| 摘要 |
1310970 Control of DC motors; protective arrangements JEUMONT-SCHNEIDER 8 July 1970 [8 July 1969] 33152/70 Headings H2J and H2K A series machine MG which may operate as a motor or a generator is connected to a D.C. source E having impedance L2, R2, through a chopper circuit comprising thyristor T1 and quenching unit X as well as a free-wheeling diode D2. The system also includes a filter Lo, Co, associated with a power-dissipating circuit having resistor R and thyristor switch T3. An actuating and protective logic unit P controls the copper operation and protects the system against over-voltage. When the voltage across terminals A, B, reaches a predetermined level due to the inability of the source E to absorb regenerated power, thyristor T3 fires to introduce resistor R whereby excess voltage is prevented. During normal motoring operation when no rapid variation of chopper operation is called for, the current of the machine is reduced gradually in response to an over-voltage. However, under emergency conditions, the chopper is blocked instantaneously, the power-dissipating circuit is brought into operation simultaneously, and the circuit breaker D1 is opened. |
