초록 ▼

The isolation operation of a non-utility generation system (7) interconnected to a power system enable to be reliably detected in the non-utility generation system, providing a transfer breaker. When the frequency change rate of the non-utility generation system (7) has a positive value, the advance

The isolation operation of a non-utility generation system (7) interconnected to a power system enable to be reliably detected in the non-utility generation system, providing a transfer breaker. When the frequency change rate of the non-utility generation system (7) has a positive value, the advanced reactive power of the non-utility generation system (7) is increased. When the frequency change rate of the non-utility generation system (7) has a negative value, the delayed reactive power of the non-utility generation system (7) is increased. Further, the gain of the power control section (9) of the non-utility generation system (7) is adjusted in accordance with the frequency change rate. As the gain is thus adjusted, the voltage of the non-utility generation system (7) changes. This change in the voltage is detected. In accordance with the voltage change, the non-utility generation system (7) is disconnected from the system power supply.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for protecting a non-utility generation system which is interconnected by a breaker to a power system and which has a voltage control system, said apparatus comprising:a frequency detector for detecting an output frequency of the non-utility generation system

[ What is claimed is:] [1.] An apparatus for protecting a non-utility generation system which is interconnected by a breaker to a power system and which has a voltage control system, said apparatus comprising:a frequency detector for detecting an output frequency of the non-utility generation system;a frequency-change rate detector for detecting a rate at which the frequency detected by the frequency detector changes;arithmetic means for calculating a change reference for a voltage or reactive power output by the non-utility generation system, from the frequency change rate detected by the frequency-change rate detector;first control means for increasing an advanced reactive power of the non-utility generation system or decreasing the output voltage of the non-utility generation system, when it is determined from the change reference that the frequency change rate has a positive value;second control means for increasing a delayed reactive power of the non-utility generation system or increasing the output voltage of the non-utility generation system, when the frequency change rate has a negative value;gain adjusting means for adjusting a gain of a power control section of the non-utility generation system, in accordance with the frequency change rate; andprotecting means for detecting a frequency change which increases as the voltage of the non-utility generation system changes, and for disconnecting the non-utility generation system from the system bus line in accordance with the frequency change detected.