Static voltage stability improvement with battery energy storage considering optimal control of active and reactive power injection

Voltage stability analysis and improvement remain a major concern of power system operators due to the recurrent risk of voltage collapse. Many approaches have been used to analyze voltage stability but an approach that can directly indicate the closeness of power system to voltage collapse can be used to optimally plan for the improvement of the power system voltage stability condition when compensation devices are to be deployed. In this study, optimal active and reactive power compensation was performed on a continuously loaded power system, using the battery energy storage system (BESS). In order to achieve this, a voltage stability evaluation model which contains information concerning the active and reactive power flow along the transmission line was adopted. The BESS is considered as a combination of storage units and voltage source converter (VSC) in order to facilitate independent control of both the active and reactive injection to the grid. The optimal control of the output of the BESS minimizes its installed capacity and consequently, reduced the cost as shown by simulation on the IEEE 14 bus system.