| 摘要: |
| 目的 多数并网逆变器采用 L 型或 LC 型滤波器结构,其缺点是当逆变器用于并网时,L 或 LC 滤波器会占用
逆变器较大空间,故考虑逆变器的成本,同时又能够输出良好的并网电流,提出一种基于 LCL 滤波器的分时复合控
制两级式并网逆变器。 方法 该控制策略将系统划分为 Buck 工作模式和 Boost 工作模式。 在 Buck 工作模式下,以
并网电流为反馈量,采用 PI 控制器实现电流调节,并引入有源等效阻尼抑制 LCL 滤波器谐振峰;在 Boost 工作模式
下,用前级斩波电路电感电流为反馈量,采用补偿网络和 PR 控制器进行调节,并通过陷波器抑制谐振峰值。 结果
仿真结果表明,LCL 滤波器会在控制系统开环频率响应中引入明显的谐振峰,若不加抑制将导致并网电流谐波增
大,验证时会引起系统失稳。 与 LC 滤波器相比,在满足并网电流谐波指标的前提下,LCL 滤波器所需电感参数
可进一步减小,有利于降低系统体积。 结果 Simulink 仿真验证了本文所提控制策略在 Buck 和 Boost 两种工作模
式下均能实现并网,并满足谐波要求的并网电流,可为 LCL 滤波器谐振抑制及分时复合控制并网逆变器设计提
供参考。 |
| 关键词: :LCL 滤波器 分时复合控制 有源等效阻尼 并网电流 |
| DOI： |
| 分类号: |
| 基金项目: |
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| Control Strategy for Grid-Connected Inverters Based on LCL Filter and Time-Sharing Composite Control |
|
LIN Pei
|
|
School of Electrical and Information Engineering Anhui University of Science and Technology Huainan 232001 Anhui
China
|
| Abstract: |
| Objective Conventional grid-connected inverters often employ L- or LC-type filters which require relatively
large passive components to meet grid-current harmonic limits. To address this issue while maintaining cost-effectiveness
and good grid-connected current quality this paper proposes a two-stage grid-connected inverter based on an LCL filter
with a time-sharing composite control strategy. Methods The proposed strategy divided system operation into Buck mode
and Boost mode. In Buck mode the grid-connected current was selected as the feedback variable and a PI controller
performed current regulation. Active equivalent damping was introduced to suppress resonance peaks from the LCL filter.
In Boost mode inductor current from the front-stage chopper circuit was used as the feedback variable. A compensation
network together with a PR controller carried out regulation with a notch filter used to suppress resonance peaks. Results
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r suppressing resonance in LCL filters and designing |
| Key words: LCL filter time-sharing composite control active equivalent damping grid-connected current |
