| 摘要 |
PURPOSE:To improve the controllability of a current type inverter by detecting an influence to the load current of an overvoltage absorbing capacitor, and determining a correction corresponding to the detection to increase or decrease the phase difference of DC or load currents. CONSTITUTION:A main circuit of a current type inverter comprises a power reactor 2 composed of switching elements S1-S6, a DC reactor 3, a power inverter 4 composed of self-arc extinguishing elements G1-G6, and a capacitor 5 for absorbing an overvoltage. A controller 8 comprises a speed controller 9, a load detector 10, correction signal generators 11-12, command correctors 13, 15, a current controller 14, and a power inverter controller 16. A slip is obtained from the rotating speed of an induction motor 6 of a load and from an inverter frequency, and a load impedance is further obtained. A correction amount for coinciding as the output current value of the inverter together with the capacitor 5 is obtained as the function of the flip, and the commands are increased or decreased on the basis of the correction amount.
|
