PWM controlled DC/AC power converter

DETAILED DESCRIPTION Therefore, an object of this invention is to provide an apparatus for controlling a power converter interposed between the d.
c.
power source and the a.
c.
system to interchange power therebetween, which is capable of eliminating the above-described overcurrent or d.
c.
polarized magnetization based on imbalance of the a.
c.
system voltage or unevenness between element characteristics.
In accordance with this invention, there is provided an apparatus for controlling a power converter comprising synchronous detector means for detecting a phase of an a.
c.
system voltage to output it as a synchronizing signal, output voltage phase signal generator means for determining a phase of an output a.
c.
voltage from a phase difference angle adjustment signal for determination of a phase difference between the a.
c.
system voltage and the output a.
c.
voltage and the synchronizing signal from the synchronous detector means to output it as an output voltage phase signal, phase voltage amplitude signal generator means for obtaining a voltage amplitude adjustment signal for determining an amplitude per phase of the output a.
c.
voltage to switch voltage amplitude adjustment signals of at least two phases in accordance with an output voltage phase signal for the output voltage phase signal generator circuit to output a signal obtained by switching as a phase voltage amplitude signal, and firing signal generator means for determining energization periods of respective controllable rectifier elements constituting the power converter from the voltage phase signal on the basis of the output voltage phase signal generator circuit and the phase voltage amplitude signal from the phase voltage amplitude signal generator circuit.