Abstract
In the power sector, total capacity of wind power generations has been increasing drastically. However, the wind power affects the power grid frequency and the tie-line flow adversely because of the instability of output. In particular, these problems become significant at nighttime when the capacity of Load Frequency Control (LFC) tends to be insufficient. On the other hand, in the transport sector, Plug-in Hybrid Electric Vehicle (PHEV) is being developed as environmentally friendly vehicles. The electric energy of PHEVs is charged mainly during nighttime. Therefore, we have proposed a charging power control of PHEVs to compensate the LFC capacity in the nighttime.
In this study, we propose a control method based on frequency characteristic of PHEV KPHEV, which is defined as a ratio of the change in charging power to the change in frequency. Area Requirement (AR) calculated by the LFC system is a required increment in generation; hence, we can also keep the balance of supply-and-demand by decreasing as much demand as AR. LFC signal fshift calculated by the following equation fshift = -AR/KPHEV is transmitted to all PHEVs in the area; then, PHEVs control the charging power on the basis of input signal. We evaluated the proposed control method by using an interconnected 2-area model and obtained the following results. Charging power control based on the proposed method can effectively suppress the tie-line flow deviation and it could substitute for LFC capacity.
