Photovoltaic Auxiliary DC Power System for Substation Reliability Enhancement

One of the most important components of the substations is the auxiliary power supply system. Under normal operation, the battery charger supplies the continuous loads and charges the battery, and the battery supplies power to the momentary loads. If a failure of the AC systems occurs, the batteries should support the required power for the DC loads on the auxiliary DC systems as well. However, these conditions may continue for several hours. Upon long outage duration, the battery supply would fail to support the loads. Therefore, the outage duration of a battery charger as well as the correct sizing of the battery is a critical factor for designers and network planners. This paper suggests an innovative solution to use a combination of renewable generations and storage systems in Distribution Substations to enhance the energy efficiency of the system especially in long lasting power outages. To assess the efficiency of this method, the design of the photovoltaic systems would be applied to the Qods City Substation, one of the projects carried out in Niroo Consulting Engineers Company, as the case study of this work. The goal of this design in competitive advantage analysis is to prove and show that by using the proposed photovoltaic auxiliary DC power systems in the substations versus the distribution systems, the reliability of the substations, and consequently, utility grid will be increased.

Keywords:

photovoltaic systems , battery , auxiliary power supply