  This paper presents a generalized energy storage system model for voltage and
angle stability analysis. The proposed solution allows modeling most common
energy storage technologies through a given set of linear differential
algebraic equations (DAEs). In particular, the paper considers, but is not
limited to, compressed air, superconducting magnetic, electrochemical capacitor
and battery energy storage devices. While able to cope with a variety of
different technologies, the proposed generalized model proves to be accurate
for angle and voltage stability analysis, as it includes a balanced,
fundamental-frequency model of the voltage source converter (VSC) and the
dynamics of the dc link. Regulators with inclusion of hard limits are also
taken into account. The transient behavior of the generalized model is compared
with detailed fundamental-frequency balanced models as well as commonly-used
simplified models of energy storage devices. A comprehensive case study based
on the WSCC 9-bus test system is presented and discussed.
