Power Symmetrical Components as Grid Usage Indicator for Unbalanced Prosumers

Presence of a power generating plant in a three phase customers' installation associated with prosumers may lead to unbalanced bidirectional energy flows at point of connection into relevant distribution system. This study shows that current metrics of energy measurement and registration in three phase revenue meters may fail in a fair charging for the distribution system usage as an inherent phase-to-phase balancer. Alternatively, positive sequence power/ energy measurement based metric is tested and proposed to be employed. The comparative study is performed on representative unbalanced cases, which may be reached by the prosumers naturally and even intentionally and it is shown how much the grid usage as a balancer might be charged more fairly when registering positive sequence power/ energy. Furthermore, it is shown that the increase in the system losses caused by unbalanced prosumers; in comparison to equivalent symmetrical cases of the same net-power; can be estimated from negative and zero sequence power measurement at the point of connection.