| 摘要 |
PURPOSE:To prevent an induction generator from generating self-excited in outage of power source, by interposing a three-phase three-winding transformer between a three-phase induction generator and the power source system. CONSTITUTION:The primary winding 2 of a three-phase three-winding transformer 1 is connected to the power source, the secondary winding 3 to the load and the tertiary winding 4 to an induction generator 6 through a breaker 5 respectively. In operating the generator 6 if the power is cut off while the system is connected to the primary winding, then the generator 6 is forced to stop when the power flowing into the primary winding 2 falls down less than the set value. In case the control system does not work and the condition to cause the self-exciting phenomenon is satisfied, that is, in case there is relatively large electrostatic capacity in the load, the leading current of generated power flows through the secondary winding 3 and the tertiary winding 4 of a transformer 7 and it does not flow backward to the system as the electric power, so that the safety on the system side is well aswured. |
