L. Ängquist

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Modular multilevel converters (M2C) are increasingly used in the high voltage direct current (HVDC) systems. The efficiency of M2C is highly related to the modulation technique which determines the switching frequency and capacitor voltage ripple in the converter station. A new approach to modulation of M2C is presented in this paper. Tolerance band methods(More)
This paper describes an open loop method of controlling FACTS devices for power oscillation damping. The method is based on step-wise series reactance modulation. The principle of the method is to stabilize an oscillation in a power system which is characterized by one major mode of oscillation by switching a reactance in series with one transmission line,(More)
We describe a new method for identification of confident associations within large clinical data sets. The method is a hybrid of two existing methods; Self-Organizing Maps and Association Mining. We utilize Self-Organizing Maps as the initial step to reduce the search space, and then apply Association Mining in order to find association rules. We(More)
SUMMARY Experience and theoretical analysis show that the voltage and power stability becomes an important issue when high-voltage direct current (HVDC) systems using line-commutated converters (LCC) are connected to AC systems with low short-circuit capacity and that these problems become more pronounced the lower the short-circuit capacity of the(More)
This paper describes an adaptive method of controlling FACTS devices for power oscillation damping. The method is based on step-wise series reactance modulation. Here, a reduced model of the power system with only two rotating masses is used as a basis for the control design. The model parameters are updated using local measurements of the active power on(More)
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