Design and Evaluation of Solar Based DC Distribution over AC System for Data Center Efficiency and Reliability Improvement Case Study: Debre Berhan University Data Center

Abstract

Recently, DC distribution system have many advantages over an AC distribution system. It offers higher efficiency and reliability at an improved power quality. Since the power is distributed in DC, there is no reactive power or skin effect in the system and it does not require any synchronization. Telecommunication systems and data centers are among the few surviving examples of DC distribution systems. Data centers are very fast growing structures with significant contribution to the world’s energy consumption. A data center is a multipurpose internet based center which needs to perform different tasks without any perturbation of electric power. A data center’s critical and sensitive load consists of IT equipment’s such as servers, switches storage devices and UPS systems that are typically DC-based loads. Thus, this study leads to push on the design of DC distribution system for data center power distribution architecture to improve the efficiency and reliability of the system. To do this, Debre Berhan University data center is selected for reliability and efficiency evaluation of both AC and DC distribution system architecture. The study is based on two power distribution cases for selected data center electrical power architecture. One is the existing AC power distribution layout of the selected case area which gets supply from Ethiopian electric utility (EEU) with a nearby diesel generator as a backup power supply system in a case of power outage from the utility system. Another case is the proposed data center power distribution model with an off grid solar powered 380 V DC distribution system. Results show that an AC distribution system have an average efficiency of 72.96% while a proposed DC distribution system have an average efficiency of 82.63%. From this it shows that, a DC power distribution system is 9.67% efficient than AC power distribution architecture of a selected data center. The reliability comparison of both AC and DC powering option for power distribution in data centers IT load is also considered and results show that 380V DC distribution system is more reliable than existing AC distribution system with a relative lower failure rate. The simulation analysis was done in both Powertechnic’s Analyst tool and MATLAB.