An Effective Method for Improvement of Voltage Stability by Optimizing LTCs in Preventive Control

摘要

A number of studies of voltage stability preventive control schemes have been carried out in recent years due to the fact that power plants are away from power load centers and reactive power losses tend to increase in transmission system with heavier power flow and long distance transmission. This paper discusses the effect of load tap changers of autotransformers between higher voltage levels, which in many cases are controlled manually, on the voltage stability of a power system. Based on the gradient projection method, an effective algorithm for optimizing the LTCs, which will maximize the loadability margin, is presented. Finally, the algorithm is applied in an example of power system voltage stability, the numerical results obtained show that the presented algorithm is feasible and effective.