A Building Block Method for Input-Series-Connected DC/DC Converters

DC/DC converters are connected in series at the input so that low power devices can be used in high-voltage conversion applications. This article proposes a building block method for constructing an input-series-connected dc/dc converter, which combines voltage sharing modules (VSM) with voltage source modules or current source modules. A VSM consists of two MOSFETs, an inductor, and an open-loop driver. The input voltage sharing between the individual modules is achieved by connecting one VSM to the inputs of the two power modules. The proposed method makes the standardized functional modules can be combined together like building blocks, which greatly simplifies the converter complexity and shortens the system development cycle without sacrificing the high dynamic response performance and excellent sharing effect. This article first analyzes the working principle of the converter. Second, the stability constraints of the proposed method are revealed, and the effects of various parameters on the performance are discussed. Furthermore, the theoretical analysis results are verified by simulation. Finally, taking the voltage source module as an example, a prototype is built to test its steady-state and dynamic performance.