A novel approach to evaluating small-disturbance voltage stability of large scale AC/DC power systems

Considering generator dynamics, load dynamics and HVDC dynamics, the differential and algebraic equations for analyzing small-disturbance voltage stability of large scale AC/DC power systems are established and a new voltage stability criterion is presented based on some reasonable assumptions and rigorous mathematical derivation. The criterion is that the determinants of two different power flow Jacobian matrices should have the same signs. By using the criterion, the dynamic problem of power system small-disturbance voltage stability can be treated as a static problem, so the eigenvalue analysis is avoided and the computation burden is reduced. The calculation results on two sample systems show that the novel approach proposed in this paper is correct and feasible.