Smart distribution network self-restoration optimization method considering power quality and uncertainty constraint thereof

Abstract

The present invention provides a smart distribution network self-restoration optimization method considering a power quality and an uncertainty constraint thereof. With regard to each island, a load shedding optimization model is established for the goal of high important grade load optimization restoration and maximum total restoration quantity, a bi-level optimization model formed by a network reconstitution optimization model for the goal of the least number of switch motions and minimum transmission losses, and an optimal load shedding scheme is taken as the input of the network reconstitution optimization. Especially, in the network reconstitution optimization model, an uncertainty analysis of a negative sequence and a harmonic wave is performed through an entrance point method of estimation, so that a power quality comprehensive constraint set containing frequency constraint, the negative sequence, the harmonic wave and the uncertainty constraint thereof is established according to the possible variation range of the negative sequence and the harmonic wave obtained by the uncertainty analysis, therefore the power quality of the recovery scheme may be improved and the restoration failure may be avoided. Through the establishment of a power quality comprehensive constraint set, the goal of safe and reliable power supply restoration may be achieved.

Description

technical field [0001] The invention relates to a self-healing restoration optimization method of an intelligent distribution network considering power quality and its uncertainty constraints. Background technique [0002] The research on power supply recovery after distribution network failure has always been one of the hot issues in distribution network research. After a fault occurs in the traditional distribution network, the fault is first isolated by disconnecting the segmental switch at the fault point, and then the network reconstruction of the non-faulty grid is performed to restore power supply. With the access of distributed generation (DG), it is possible to guarantee the normal operation of part of the load in the form of an island after a fault. The traditional principle of dealing with isolated islands is: once the system fails, immediately disconnect all distributed power sources to prevent possible damage to the equipment in the system, eliminate potential ...

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Problems solved by technology

However, the existing methods only consider the island power balance constraints, and do not take into account the influence of power quality factors

Due to the small capacity of the island, its negative sequence and harmonic problems are more serious than those of non-islanded operation. The large negative sequence component may cause the negative sequence protection action of the distributed power supply and make the DG stop running, and the harmonic content is high. It poses a threat to the safe operation of various equipment such as shunt capacitors, and may cause equipment damage or out of operation, resulting in an imbalance of active or reactive power in the system, further leading to recovery failure, and it is difficult to guarantee the reliability of power supply recovery

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