全直流海上风电场高升压比DC/DC变换技术综述

采用直流汇聚、直流传输的全直流海上风电场,可以避免使用笨重的工频交流变压器,在功率密度、建设成本、系统损耗等方面具有较大的优势,因此基于直流汇聚、直流传输的全直流海上风电是目前海上电能传输的研究热点。在全直流海上风电系统中,风机端口电压需进行高变比升压后才能远距离传输,所以高升压比DC/DC变换器是整个风能变换传输系统中的重要环节。首先从变比、容量、故障隔离等角度对适用于全直流海上风电的直流变换器进行需求分析。其次对各种直流变换器的拓扑实现进行总结分类,并指出各种拓扑的优缺点以及应用前景。最后对各种拓扑结构及控制方法进行比较,对未来适用于全直流海上风电场的高升压比直流变换器进行展望。

Research review on high step-up ratio DC/DC converter for offshore DC wind farm

The offshore DC wind farm with DC collection and transmission system eliminates the bulky power frequency transformer and multiple power converters. It has advantages on power density, cost and efficiency. These advantages let the pure DC system become an advisable choice of offshore wind farm. In the offshore DC wind farm, the high set-up ratio DC/DC converter is a very important part. This paper firstly analyzes the requirements of the step-up ratio, capacity and fault isolation for the DC/DC converter. Then a detailed classification is made about different kinds of DC/DC converters. The advantages and disadvantages of various DC/DC converter topologies and their prospects are pointed out. Finally, this paper compares the structure and control methods of these different topologies and affirms the future development of the high step-up ratio DC/DC converters which can be applied in the offshore DC wind farm. This work is supported by National Natural Science Foundation of China (No. 61374155), Research Fund for the Doctoral Program of Higher Education of China (No. 20130073110030) and Natural Science Foundation of Shanghai (No. 18ZR1418400).