Self-adaptive emergency load shedding method based on voltage drop amplitudes

Abstract

The invention discloses a self-adaptive emergency load shedding method based on voltage drop amplitudes. The self-adaptive emergency load shedding method based on the voltage drop amplitudes comprises the steps that the voltage drop amplitudes of all load nodes of a whole grid are calculated; all the load nodes are ranked according to the voltage drop amplitudes; all the ranked load nodes are cut off in sequence according to the voltage drop amplitudes in a descending order, and load shedding is completed when the total amount of the shed load is equal to the active power loss of the whole grid. According to the self-adaptive emergency load shedding method based on the voltage drop amplitudes, the transient voltage response of a power system is fully considered. Compared with an existing load shedding method, a weak bus in the power grid can be effectively and rapidly selected for load shedding, the number of positions where load shedding is conducted can be adjusted according to the actual condition of the power grid and the active power loss caused when a failure occurs, the spatial and temporal distribution characteristic, existing when serious disturbance happening to the system, of the voltage of all the load nodes is fully considered, the state of the system is effectively controlled, the phenomenon of voltage collapse is avoided, and the stability of the frequency of the power system and the stability of the voltage of the power system are guaranteed.

Description

technical field [0001] The invention relates to the technical field of self-adaptive emergency load shedding by using voltage response information, in particular to a method for self-adaptive emergency load shedding based on voltage drop amplitude. Background technique [0002] When the power system is in normal operation, the reactive power output of the power supply is balanced with the reactive power consumption of the load and the reactive power loss of the network. If there is a shortage of power supply or reactive power compensation capacity, the load terminal voltage is forced to drop. When the voltage drops to a certain critical value, the voltage value continues to drop and cannot be recovered, which is a voltage collapse. The voltage collapse forces all loads in the area to be blacked out, and may even extend to a loss of synchronization between several parts of the system, causing asynchronous oscillations, causing system-wide accidents, and loss of more loads ...

AI Technical Summary

Problems solved by technology

The voltage collapse forces all loads in the area to be blacked out, and may even extend to a loss of synchronization between several parts of the system, causing asynchronous oscillations, causing system-wide accidents, and loss of more loads

[0003] At present, low-voltage load shedding has been widely used to avoid blackouts caused by voltage collapse, but the design process of low-voltage load shedding mainly adopts traditional solutions, that is, setting a certain threshold and delay, when the voltage drops below the threshold After a certain delay, the load is removed according to a certain ratio. This scheme uses local voltage response information, which belongs to decentralized voltage control, and does not take into account the frequency response of the system. It is independent of low-frequency load shedding, and it is not fully Considering the time-space distribution characteristics of the voltage of each load node after a large disturbance occurs in the system, it is often impossible to effectively control the system state, and even after load shedding, frequency or voltage collapse still occurs

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