林盛超, 熊健, 贺诗明, 邱增广. 基于并网电流反馈的新型有源阻尼方法[J]. 电网技术, 2021, 45(3): 926-936. DOI: 10.13335/j.1000-3673.pst.2020.0631
引用本文: 林盛超, 熊健, 贺诗明, 邱增广. 基于并网电流反馈的新型有源阻尼方法[J]. 电网技术, 2021, 45(3): 926-936. DOI: 10.13335/j.1000-3673.pst.2020.0631
LIN Shengchao, XIONG Jian, HE Shiming, QIU Zengguang. New Active Damping Method Based on Grid Current Feedback[J]. Power System Technology, 2021, 45(3): 926-936. DOI: 10.13335/j.1000-3673.pst.2020.0631
Citation: LIN Shengchao, XIONG Jian, HE Shiming, QIU Zengguang. New Active Damping Method Based on Grid Current Feedback[J]. Power System Technology, 2021, 45(3): 926-936. DOI: 10.13335/j.1000-3673.pst.2020.0631

基于并网电流反馈的新型有源阻尼方法

New Active Damping Method Based on Grid Current Feedback

  • 摘要: LCL型滤波器具有比单L滤波器更好的滤波效果,但是其容易使系统引发谐振,并导致系统不稳定。在基于LCL型滤波器的并网逆变器中,为了保证系统的稳定性,通常会采取相关的有源阻尼措施。目前常用的电容电流比例反馈有源阻尼需要引入额外的高精度电流传感器导致系统成本的增加,因此提出了一种基于并网电流反馈的新型有源阻尼方法。该阻尼环节能够给阻尼环的开环传递函数提供一定的相位偏移从而使得阻尼内环稳定,并达到良好的阻尼效果。与无阻尼单并网电流反馈控制相比,引入所提有源阻尼能够降低有效阻尼区间的频率下限,提高了系统对电网阻抗变化的鲁棒性。文章还围绕系统的稳定裕度以及稳态精度探讨了阻尼环节参数与电流控制器参数的设计方法,并给出了简单便捷的参数设计步骤。最后,仿真和实验结果验证了所提方法的有效性。

     

    Abstract: An LCL filter has better filtering ability compared with an L filter. However, it is apt to cause resonance issue and lead to instability of the power system. In the grid connected inverter based on LCL, some relevant active damping methods are usually adopted in order to ensure the stability of the system. At present, the widely used active damping with proportional feedback of capacitive current requires the introduction of additional high-precision current sensors, which brings an increase in system costs. Therefore, this paper proposes a new active damping method based on grid current feedback. The damping link is able to provide a certain phase shift for the open-loop transfer function to stabilize the damping loop and achieve a better damping result. Adopting this active damping method will reduce the lower frequency limit of the effective damping region and improve the system's robustness to changes of grid impedance, compared with the traditional single-grid current feedback control. This paper also discusses the design methods of the damping link parameters and the current controller parameters according to the stability margin and the steady-state accuracy of the system. It also lists convenient design steps of the parameters. Finally, simulation and experimental results verify the availability of this active damping method.

     

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