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| Abstract: |
| Through a third-order mathematical model of grid-oriented LCL-type converters, this paper analyzes the complicated dynamic characteristics and resonance problems which may influence the system stability. To realize active damping for LCL filters and improve dynamic performance of current regulators, a state space current PI controller is proposed whose parameters can be tuned based on the polynomial equations approach. An extended state observer is integrated with the regulation scheme, where additional sensors are not necessary in contrast with conventional active damping strategies. Synchronous reference frame PLL (SRF-PLL) equipped with filter technology is proposed for grid voltage disturbance suppression. This method is then applied to establish a double-closed-loop power regulator that demonstrates improved performance compared with other controllers. The simulation results are displayed to illustrate the efficiency of the regulation methods. |
| Key words: LCL-type grid-oriented converters state space current control SRF-PLL closed loop power control |
| DOI：10.11916/j.issn.1005-9113.21041 |
| Clc Number:TM726 |
| Fund: |
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| Descriptions in Chinese: |
| 面向LCL型并网变换器的状态空间功率控制策略研究 陆春宇，花为，胡铭觐 （东南大学 电气工程学院,南京 211189） 摘要：针对带LCL滤波器的网侧变换器三阶数学模型，分析了其复杂动态特性及可能影响系统稳定性的谐振问题。为实现LCL型系统的有源阻尼谐振抑制及提升电流调节性能，提出一种考虑参数整定的状态空间电流调节策略，相关参数基于模型等效方法计算获得。相比于传统有源阻尼方法，本文将扩展状态观测器与电流控制策略相结合，有效避免了额外传感器的使用，同时结合滤波策略的同步锁相环能够有效抑制电网电压。最终，基于上述策略构建的双闭环功率调节器能够有效提升功率控制的动态性能及稳态精度。仿真结果验证了调节策略的有效性。 关键词：LCL型并网变换器，状态空间电流控制，同步锁相环，闭环功率控制 |
