Calculation of transfer functions for a forced-commutated voltage-source converter

A technique for deriving the transfer functions for small superimposed oscillations in a forced-commutated voltage-source converter is presented. It is shown that the resonance determined by the capacitor on the DC-side, and the inductance of the converter transformer can be critical at the control of the DC-voltage. This is illustrated by a Bode diagram of the open-loop transfer function and recordings from simulator tests and digital simulation programs.<
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