Hello to all,

I'm here to ask a question about the energy meter I've developed.

The problem concerns the 3P3W system (neutral line not available).

In this case i can measure two line to line voltages and the phase between them to reconstruct the ideal 3 vectors system(with a ideal phase of 120° between phases).

The main problem is that the alghorithm i developed is too slow on an stm32 M4 @80Mz: in a worst case it takes about 60ms to find the 3 vectors who generate the aquired two line to line voltage measurements and their phase displacement (with an acceptable error).

I searched a lot without founding a method to reconstruct 3P4W from a 3P3W system(unbalanced); the uniqe useful documents i've found is this one: Calculating Line-to-Line Voltages from Line-to-Neutral Measurements with the NI 9225 - National Instruments

and is the same method i developed to construct my slow algorithm(it does a convergence to find the solution to the problem)

The question is: there's somewhere a relation or a library already developed than convert a DELTA three phase system to WYE ones just passing 2 vectors and the phase displacement?

Thanks!

What does this algorithm consist of ?

A Cortex M4 @ 80MHz can do an awful lot of stuff.

Do you use double variables ?

Do you use trigonometric functions (sin, cos), perhaps in double precision ?