Research On Application Of Buck-Boost Converter In Portable Power Supply System

With the continuous development of power electronics technology,the types and quantity of portable electronic products have continued to increase,the performance and power consumption have improved significantly.Therefore,the demand for high-efficiency DC-DC converters with a wide input voltage range for power supply systems of portable electronic devices has increased.In the field of portable power supply systems such as adapters,LED drive power supplies,and intelligent mobile terminals,conventional Buck-Boost converters are difficult to meet the equipment requirements for power efficiency due to their low efficiency and narrow input voltage range.In order to improve the efficiency,power density and reliability of the portable power supply system,this paper studies the application of buck-boost converters in the field of portable power supply systems,Furthermore,the working mode and circuit characteristics of the proposed converter topology are analyzed.A capacitor series-connected interleaved buck-boost converter topology proposed in this paper.The converter works in continuous conduction mode.The topology of the proposed converter is improved by connecting energy storage capacitors in series at the input of the converter.The purpose of optimizing the voltage transmission gain and widening the input voltage range is achieved.At the same time,the converter reduces the circuit voltage stress,and the efficiency is effectively improved.The interleaved parallel Buck-Boost converter proposed in this paper has a small inductor current ripple.When the duty ratio is less than 0.5,the step-down effect is outstanding and the inductor current can be automatically shared.The above advantages solve a series of problems such as excessive voltage stress,narrow input voltage range and low efficiency of the conventional buck-boost converter.In this paper,the working principle,working mode,performance characteristics,and loss of the proposed converter are analyzed in detail,and compared with the conventional buck-boost converter topology performance comparison.An active clamp capacitor series-connected interleaved Flyback converter proposed in this paper.The conventional Flyback converter is affected by circuit parasitic parameters and the control mode is complicated.At the same time,the leakage inductance on the primary side of the transformer will cause a high turn-off voltage spike,which will cause large voltage stress makes it difficult to improve converter efficiency and power density.To solve this series of problems,an active clamp capacitor series interleaved Flyback converter topology with low voltage stress proposed in this paper.The converter works in continuous conduction mode,and the energy storage capacitor is connected in series at the input through two-phase parallel connection,which improves the original topology.Compared with the conventional Flyback converter topology,the converter proposed in this paper introduces an active clamping circuit.The clamping capacitor and the parasitic capacitance of the switch resonate with the resonance inductance,and the power switch of the proposed converter can achieve ZVS in the CCM mode which solves the problem of the turn-off voltage spike caused by the leakage inductance on the primary side of the transformer in the conventional Flyback converter.At the same time,the converter proposed in this paper has lower voltage stress and a wide range of input voltage,which is suitable for small and medium power applications.Finally,by setting up an experimental platform,the two converter topologies proposed in this paper are simulated and experimentally verified,the corresponding experimental results and experimental data are given to verify the feasibility and theoretical analysis of the proposed converter topology Correctness.