Influence and Prevention of Voltage Violation and Momentary Electricity Interruption Resulting from Renewable Energy Sources

Distributed Generation (DG) provides many advantages to distribution systems. However, the presence of DG units usually causes voltage fluctuation in the systems, and even causes voltage violation. These issues are widely known for years and a number of researches have paid attention to them. The other fact that is revealed in this paper is momentary electricity interruptions due to the voltage violation. To prevent damages resulting from voltage violation, sensitive loads are normally equipped with over/under-voltage relays. As a result, the more frequent bus voltages violate their limits, the more momentary electricity interruption tends to occur. In this paper, Momentary Average Interruption Event Frequency Index (MAIFI_E) is evaluated to study this influence. In addition, uncertainty from renewable resources is integrated into the proposed voltage regulation method by using Probabilistic Load Flow (PLF). For IEEE-34 Bus test system, the numerical examples show that the uncertainty from renewable energy resources causes voltage violation and considerable MAIFI_E, and the proposed method can serve as an effective prevention for the problem.