| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control system which prevents the enlargement by providing a power conversion apparatus with first and second power converters in parallel and connecting a synchronous motor via the first and second circuits provided on the output side and starting it with the first circuit without a transformer and boosting the supply voltage with the transformer in the second circuit thereby elevating the voltage of the motor, and reduces the torque ripple caused by higher harmonics by sliding the phases of each carrier frequency of inverters. <P>SOLUTION: In the control system for the synchronous motor, the first and second power converters are provided in parallel, and it is started with the first circuit where a transformer is not connected, and it is supplied with power boosted with the second circuit, and the phases of each carrier frequency of the first and second inverters are slid from each other. Accompanying the capacity increase of a low voltage system of thyristor starter, a transformer is connected to the circuit, and at the start of the synchronous motor, the power is supplied by bypassing the transformer, and the two kinds of a load commutation type and a compulsive commutation type are available as an inverting circuit. However, to solve the problems that the torque ripple of the motor is large since the output current is of rectangular waves and that a power harmonic current is large, a power converter circuit is made to carry a small harmonic current so as to reduce the torque ripple of the motor. <P>COPYRIGHT: (C)2004,JPO |
