双输入Buck变换器的单周期控制

One-Cycle Control for Double-Input Buck Converter

在可再生能源联合发电系统中,采用单个多输入直流变换器(MIC)代替原有的多个单输入直流变换器,可以简化电路结构,降低系统成本。MIC通常需要进行能量管理以实现可再生能源的优先利用,因此采用MIC构成的可再生能源联合发电系统是一个典型的多输入-多输出的耦合系统,其闭环设计复杂。因此本文针对双输入Buck变换器,提出单周期控制方式来消除环路之间的耦合。同时本文还提出了模式切换电路以实现各个模式之间的平滑切换,并推导了双输入Buck变换器在不同工作模式下的单周期控制小信号模型。由该小信号模型可知,采用单周期控制无需电流调节器,而且电压调节器在不同工作模式下的设计条件相同,因此调节器的设计大大简化。最后本文设计制作了一台800W的实验样机,实验结果验证了所提出单周期控制方法的有效性。

In hybrid power systems,the use of a multiple-input converter（MIC） instead of several single-input converters leads to simpler circuit and lower cost.The energy management is always required for the MICs to make the most utilization of renewable energy.The MIC-based hybrid power system is a typical multiple-input multiple-output（MIMO） coupling system,and it has multiple operating modes.As a result,the design of the controllers is very complicated.This paper proposes one-cycle control（OCC） for double-input buck converter（DIBC） to eliminate the interactions of the control loops and thus to simplify the design of the controllers.The mode transition circuit is further proposed to realize seamless mode transition,according to the available renewable energy and the output power.The small signal models of DIBC in different operating modes are derived.It can be seen that with OCC,the two control loops are independent with each other,and no current regulator is required.Moreover,the design conditions of the output voltage regulator in different operating modes are the same.As a result,the controller design is greatly simplified.An 800 W prototype has been built and tested in the lab,and the experimental results validate the proposed OCC.