Revenue Metrics Ability to Correctly Register Bidirectional Active Energy Flows in Active Distribution Networks

Distributed generation in combination with switching adaptive loads providing optimized energy management in the prosumers' installations results in bidirectional active energy flow. If the changes are frequent or even periodical with period close to the aggregation time window of standard revenue meters, the deviation from really correct readings in export and import registers might be significant. Subsequently, the concepts of allocating the costs of distribution system operation to the network users might fail. The paper presents an overview of the active energy metrics, which are either already implemented in revenue meters or derived from other applications of active power measurement. In the paper, a set of test scenarios is proposed and analysis of the metrics ability to account for the active energy flow and, subsequently, to correctly distinguish between active energy import and export is carried out. The results show the limitations of each metric considered as a function of the frequency/rate of changes in the active energy flow direction. It is demonstrated that the performance of the most adopted metrics exhibits potentially the largest mismatch between the measurements and the actual active energy flows.