رضا همتی

This paper presents a new concept for district energy (DE) systems using central battery storage and decentralized hybrid renewable systems. The proposed DE consists of five buildings integrated with centralized 300 (V), 6.5 (A.h) batteries, locally distributed generations such as 8.5 (kW) wind turbines and 10 (kW) solar cells rated at 110 (V) and three-phase loads. The central battery can be connected to each home for exchanging power. To increase the resilience, the proposed control system connects home 1 to the external 380 (V) and 50 (Hz) network when the battery is operating above the limited power (ie, 50 [kW] for this case study). The connection to the external grid is done by assessing and confirming a set of necessary conditions. The proposed integrated control system for DE is designed to achieve the following objectives: maximum power extraction from local wind/solar units by maximum power point tracking, optimal charge-discharge process for central battery, connecting DE to the upstream network under outages and supplying the loads under all operating conditions. These goals are investigated by implementing six different scenarios of performance. In scenario 1, wind and solar units produce 6.6 (kW) and 24 (kW), respectively. Therefore, to feed the total load of 42.5 (kW), the central battery produces 15 (kW). In scenario 2, the total load in the first step is 35 (kW) and it is 95 (kW) in the second step. The power of solar and wind units in both loading steps is constant. The battery power increases from 6.5 (kW) absorption in the first step to 22 (kW) injections in the second step. In scenario 3, the solar units are switched off and in scenario 4, both solar and wind units are switched off. In such conditions, the battery responds to supply loads of homes. Increasing the energy resilience of DE during grid outages is modeled in scenario 5; where the battery power increases from 21 to 51.7 (kW) to deal with such outages. The nonlinear simulations in MATL