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The matrix converter (MC) is arousing considerable attention as an alternative for conventional ac/ac converters due to the advantages it offers. However, the control and modulation of this converter is complex. This, together with the fact that the MC usually operates at high modulation frequencies, makes the computational load of the platform to be simulated excessively high. All this makes the simulation time of models including the MC excessively long, even more so when both the transient and steady state of the system must be analyzed. This paper presents a new MC simulation technique called Switching State Matrix Averaging (SSMA). Although this is a fixed-step technique, a long simulation step can be used without forfeiting the accuracy of an ideal variable-step simulation. Likewise, the SSMA drastically speeds up the simulation, reducing the amount of required resources and the tuning time of the complex platforms in which the MC is used. A series of simulations has been performed in order to verify the proposed method. Moreover, a comparison between experimental and simulation results has been made, demonstrating the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper compares several medium-voltage power conversion systems for plasma torch application. The thermal plasma torch rated for 3 MW, 2 kA with the physical size of 1 m long is selected. The dynamic characteristics of the dc arc in a plasma torch are investigated using advanced 3-D magnetohydrodynamics simulation. The arc voltage noise of ±10% due to the periodic pressure wave is modeled as a sawtooth waveform in arc power loss term. The parameters of the Cassie-Mayr arc model are calculated based on 3-D simulation. A 12-pulse thyristor rectifier and two-phase staggered three-level step-down dc-dc converter having 12-pulse front-end diode rectifier are compared under the same dynamic operating condition. The three-level dc-dc converter has superior dynamic performance over the 12-pulse thyristor rectifier under the existence of arc disturbance noise. This power converter topology provides higher ignition voltage around 5 kV during ignition phase and higher arc stability. [ABSTRACT FROM AUTHOR]