| 摘要 |
Apparatus for synchronizing the relative positions of motor-driven machines. Preliminary to operating the machines in synchronism, the rotors of individual synchronous motors that drive the machines are moved to a stop at certain angular positions. The angular positions are such that when inverter voltage is thereafter applied to the stators of all of the motors from a common inverter, the instantaneous angular position of the stator magnetic field with respect to the respective rotor is the same for all of the motors. In one embodiment, several machines are synchronized as to position by first operating each at low speed to a home position. Arrival of each machine at its home position is detected by detecting the simultaneous existence of two signals: (a) a first signal indicating that the instantaneous phase of inverter voltage applied to the stator is within a predetermined range, (b) a second signal indicating that the position of the machine member driven by the respective motor is within a predetermined tolerance range of the home position. Thereupon, if a third signal indicates that the speed of the motor is below a predetermined threshold speed, a brake is applied to hold the machine in its home position. After all of the machines reach their home positions their respective brakes can be released and all motors can be energized from a common inverter in order to operate the machines in positional synchronism.
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