This page collects reference datasets of distribution networks in the city/suburb/countryside for different regions of the world.
REDS: REpository of Distribution Systems
http://www.dejazzer.com/reds.html
Lists 8 radial distribution system datasets, focus seems to be on US.
IEEE PES Distribution Test Feeders
http://www.ewh.ieee.org/soc/pes/dsacom/testfeeders/index.html
INEXIS Gas and Electricity Network Open Data
https://www.enexis.nl/over-enexis/open-data