| 摘要 |
PURPOSE:To minimize reduction of motor output upon occurrence of fault, by classifying PWM converters into plural groups containing smoothing capacitors and motor control circuits/and releasing only such group as containing a faulty PWM converter or motor control circuit. CONSTITUTION:Secondary winding of a main transformer MT is splitted into four sections/each of which is connected respectively through contactors K1-K4 with four PWM converters CV1-CV4. The PWM converters CV1-CV4 are classified into groups corresponding to the number of inverters IV1, IV2. Upon malfunction of the PWM converter CV1, the contactors K1, K2 and K5 are released while the contactors K3, K4 are kept in the closed state. By such arrangement, a motor M1 stops operation but a motor M2 can continue operation. |
