Background
The presence of increasingly large power-electronics equipment (inverters, converters, motors with variable-frequency drive supplies, etc.) and power consuming IT devices (data centres) implies the circulation of significant harmonic currents in modern distribution grids. At the same time, voltage quality of a grid is a critical objective which is subject to specifications and standardizations.
Requirement
In addition to raising the effective value of the current circulating in the grid, these harmonics if generated at certain orders and at sufficient amplitude, can create significant overvoltage at specific points on the grid and can destroy equipment, particularly electronic and IT equipment.
Service principles
Capsim carries out harmonic studies thanks to the following :
- Evaluation of the harmonic currents generated by the loads according to their characteristics
- Calculation of harmonic propagation using numeric simulation tools
- Analysis of the impedance vs frequency variation at several points on the grid to highlight resonance risks
Results
It is thus possible to do the following :
- To measure the amplitude of the harmonic currents circulating in each branch and the rate of harmonic distortion of the voltages at each point on the grid
- To propose and validate solutions for harmonic filtering and thus decreasing harmonic levels on the grid
Capsim performs harmonic calculations with the following software: ETAP, PowerFactory, Cyme-Harmo, PSS-E and EDSA. CAPSIM also uses tools such as PSIM, EMTP, PSCAD, and Matlab-Simulink in order to evaluate harmonic spectra of specific electrical equipment.
