基于扩展状态平均法的隔离型多端口移相全桥双向直流变换器建模研究

Research on Modeling of Isolated Multi-port Bidirectional DC-DC Converter with Phase-shifted Full-bridge Based on Extended State-space Averaging Method

建立了一种用于混合储能系统的隔离型多端口双向直流变换器的一般数学模型。通过星-网变换建立了移相控制下直流变换器多端口网型等效电路,通过扩展状态平均法建立了N端口变换器在电感电流连续时的状态平均模型和小信号模型,并分析了各端口之间传输的功率。仿真比较了不同端口数下变换器的模型输出和拓扑输出,并以三端口变换器为例,分析了移相比扰动和端口电源下的模型和拓扑电路的动态响应。结果表明,所提多端口直流变换器的数学模型能够准确反映移相控制下多端口变换器的稳态性能和动态性能,且在端口电压不受约束的前提下,对于不同端口数量的直流变换器具有普遍适用性。

A general mathematical model of an isolated multi-port bidirectional DC-DC converter used in hybrid energy storage systems is presented.The multi-port mesh equivalent circuit of a DC-DC converter under phase-shifted control is established by the wye-mesh transformation,and a state-space averaging model and a small-signal model of a N-port DC-DC converter in continuous conduction mode are established using the extended state-space averaging met-hod.In addition,the power transmitted between each port is analyzed.The comparison of output from the mathematical model and the topology circuit among converters with different numbers of ports is carried out through simulations.A three-port DC-DC converter is taken as an example,and the dynamic responses of the model and the topology circuit under disturbances of phase-shifted ratio and port sources are analyzed.Results show that the proposed mathematical model of the multi-port DC-DC converter can accurately reflect its steady-state and dynamic performances under phase-shifted control.Moreover,it is universally applicable for converters with different numbers of ports when there is no restrictions on the port voltage.