A dynamic simulation approach to identify additional reactive reserves against long-term voltage instability

A simple method is proposed to identify additional
reactive reserves enabling to counteract long-term voltage instability
after a large disturbance. In contrast to the many references
based on power flow calculations, the method resorts to dynamic
simulation. The post-disturbance system evolution is simulated
in the presence of time-varying shunt susceptances with specified
rate of change. This allows to deal with dynamic issues such as
the required speed of the additional reactive power sources, or the
onset of unstable electromechanical oscillations. Furthermore, a
compromise is sought between the speed of action and the volume
of additional compensation. The method is demonstrated on a
detailed model of the Nordic test system.