Chain type SVG (static var generator) device low-pressure power supply system

Abstract

The invention discloses a chain type SVG (static var generator) device low-pressure power supply system which comprises a mid-frequency constant current power supply, mid-frequency isolation transformers, a high-voltage insulation cable, energy-taking current transformers, power supply changeover plates, an SVG power unit and an SVG power unit control box, wherein an external power supply is input into the mid-frequency constant current power supply, the mid-frequency constant current power supply is connected with the mid-frequency isolation transformers, and more than one energy-taking current transformers are connected with the mid-frequency isolation transformers through the high-voltage insulation cable; and the energy-taking current transformers are connected with the SVG power unit through the power supply changeover plates, and the power supply changeover plates are arranged in the SVG power unit control box. The chain type SVG device low-pressure power supply system provided by the invention adopts complete current transformer energy-taking manner to provide an energy for a control power supply of the SVG power unit, can realize small power supply energy input and large power supply energy output, and can effectively reduce volume and cost; the installation and the maintenance are convenient, and the efficiency is high; and meanwhile, the maintenance of an open-close type current transformer is more convenient relative to a straight-through current transformer.

Description

technical field [0001] The invention relates to a power supply system of a reactive power compensation device, in particular to a low-voltage power supply system applied to a chained SVG (Static Var Generator, static var generator) device. Background technique [0002] With the vigorous development and wide application of power electronics technology, there have been many technological innovations and production applications in power system automation, which have brought a lot of convenience to our work and life. But at the same time, technological innovation has also brought many unstable factors to the power system, such as low power factor, grid harmonic pollution, three-phase voltage unbalance, voltage fluctuation and flicker. As a result, the power quality of the power grid is poor, the productivity of users is reduced, and the competitiveness is weakened. It also affects the employment of employees and even the entire economy and society. [0003] With the implementat...

AI Technical Summary

Problems solved by technology

[0006] The first is to use power frequency isolation transformers and energy harvesting currents to realize low-voltage energy harvesting. The disadvantage of this method is that the current transformers and isolation transformers on each power unit are designed according to power frequency, the iron core size is large, and the voltage source is used mode, poor control accuracy and adjustment ability

[0007] The second is to use the DC capacitor of the power unit to obtain energy. This disadvantage is that the control system cannot be self-inspected before the system is charged, and the voltage fluctuation of the DC capacitor and the bypass switch in case of failure cannot provide energy.

In the paper, four energy harvesting methods including CT energy harvesting, transformer energy harvesting, capacitor energy harvesting, and high-frequency energy harvesting are proposed, but neither of these two energy harvesting methods is given in the paper. The principle introduction of the energy harvesting method itself

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