Buck type three-level alternating current-alternating current converter-based reactive power and harmonic compensation device

Abstract

The invention discloses a Buck type three-level alternating current-alternating current converter-based reactive power and harmonic compensation device. A main circuit of the device consists of Buck type three-level alternating current-alternating current converters with low-power transformers and conventional reactive power compensation capacitors, and reactive power and harmonic current of a three-phase three-wire system power grid side can be comprehensively compensated. The device comprises three single-phase reactive power and harmonic compensation main power circuits, wherein the Buck type three-level alternating current-alternating current converter with the low-power transformer in each phase comprises an alternating current input unit, an input filter, a Buck type three-level alternating current-alternating current conversion unit with the low-power transformer, an output filter and a reactive power compensation capacitor. According to the device, an even-order harmonic modulation technology and a successive harmonic compensation control solution are adopted to compensate a specific-order harmonic component. The device is small, low in cost and high in reliability and hasthe advantages of easiness for modular manufacturing, simple control strategy and more pertinent compensation.

Description

technical field [0001] The invention belongs to the technical field of power quality management, in particular to a reactive power and harmonic compensation device based on a Buck type three-level AC-AC converter. Background technique [0002] With the development of the industrial economy, a large number of inductive loads such as induction motors, transformers, and power electronic converters are connected to the power grid. The voltage drops. When the voltage drops to a certain threshold, equipment and loads cannot work normally; if the voltage continues to drop, the grid will collapse because the voltage exceeds the stable operating range. At the same time, a large number of nonlinear loads, especially various power electronic devices, are connected to the power grid, which produces a large amount of harmonic pollution in the power grid. In order to support the grid voltage, improve the power quality of the grid, and ensure the safe and reliable operation of the power ...

AI Technical Summary

Problems solved by technology

However, the technology is still in a development stage at present, and still has the disadvantages of high cost and complex control strategy, and it is impossible to realize the reactive power and harmonic comprehensive compensation of the three-phase grid current.

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