Protection is an important aspect when designing a microgrid system, as it ensures the network is able to run safely. As the debate between AC vs. DC protection schemes continue, there appear to be distinct advantages and disadvantages on each side with respect to reliability, efficiency, security, environmental and economic concerns. In this thesis, a low voltage DC microgrid protection scheme used in a data center is proposed. The final goal of this project is to develop a network and perform a fault analysis study while investigating different aspects of power protection schemes. Research is done on different protection devices which will be used to protect their respective components.
Three types of faults will be tested on the system for fault current observation purposes. In order to calculate the theoretical fault current of the battery and converter, Microsoft Excel will be used. ICAPS by Intusoft will be used to simulate three different faults in the network. Fault 1 will be on the positive and negative pole of the converter/battery and the load. Fault 2 is a double line to ground fault located on one of the feeders near the load. Fault 3 is a single line to ground impedance located on one of the positive pole of the feeder with a high impedance.
Results show that there are commercial devices available to protect components in such a system. Ultra hybrid DC circuit breakers are used to protect the converter, Molded Case Circuit Breakers are used for feeder protection, and lastly fuses or circuit breakers can be used for battery protection
