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In this paper, the problem of maximizing power-system loadability with multiple complementarity constraints representing generator limits is examined. The structure of the loadability surface is investigated, the various type of limits are classified and a general algorithm to optimize settings of control variables, in order to maximize loadability margin(More)
The scope of this paper is to show that an extended quasi-steady-state model of long-term dynamics that includes low-frequency interarea oscillations can be used effectively for the design of power system stabilizers (PSSs). All local and intra-area electromechanical oscillations are replaced in this model by equilibrium (algebraic) equations. In addition,(More)
The subject of this paper is the extension of QSS modeling to include low frequency interarea oscillations in power system long-term dynamics. All other electromechanical oscillations, such as local or intra-area are replaced by equilibrium (algebraic) equations. Modal analysis and simulations are made on a classical test system of 11 buses and 4(More)
A Smart Transformers (ST) is an automated transformer based on the latest power electronics and communication technologies. It aims not only at replacing the traditional transformer, but at providing also ancillary services to the grid, thanks to the greater flexibility offered by power electronics. However, in the case of grid overload caused by high load(More)
A Smart Transformer (ST) is a power electronics-based transformer that aims not only to substitute the traditional transformer but to upgrade also the LV and MV grid. In order to limit the costs, the ST must be carefully designed, constraining the current carried by the ST. In this paper a Combined Frequency and Voltage Controller is proposed, in order to(More)
This letter proposes a new on-line load sensitivity identification by means of power electronics-based devices. Applying a voltage and frequency perturbation and measuring the consumed power of the loads, the proposed method computes in real time the voltage and frequency dependency of the load active and reactive power. In this letter, a smart transformer(More)
This paper extends some previously obtained results on load tap changer (LTC) stability and derives detailed conditions for the stability of a dynamical system consisting of discrete LTC transformers based on Lyapunov's direct method and its extension according to LaSalle's Invariance Principle. The exact region of attraction of a two LTC system is(More)
This paper presents a methodology to simplify a distribution network, which consists of a number of wind farms equipped with induction generators and MV lines. The methodology leads up to an approximate equivalent network, which consists of an equivalent wind farm and an approximate equivalent MV feeder. The proposed methodology reduces the complexity of an(More)