A digital soft-start method for a full-bridge llc converter

A soft-start, converter technology, applied in the direction of output power conversion devices, electrical components, etc., can solve the problem of inability to effectively limit inrush current, and achieve the purpose of reducing inrush current and voltage stress, and reducing inrush current. Effect

Inactive Publication Date: 2018-03-06
GUANGDONG UNIV OF TECH
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At the same time, using this soft start method cannot effectively limit the inrush current within a certain range

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A digital soft-start method for a full-bridge llc converter
  • A digital soft-start method for a full-bridge llc converter
  • A digital soft-start method for a full-bridge llc converter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0031] Such as figure 1 , figure 2 As shown, the present invention is a digital soft-start method for a full-bridge LLC converter, which is divided into three steps.

[0032] First, set the upper limit of the resonant inductor current I for initial soft start rh (attached figure 2shown in ①) and the lower limit-I rl (attached figure 2 shown in ②). When the bus voltage V in For the rated range, applying a drive pulse requires I rh rl . Then according to the design parameters of the circuit, the switching time of each switching tube is accurately calculated by solving the differential equation. The formula is given as follows:

[0033] Q 1 , Q 2 , Q 3 , Q 4 Opening time calculation formula (Q 1 , Q 4 Simultaneously turn on and turn off; Q 2 , Q 3 Simultaneous turn-on and turn-off):

[0034]

[0035]

[0036] Among them, U cr , I Lr for each cycle Q 1 , Q 4 tube open or Q 2 , Q 3 Calculate the initial value of the tube turn-on start state, V in i...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a digital soft start method for a full-bridge LLC converter, comprising the following steps: S1, setting the upper limit Irh and the lower limit -Irl of the resonant inductor current for the initial soft start, and accurately limiting the surge current at start-up to Within the stable working range of the circuit; S2, according to the design parameters of the circuit, accurately calculate the switching time of each switching tube by solving the differential equation; S3, keep the switching frequency of f1 unchanged until the output voltage is at this switching frequency The stable value Vo1 that can be reached; S4, the switching frequency from f1 is continuously reduced within a fixed time interval until the output voltage reaches the rated output voltage Vo, or when f1 is less than the resonant frequency fr, the soft start ends. The invention optimizes the design of the soft start process, sets the upper limit and lower limit of the resonance network current according to the design parameters of the circuit, accurately calculates the switching time of each switching tube through the differential equation, and then uses the method of digital control look-up table to strictly control the entire Soft start process.

Description

technical field [0001] The invention relates to the research field of electronic power and electric drive, in particular to a digital soft start method for a full-bridge LLC converter. Background technique [0002] With the rapid development of power electronics technology, more high frequency, high efficiency, high power density and low noise requirements are put forward for switching power supply. At present, the relatively mature soft switching technology, such as phase-shifted full bridge, is difficult to achieve a truly ideal soft switching (including the main switching tube and the secondary rectifying diode), and as the switching frequency increases, its loss continues to increase , so seeking a more efficient, high switching frequency and high power density topology has become the focus of current research. LLC resonant full-bridge converter, as one of the more outstanding performances in the full-bridge topology, has the following advantages: the primary MOSFET ZVS...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): H02M1/36
CPCH02M1/36H02M1/0012
Inventor 李志忠兰尚荣李学易李优新刘东峰程昱黄国宏
Owner GUANGDONG UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap