Dynamic voltage compensation device and control method for AC-DC hybrid distribution network

Abstract

The invention relates to a dynamic voltage compensation device and a control method thereof for an AC / DC hybrid distribution network, wherein the device includes: an A-phase rectification and transformation module, a B-phase rectification and transformation module, and a C-phase rectification and transformation module that are electrically connected to each other; The A-phase rectification and transformation module, the B-phase rectification and transformation module and the C-phase rectification and transformation module all include: electrical connection terminals on the high-voltage input side, reactors, multiple power units connected in series on the input side and multiple primary sides electrically connected in sequence The isolation transformers are electrically connected to the output side of each power unit; the power units at each end of the A-phase rectification and transformation module, B-phase rectification and transformation module, and C-phase rectification and transformation module are electrically connected to each other, and the isolation transformers at each end are connected to each other. Electrical connection; the input side outlet terminals of the power units at each end are shorted together to form a high-voltage neutral point N; the DC bus lead-out terminal of one of the end power units is used as the negative terminal of the low-voltage DC output side and the positive terminal of the low-voltage DC output side terminals.

Description

technical field [0001] The invention relates to the technical field of power quality control, in particular to a reconfigurable dynamic voltage compensation device and a control method thereof for an AC / DC hybrid distribution network. Background technique [0002] Natural disasters such as lightning strikes, short circuits, large-capacity load switching, grounding, and grid failures will cause transient power quality problems such as voltage sags and short-term interruptions, which will bring huge economic losses to sensitive load users such as chip processing and scientific research parks. Its harmfulness has surpassed steady-state power quality problems such as harmonics, three-phase unbalance, and voltage deviation. At present, the voltage sag and short-term interruption control devices mainly include low-voltage dynamic voltage restorer (DVR), solid-state transfer switch (SSTS), uninterruptible power supply (UPS), etc., which generally have defects, such as complex DVR e...

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Problems solved by technology

[0002] Natural disasters such as lightning strikes, short circuits, large-capacity load switching, grounding, and grid failures will cause transient power quality problems such as voltage sags and short-term interruptions, which will bring huge economic losses to sensitive load users such as chip processing and scientific research parks. Its harmfulness has surpassed steady-state power quality problems such as harmonics, three-phase unbalance, and voltage deviation.

At present, the voltage sag and short-term interruption control devices mainly include low-voltage dynamic voltage restorer (DVR), solid-state transfer switch (SSTS), uninterruptible power supply (UPS), etc., which generally have defects, such as complex DVR equipment and series safety factor requirements The high compensation range is small, and the dynamic response of the parallel type is relatively poor; SSTS requires dual-circuit, independent power supplies, the switching logic is complex, and there is a long power outage time during the switching process; UPS is usually applied to small-capacity loads, with slow response speed and low efficiency. And accompanied by power quality problems such as harmonic pollution

[0003] On the other hand, more and more sensitive loads on the user side, such as data centers, use DC power distribution, which saves a lot of commutation links and effectively reduces distribution power loss. However, current voltage sag control devices generally do not have DC output ports. , unable to meet the transient voltage problem management requirements of the above occasions

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