Power grid filtering method for harmonic waves generated in intermediate frequency furnace of iron and steel plant

A technology for intermediate frequency furnaces and steel plants, applied to AC networks to reduce harmonics/ripples, harmonic reduction devices, energy industries, etc., can solve the problems of high and low average power factors, only about 0.5, and achieve compensation Effects of power factor, reduction of harmonics, and suppression of voltage fluctuations

Inactive Publication Date: 2014-12-10
STATE GRID CORP OF CHINA +3
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The characteristic of the intermediate frequency furnace is that the power factor is high when it is close to full load, which can reach 0.9 (or even higher), but its power factor is low when the load is light, only about 0.5, and its average power factor is generally higher.

Method used

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  • Power grid filtering method for harmonic waves generated in intermediate frequency furnace of iron and steel plant
  • Power grid filtering method for harmonic waves generated in intermediate frequency furnace of iron and steel plant
  • Power grid filtering method for harmonic waves generated in intermediate frequency furnace of iron and steel plant

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Experimental program
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Effect test

Embodiment 1

[0033] For the harmonic control of large-capacity intermediate frequency furnaces, two schemes can be adopted: low-voltage filter compensation design scheme and high-voltage filter compensation design scheme. The low-voltage filter compensation design scheme refers to the filter on the low-voltage side of the rectifier transformer, and each transformer is equipped with a set of low-voltage filter devices, which can be switched on or off with the start and stop of the furnace. The high-voltage filter compensation design scheme filters on the 35kV side of the system. Since the high-voltage filter has the advantage of low cost, it can reduce most of the burden for the user; at the same time, because the harmonic content of the high-voltage side is much smaller than that of the low-voltage side, a smaller capacity can be used, and it is easy to achieve the filtering effect without compensation. The harmonic control of Jianshun Iron and Steel Works adopts a high-voltage filter comp...

Embodiment 2

[0061] The low-voltage side harmonic control scheme is adopted for the harmonic control of small-capacity intermediate frequency furnaces. In this embodiment, 6 sets of filtering devices are arranged on 6 six-pulse rectifier furnaces.

[0062] The content of this test is the 35kV bus harmonic voltage and the user's harmonic current. There are currently 8 intermediate frequency furnaces (two of them have been changed to 12-pulse rectification without filter devices; the remaining 6 furnaces have been changed to 6-pulse rectifiers, all of which are equipped with filters). According to the actual situation on site, the test process is divided into three types Different working conditions are described as follows:

[0063] Working condition 1: 6 six-pulse rectifier furnaces with filtering devices are put into production, and two 12-pulse rectifier furnaces are in production at the same time;

[0064] Working condition 2: Keep the operation status of the intermediate frequency fur...

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Abstract

The invention relates to a power grid filtering method for harmonic waves generated in an intermediate frequency furnace of an iron and steel plant. The power grid filtering method comprises the following steps of firstly, determining that transfinite harmonic frequencies generated in the intermediate frequency furnace are 5-frequency low and odd harmonic waves, 7-frequency low and odd harmonic waves and 11-frequency low and odd harmonic waves according to acquired transfinite harmonic wave conditions generated in harmonic source intermediate frequency furnaces, which are mainly used for generating harmonic waves, in various iron and steel plants; secondly, determining the capacity of the intermediate frequency furnaces of the iron and steel plants; thirdly, using different compensation modes for the intermediate frequency furnaces with different capacities, namely, using different supplementing modes for the intermediate frequency furnaces with the different capacities; and finally, mounting static var compensators in the intermediate frequency furnaces in a parallel-connection manner and restraining voltage fluctuation, voltage flicker, three-phase unbalance degree and compensation power factors so that integral power grid filtering is finished. By the filtering method, fluctuation harmonic capacity can be effectively reduced; and moreover, voltage fluctuation, voltage flicker, three-phase unbalance degree and compensation power factors can be restrained.

Description

[0001] A power grid filtering method for harmonics generated by intermediate frequency furnaces in iron and steel plants. technical field [0002] The invention relates to a power grid filtering method for harmonics generated by an intermediate frequency furnace in a steel plant. Background technique [0003] The suppression of harmonics in the power system is how to reduce or eliminate the harmonic current injected into the system, so as to control the harmonic voltage within the limit value. Power system harmonic suppression is an important aspect to improve power quality. There are two main ways to suppress harmonics: the first is to start with improving power electronic devices to reduce the harmonic current injected into the grid, that is, to take measures on the harmonic source to avoid the generation of harmonics to the greatest extent ; The second type is to use LC passive filter and power active filter to provide frequency domain harmonic compensation and time doma...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/01H02J3/16H02J3/26
CPCY02E40/30Y02E40/40Y02E40/50Y02P80/10
Inventor 丁智华章浦军赖志强何邦生涂承谦
Owner STATE GRID CORP OF CHINA
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