Acceptable capacity of PV system according to capacity of NaS battery in a microgrid under 30 min Power balancing control

On constructing a microgrid, it is essential to balance capacity of photovoltaic power generation (PV) systems and storage batteries in accordance with a control target. In the present study, we constructed a simulation model of energy control system in the microgrid. By using this model, we investigated the acceptable capacity of PV systems according the capacity of NaS battery for keeping the target supply-demand power imbalance over 30-min. within ±3 %. Under keeping the control target of power imbalance over 30 min. within ±3 %, we verified the relation between acceptable capacity of PV systems and NaS battery in a microgrid as follows. (1) the minimum required capacity of NaS battery in relation to the capacity of installed PV systems (330 kW) is of the order of ±20 kW, (2) the acceptable capacity of PV systems in relation to the capacity of installed NaS battery (±500 kW) is of the order of 890 kW. Moreover, we clarified the constrained conditions which impact to the power balancing in the microgrid according to the acceptable capacity of the PV systems.