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Research On A Novel Soft-switching Technology Of The High-power Supply

Posted on:2017-01-13Degree:MasterType:Thesis
Country:ChinaCandidate:L M WuFull Text:PDF
GTID:2272330503485078Subject:Control engineering
Abstract/Summary:PDF Full Text Request
With the expansion of the depth and scope of application of the switched mode power supply(SMPS), high-power SMPS plays an increasingly important position on Power Electronics Technology. Nowadays, SMPS is moving in high-frequency, miniaturization, intelligent direction. However, the switching devices of traditional PWM converter work in hard-switching state. With the improvement of operating frequency, it can occur lots of problems such as large switching losses, high stress of switching devices, serious electromagnetic interference and so on, which conversely limits the improvement of its operating frequency. Because soft-switching technology can solve the problems on hard-switching technology, it has become a hot spot of the development of SMPS, and there has a great significance on it.This paper analyzes the working principle and key technologies of the traditional phase-shifted full-bridge ZVS PWM converter. To overcome the problem about instantaneous high current stress on the main switches when they are switching and it is lightly loaded, a novel soft-switching technology of the high-power supply is proposed, including a novel transistor and two corresponding control strategies. The novel converter will work at soft-switching state when overloaded and can protect the main switches from the influence of instantaneous high current stress at light load.Based on the 150V/400 A output, this paper designs the hardware circuit to meet the requirements, and it provices the required parameters for the analysis of feedback controllers and simulation. The hardware includes input filter capacitor, rectifier bridge, high-frequency transformers, power switches, output rectifier filter circuit, chip and drive circuit, comparator and sampling circuit, etc. After that, the small signal model of phase-shifted full-bridge ZVS PWM converter is proposed by using the state space averaging method(SSA). At last, based on the small signal model, the feedback controllers are also proposed, which include an incomplete derivative PID controller and a conventional PI controller.Finally, based on the MATLAB simulation software, the simulation module is built, and the experimental waves of the novel transistor at heavy and light load with different control strategies are analyzed. The feasibility of the novel soft-switching technology are confirmed eventually.
Keywords/Search Tags:Soft-switching technology, High-power SMPS, Phase-shifted full-bridge, Small signal analysis, Simulation based on MATLAB
PDF Full Text Request
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