| 摘要 |
<p>A power conversion system including a DC power source, a plurality of unit converters connected in parallel, each composed of a bridge connected switching devices, a plurality of DC reactors and a control circuit. The control circuit includes a conduction arm number calculating circuit for determining conduction arm numbers of the unit converters of each phase, each being determined based on a ratio of the current instruction value of respective phase and a mean value of the DC currents. The control circuit further includes a current balance control circuit for generating a plurality of conduction instructions for the switching devices at a time of change of one of the conduction arm numbers based on a first order of magnitude of the AC voltages, a second order of magnitude of the DC currents and the conduction arm numbers of each phase at that point. The conduction instructions are applied to the unit converters for switching ON or OFF the switching devices, thereby balance control of the DC currents of the unit converters is exercised.</p> |
