Distribution Network Optimisation
DIgSILENT PowerFactory incorporates features to assist the user in distribution network optimization, and comprises of the following options:
- Optimal capacitor placement optimizing investment costs and losses
- Open tie optimization optimizing losses, supply reliability or any other user-defined function
- Cable reinforcement optimization (see also "LV Network Analysis Functions)
The user is also able to write is own DPL scripts for other user-defined optimisation functions. Alternatively, DIgSILENT could prepare such scripts upon request.
Optimal Capacitor Placement (OCP)
The DIgSILENT PowerFactory Optimal Capacitor Placement determines the optimal locations, types and sizes of capacitors to be installed in radial distribution networks. Using "Gradient Search" or "Tabu Search" methods, a cost function considering losses, cost of losses, capacitor installation costs, various load profiles, operational voltage limits and available capacitor types and costs is minimized over a period defined by feeder load profiles.
The result of the optimization procedure is a set of locations where capacitors should be installed, which type of capacitor(s) should be installed at each site, and whether or not a switched capacitor is suggested. Proposed capacitors are selected from a user defined capacitor library.
Tie Open Point Optimisation (TOPO)
The DIgSILENT PowerFactory Tie Open Point command will minimize the losses in the network by changing the network topology, while preserving voltage and loading limits. The command is implemented as a DPL-script, which can be used as-is, or which can be adjusted to specific needs. The heuristic method used by the script is applicable to radial distribution networks.
- No parts of the system will be isolated
- No meshed structures will be introduced
- Any switch can be marked as an "optional open tie" and only user-defined optional Open Ties will be opened/closed.
The default script uses a penalty function which optimizes losses when voltage and loading are in range. This penalty function can be easily adjusted to include specific loading limits for network components, short-circuit power limits, transformer tap limits, or any other condition.
Further features:
- New system topology can be accepted/rejected
- Topology changes are made visible in single line graphics
- All changes in switch positions, system losses and penalty functions are reported.