Generator tripping computing method for power system

Abstract

The invention discloses a generator tripping computing method for a power system. The generator tripping computing method includes: computing power transmission proportion K of local power grid transmission power and total output capacity of local generators, judging whether to implement generator tripping or not when the local power grid is disconnected with a major grid according to the power transmission proportion K, simultaneously setting action threshold proportion definite value K threshold to judge whether to implement generator tripping, and implementing generator tripping immediately when power transmission proportion meets K>=K threshold before transmission channels of the local power grid are disconnected. Computing accuracy of generator tripping can be improved after the transmission channels of the local power grid are disconnected, and conditions are created for grid synchronization.

Description

technical field [0001] The invention relates to a calculation method for cut-off quantity in an electric power system. Background technique [0002] The local power grid with excess power sends power to the system during normal operation. When the power transmission section is disconnected due to a fault in the interconnection line, if the proportion of power transmission is large, appropriate control measures need to be taken to maintain the power balance of the local power grid. Create conditions for grid connection at the same time, or maintain stable operation of local isolated grids. If the control measures are not taken properly, it may cause the frequency of the local power grid to oscillate repeatedly after the fault, and eventually lead to the breakdown of the isolated small grid. The increase of network frequency will cause the high-frequency cutting machine to cut off the machine. The controllability of the high-frequency cutting machine action is poor and it may...

AI Technical Summary

Problems solved by technology

If the control measures are not taken properly, it may cause the frequency of the local power grid to oscillate repeatedly after the fault, and eventually lead to the breakdown of the isolated small grid. The increase of network frequency will cause the high-frequency cutting machine to cut off the machine. The controllability of the high-frequency cutting machine action is poor and it may be overcut. Overcutting will cause the system frequency to drop. After the system frequency drops, the low-cycle load shedding device Action, low-cycle load shedding may overcut and cause the system frequency to rise again, such repeated oscillations and eventually lead to local grid collapse, local grid frequency oscillations after failures and accidents that eventually lead to grid collapse have occurred both at home and abroad

[0003] At present, for the failure of the disconnection of the transmission channel of the local power grid, most of the schemes are adopted to take control measures according to the power sent before the failure. The calculation standard of the control amount is the power sent before the isolated grid accident. This scheme cannot fully consider the operation mode of the power grid The change of the judgment threshold makes it more difficult to set the judgment threshold. For example, when the power grid is running in the peak period of power consumption, the power load of the entire power grid and the output of the generator are relatively large. For the same external power, if the generator and load are considered Frequency adjustment effect, the impact on the isolated small grid after the outbound channel is disconnected is relatively small, but during the low power consumption period, the power load of the entire grid and the output of the generator are relatively small, for the same outbound power, the impact on the isolated small network will be greater after the outgoing channel is disconnected

[0004] In addition, the current method only takes one control measure, and it is hoped that the isolated small network can maintain stable operation after the control measures are taken. its collapse

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