During its expansion process, the BHP mining company Billiton Tintaya built a new Oxide Plant.

The loads of this plant include two 6-pulse rectifiers and a bank of 5 harmonic filters.

This new plant was to be connected to an electrical system that included a Static Var Convertor (SVC), which generates a high content of harmonic currents.

To guarantee the reliability of its electrical system and to avoid potential parallel resonance situations, BHP Billiton Tintaya requested a harmonic study.

The study determined two operating conditions that would cause a parallel resonance scenario between the new harmonic filters and the existing electrical system.

Parallel resonance in an electrical system with harmonic currents can cause catastrophic damage to electrical and electronic equipment.

EISAC, as the representative of the Canadian company A.COMEAU, made the final report of the study and gave operating recommendations for harmonic filters to avoid parallel resonance conditions, which were implemented by the client.