The sensitivity of relay protection is a key factor to ensure the rapid detection and accurate action of power system faults
but it is not considered in the current distribution network planning. With the integration of distributed generation
the sensitivity of relay protection may be lower than the minimum threshold
which cannot meet the requirements of electrical installation. Therefore
this paper proposes an optimal configuration method of inverter-interfaced distributed generation(IIDG) considering the sensitivity of current protection in unbalanced distribution network. Firstly
the influence of IIDG grid connection on the effective boundary of protection sensitivity is analyzed
and a re-evaluation method of relay protection sensitivity of unbalanced distribution network with IIDG is proposed. Then
considering the sensitivity evaluation constraints of relay protection
a multi-objective IIDG planning model with the maximum IIDG grid-connected capacity and the minimum system comprehensive cost and network loss is constructed. Finally
an example analysis is carried out in the improved IEEE33 node three-phase distribution network. The results show that compared with the optimization method without considering the sensitivity limit
the proposed method improves the average sensitivity of the protection device as the backup protection of the local line by 8.67% and the average sensitivity as the backup protection of the adjacent line by 6.18%
which verifies the effectiveness of the IIDG optimization configuration method proposed in this paper.
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