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A DC step-down half-voltage four-quadrant rectifier

A four-quadrant rectifier and AC power supply technology, applied in the direction of converting AC power input to DC power output, AC network circuit, output power conversion device, etc., can solve the problems of limited application range and can only work at high DC voltage, etc.

Active Publication Date: 2022-08-05
张超 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, as we all know, there is an obvious shortcoming in the voltage source bridge FQR structure, that is, in order to ensure its normal operation, especially in order to ensure the transient controllability of the current waveform on the AC side, the DC side voltage must be raised high enough , this feature is derived from the boost topology of the voltage-type bridge FQR, which limits its application range to a certain extent and can only work in a high DC voltage state

Method used

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  • A DC step-down half-voltage four-quadrant rectifier
  • A DC step-down half-voltage four-quadrant rectifier
  • A DC step-down half-voltage four-quadrant rectifier

Examples

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Embodiment 1

[0036] If the AC side input power e of each FQR unit is selected k (k=1, 2, 3) are power frequency 50Hz, RMS 220V grid sine wave voltage, then for the traditional half-bridge FQR unit, the DC side voltage U d The lower limit of the value range is required to be: U dmin >2E km = 622V, which is slightly higher than a certain margin in practice. Usually, the recommended margin factor is 1.12, which is about 697V; for traditional three-phase FQR, the lower limit is required to be: Take 1.12 according to the margin factor, and the actual value is about 604V. Compared with the present invention, no matter the DHV type FQR unit or the three-phase FQR, etc., the DC side voltage U d1 The lower limit of the value range is required to be: U d1min >E km = 311V, which is slightly higher than a certain margin in practice. According to the commonly recommended margin factor of 1.12, it is about 348V, which is nearly half of the traditional FQR structure.

Embodiment 2

[0038] The implementation case of DHV type FQR applied to photovoltaic power generation grid-connected inverter The system structure is as follows Figure 4 shown. In view of the fact that the DC side voltage requirement of DHV-FQR is much lower than that of traditional bridge FQR, when implementing photovoltaic power generation inversion, there is no need to go through the step-up DC / DC conversion, and the lower voltage photovoltaic cell array can be directly connected to the DHV -FQR DC side. Its control method can still use the typical double closed-loop control system basically consistent with the traditional bridge FQR. Figure 4 .

[0039] Assume that the grid-connected voltage on the AC side is a three-phase line voltage of 380V (or a single-phase voltage of 220V), and considers the actual DC side voltage U according to Embodiment 1. d1 The lower limit of the value range should be higher than a certain margin, U d1min The recommended value is 348V.

[0040] Select ...

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Abstract

The invention belongs to the technical field of power electronic conversion and new energy power generation, and in particular relates to a direct current step-down half-voltage four-quadrant rectifier (DHV-FQR). The new circuit structure of the rectifier is aimed at an obvious shortcoming of the traditional voltage source bridge FQR, that is, in order to ensure its normal operation, especially in order to achieve excellent control performance of the AC side transient current waveform, the DC side voltage must be The rise is high enough to limit its application range. This patent provides a DC side step-down half-voltage four-quadrant rectifier, including a power input circuit unit, a cross-over H-bridge circuit unit and an output load unit. The traditional structure can be reduced by approximately half, which is suitable for power electronic conversion applications with lower requirements on the rated working voltage of the DC side.

Description

technical field [0001] The invention relates to a novel direct current step-down half-voltage four-quadrant rectifier, which belongs to the technical field of power electronic conversion and new energy power generation. Background technique [0002] Voltage source type four-quadrant PWM rectifier (FQR, Four-Quadrant Rectifier), because the phase of its AC side current relative to the AC voltage can be set arbitrarily in four quadrants from 0° to ±180°, and its current waveform can also pass through The flexible control of transient current tracking gives four-quadrant PWM rectifiers four performance advantages, including: [0003] 1) The AC side current can be tracked and controlled according to the set waveform, especially in the case of the commonly used sine wave, there is no harmonic pollution to the power grid; [0004] 2) The AC side can present inductive, capacitive or power factor equal to 1 through current control; [0005] 3) The AC-DC side energy can be transmit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02M7/219H02M7/797H02J3/38
CPCH02M7/219H02M7/797H02J3/381H02J2300/26Y02E10/56
Inventor 张超张加胜
Owner 张超