Evaluation of expanded allowable capacity of wind power in power systems by charge control for plug-in hybrid electric vehicles

In recent years, the total capacity of wind power generations is increasing drastically. However, the wind power can negatively influence the power grid frequency because of the output instability. In particular, the problem of frequency fluctuation becomes significant at nighttime, when the capacity of Load Frequency Control (LFC) tends to be insufficient. On the other hand, in the transport sector, the Plug-in Hybrid Electric Vehicle (PHEV) has been developed as an environmentally friendly vehicle. The batteries of PHEVs are charged mainly during nighttime, when the electricity price is low. Therefore, we propose a charging power control of PHEVs to compensate the LFC capacity in nighttime, and evaluate the expanded allowable capacity of wind power. We obtained the following results. (1) Charging power control can effectively suppress the frequency deviation caused by the output fluctuation of wind power. (2) Even if the number of PHEVs is small, optimum distribution of a daily charge demand could suppress the frequency fluctuation effectively. (C) 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(4): 3948, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21066