Three-phase unbalanced load adjustment method based on power and electricity consumption of low-voltage power distribution network

Abstract

A three-phase unbalanced load adjustment method based on the power and electricity consumption of a low-voltage power distribution network comprises the following steps of 1, acquiring the power dataof the low-voltage power distribution network, establishing an active power matrix, and calculating the average active power, the average active power and the three-phase average total power of the phases A, B and C according to the active power matrix; 2, obtaining a calculation formula for calculating the three-phase unbalance degree in the low-voltage power distribution network by the active power; 3, calculating the total unbalance degree of the low-voltage power distribution network by adopting the active power; 4, when the total unbalance degree is larger than a set threshold value, solving the active power adjustment amount; and 5, according to the active power adjustment amount, solving a user needing phase modulation and carrying out phase modulation on the user. According to themethod, the problem of misadjustment caused by the random load access or fluctuation when the load current is detected on a site to guide the load adjustment is avoided, the working efficiency is improved, and guidance can be provided for the user to optimize the access phase selection, and therefore the three-phase imbalance degree of the low-voltage distribution network is restrained.

Description

technical field [0001] The invention belongs to the technical field of power grids, in particular to a method for adjusting three-phase unbalanced loads based on the power and consumption of low-voltage distribution networks. Background technique [0002] my country's distribution network structure is weak, and the degree of automation and intelligence of the distribution system is low. The single-phase loads in the distribution network are mostly, and the single-phase and three-phase loads are cross-mixed, especially in the rural distribution network, which has a wide area and many users. In scattered areas, there have been serious three-phase unbalance problems for a long time. The long-term unbalanced three-phase load in the distribution station area will increase the loss of distribution transformers and lines, reduce power quality and output of distribution transformers, and in serious cases will It endangers the safety of equipment and has a serious impact on grid securi...

AI Technical Summary

Problems solved by technology

Among them, the reactive power compensation method and the asymmetric compensation method refer to adjusting the three-phase load through compensation on the low-voltage side of the distribution transformer. By changing the topology of the distribution transformer, the three-phase unbalance problem can be solved to a certain extent, but it is easy The introduction of harmonics, resulting in resonance, cannot fundamentally solve the three-phase imbalance from the source

As for the station controller, due to the limited number of users connected to each station controller, the price of the station controller is high, and the operation and maintenance costs are high, it is not suitable for large-scale promotion and use.

Therefore, the manual line adjustment method is still the mainstream method in practical engineering applications. When using the ammeter to detect the three-phase load current and use it as a calculation index to plan the number of users to be adjusted, it is easily affected by the instantaneous load, resulting in misadjustment.

However, for the users in the low-voltage distribution network of the power system, the power system only collects the meter data of the user's electricity consumption. Data cannot be collected in real time

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