Isolation transformer for filter circuit and filter circuit system

Abstract

The invention provides an isolation transformator for a filter circuit and a filter circuit system. The filter circuit system comprises the isolation transformator for the filter circuit, a filter capacitor bank and an electric electronic circuit, wherein the isolation transformator for the filter circuit comprises main iron cores, low-voltage coils, leakage reactance iron cores, high-voltage coils, clamping pieces, straight-through screw rods, lateral screw rods, leakage reactance iron core fixing plates and reactor coils; the leakage reactance iron cores are fastened through clamping pieces, straight-through screw rods, lateral screw rods and the leakage reactance iron core fixing plates; the main iron cores are fastened through clamping pieces, straight-through screw rods and lateral screw rods; and the reactor coils are sleeved on the leakage reactance iron cores and connected with the filter capacitor bank. Through implementation of the isolation transformator, system equipment can be simplified, the system cost can be lowered, loss and the phenomenon of metal heating can be reduced, and the system efficiency can be improved.

Description

technical field [0001] The invention relates to the field of power systems, in particular to an isolation transformer for a filter circuit and a filter circuit system. Background technique [0002] In traditional large-capacity power electronic circuit filter systems, LCL filter circuits are often used, which can suppress high-order harmonic currents very well. The LCL filter circuit usually includes two reactor devices, which are connected to the power grid through an isolation transformer. The system circuit diagram is as follows figure 1 As shown, in this system, the LCL filter circuit and the isolation transformer are usually independent devices, which have high cost, large floor space and low efficiency. [0003] The patent application number is: CN201020679395.X, and the title of the invention is: "A schedulable three-phase photovoltaic grid-connected inverter device based on LCL filtering" Chinese patent application discloses a schedulable three-phase photovoltaic gr...

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Problems solved by technology

[0004] The technical solution disclosed in the above patent application can obtain high-quality grid-connected current at a relatively low switching frequency, and the active power fed into the grid can be changed by changing the phase angle difference between the inverter output voltage and the grid voltage, so as to realize the grid-connected photovoltaic The scheduling function of the system, but it still has not solved the technical problems of high equipment cost, large floor area and low system efficiency in the filter circuit system

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