基于阻抗无源性重塑的变流器与电网交互谐振抑制理论与方法研究

Recently, the converter-grid interaction resonance problem, caused by large scale grid-connected converters for renewable energy sources, brings serious challenges to the safety and stable operation for utility grid. This project proposes a passivity output impedance reshaping solution which is based on the idea of resonance energy dissipating to eliminate the converter-grid interaction resonance and enhance the stability of utility grid operation. If the impedance of all controllable converters have passivity properties, the output impedance can provide positive damping to resonance, dissipate resonance energy, suppress resonance and enhance the stability of utility grid operation. This project focus on the following three topics: the method of passivity output impedance reshaping; the inner mechanism of converter-grid interaction resonance and its damping method; the coordination control method and its optimization for damping interaction resonance based on grid impedance reshaping with passivity property. The effectiveness of the proposed solution will be verified by theory analysis, simulation results and experiment results. This project will provide theoretical basis and technical support for damping interaction resonance caused by renewable energy source, grid friendly inverter design and operation for utility grid with high penetration renewable energy sources. Meanwhile, the implementation of this project has great practical meaning for promoting renewable energy development in China.

近年来，大规模可再生能源并网变流器与电网的交互谐振问题给电力系统的安全稳定运行带来了严峻的挑战。本项目旨在利用电网中的可控变流器，基于谐振能量耗散的思想，提出变流器输出阻抗无源性重塑的解决方案，通过具有无源性阻抗的可控变流器来为谐振提供正阻尼，以消耗振荡能量，实现谐振的有源抑制，从而提高电网运行的稳定性。本项目重点研究：并网变流器的输出阻抗无源性重塑方法；变流器与电网交互谐振的内在机理及其抑制方法；基于电力网络无源性重塑的交互谐振协调抑制及优化设计方法。通过理论分析、仿真验证和实验验证的技术路线来论证所提方法的有效性。本项目为可再生能源并网交互谐振问题的解决、“电网友好型”并网逆变器的设计及含高比例可再生能源电网的运行提供理论依据和技术支撑，对于推动我国可再生能源发展具有重要的现实意义。

本项目基于谐振能量耗散的思想，利用电网中的可控变流器，提出了变流器输出阻抗的无源性重塑的解决方案，通过具有无源性阻抗的可控变流器来为谐振提供正阻尼，以消耗振荡能量，实现谐振的有源抑制，提高电网对可再生能源的接纳能力。.本项目的主要成果如下：1、建立了不同结构的变流器的输出阻抗模型，分析了输出阻抗的影响因素，探索了变流器与电网交互谐振的作用机理；2、提出了基于误差传递函数的高阶电流控制器的参数设计方法，确保复杂电网环境下变流器本体电流控制的稳定性；3、分析了锁相环和控制延时对变流器输出阻抗的影响机理，提出了相应的补偿控制方法，提高了变流器输出阻抗的无源性；4、建立了LCL滤波的变流器输出阻抗的统一模型，提出了全频率无源性的电路参数和控制参数设计方法，提供了电力网络全局无源化的解决方案。5、本项目发表SCI期刊论文12篇，在APEC、ECCE等学术会议发表论文4篇；申请发明专利4项；培养博士研究生1名、硕士研究生5名。.本项目的研究工作，具有良好的应用前景，为可再生能源并网交互谐振问题的解决、“电网友好型”并网逆变器的设计及含高比例可再生能源电网的运行提供了理论依据和技术支撑，对于推动我国可再生能源发展具有重要的现实意义。