Adaptive Multi-scale Transient Modeling and Efficient Simulation of Wide-area AC/DC Power Systems

频率自适应暂态仿真(FAST)理论为交流电力系统的多尺度仿真提供了方法论框架。它依赖于向实际交流波形添加一个正交虚部，从而允许所产生的解析信号的傅里叶频谱在频域中移位。在没有移位的情况下，解析信号的实部代表原始波形。通过将解析信号的频谱以50赫兹的载波移位到更低的频率，有效地消除了载波，并且可以在大时间步长下有效地跟踪包络。然而，未来的电力系统不仅依赖交流，而且越来越依赖直流信号。集成了交流和高压直流技术的交直流电力系统，包括电力电子换流器，越来越受到人们的关注，特别是在中国和欧洲。交直流电力系统的运行、控制和保护比纯交流系统复杂得多，本项目旨在推动交直流电力系统多尺度暂态建模与仿真的发展。准确、高效地模拟大时间尺度上的各种交直流暂态过程将为深入分析提供支持，并为实时应用提供了机会，以确保交直流电力系统的运行安全和稳定。通过建立饱和状态下电力电子换流器或变压器等强非线性元件的多尺度模型，使基于快速移频理论的建模方法完全具有仿真大规模交直流电网的能力，充分利用细粒度并行计算和快速方法的优势，研究开发了一种高性能的仿真技术和平台，以加快多尺度仿真的速度，从而实现快速、准确的交直流电力系统分析。该平台通过云计算能力得到进一步丰富。由此产生的功能提供了一种新的仿真协作工作范例。欧洲的项目合作伙伴和中国将首先通过国际合作将这一概念付诸实践。然后，通过提供高度可扩展和高效的分析能力，它被扩展到为两国电力领域学术界和工业界更广泛的合作做出贡献。

The theory of frequency-adaptive simulation of transients（FAST）offers a methodological framework of multi-scale simulation of AC power systems. It relies on the addition of an orthogonal imaginary part to the real AC waveforms and so allowing the Fourier spectra of the resulting analytic signals to be shifted in the frequency domain. Without shifting, the real part of the analytic signal represents the original waveform. By shifting the spectrum of the analytic signal by the carrier of 50 Hertz towards lower frequencies, the carrier is effectively eliminated, and the envelope can be efficiently tracked at a large time step size. However, future power systems do not only rely on AC, but increasingly also on DC signals. AC/DC power systems with integrated AC and HVDC technologies including power electronic converters are of increasing interest, in particular also in China and Europe. The operation, control, and protection of AC/DC power systems are significantly more complex compared with the AC-only system.This project aims at pushing forward the state of art in multi-scale transient modeling and simulation of AC/DC power systems. The accurate and efficient simulation of diverse AC/DC transients across large time scales will support the in-depth analysis and opens the opportunity of real-time applications to ensure operational security and stability of AC/DC power systems. By developing multi-scale models of components with strong nonlinearities, such as power electronic converters or transformers in saturation, the modeling method based on the FAST frequency-shifting theory becomes fully capable of emulating large-scale AC/DC power grids.Taking full advantage of fine-grained parallel computing and the FAST method, a high-performance simulation technique and platform is researched and developed for speeding up multi-scale simulation to enable very fast and accurate AC/DC power system analysis. The platform is further enriched through cloud computing capabilities. The resulting functionality offers a novel paradigm of cooperative work on simulation. The concept will first be put into evidence by international collaboration between the project partners in Europe and China. It is then extended to contribute to broader collaboration of power-area academia and industry in both countries by offering highly scalable and efficient analytic capabilities.