双Buck/Boost集成双有源桥三端口DC-DC变换器

在传统的双有源桥变换器的基础上集成两个双向Buck/Boost电路,提出了一种双Buck/Boost集成双有源桥三端口DC-DC变换器,该变换器实现了桥臂开关管的复用,提高了功率密度。以光伏-蓄电池混合发电系统为例对该变换器拓扑进行分析,采用移相+PWM进行控制,通过控制移相角实现输入与输出端口间功率传输,通过调节占空比来匹配输入端口电压等级,以实现光伏端口的最大功率点跟踪和平衡蓄电池端口的能量传递。分析了该变换器的工作原理、稳态与软开关特性,该变换器较大程度地改善了传统移相控制下DAB在移相角较小时的软开关条件,使得在宽工作范围内能够实现所有功率开关管的软开关。最后建立300W实验样机进行方案验证。

Dual Buck/Boost Integrated Dual Active Bridge Three-Port DC-DC Converter

In this paper, Dual Buck/Boost integrated dual active bridge (DAB) three-port DC-DC converter combines the conventional DAB and two bidirectional Buck/Boost circuits. Hence power switches are shared, and the power density is improved. The PV-battery hybrid power system is taken as an example to analyze the proposed converter topology. The phase shift plus PWM control is adopted here. The phase shift angle is used to control the power flow between the input port and the output port, while the duty cycle is employed to match the input voltages. Thus the maximum power point tracking (MPPT) can be achieved and the power flow between PV and battery can be balanced. The basic operation principles, steady state characteristics and zero voltage switching (ZVS) conditions are analyzed. The ZVS conditions for the conventional DAB operating in small phase shift angle can be greatly improved, and thus the converter can operate under ZVS in a wide operation range. A 300 W converter prototype is built to verify all considerations.