Method for evaluating current three-phase unbalance degree of distribution network

Abstract

The invention relates to a method for evaluating the current three-phase unbalance degree of a distribution network. The method is characterized by comprising the following steps of: (1), performing mutation data correction of three-phase current acquired data of a three-phase alternating-current system of the distribution network by adopting a BP neural network algorithm; (2), according to the corrected three-phase current acquired data of the distribution network, respectively selecting maximum load days as typical days in workdays and non-workdays in every month so as to obtain three-phase current acquired data of the distribution network of 24 typical days in one year; (3), respectively evaluating the current three-phase unbalance degree of the distribution network in 24 typical days; and (4), calculating an average value of the current three-phase unbalance degree of the distribution network in 24 typical days in one year so as to obtain the current three-phase unbalance degree of the distribution network in one year. According to the method disclosed by the invention, when the current three-phase unbalance degree of the distribution network is calculated, multiple variable factors, such as seasons, workdays and current values at different times in one day, are comprehensively considered; and thus, the evaluation result is more accurate and objective.

Description

technical field [0001] The invention relates to the technical field of distribution network operation, in particular to an evaluation method for three-phase unbalance degree of distribution network current. Background technique [0002] In an ideal distribution network three-phase AC power system, the three-phase current should have the same magnitude, so that the neutral wire in the distribution network three-phase AC system will not flow current and will not cause loss on the neutral wire. In the actual distribution network three-phase AC system, due to the uneven load of each phase, these unbalanced currents will not only cause losses on the phase lines, but also cause losses on the neutral line, increasing the total loss. Therefore, it is proposed to use the magnitude of the current three-phase unbalance to analyze and evaluate the load balance. However, the existing evaluation methods for the current three-phase unbalance cannot effectively solve the problems of load se...

AI Technical Summary

Problems solved by technology

In the actual distribution network three-phase AC system, due to the uneven load of each phase, these unbalanced currents will not only cause losses on the phase lines, but also cause losses on the neutral line, increasing the total loss

Therefore, it is proposed to use the magnitude of the current three-phase unbalance to analyze and evaluate the load balance. However, the existing evaluation methods for the current three-phase unbalance cannot effectively solve the problems of load seasonality, transient and data collection errors. Problems, can not reflect the actual operation of the distribution network, resulting in the inability to effectively guide the daily work, and can not solve the actual work problems

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