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Research On Input-series-output-parallel Charging Power Supply And Its Control Strategy

Posted on:2016-04-16Degree:MasterType:Thesis
Country:ChinaCandidate:S W FengFull Text:PDF
GTID:2272330479491158Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Battery as a power storage and supply equipment, has been widely used in many fields. The charging power supply as its supporting facility has also become one of the research hotspots. In recent years, the battery capacity is growing because of the need for longer battery life of electronic devices. Capability of charging power supply’s voltage, current and power becomes ever more demanding.The main technical strategies for high input voltage high power charging power supply include device voltage current stress, system heat dissipation difficulty and serious electromagnetic interference etc. The paper proposed a solution called input-series-output-parallel(ISOP). This solution not only reduced the voltage and power level of each monomer, but also optimized the advantage of switching power supply. In order to improve the efficiency of the monomer, resonant inductor and clamp diodes improved ZVS-PWM phase-shift full bridge converter was chosen as the main circuit. Detailed analysis of its operating principle was presented, device parameters were calculated and selected based on operating principle analysis. The article analyzes the problem of MOSFET failure in ZVS phase-shifted full-bridge converter which adopts peak current mode control. With the Pspice simulation, theoretical analysis and design were verified.In order to achieve balanced working condition of two monomers, the relationship between power input ISOP charge equalization and output streams was analyzed. It was found that input voltage equalization can achieve output current sharing and vice versa, but only input voltage equalization control ensures the stability of the system. A strategy of equalizing control grading ring was proposed which can realize input and output voltage/current loop decoupled equalizing control. This strategy simplify the complexity of the controller design.When calculating the control parameter, we based on the small signal model of the full bridge converter monomer and build small signal model of ISOP system. Classical control theory was chosen to design closed-loop parameters. Simulation of the system in Matlab/Simulink was conducted to verify the effectiveness of the control strategy and the rationality of the design of parameters.Taking the optimal charging curve as a reference, this paper selected fi ve-stage charging constant voltage limiting control strategy with charging control program edited by MCU. The main control program consists of a charging control subroutine and a protection subroutine. Intelligence charging of the charging power supply is realized by this method.A 3.6k W of two-monomer ISOP charging power supply prototype was builted, their output characteristics and equalizing effect were tested based upon the theoretical analysis and objectives proposed for this study. The results illustrated that ISOP charging power supply in the full load efficiency reached 93% with high stable precision and fast transient response. It is concluded that the input voltage equalization achieves satisfactory effects.
Keywords/Search Tags:charging power supply, phase-shifted full-bridge converter, input-series-output-parallel, voltage sharing
PDF Full Text Request
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