This 0.0168 6323 / – 0.0139 9308 /

This include medium to high voltage grids with up to 300 nodes. Test feeders are different in USA than European standards. Generic profiles for load values and environment household parameters are given. IEEE models cannot evaluate grid control strategies. Also few models are publically available. None of scenarios are for the topology and parameters of suburban grid.  Two prominent methods to model households are top-down and bottom-up. Top-down models are suitable for simulating several hundreds of households. OSH is building EMS used to control real buildings. OSH is simulation framework for virtual buildings. It can simulate all energy flows like hot water, cold water and natural gas. For household energy optimization it uses genetic algorithm.  Households were simulated with resolution of one second. Per second power consumption decide either optimization was necessary or not. Power flows were calculated using Newton-Raphson algorithms. In scenario 1 no in-house optimization was done. In scenario 2 EMS were used to enhance consumption rates. The simulation period was in July only one week.  Radial Grid Two different grid topologies were used to represent both scenarios. First one shows radial nature, all switches. The upper part shows radial grid and lower part shows values for meshed grid. Each single bus values were calculated to represent whole simulation time. All the buses and time slots were computed using grid values. For showing standard deviations with respect to time slots ?max was used. Feature Scenario I Scenario II voltage time / bus voltage time / bus (pu) (min) / (#) (pu) (min) / (#) abs-min 0.9740 1310 / 62 0.9751 5413 / 82 bus-min 1.0000 – / 1 1.0000 – / 1 time-min 0.9884 8415 / – 0.9882 5416 / – grid-mean 1.0032 – / – 1.0030 – / – bus-?max 0.0141 – / 82 0.0137 – / 82 time-?max 0.0168 6323 / – 0.0139 9308 / – grid-? 6.2E-5 – / – 5.7E-5 – / – abs-max 1.0576 6323 / 103 1.0460 9268 / 82 bus-max 1.0070 – / 104 1.0069 104 / – time-max 1.0269 6323 / – 1.0219 2060 / – abs-min 0.9833 5429 / 103 0.9822 5416 / 73 bus-min 1.0000 – / 1 1.0000 – / 1 time-min 0.9888 8415 / – 0.9891 6930 / – grid-mean 1.0032 – / – 1.0030 – / – bus-?max 0.0109 – / 104 0.0104 – / 103 time-?max 0.0142 6323 / – 0.0111 9308 / – grid-? 4.1E-5 – / – 3.8E-5 – / – abs-max 1.0440 6323 / 104 1.0339 9308 / 102 bus-max 1.0051 – / 104 1.0049 104 / – time-max 1.0267 6323 / – 1.0209 9308 / –At the end of feeders with high load density highest voltages were measured. Meshed GridBoth scenarios were also simulated with the meshed grid. All the switches were closed and then bus voltages were computed to compare both topologies. In 1st scenario, the maximum increase in voltage was reduced to 4.4% and the maximum voltage decrease was reduced to 1.67%. In short, the simulation results show that suburban low voltage grids are stable, even with high DG penetration. The single weak spot in the presented scenario was a transformer with 2 kva capacity per household. ConclusionA comprehensive bottom-up simulation of households and their interconnecting LV power grid was presented. It covers 101 one family households that are connected to a 106-bus grid. Simulations showed it’s possible to relieve the load on the grid and improve its state with increasing self-consumption. Future work will include additional LV power grids that will cover other scenarios. Further models will be used to develop and evaluate sophisticated smart grid applications.  

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