| 摘要 |
PROBLEM TO BE SOLVED: To downsize a converter which supplies the compensating current of fault currents superposed on a distribution line, and reduce the cost. SOLUTION: A compensating current detector 4 receives the input of load currents iLu, iLv, and iLw flowing to each phase of a distribution line 1 by a current transformer CT, and detects the fault current (reverse current + higher harmonic current) ik (k=u, v, w) of each phase from the load current. A current control converter 5 generates compensating currents iCu, iCv, and iCw, based on the fault current ik (becomes a command value Kik, being increased k (k>1) times with a detector 4). The primary winding of each phase of a three-phase transformer 6 is supplied with compensating currents iCu, iCv, and iCw outputted from the current control converter 5. One end of the secondary winding of each phase of the three-phase transformer 6 is connected to a three-phase cage rotor induction motor 7, and the other end is connected to each phase of a distribution line. The three-phase cage rotor induction motor 7 rotates with no load, and takes partial charge of positive-phase voltage. |
