基于直流系统强度的新型协同式虚拟同步机研发

With the rapid development of power electronic interfaced non-synchronous generation, the frequency and voltage stability of future power grid will be severely tested in the future. In recent years, the emerging virtual synchronous machine (VSG) technology, which simulates the dynamic characteristics of power electronic converters as synchronous generators, realizes the important stabilization mechanism of synchronous generators such as self-synchronization, mechanical inertia and excitation, will fundamentally resolve the stability challenges caused by renewable power generation grid integration. This project aims to provide theoretical and technical support for the safe and stable operation of future power grid with high proportion of VSG by developing new VSG technologies based on DC system strength. Firstly, it will seek to master the design and operational characteristics of typical VSG control systems in grid-connected mode, islanded mode and multi-VSG parallel-connected mode, and conducts stability analysis based on time-domain and frequency-domain mathematical models in order to compare the similarities and differences between VSG and real synchronous generators as well as their advantages and disadvantages. Secondly, a new VSG technology based on DC supercapacitor energy storage effect will be proposed to overcome the shortcomings of the existing VSG in providing the effective inertia to the grid. Furthermore, in order to operate and optimize parallel-connected multi-VSG in future power grid, the multi-VSG adaptive cooperative control scheme will be developed. Finally, in order to enhance the VSG reactive power and voltage regulation capability, a VSG enhanced reactive power capability control scheme will be proposed based on expanded DC capacitance and flexible DC voltage levels.

随着以电力电子为接口的非同步新能源发电的高速发展，未来电网的频率和电压稳定性将受到严峻考验。近年来新兴的虚拟同步机技术（VSG），是将换流器的动态特性模拟为发电机，实现自同步、机械惯量和励磁等重要稳定机制，从根本上解决新能源接入电网所带来的稳定性问题。本项目将研发基于直流系统强度的新型VSG技术，为未来含有高比例VSG电网的安全稳定运行提供理论与技术支持。首先，寻求掌握VSG在并网、孤网和多机并联的典型控制系统设计和运行特性，结合时域和频域数学模型进行稳定性分析，比较VSG与真实同步发电机组之间的异同点和优缺点。其次，针对既有VSG对系统惯量缺乏有效提供的缺点，提出基于直流超级电容储能效应的新型VSG技术。进一步，面向未来电网对多机VSG并联的运行优化需求，研究多机VSG自适应协同控制系统。最后，为提高VSG无功调压能力，提出基于扩大直流电容和灵活直流电平的VSG无功能力提升控制策略。

内容获取失败，请点击重试