| 摘要 |
705,409. Control of several motors; protective cut-out arrangements. ENGLISH ELECTRIC CO., Ltd. May 2, 1952. [May 18, 1951], No. 11667/51. Classes 38(3), 38(5) When electric traction motors M1-M6 are connected in three parallel groups each comprising two motors arranged in series, the junction-points between the motors of each group are normally at the same potential and are joined by an equalizer connection E1. In the event of wheel slip, however, circulating currents are set up which tend to reduce the voltage of the motor coupled to the slipping wheels and to restore the balance of the motor circuits. Earth fault protection is provided by a relay EF connected between the equalizer E1 and earth. In the case of groups comprising three or more series-connected motors the several equalizer connections are inter-connected by resistors, and relays connected between the mid-point of each resistor and earth affords earth fault protection, Fig. 2 (not shown). |
