面向新型电力系统的双有源桥变换器及其混合调制研究

Research on Dual Active Bridge Converter and It's Hybrid Modulation for New-Generation Power Systems

新型电力系统以高比例的新能源并网为主,直流变压器作为其中重要的能量管理环节,需要具备更高的性能和转换效率。为了减小直流变压器的电流有效值并提升控制的灵活性,提出一种基于可调制耦合电感的组合式双有源桥变换器。该变换器通过调制脉宽调制信号来控制可调制耦合电感的等效感值,并无需额外的辅助电路。为了减小变换器的电流有效值,当变换器工作在轻载且电压不匹配时,可调制耦合电感控制成较大的等效电感;当变换器工作在重载时,可调制耦合电感控制成较小的等效电感。同时,基于可调制耦合电感的工作原理提出变换器的混合调制策略,并设计最小电流复合控制律。最后,通过试验对该拓扑进行验证,结果表明所提出方案的有效性。

The new-generation power systems mainly relies on a high proportion of new energy grid connection.DC transformers is an important energy management unit in new-generation power systems,need to have higher performance and conversion efficiency.In order to reduce current effective value of the DC transformer and improve the control flexibility,this paper proposes a combined dual active bridge converter based on modulated coupled inductor.The proposed converter controls the equivalent inductance of the modulated coupled inductor by modulating pulse-width-modulation signals,without any additional auxiliary circuits.In order to reduce the current effective value of the converter,when the converter operates at light load and the voltage does not match,the coupled inductor can be modulated and controlled to a larger equivalent inductance.When the converter operates at heavy load,the coupled inductor can be modulated and controlled to a smaller equivalent inductance.Meanwhile,a hybrid modulation strategy for the converter is proposed based on the working principle of the modulated coupled inductor,and a minimum current compliance control law is designed.Finally,the proposed converter is validated through experiments,and the results show the effectiveness of the proposed method.