Summary: | Aiming at the problem of safe operation in the medium voltage distribution network with neutral point grounding through small resistance, the distribution network model was built, and on this basis, MW-level photovoltaic (PV) system, doubly fed Induction generator (DFIG) wind turbine, permanent magnet synchronous generator (PMSG) wind turbine and energy storage device was connected respectively in this paper. The ground current and earth potential rise was studied when the power was delivered by mistake. The simulation results show that in the system with neutral point grounding through small resistance, whether it is the traditional or the active distribution network, the three-phase power delivery method is more able to ensure the personal safety of power grid operators. However, The access to distributed generator (DG) in the distribution network will have a greater impact on ground current and earth potential rise in the case of three-phase power delivery. Especially when the ground current and earth potential rise will increase after DG connected to distribution network, which is still likely to pose a threat to personal safety and needs further research.
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