| 摘要 |
1,163,996. Control of A.C. motors. CKD PRAHA, OBOROVY PODNIK. 24 April, 1967 [26 April, 1966], No. 18672/67. Heading H2J. Correct starting operation of a synchronous machine is indicated by a unit BM when the rectified rotor voltage becomes equal to a standard voltage V. For further starting operation, the source U is shunted by contact B1, and capacitor C is charged through contact B2. When the machine approaches full speed, the voltage across the capacitor drops to zero and the indicator BM responds to apply excitation to the machine. After the machine has started, the indicator BM responds to an A.C. component in the rotor circuit, to switch off the machine when it operates asynchronously. The source U is connected in series with a protective device P, resistor R, and diode D. The contacts B1, B2 may be replaced by static switches. |
