ELECTROMAGNETIC SIMULATION FOR POWER, GROUNDING AND LIGHTNING PROTECTION SYSTEMS
XGSLab is one of the most powerful software of electromagnetic simulation for power, grounding and lightning protection systems and the only software on the market that takes into account IEC, EN and IEEE Standards in grounding system analysis.
XGSLab includes the modules:
1.GSA (GROUNDING SYSTEM ANALYSIS) for basic application with underground systems
2.GSA_FD (GROUNDING SYSTEM ANALYSIS in the FREQUENCY DOMAIN) for general applications with underground systems
3.XGSA_FD (OVER AND UNDERGROUND SYSTEM ANALYSIS in the FREQUENCY DOMAIN) for general applications with overhead and underground systems
4.XGSA_TD (OVER AND UNDERGROUND SYSTEM ANALYSIS in the TIME DOMAIN) for general applications with overhead and underground systems
5.NETS (NETWORK SOLVER) solver for multi-conductor and multi-phase full meshed networks
XGSLab integrates the module SRA (SOIL RESISTIVITY ANALYSIS) and XGSA_TD integrates also the module FA (FOURIER ANALISYS direct / inverse).
The XGSLab application field is so wide because the implemented model is for general use and solves the Maxwell equations in non stationary conditions taking into account the earth lack of homogeneity by the Green functions, the earth reaction by the Sommerfeld integrals and moving from the frequency to the time domain by means the Fourier transforms.
All modules are integrated in an “all in one” package and based on a hybrid calculation method (or “PEEC” method) which considers transmission line, circuit and electromagnetic theory combined into a single calculation model. Hybrid methods join the strong points of the other methods and are well suited for engineering purposes because they allow the analysis of complex scenarios including external parameters such as voltages, currents and impedances. For these reasons, XGSLab can be considered a real laboratory.
GSA is a widely utilized and recognized module for earth grid calculations and design including soil resistivity analysis.
GSA is based on the equipotential condition of the electrodes and can analyse the low frequency performance of grounding systems composed by many distinct electrodes of any shape into a uniform or multilayer soil model.
GSA can import earth grid data from “dxf” files, delivering professional numerical and graphical output useful for investigation of GPR and leakage current, earth potential, touch and step voltage distributions.
GSA can also export data and results in “dxf” files and this allows a full interactivity with CAD tools.
GSA_FD is a module for earth grid calculation and design in the frequency domain, including soil resistivity analysis and represents the state of the art of grounding software.
- Also useful for magnetic field and electromagnetic interference evaluations.
- GSA_FD adopts a rigorous approach to the study of very large grounding systems where experience shows that the horizontal variations of the soil resistivity makes inefficient sophisticated soil models (multilayer). In these cases, an accurate electric model of the electrodes including self and mutual impedances is fundamental. These parameters can be known with greater certainty than the soil resistivity because in the frequency range we are interested in, these parameters depend weakly on the soil properties.
- With the equipotential condition hypothesis, the maximum touch voltage is widely underestimated, and this may result in grounding system oversizing with additional cost sink even 50%. Neglecting the mutual impedances can lead to errors over the 20% in calculations. GSA_FD can allow a significant cost saving in grounding system construction and materials.
- GSA_FD can be used in the frequency domain range from DC to 10 MHz and then the calculation accuracy gradually decreases but results are often reliable over 10 MHz and positive tests have been made up to 50 MHz..GSA_FD takes into account the frequency dependence of soil parameters and allows setting the used model.
- Analyse grounding systems composed by many distinct electrodes of any shape, size and kind of conductor (solid, hollow or stranded and coated or bare) into a uniform, multilayer or multizone soil model.
In DC conditions GSA_FD is a good tool for cathodic protection and anode bed analysis with impressed current systems.
GSA_FD can also calculate magnetic fields due to grounding systems or cable, and electromagnetic interference (induced current and potential due to resistive, capacitive and inductive coupling) between grounding systems or cable and pipeline or buried electrodes in general.
XGSA_FD extends the GSA_FD application field to the overhead systems.
XGSA_FD can also manage catenary conductors and bundle conductors too and can take into account sources where potential or leakage current and longitudinal current are known and independent by other conditions. For these reasons
- XGSA_FD is probably one of the most powerful and multipurpose tools on the market for these kind of calculations.
In addition to GSA_FD, XGSA_FD can calculate electromagnetic fields and interference between over and under ground systems (for instance between overhead or underground power lines and installation as pipelines, railways or communications lines) and also the fault current distribution.
- Electric and magnetic fields are calculated by means the Jefimenko’s equations and then taking into account the propagation effects.
- XGSA_TD is a powerful module which extends the XGSA_FD application field to the time domain.
In this regard, XGSA_FD uses the so called “frequency domain approach”. This approach is rigorous and allows considering the frequency dependence of soil parameters.
- As known, a transient can be considered as the superposition of many single frequency waveform calculated with the forward Fourier transforms.
- Using the frequency domain model implemented in XGSA_FD it is then possible calculate a response for each of these single frequency waveforms.
The resulting time domain response can be obtained by applying the inverse Fourier transform to all these responses.
NETS is a very flexible tool to solve full meshed multi-conductor and multi-phase networks and is based on the multi-phase system representation.
This approach is general and overcome the classic method of symmetrical components and can be used to represents power systems as multi-conductor networks enabling the consideration of asymmetrical and/or unbalanced systems also in presence of grounding circuits or circuits with a different phases number.
- The network components (generators, lines, cables, transformers, loads, switches, faults ..) are represented with multi-port cells and the connection between cells is obtained by means of multi-port buses.
- NETS calculate lines, cables and transformers parameters starting on data normally available in commercial data sheet.
- NETS can be used to solve transmission and distribution networks in steady state or fault conditions and to calculate potentials and currents or short circuit currents (three phases, phase to phase, phase to phase to earth, single phase to earth) with or without fault impedances.
In particular, NETS can be used for the calculation of the fault current distribution in power networks.
NETS is then a very useful tool to calculate data input for others XGSLab modules (for instance the split factor or the current to earth) and represents the link between XGSLab and the most diffused commercial software for power systems analysis.