Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Electrical Engineering and Computer Science

First Advisor

Reinaldo Tonkoski


The rapid growth of the Internet has resulted in colossal increase in the number of data centers. A data center consume a tremendous amount of electricity resulting in high operation cost. Even a slight improvement in the power distribution system of a data center could save millions of dollars in electricity bills. Benchmarks for both AC and 380V DC data centers are developed and efficiency analyses thereof have been performed for an entire year. The efficiency of the power distribution system can be increased if number of power conversion stages can be reduced and more efficient converters are used. Use of wide band gap (WBG) converters will further improve the overall system efficiency because of its high efficiency. The results shows that 380V DC data centers are more efficient than AC data centers with and without PV integration. Using 380V DC distribution system not only improve the efficiency of the system, but it saves millions of dollars by decreasing system downtime. Maintaining high availability at all times is very critical to data centers. The distribution system with higher number of series components is more likely to fail, resulting in increased downtime. This study aims at comparing reliabilities of AC against 380V DC architecture. Reliability assessment was done for both AC and DC systems complying with Tier IV standard. The analysis was done for different level of redundancy (eg. N, N+1, N+2) in the UPS system for both AC and DC systems. Monte Carlo simulation method was used to perform the reliability calculations. The simulation results showed that the 380V DC distribution system has higher level of reliability than AC distribution system in data centers but only up to certain level of redundancy in the UPS system. The reliability level of AC system will approach to that of a DC system when a very high level of redundancy in the UPS system is considered, but this will increase the overall cost of a data center.

Library of Congress Subject Headings

Data libraries -- Energy consumption.
Power resources -- Management.
Electric power -- Conservation.
Energy conservation.


Includes bibliographical references (pages 95-99)



Number of Pages



South Dakota State University


Copyright © 2016 Bijen Raj Shrestha