Low-frequency voltage load-reducing linkage coordination control method

Abstract

The invention discloses a low-frequency voltage load-reducing linkage coordination control method which is used for carrying out real-time information acquisition and control on information of all transformer stations in the whole network on the basis of a power grid scheduling automatic system, important degree classification on loads of all transformer stations from the layer of the whole network, figuring out a load needing being cut in each turn when a power grid is borne by various kinds of large interference by assisting the optimization of rapid calculation analysis, and immediately issuing a load shedding command to a corresponding station end low-frequency low-voltage load-reducing device, thereby rapidly cutting the corresponding loads off and achieving the purpose of restoring system safety. Because the method is used for carrying out linkage coordination control of the whole system on the basis of the whole power grid, thus the problem of easy over-cutting or under-cutting of the traditional low-frequency low-voltage load-reducing device can be remarkably reduced, unnecessary line power failure loss is reduced, and power supply reliability and safety economy of the whole power grid are improved.

Description

technical field [0001] The invention relates to a low-frequency voltage load shedding linkage coordinated control method for the entire power grid. Background technique [0002] Modern power systems are characterized by large units, ultra-high voltage, and large-scale long-distance power transmission, but there is a danger of frequency and voltage collapse. When a serious fault occurs in the system, the reserve capacity is not enough to make up for the power shortage of the system, the system should selectively shed the load, give full play to the role of the low-frequency and low-voltage load shedding device, and build the third line of defense for the power grid. Current low-frequency and low-voltage load shedding control methods include the following methods: [0003] 1) Traditional method: When the system frequency is lower than the set value, the relay acts to remove part of the load. If the frequency continues to drop, it means that the shedding load is insufficient....

AI Technical Summary

Problems solved by technology

The K value varies with time, the same frequency drop value, the load value cut in the same round at different times should also be different, and it is easy to cause overcutting

[0014] 2) The change of the load of the cut line is not fully considered

[0015] In the past, the setting of low-frequency and low-voltage load shedding devices was performed offline, mainly based on typical daily loads. Due to real-time changes in loads, the preset load shedding may not be able to adapt to the power shortage in actual accident scenarios, so there is a certain degree of undercutting or overcut and may cause new system problems

[0016] 3) The working principle and operation management of decentralized control are poor;

[0019] Distributed measurement of three-phase voltage of the line, which controls one line, centralized measurement of line bus voltage, which controls the line on the bus in a certain station, and each relay can only respond according to the voltage or frequency that it can observe. The understanding and overall coordination of the global information of the system makes it difficult to achieve the effect of coordination and optimization of the entire network

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