Protection arrangement of an electric power system
First Claim
1. A protection arrangement of an electric power system, the electric system comprising a generator set, the protection arrangement comprising a relay arrangement for measuring current, voltage or both of an electric grid, which relay arrangement is adapted to detect over-current, under-voltage or both, the generator set being separable from a grid when over-current, under-voltage or both are detected, and the detected over-current, under-voltage, or both does not stop before a critical clearing time, the critical clearing time determining a period, during which resynchronization of the generator set with the grid is possible, wherein the protection arrangement comprises a speed/load controller that is in connection with the relay arrangement, which speed/load controller is arranged to drive a prime mover of the generator set as a response for said detection, said speed/load controller being connectable with said prime mover, the speed/load controller driving power output of the prime mover to a lower level when over-current, under voltage or both is detected, the driving of the power output to the lower level is arranged to initiate during a fault of the power system and before the critical clearing time of a generator of the generator set.
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Accused Products
Abstract
The inventive protection arrangement of an electric power system comprises a relay arrangement (12) for measuring current, voltage or both of an electric grid (15). The relay arrangement is adapted to detect over-current, under-voltage or both. The protection arrangement comprises also a speed/load controller (16) that is in connection with the relay arrangement (12). The speed/load controller is arranged to drive a prime mover (11) of a generator (10) set as a response for the said detection. The speed/load controller (16) is connectable with said prime mover (11). In more detail the controller (16) is arranged to drive power output of the prime mover (11) to a lower level when over-current, under-voltage or both is detected.
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Citations
8 Claims
- 1. A protection arrangement of an electric power system, the electric system comprising a generator set, the protection arrangement comprising a relay arrangement for measuring current, voltage or both of an electric grid, which relay arrangement is adapted to detect over-current, under-voltage or both, the generator set being separable from a grid when over-current, under-voltage or both are detected, and the detected over-current, under-voltage, or both does not stop before a critical clearing time, the critical clearing time determining a period, during which resynchronization of the generator set with the grid is possible, wherein the protection arrangement comprises a speed/load controller that is in connection with the relay arrangement, which speed/load controller is arranged to drive a prime mover of the generator set as a response for said detection, said speed/load controller being connectable with said prime mover, the speed/load controller driving power output of the prime mover to a lower level when over-current, under voltage or both is detected, the driving of the power output to the lower level is arranged to initiate during a fault of the power system and before the critical clearing time of a generator of the generator set.
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7. A method for protecting an electric power system, the method comprising a phase for measuring at least one of current and voltage of an electric grid, the method further comprising phases for forming a detection signal in case of measurement of at least one of over-current and under-voltage, and adjusting speed/load control of a prime mover of a generator set in response to the detection signal,
wherein the adjusting phase is arranged to drive power output of the prime mover to a lower level in response to the detection signal, the driving of the power output to the lower level initiating during a fault of the power system and before the critical clearing time of a generator of the generator set.
Specification