| 摘要 |
PURPOSE:To stabilize operation of a power conversion device by providing a current reference limiter for limiting the output current from a current reference calculator in a power controller when the system voltage drops due to fault and the output from the converter exceeds over the rated value. CONSTITUTION:A current reference calculator 70 calculates effective and reactive current references icd, icq based on set values Pdp, Qdp in effective and reactive power reference setters 71, 72. When formula I is satisfied a current reference setter 90 outputs icd=icd', icq=icq' to a current controller 80, while when the formula is not satisfied the current reference controller 90 outputs reference values icd', icq', satisfying formula II, to the controller 80. The controller 80 receives a converter output current signal (i), system voltage phase theta and the reference values icd', icq' through a current transformer 45 and determines voltage commands Vuc, Vvc, Vwc, to be fed from the controller 80, so that the signal (i) will be equal to the reference values icd', icq' then the voltage commands are fed to a gate control circuit 350 which determines the conduction time width of each GTO element 10. |
