海上风电直流汇集DC/DC系统实时仿真方法

随着深远海风电的开发与快速发展，采用柔性直流输电技术逐渐成为海上风电系统的首选方案。然而，海上风电及其输电系统的安全运行仍面临严峻的挑战。实时仿真技术能低成本、快速模拟各种复杂运行工况，得到越来越多的关注。直流汇集DC/DC系统是海上风电系统中的关键设备，其复杂的级联结构、数量众多的元件和更高的开关频率都给实时仿真带来了巨大的挑战。为此，提出一种海上风电直流汇集DC/DC系统实时仿真方法，通过仿真算法的并行设计和等效模型的构建两个步骤，实现大规模海上风电直流汇集DC/DC系统的小步长实时仿真。首先，将EMTP算法重新设计为适用于实时仿真的并行算法，并基于此构建直流汇集DC/DC系统子模块的等效模型。其次，根据子模块之间的串联耦合关系，构建直流汇集DC/DC系统的多端口等效模型。最后，在CPU-FPGA异构实时仿真平台中进行海上风电直流汇集DC/DC系统在多种工况下的实时仿真，并与PSCAD/EMTDC离线仿真结果进行对比，验证了所提实时仿真方法的准确性和高效性。

Real-time simulation method for a DC/DC collection system in an offshore wind farm

With the rapid development of offshore wind power, flexible DC transmission technology has gradually become the preferred solution for offshore wind power systems. However, their safe operation still faces challenges. Real-time simulation technology has attracted more and more attention. It can simulate various complex operating conditions in a low cost and fast way. The DC/DC collection system is the key device in offshore wind farms, and its complicated cascade structures, the large number of components and the higher switching frequencies bring great challenges to the real-time simulation. In this paper, a real-time simulation method for a DC/DC collection system in an offshore wind farm is proposed, one which realizes the small-step real-time simulation of large-scale DC/DC collection systems in two steps: parallel design of the simulation algorithm and equivalent modeling of the system. First, the EMTP algorithm is redesigned as a parallel simulation algorithm for real-time simulation. The equivalent model of the submodule of DC/DC collection system is built based on a parallel real-time simulation algorithm. Second, the multi-port equivalent model of the DC/DC collection system is built based on the series coupling relationship of the submodule. Finally, the real-time simulation of the DC/DC collection system in various operating conditions is carried out on the CPU-FPGA heterogeneous real-time simulation platform. The results are compared with offline simulation in PSCAD/EMTDC to verify the accuracy and efficiency of the proposed real-time simulation method.