改进型本安Buck变换器的分析与设计

(1.西安科技大学 电气与控制工程学院,陕西 西安 710054; 2.榆林学院 能源工程学院,陕西 榆林 719000)

本质安全; 改进型Buck变换器; 低通滤波器; 纹波电压; 输出功率

Analysis and design of improvedintrinsically safe Buck converter
LI Yan 1,2,LIU Shu-lin1

(1.College of Electrical and Control Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.School of Energy Engineering,Yulin University,Yulin 719000,China)

intrinsic safety; improved Buck converter; low-pass filter; output voltage ripple; output power

DOI: 10.13800/j.cnki.xakjdxxb.2019.0225

备注

提出了一种输出具有LC滤波电路的本安Buck变换器,使得在特定的电气性能指标要求下,可不提高变换器工作频率,但能减小变换器内部的电感量及电容量,达到提升该变换器本质安全性能的目的 。深入分析了该拓扑电路在电感电流连续模式(CCM)时的输出纹波电压,指出输出纹波电压最大值是在输入电压最大,负载电阻为CCM与DCM的临界电阻时取得。根据最大输出纹波电压指标要求,在给定的动态范围内,得出了本安Buck变换器电感、电容参数的设计方法。为了说明改进型Buck变换器相比于传统型Buck变换器的优势,在相同的输出纹波电压指标要求下,对传统型及改进型Buck变换器的电感、电容取值进行了比较分析,得出所提出的改进型Buck变换器采用较小的电感、电容即可满足电气性能指标要求,因而可提高其本安性能。因此,通过在Buck变换器的输出附加LC滤波电路,不仅能有效提高本安Buck变换器的输出功率,还能减小其体积。给出了设计实例,仿真与实验结果验证了改进电路拓扑理论分析的正确性及减小目标电感、电容量的可行性。

An intrinsically safe Buck converter with output LC low pass filter is proposed to meet the requirements of both electrical and intrinsic safety with smaller inductance and capacitance.The output voltage ripple(OVR)of CCM is analysed in detail.Then the maximum output voltage ripple(MOVR)can be obtainedwhen input voltage Vi is the maximum and load resistance RL is equal to the critical resistance RLC.The design methods of the inductors and the capacitors based on the MOVR are deduced within the ranges of both input voltage and load resistance.At last,in comparison to the typical Buck converter for energy storage elements,the presented converter achieves better electrical requirement with smaller inductance and capacitance.Moreover,obtaining a better intrinsic safety requirement seems to be an achievable goal.This indicates that the presented converter can improve the output power and reduce the size of the intrinsically safe converter.The theoretical validity analysis of the proposed converter are verified by the simulation and experimental results.