Energy efficiency and peak load management via CVR and distributed energy storage in active distribution grid

摘要

Energy conservation through voltage reduction and distributed energy storage (DES) technology emerged as a potential candidate for peak load relief in distribution grid. However, lack of coordination between network controls such as conservation voltage reduction (CVR) and assets (DES) may cause detrimental impact on smart grid operations. Therefore, this paper reports on the need for coordination of CVR and DES for maximizing the benefits of both approaches. The impact of integrated operation of CVR devices and DES on energy saving and peak demand reduction have been investigated. The CVR scheme has been implemented using discrete gravitational search algorithm-driven Volt-ampere reactive (VAR) optimization (VVO) in the presence of distributed energy sources (DER). Such a smart grid-enabled centralized CVR scheme has been proposed to be deployed in the grid and integrated with a community energy storage (CES) as DES. The main task of the VVO engine is to minimize the total power demand through optimal settings of Volt-VAR control (VVC) devices. In order to demonstrate the benefits of integrated operation of CVR and CES, the studies have been carried out in three cases, namely without CVR, VVO-based CVR, and CVR with CES in presence of both nonrenewable and renewable (wind) type DERs. Moreover, the impact of the proposed method has not only been demonstrated on hourly varying load of the year but during peak load hour also. Besides, the techno-economic and environmental assessment of combined operation of CES and CVR has been done. The Institute of Electrical and Electronics Engineers (IEEE) 123-bus unbalanced distribution network with the modification to include the DER and CES system apart from CVR devices has been chosen to corroborate the performance of the proposed method. The test results reveal that the proposed integration method of CVR and CES achieve higher peak sharing and energy saving with reduced carbon emission. In addition, the method assists the demand balancing. Besides, the by-product of CES control strategy has been demonstrated for mitigation of rise in neutral currents.