Probabilistic Optimal Storage Allocation and Operation to Ensure Voltage Stability Margin

Voltage Stability has become an issue for many of the today's power systems, due to the uncertain characteristics of loads and renewable energy resources. On the other hand, recent advances in Energy Storage Systems (ESSs) have initiated global interest to harness their potential in enhancing reliability and robustness of power systems. In this paper, optimal placement, sizing, and operation of ESS devices in power systems with embedded wind farms are studied. The objective of the allocation problem is to minimize the required ESS size to be installed such that a desired level of Voltage Stability Margin (VSM) is always ensured. The uncertainties of wind power generation and loads are taken into account, by considering their corresponding probability density functions (PDFs) and using a probabilistic optimization approach. Reactive power capabilities of both ESS devices and wind farms, as well as a 10% extra rating of their associated inverters are also used as additional flexibilities to reduce the required ESS sizes. The method is tested on IEEE 30-bus test system.