基于扩展移相控制的双向有源桥变换器回流功率优化

Backflow Power Optimization of Dual Active Bridge Converter Based on Extended-phase-shift Control

为了更好地将分布式电源与负荷接入直流配电网,并提升功率传输效率,针对双向有源桥(dual active bridge,DAB)变换器的运行控制,研究其回流功率的优化控制技术策略。建立基于扩展移相控制的DAB变换器的传输功率与回流功率数学模型,详细阐述回流功率的产生机理,在传输功率特性中引入电路的回流功率特性。其次,分析不同电压转换比下,回流功率与传输功率的耦合关系,提出DAB变换器的回流功率最优控制模型。搭建DAB变换器的实验样机,分析最优回流功率控制下的变换器工作特性,对比研究不同控制策略下DAB内部的回流功率,验证了所提回流功率最优控制模型的有效性。

To interface distributed renewable energy sources and loads into the DC.distribution network and improve the efficiency of power delivery,optimal control to reduce the backflow power in bidirectional dual active bridge (DAB)DC-DC converter was highlighted in this paper.With built mathematical models for the transmission and backflow power in the converter under extended-phase-shift control,the mechanism of backflow power was addressed.By introducing the backflow power into the transmission power characteristics and combining of these kinds of power,interactions between backflow power and transmission power under different voltage conversion ratios were proposed.Then,models and strategies of optimal control were presented to minimize the backflow power.Finally,a prototype of DAB converter was set up to analyze the characteristics of DAB converter under the proposed optimal control strategy.Comparative experimental results verify the performance of studied optimal control to reduce the backflow power in a DAB converter.