Analysis of efficiency for AC and DC load in LVDC distribution system

In modern power system, the use of electronic devices continues to increase annually. Power conversions using these devices result in loss of power unfortunately. Recently, new distribution systems using Low Voltage Direct Current (LVDC) have been proposed as a solution to reduce the energy loss from power electronic converter. In DC distribution system, DC loads, which need only DC/DC converter, are very efficient due to decrease the stages of power conversion and connection directly with DC supply. However, if the LVDC distribution system is adopted, it is difficult to replace the all AC loads existing in conventional AC system with DC loads. Thus, the DC distribution system can be operated with two types of load and needs the inverter to supply the DC power to AC loads. According to these load types, a study on efficiency of power system is required to adopt new LVDC distribution system. In this paper, the analysis of power efficiency for AC and DC loads in low-voltage DC distribution systems is performed. This paper models various power electronic converter, AC load, DC load using Electro-Magnetic Transient Program (EMTP) software.