Zero-sequence harmonic suppression device for distribution network neutral line with changed iron core structure

Abstract

The invention discloses a power distribution network neutral line zero sequence harmonic suppression device with a changed iron core structure. The device comprises a zero-sequence filter, the zero-sequence filter comprises four core columns and six windings, the winding numbers of the windings are same, the core columns are parallel to one another, the included angle between a first parallel plane and a second parallel plane, the included angle between the first parallel plane and a third parallel plane and the included angle between the second parallel plane and the third parallel plane are all 120 degrees, the first parallel plane is composed of the first core column and the second core column, the second parallel plane is composed of the first core column and the third core column, the third parallel plane is composed of the first core column and the fourth core column, three windings are wound around the first core column, and the other core columns are each provided with one winding in a winding mode; each winding phase is divided into two half windings which are located on two different core columns respectively, each phase of voltage is obtained by reversely connecting the two half windings located on the different core columns, the leading-out ends of three lower half windings are in short connection with one another and then are connected to a power grid neutral line, and three upper half windings are directly connected with a three-phase power grid in parallel. Accordingly, a low-resistance channel is provided for zero-sequence harmonic currents of a power distribution network, and then the zero-sequence harmonic currents in the power distribution network neutral line are filtered out.

Description

technical field [0001] The invention relates to the technical field of power quality control, in particular to a zero-sequence harmonic suppressing device for a neutral line of a distribution network with a changed iron core structure. Background technique [0002] In the low-voltage power distribution system, the three-phase four-wire power supply mode is the most important power supply mode. With the modernization of the city, a large number of nonlinear electrical equipment such as personal computers, office automation equipment, frequency conversion air conditioners, lighting power supplies and uninterruptible power supplies will generate a large amount of harmonic currents, especially zero-sequence harmonics, even if their single power Smaller, but because of its huge total number, the harmonic pollution it brings is extremely serious. [0003] The zero-sequence harmonic current, especially the third-order harmonic current, is superimposed on the neutral line without c...

AI Technical Summary

Problems solved by technology

Excessive neutral line current not only increases the network loss of the distribution network but also causes the neutral line to be overloaded and overheated

In the distribution network, the neutral wire overload and overheating often cause the neutral wire disconnection, the neutral wire disconnection will cause the neutral point potential shift, and the neutral point potential shift will cause adverse effects on single-phase loads with a rated voltage of 220V. Affected, resulting in three-phase equipment (such as motors, etc.) output drop, overheating or even burning abnormal phenomena

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