Dynamic voltage recovery system based on double-bus cross power supply

Abstract

The invention discloses a dynamic voltage recovery system based on double-bus cross power supply, and the problem that the temporary drop compensation is difficult when the load-side multi-sensitive loads generate voltage sag faults at the same time is solved. A full-bridge direct-current booster circuit and a cascade 27-level inverter main circuit topology structure are adopted; a direct-currentunit supplies power according to needs by adopting super-capacitor energy storage and a storage battery pack, so that the investment of a large power grid is reduced. The voltage recovery system judges the voltage sag and voltage interruption by detecting the magnitude of the voltage sag, and which system is determined to be merged into the power grid for voltage compensation. On the basis of thedouble-bus cross power supply mode during voltage interruption compensation, the island mode and grid-connected operation modes of the compensation device are controlled to be switched, and due to thefact that the micro-grid works in three operation modes of the island mode, the operation mode of switching from the island mode to the grid-connected mode, and the grid-connected operation mode, thecross power supply of two sections of buses is realized, and the reliability of the power supply of the sensitive loads in the microgrid is ensured. According to the dynamic voltage recovery system,the voltage sag is effectively compensated, and the electric energy quality is improved.

Description

technical field [0001] The invention relates to a dynamic voltage recovery system based on double-busbar cross power supply, and belongs to the technical field of analysis and treatment of transient power quality disturbance signals. Background technique [0002] For a long time, power supply companies have paid more attention to power quality on the grid side. The main monitoring indicators include voltage and frequency. However, in the qualified power quality provided by power supply companies, sometimes factors such as voltage sags caused by system disturbances cannot To meet the requirements of some special enterprises, it is generally concentrated in users and manufacturers with imported equipment or precision instruments. At present, the country has not issued clear standards and requirements for voltage sags, so power supply companies have little research on the internal electricity demand of special users. If these special companies want to ensure the normal operatio...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a dynamic voltage recovery system based on double-bus cross power supply, to solve the problem that the traditional compensation device based on power electronics does not start from the perspective of the entire power supply system, and the device is limited by cost and power, which cannot satisfy The problem of the actual demand of multiple sensitive loads on the load side, the present invention uses the double-busbar cross power supply mode to realize the dynamic voltage recovery system of the grid-side voltage sag and interruption centralized compensation, and fully utilizes the power supply of dual busbars in industrial sites, and the dual busbars simultaneously In the actual situation where the probability of voltage sag is very small, the centralized compensation for voltage sag and interruption on the grid side is realized

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