 0.5% three-phase metrology with galvanically isolated shunts using isolated, low cost current and voltage measurement AFE Distributed computing: metrology parameters calculated locally at each phase and sent to host microcontroller Reinforced isolation of 5kVrms and 8KV peak Magnetically-immune cap-drop high-side power External crystals or clock not necessary for metrology AFE Phase sequence detection