谐振型功率滤波器在并网变换器稳定域下的设计集成与系统性能优化研究

With the development of more-power-electronics-based power system, grid-connected converters have been widely developed and applied in several areas. In the basis, optimizing system energy consumption, including conversion efficiency, power density, weight, cost and volume, becomes the inevitable trend of its research and development. Aiming to improve power density of grid-connected converters, reduce weight, cost and volume of the systems, this project takes resonant-type-based high-order power filter as the research object, and focuses on system stability, magnetic component nonlinearity and filter inductor integration. The research targets are to explore design and integration methods of resonant-type-based power filter and optimize system performance with system stability constraints. Through establishing stability design region of the filters, the stability problem caused by filter resonance and grid impedance in weak electric network can be solved. Considering the nonlinear operation region of magnetic components for improving the utilization ratio of magnetic cores, this project reveals the influence mechanism of the nonlinear behavior on system stability, output power quality and interphase coupling. Meanwhile, in order to further optimize system power density, the project establishes filter inductor integration schemes for resonant-type-based power filters, and reveals the influence mechanism of magnetic coupling on system stability and filter performance, thus to optimize magnetic integration design. Through the research of this project, it is expected to optimize system energy consumption, enrich theoretical knowledge of resonant-type-based power filter design, and provide technical guidance for grid-connected power conversion applications, such as renewable energy generation, etc.

随着电力系统电力电子化发展，并网型功率变换器在多个领域得到了广泛开发及应用，这就使得提高系统效能，具体包括转换效率、功率密度、重量、成本及体积，成为其研究及发展的必然趋势。本项目以提高并网变换器功率密度、降低系统重量、成本和体积为研究背景，以谐振型高阶功率滤波器为切入点，重点围绕系统稳定性、磁元件非线性以及电感集成三个方面展开，探讨其在并网系统稳定域下的设计集成与性能优化。通过建立滤波器的设计稳定域，解决由滤波器谐振以及弱电网阻抗导致的稳定性问题。为提高磁芯利用率，考虑磁元件非线性运行区域，揭示其对系统稳定性、输出电能质量以及相间耦合的影响机理。为进一步优化系统功率密度，建立滤波器电感集成方案，并研究线圈磁耦合对系统稳定性及滤波器性能影响机制，进而优化磁集成设计。通过本项目研究，有望提高并网功率变换系统效能，丰富谐振型功率滤波器设计理论体系，为可再生能源发电等并网功率变换应用提供技术指导。

本项目以并网变换器性能优化为背景，围绕并网稳定性、磁元件非线性以及电感集成三个方面展开研究，具体如下：.1）滤波器谐振及弱电网与并网系统交互稳定性：研究了谐振型功率滤波器的拓扑衍生规律及设计原则，分析了控制频域外谐振映射规律，研究了控制频域外谐振特性约束下系统的稳定性以及弱网下鲁棒设计域。分析了离/并网双模式运行的微网变换器稳定性盲区，提出了一种无稳定性盲区的控制设计方法。研究了组网型并网逆变器阻尼特性，基于无源性原则，提出了系统参数优化设计方法。研究了计及锁相环的跟网型并网系统阻抗模型，分析了系统负阻尼特性，研究了锁相环引起的负阻尼补偿方法。针对弱电网与并网系统集群的交互稳定性问题，研究了宽频域补偿型有源阻尼器，提出了一种基于准广义积分器的阻尼优化补偿控制方法。针对单级式高频隔离型AC-DC并网变换器，提出了一种基于调制信号闭环补偿的控制方法。针对基于SiC MOSFET的并网变换器，为抑制桥臂串扰以及栅源电压振荡，提出了一种基于推挽式电容辅助电路的SiC MOSFET驱动及其参数设计方法。.2）磁元件非线性对并网系统性能影响机理及对策：基于法拉第电磁感应定律以及磁芯B-H曲线，搭建了电感的时变受控电流源模型，分析了电感值时域变化特性。建立了两相静止坐标系下控制系统多输入多输出交叉耦合模型，分析了等效谐振特性，给出了网侧和变换器侧电流单环反馈控制下LCL滤波器谐振频率设计约束以及控制参数设计原则。分析了电感非线性所导致的并网电流谐波特性，研究了电流环带宽外的谐波补偿器低频稳定性问题。.3）谐振型功率滤波器电感集成与线圈磁耦合：研究了LCL、LTL、LT2L滤波器磁集成方法。考虑电磁干扰以及滤波性能因素，提出了一种LCL滤波电感和共模电感解耦磁集成方法，给出了复合磁芯结构、气隙以及电感线圈配置方案，并给出了详细设计方法。.基于该项目研究，发表或录用学术论文6篇，申请发明专利3项，协助培养毕业硕士研究生6名，其中1名获得2021年江苏省优秀硕士学位论文。