自适应下垂控制的三电平DC/DC变换器并联均流方法研究

分析传统下垂控制的三电平DC/DC变换器多模块并联均流电压偏差较大,且各并联模块功率不均分的原因,提出了一种自适应下垂控制的三电平DC/DC变换器多模块并联均流控制方法。通过实时采集各并联变换器的电压和电流,建立变换器下垂系数与负荷功率之间的数学模型,自适应调整下垂系数使直流母线电压跟随给定值。构建直流微电网仿真模型,在相同工况下利用MATLAB/Simulink软件平台,仿真分析传统下垂控制和自适应下垂控制对三电平DC/DC变换器多模块并联直流母线电压降落和功率分配进行对比分析,验证了自适应下垂控制对三电平DC/DC变换器多模块并联的可行性,实现了不同额定功率的三电平DC/DC变换器间的“功率均分”,同时极大地改善了由于线路阻抗导致的电压降,提高了直流母线的电能质量。

Study on adaptive droop control of parallel current sharing method for three-level DC/DC converter

Based on the analysis of the reasons that the voltage deviation of the conventional three-level DC/DC multi-module parallel current sharing method is large and the power of each parallel module is not power sharing,the adaptive droop of parallel current sharing method for three-level DC/DC is proposed in this paper.By collecting the voltage and current of each parallel converter in real time,the mathematical model between the droop coefficient of the converter and the load power is established,and the droop coefficient is adjusted adaptively to make the DC bus voltage follow the given value.The simulation model of DC micro power grid is built under the same conditions using MATLAB/Simulink software platform,the simulation analysis of traditional drooping droop control and adaptive control method of three-level DC/DC module in parallel DC bus voltage drop and power allocation were analyzed,the feasibility of the sagging adaptive droop control method for three-level DC/DC converter in parallel with multi-modules is verified,and the power sharing between the three-level DC/DC converters with different power ratings is realized,as well as greatly improves the voltage drop caused by the line impedance,and enhances the power quality of DC bus.