Improvement of voltage stability by OLTC and shunt compensation in large multibus power system

In heavily loaded systems, voltage stability limit is usually dominant and voltage instability is usually observed following large disturbance. This is typically the case in the deregulated environment as the transmission systems are operating under more stressed condition due to increased transaction level associated with open access. In recent years, abnormal voltage instability has occurred in several countries. More attention is thus required to be paid to keep voltage profile and hold the voltage stability under control. In this paper simple voltage stability analysis is carried out for a multibus power system (26 Bus System).The effect of shunt compensation and transformer on load tap changing (OLTC) is established for improvement of voltage stability and system loadability.