An Adaptive Control System for a Dc Microgrid for Data Centers

In this paper, an adaptive control system for a dc microgrid for data centers is proposed. Data centers call for electric power with high availability and a possibility to reduce the electric losses and hence the need for cooling. By using local energy sources, high reliability can be achieved, and by using dc the number of conversion steps, and therefore also the losses, can be reduced. The dc microgrid can also be used to supply closely located sensitive ac loads during outages on the utility grid. The proposed dc microgrid can be operated in eight different operation modes described here, resulting in 23 transitions. The adaptive control system coordinates the control of converters, sources and switches used in the dc microgrid. The adaptive control system is tested in the simulation software packages PSCAD/EMTDC, and the results of the most interesting operation modes and transitions are presented. The results show that it is possible to use the proposed dc microgrid to supply sensitive electronic loads, and also during utility grid outages, supply closely located sensitive ac loads. To reduce transients in the voltage experienced by the sensitive ac loads, the dc microgrid requires fast utility outage detection and fast switches.