摘要: |
LCL滤波器在提高并网变流器电流质量的同时,却不可避免地引入了谐振和稳定性的问题。在讨论和研究了不同侧电感电流反馈控制方法的基础上,针对并网侧电感电流反馈,提出了通过协调优化数字控制系统中的采样频率与谐振频率的比值关系,从而实现并网变流器的无阻尼控制的方法。针对并网变流器侧电感电流反馈控制方式,提出了利用改进的高通滤波器来提取谐振分量进行滤波阻尼的控制方法。这两种LCL滤波器阻尼控制方法,均不需要在主回路中增加额外的传感器,设计过程简单、可靠性高,便于工程实际应用。最后,通过实验结果验证了理论分析的正确性 |
关键词: 并网变流器 LCL滤波器 有源阻尼 电流反馈 高通滤波器 无传感器 |
DOI: |
投稿时间:2013-11-28 |
基金项目:国家863计划项目(2011AA05A104);国家电网科技项目(电网友好型大型风电场关键技术研究与示范)资助 |
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Study on feedback damping control methods of grid-connected inverter with LCL filter |
HAN Gang,CAI Xu |
(Wind Power Research Center, Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;Wind Power Research Center, Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) |
Abstract: |
LCL filters have greatly improved the current quality of grid-connected inverters, however, the problems of resonance and stability are also brought in inevitably. In this paper, feedback control methods with two different side inductance currents are studied and discussed, respectively. Based on feedback control method with grid side inductance current, the paper proposes a no damping control method, in which optimal designing of the ratio relationship between sampling frequency and resonance frequency are used in the digital control system. For another, while the system adopts the feedback control method with inverter side inductance current, a filter damping control method is proposed, where the resonant component extracted by an improved high-pass filter is adopted. Both of the two methods can avoid using any additional sensor in the main circuit, not only the design procedure is simple, but the reliability is high, and it is convenient for the engineering applications. At last, experimental results show that the theoretical analysis is correct and the control methods are feasible. |
Key words: grid-connected inverter (GCI) LCL filter active damping current feedback high-pass filter sensorless |