| 摘要 |
PURPOSE:To decrease the pulsation of torque in case of starting by a method wherein a multiple circuit is formed by a converter directly connected to armature winding and a converter having a Y-DELTA connection transformer at its output side, and a commutatorless motor is driven only by the output of the directly connected converter when starting. CONSTITUTION:When starting, an electromagnetic contactor CTT is previously opened, and a motor 4 receives the supply of power only from a power inverter 3A by current intermittent commutation and is driven. In this case, a contact RY1 is closed, and the current reference signal output of an amplifier 7 for controlling speed is transmitted only to an amplifier 8A for controlling currents of a power rectifier 1A. When the motor 4 is accelerated and the electromagnetic contactor CTT is made by the action of a logical cicuit 13, the sum of the output of power inverters 3A, 3B forming a multiple circuit is fed to the motor 4, contacts RY2, RY3 are closed, and the current reference is given by means of a potential divider RH. Currents supplied to the motor have wave-forms close to a sine wave with 30 deg. phase difference to the commutation timings of the power inverters 3A, 3B by means of a phase-shifting circuit 12 and the action of a Y-DELTA connection transformer 11. |
