Power Conversion Device

摘要

In a system for driving an electric motor by an engine generator, there is a possibility that the effects of harmonics and DC voltage fluctuations of a power converter cause shaft oscillation to increase due to a phenomenon in which current pulsations caused by voltage disturbances at a d-axis and a q-axis are strengthened each other and thus oscillation and d-axis current are increased under the effect of interference between the d-axis and the q-axis. In an engine generator system, a power converter (105) controls a generator (104) by regulating the d-axis voltage Vd* by an amount of ΔVd* using d-axis voltage adjusting means (117) so that the phase of an oscillating component included in the d-axis current in the rotor magnetic flux direction of the generator (104) advances by 90 degrees or more with respect to the phase of an oscillating component of the identical frequency included in the rotating electric angular frequency of the generator (104), and further by regulating the q-axis voltage Vq* by an amount of ΔVq* using q-axis voltage adjusting means (118) so that the phase of an oscillating component included in the q-axis current advances by 90 degrees or more with respect to the phase of an oscillating component of the identical frequency included in the rotating electric angular frequency of the generator (104).

主权项

1. A power conversion device for an engine generator system,
the engine generator system comprising: a generator; an engine for driving the generator; a PWM signal controller for performing pulse width modulation on a three-phase voltage command signal via a carrier signal, the three-phase voltage command signal being in accordance with current flowing through the generator; a power conversion device driven by a pulse width modulated gate signal; an electric motor; and a power converter for driving the electric motor, wherein the power conversion device regulates a voltage command on a d-axis in the magnetic flux direction of a rotor in the generator so that the phase of an oscillating component included in current of the d-axis in the generator advances 90 degrees or more with respect to the phase of an oscillating component of identical frequency included in a rotating electric angular frequency of the generator, and further regulates a voltage command on a q-axis perpendicular to the d-axis so that the phase of an oscillating component included in current of the q-axis advances 90 degrees or more with respect to the phase of an oscillating component of the identical frequency included in the rotating electric angular frequency of the generator.