Verification of Voltage Stabilization Effects in a Hybrid Microgrid by Experimental and Simulation Studies

This paper presents the experimental study results related to microgrid voltage stability by use of a hybrid microgrid prototype system that has been developed and installed at the Itsutsubashi Campus of Tohoku Gakuin University, Japan. In addition, microgrid system simulation model has also been completed based on the system configuration of this experimental system, and simulation studies have been conducted for making comparison of the results from both experimental and simulation studies. The developed microgrid system is designed for facilitating the utilization of renewable power generations. Therefore, in the proposed microgrid, PV and wind power generation are used as the major power sources and supply power simultaneously to DC loads (such as EV chargers, LED or other DC-driven electrical equipment) and AC loads (such as those driven by conventional AC motors). In addition, for purpose of mitigating DC voltage fluctuations caused by renewable power generations and DC load change, two types of power storage devices with different electrical characteristics are introduced, which are rechargeable battery and EDLC (Electric Double Layer Capacitor), respectively. The purpose of this study is to verify whether the DC voltage can be effectively stabilized by the coordinated control of battery and EDLC and be able to supply power to AC and DC loads stably in case with considerable power fluctuations due to renewable power generations and load change in a microgrid, as well as to compare and discuss the results obtained from both experimental and simulation studies.