中低压直流变压器拓扑与控制综述

直流变压器作为直流电网中实现电压变换与电能分配的核心装备,其运行特性对直流电网影响深刻.基于此,对中低压直流电网中直流变压器的研究现状进行了总结与分析.首先,简要阐述了直流变压器的基本功能和典型运行场景;考虑到拓扑是直流变压器适应不同电压等级应用场合的关键,从端口数量和能量耦合方式的角度对直流变压器拓扑进行了分类,明确了各类拓扑的主要特征;其次,全面分析了直流变压器在稳态与暂态运行过程中包括效率优化、软启动、直流偏置电流抑制等方面的控制策略,有利于保障直流变压器在复杂工况下的高效可靠运行;然后,对直流变压器核心部件——高频变压器的关键技术进行了讨论,为高频变压器的选型和设计提供了参考;最后,对直流变压器未来的发展趋势进行了展望.

Review of topology and control strategy of medium-and low-voltage DC transformer

The DC transformer is the core equipment for voltage conversion and energy distribution in DC power grid, and its operating characteristics have profound impacts on DC power grid. Based on this, the current research status of DC transformers in medium-and low-voltage DC power grids is summarized and analyzed. Firstly, the basic functions and typical operating scenarios of DC transformers are briefly explained. Considering that the topology of DC transformer is the key to adapt to different voltage levels, the topologies of DC transformer are classified from the perspectives of the port numbers and energy coupling methods, and the main characteristics of various topologies are distinguished. Secondly, the control strategies of DC transformers in steady-state and transient operation processes, including efficiency optimization, soft-start, DC bias current suppression, etc.,are comprehensively analyzed, which can ensure the efficient and reliable operation of DC transformer under complex working conditions. Thirdly, the key technologies of the core component of DC transformer, i. e. high-frequency transformer, are discussed to provide a reference for the selection and design of high-frequency transformers. Finally, the future development trend of DC transformer is prospected.