Modelling of three-phase four-wire low-voltage cables taking into account the neutral connection to the earth

Local energy communities (LECs) usually occur at the level of low-voltage distribution networks, which are inherently unbalanced due to single-phase household appliances and distributed generation. To simulate and optimise the behaviour of an LEC, the three phases and neutral must be modelled explicitly. This paper aims at numerically assessing the influence of the modelling of the earth and the connection between the neutral and the earth, in terms of voltages and currents. The simulations are performed on an existing Belgian low-voltage feeder supplying 19 houses, which are all equipped with a smart meter measuring the mean voltage, current, and active and reactive power every minute for each phase. The simulations show that the explicit modelling of the earth using Carson's equations has a moderate effect on the simulation results. In particular, it creates differences in the simulations that are around ten-times smaller than the errors between simulations and measurements.