The propose of this research present a comparative study of the Reliability Improvement of Electrical System for Electric Mass Rapid Transit Train which describes in term of the power supply efficiency including voltage imbalance that could indicate how much the electric power quality is being more or less. The electrical system to be used in the Mass Rapid Transit system has 4 types of connection between three (3) phases of Metropolitan Electricity Authority (MEA) transformer and station transformer which is Single phase V-Type Scott and Le- Blanc to be considered for the different transformer connections type could be carried out and resulted in the most unbalanced in power supply as well as properly solution for power supply mitigation of voltage imbalance. From foregoing the data analyst was discovered that a single phase connection could cause the most unbalance voltage but on the other hand Le-Blanc connection is the least unbalance which could be reduced the impact on the Mass Transit Train and increase the credibility of consumers in order to continuity implement service usage.