Effects of average power factor management in distribution systems with dispersed generation

Electrical systems are inevitably affected by power losses, mainly due to the current flowing through lines and transformers. Currents depend on end-users' power absorption and are strictly related to the overall power factor, resulting from loads, compensating units and distributed generation. The power factor management has a great influence on network power losses and voltage profiles along distribution lines. In the past, before the distributed generation diffusion, the network losses minimization could be obtained by requiring a high average power factor to end-users, evaluating the parameter on the bill period. Differently, nowadays the power factor management for active users is requiring different rules, since the previous statement is no longer valid. The paper investigates inconsistences between local generation and present power factor requirements in the Italian context. Considerations about sizing compensating devices are introduced, in accordance with the recent evolution of connection codes. Losses are compared considering different reference power factors, local generation amount and generators' connection topologies. Results are verified basing on data from meters installed in distribution networks.