Voltage stability margin improvement using shunt capacitors and active and reactive power management

Improvement of the power system economical dispatch from voltage stability margin viewpoint is studied in this paper and for that a methodology is proposed. The considered time interval is short term operation. Active and reactive power (generation) re-dispatch injection is the basis of proposed method and voltage stability will be achieved using generated reactive power by shunt capacitors in power system. This method is implemented via modal analysis with specifying participation factor of generators and Synchronous condensers (units), and shunt capacitors. Using modal index, units with negative impact on voltage stability margin are revealed and penalized with high costs in objective function of the optimal power flow program used to run the re-dispatch process. Results indicate significant improve in voltage stability margin. So, the new method is applied in order to update penalty factor of units. In this research it is assumed that contingency occurred in system does not lead the stability margin to under zero Level and load shedding is not necessary for recovering a desired criteria. Finally, proposed method is performed in modified 30-bus IEEE power system in contingency condition.