Voltage drop in lv grids

[piaulous]

Currently cable types in synthetic low-voltage grids are chosen only based on the cumulative load of a feeder while the feeder's voltage drop is not checked. This might explain the relatively high number of grids not converging during power flow analysis.

As a new method, the already implemented equation for calculating the longitudinal voltage in medium-voltage half-rings should be applied to low-voltage grids by

1. Finding the longest path of a feeder
2. Aggregate all loads of the feeder's leaves / branches to the longest path nodes
3. Calculating the longitudinal voltage drop of the longest path
4. Iteratively determine a low-voltage cable type which satisfies the max. allowed voltage drop

Also the chosen low-voltage standard cable type / load factor to calculate the number of feeders a low-voltage grid is partitioned to might effect the voltage drop and could be adapted to get more feeders per grid.

[piaulous]

Current investigations (checked up for 2 MVGDs) indicate reinforcement requirement due to exceeded critical voltage drop for around half of all lv feeders after reinforcement based on the feeder's load already has been done.
This seems like a rather high number. Maybe its best to adapt config parameters such that a higher number of feeders or a smaller size of lvgds can be achieved.