| 摘要 |
An engine-driven dual winding separately excited alternator supplies electric power to a parallel array of d-c traction motors via a power rectifier assembly comprising three legs of serially interconnected diodes. The alternator has a first set of 3-phase windings respectively connected to the three rectifier legs at points between first and second diodes thereof and another set of duplicate windings respectively connected to the corresponding legs at points between third and fourth diodes thereof. First and second switching means are used to interconnect the respective junctures of the second and third diodes of all three rectifier legs, and in response to transition command signals these switching means are selectively closed (or opened) in sequence to change the connection of the alternator windings from parallel to series (or vice versa). Stabilizing means associated with the excitation system of the alternator is temporarily disabled during the transition interval. |
