| 摘要 |
To provide for high efficiency of recuperation of energy stored in the rotating and electromagnetic system of a dynamo electric machine, upon dynamic braking thereof, in which the dynamo electric machine is connected in a chopper-controlled series circuit, a field diode (10) is connected across the field winding (11); a controlled switch (18), for example a transistor or a thyristor, is connected to the junction between the field winding (11) and the aramature (12, 13) and a return line (N) to a storage battery, the controlled switch being controlled to close by a control circuit (19) which opens a brake switch (16) connected between the battery and the dynamo electric machine series circuit under motor operating conditions, to provide for continued current flow through the field, which then is reversely connected by a field reversal switch (8, 9), with continued current flow being maintained by a free-wheeling diode (10) connected across the field. The chopper may be a thyristor (2) connected to a turn-off circuit, the turn-off capacitor (4) also furnishing initial field current through the controlled switch (18) or it may be a transistor (2') which is energized to conduction with a slight delay with respect to closing of the controlled switch (18). |
