Vacon Oyj

Vacon Oy

Toni Itkonen

Stefan Strandberg

Ari Ristimäki

Jussi Pouttu

Kimmo Rauma

Jorma Vesti

Mika Ikonen

A method and arrangement for controlling semiconductor power switches, e.g. IGBTs, in parallel connected power devices, e.g. in frequency converters, wherein the semiconductor power switches connect either the positive or the negative pole of the intermediate DC-voltage of the power device to an output phase of the power device. In the method the voltages of those output phases which are connected in parallel are measured, the timing differences of the output voltage state changes are calculated on the basis of the output voltage measurement results, and the control signals of the semiconductor power switches are advanced or delayed such that the output voltage state changes in the phases which are connected together via output impedances occur at desired time instants.

Control of parallel connected power devices

A method and a parallel connection arrangement for equalizing the output powers of power converter units (INU, INU), in which power converter units is a semiconductor switch bridge controlled with pulse width modulation, and in which is a control unit arrangement (CU, CU) for forming control pulses, with which the semiconductor switches are controlled. The control unit arrangement delays the falling edge of the control pulses of at least one semiconductor switch of at least one power converter unit.

Power level balance of frequency converters connected in parallel

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Lappeenranta, Finland

Toni Itkonen