抄録
In long distribution system, Step Voltage Regulators (SVRs) are installed to regulate the system voltage. There are some papers about finding optimal placements of SVRs in the system. However, there is not analytic method in the view of the voltage margin i.e. optimal on the system voltage.
The Authors propose a method finding the placement of a SVR so that the voltage margin from the upper (or lower) voltage limit is the largest in heavy load.
In order to deal with sets of loads that are dispersed on distribution line completely, the authors have drawn differential equation of complex power and one of voltage drop which are expressed by function of distance from a substation by transforming. The voltage profile is given as the polynomial expression by solving the voltage equation if load distribution is trapezoid type. The method finding optimal placement of a SVR is distinguished in three modes by three different voltage profiles. One is the case of that ratio of transformation of a SVR is small and the system length is short. Another is the case of that ratio of transformation of a SVR is large and the system length is short. The other is the case of that the ratio of transformation of a SVR is large and the system length is long. The optimal placement and the tap position of a SVR are calculated by solving above-mentioned equations in these three modes.
It has been confirmed that the proposed analytical method is appropriate by a model calculation result.
