双有源桥三重移相电感峰值电流优化

Triple Phase Shifting Optimization of Peak Current of Dual Active Bridge Converters

针对双有源桥效率的提高,提出三重移相最小电流优化的控制方法。阐述了三重移相的基本原理,通过控制原副边内移相角、桥间移相角3个自由变量进而改变功率的输出;分析了三重移相正向的6个工作模式。在此基础上,进一步推导三重移相功率特性,得到不同模式下的表达式,并给出各模式的功率范围;再利用6种模式特性,得到其峰值电流特性,并以峰值电流优化作为目标,结合KKT推导得到最小峰值电流控制。最后通过1.2 kW实验平台,进行了单移相控制与三重移相峰值电流优化控制实验。实验结果表明峰值优化控制可以减小功率电感峰值电流,效率得到提高。

The control method of triple phase shifting optimization of minimum current is proposed aiming at improving efficiency of dual active bridge converters.The basic principle of triple phase shifting is described as changing power output by controlling the three free variables of primary and secondary intra-phase shift angles and the inter-bridge phase shift angle.The six operating modes of triple phase shifting forward are analyzed.On this basis,the triple phase shifting power characteristics are further derived to obtain expressions in different modes and to determine power range of each mode.Then using the six mode characteristics,their corresponding peak current characteristics are obtained,and minimum current control is achieved by taking peak current optimization as the objective and by using KKT derivation.Finally comparative analysis through 1.5 kW experimental platform confirmed a significantly reduced inductor peak current and consequently improved efficiency of triple phase shifting control compared with single phase shifting control method.