高频隔离光伏并网系统中DC/DC变换器的研究

Research on DC/DC Converter for High-frequency Isolated Grid-connected Photovoltaic System Application

针对光伏电池阵列的宽输出电压范围特性,为了实现变换器的宽电压输入和输出范围特性,采用滞后臂串阻塞二极管的FB-ZVZCS-PWM变换器拓扑对光伏并网系统中的DC/DC环节进行了设计分析。该电路拓扑通过超前桥臂开并管上并联电容实现ZVS,利用滞后臂串二极管阻止零状态下反向环流的产生从而实现ZCS。论文分析了该变换器的工作原理及各阶段工作模态,介绍了变换器主要器件的参数设计,通过平均电流采样的控制方式制作了一台3KW,36KHz光伏并网系统直流变换器样机,通过实验波形对变换器进行了验证。

In this paper,regarding to the wide range of output voltage character of solar cell,in order to achieve the wide range input and output character of the converter,a FB-ZVZCS-PWM converter topology with blocking diodes connected in series in lagging leg switches is applied to analyze and design the DC/DC part in grid-connected Photovoltaic System.In this topology,a capacitor connected parallel with the leading switch realizes ZVS,and blocking diodes is connected in series in lagging leg switches to prevent reverse current which should be produced in zero state and make ZCS.This article analyzes the converter＇s operating principle and its modes of all stages,and introduces the parameters design of its main devices,then makes a 3KW,36KHz grid-connected photovoltaic system DC/DC converter by controlling the sampling of average current.This converter is finally validated through the waveform experiments.