苏州中压直流配电工程设计方案及仿真验证

随着中压柔性配电技术的发展，基于电力电子技术的柔性直流配电网在相位和频率同步、灵活控制、线损等方面较交流配电网有着一定的优势，但在技术的成熟性、稳定性以及成本等方面还存在不足。针对苏州中低压直流配用电系统示范工程的中压直流配电网网架，在传统环型与辐射型结构的基础上，通过技术经济比较采用基于单母线分段“双端环型”网架结构设计方案；为适应故障穿越的主动控制需求，发挥改进型网架结构供电方式灵活的特点，提出采用半桥换流站+混合桥换流站的非对称主站设计方案；结合换流阀参数设计与系统接地方式，在PSCAD/EMTDC平台上搭建了系统仿真模型，对工程设计方案的可行性及故障处理能力进行了仿真验证，为示范工程方案设计与设备选型提供分析依据。

Design Scheme and Simulation Verification of Suzhou Medium Voltage DC Distribution Project

With the development of medium voltage flexible DC distribution technology, the flexible DC distribution network based on power electronics technology has certain advantages over the AC distribution network in phase and frequency synchronization, flexibility of control, transmission line loss, etc., but still has deficiencies in the maturity and stability of technology, as well as the construction cost. For the medium voltage DC distribution network structure of Suzhou medium and low voltage DC distribution system project, a single-bus segmentation based " double-terminal ring " grid structure design scheme is adopted on the basis of comparison of the traditional ring structure and radiation structure. In order to meet the demand of active control of fault ride through and give full play to the flexible power supply modes of the improved grid structure, the design scheme of asymmetrical main station with half bridge converter station + mixed bridge converter station is proposed, and combined with the design of converter valve parameters and system grounding mode, a system simulation model is built on the PSCAD / EMTDC platform to verify the feasibility and fault handling ability of the engineering design scheme, which provides the analysis basis for the scheme design and equipment selection of the demonstration project.