直流供电交错并联双向DC/DC变换器切换控制策略

分布式可再生能源的推广应用、节能减排的需求以及用户终端负荷特性的变化，给传统交流供电带来了巨大挑战，直流供电因其强大的节能优势受到广泛关注。作为直流供电系统的关键组成部分，DC/DC变换器对稳定性有较高的要求。目前变换器普遍采用小信号建模，建模精度不高，在面临大的扰动时系统可能变得不稳定。文中基于切换系统理论，提出一种储能交错并联双向DC/DC变换器的切换控制方法，直接对系统进行大信号建模，建模精度高。首先选取系统储能函数作为共同的Lyapunov函数并设计最优切换率，然后分析了该切换率条件下系统在切换平衡点处的稳定性，最后在Matlab中进行了仿真，搭建了基于SiC MOSFET的双向DC/DC变换器样机进行验证。实验验证了该切换控制策略的有效性。

Switching control strategy of DC power supply bidirectional DC/DC converter

The popularization and application of distributed renewable energy,the demand of energy saving and emission reduction,and the change of user terminal load characteristics have brought great changes to the traditional AC power supply,DC power supply is widely concerned because of its powerful energy-saving advantage. As DC/DC converter is a key part of DC power supply system,the stability of the converter is required. At present,small signal modeling is widely used in converters,and the modeling accuracy is not high,and the system may become unstable in the face of large disturbance. Based on the switching system theory,a switching control method of energy storage staggered parallel bi-directional DC/DC converter is proposed in this paper,and the large signal modeling of the system is directly carried out,and the modeling accuracy is high. Firstly,the energy storage function of the system is selected as the common Lyapunov function and the optimal switching rate is designed. Then,the stability of the system at the switching equilibrium point under the switching rate is analyzed. Finally,the simulation is carried out in Matlab and a bidirectional DC/DC converter prototype based on SiC MOSFET is built for verification. Experiments verify the effectiveness of this switching control strategy.