Load flow and selectivity studies
I model your network in DIgSILENT PowerFactory and check by calculation whether it meets the requirements in normal operation and under fault conditions – and where changes are needed: load flow, short-circuit currents, protection coordination and relay settings.
What it is about
Whether a network responds correctly in an emergency is not apparent in normal operation. What matters is that, in a short circuit, only the protective device directly upstream of the fault trips and the rest of the installation keeps running. This requires known short-circuit currents and protective devices that are coordinated with each other.
I model your network with DIgSILENT PowerFactory – backed by more than seven years of practice in network studies and selectivity.
Scope
- Network model from as-built documents, data sheets and nameplate data
- Load flow for normal and special switching states, such as standby generator operation
- Short-circuit calculation to DIN EN 60909-0 (VDE 0102), based on IEC 60909-0:2016, for minimum and maximum currents
- Selectivity verification and protection coordination with time-current diagrams
- Setting recommendations for protection relays and circuit breakers
- Verification of disconnection conditions
Result
You receive a traceable calculation report with the network model, result tables, grading diagrams and settings – and, on request, the PowerFactory model for further use.
Typical situations
- New build, extension or conversion of an installation
- Changes to infeed, transformers or standby generators
- Unwanted or unexplained tripping
- Evidence for the grid operator, insurer or client