Load Flow Analysis

DIgSILENT PowerFactory offers a range of load flow calculation methods, including a full AC Newton-Raphson technique (balanced and unbalanced) and a linear DC method. The enhanced non-decoupled Newton-Raphson solution technique with current or power mismatch iterations, typically yields round-off errors below 1 kVA for all buses. The implemented algorithms exhibit excellent stability and convergence. Several iteration levels guarantee convergence under all conditions, with optional automatic relaxation and modification of constraints. The DC load flow, solving for active power flows and voltage angles, is extremely fast and robust (linear system; no iterations required).


  • Balanced and unbalanced load flow for coupled AC and DC grids
  • Meshed DC supergrid load flow analysis
  • State-of-the-art numerical solvers for fast and robust convergence from arbitrary starting-points
  • Active/reactive power and voltage regulation options, such as SVC, shunt and tap controllers
  • Station- and network control features, including Q(U)-, cosphi(P)-, Q(P)-, and droop
  • Local- and remote control options
  • Secondary and primary control, inertial response
  • Distributed slack by load and generation, including interchange schedules
  • Consideration of active and reactive power limits, including (voltage-dependent) generator capability curves
  • Accurate modelling of induction machines
  • Voltage dependent load models
  • User-definable load flow controller models
  • Simple load/generation scaling, as well as automated feeder load scaling (balanced and unbalanced)
  • Determination of "power at risk"
  • Consideration of temperature dependency
  • Reporting against continuous and short-term thermal ratings, which can optionally include dependencies on ambient temperature, wind speed or solar irradiance