LCL型并网逆变器重复双闭环控制方法

发布时间：2019-01-26 19:20

【摘要】：并网逆变器需要具有较高的稳态控制精度、快速的动态响应性能以及较强的抗干扰能力。而传统单环重复控制方法动态特性较差,基于逆变侧电流反馈的重复双闭环控制方法和网侧电流反馈单环控制方法纹波较大,稳态精度不高。因此,提出了一种基于电网电流反馈内环和重复控制外环的双闭环控制策略。利用数字控制固有的一拍延时特性,设计了控制系统内环,实现LCL滤波器的稳定控制;根据内环闭环传递函数特性,设计了相应陷波器、二阶滤波器以及超前环节作为控制系统外环;同时,引入了给定前馈和电网电压前馈控制环节来抑制电网电压对系统的影响,以增强系统的动态性能。理论分析和实验结果表明,该方法使LCL型并网逆变器具有稳态精度高、动态性能好以及抗干扰能力强的优点。
[Abstract]:Grid-connected inverters need high steady-state control accuracy, fast dynamic response and strong anti-jamming capability. However, the dynamic characteristics of the traditional single-loop repetitive control method are poor. The repetitive double-loop control method based on inverter side current feedback and the net-side current feedback single-loop control method have large ripple and low steady-state accuracy. Therefore, a double closed loop control strategy based on current feedback inner loop and repetitive control outer loop is proposed. The internal loop of the control system is designed to realize the stable control of the LCL filter by using the inherent beat delay characteristic of digital control. According to the characteristics of the closed loop transfer function of the inner loop, the corresponding notch filter, second order filter and leading link are designed as the outer loop of the control system. At the same time, the given feedforward and voltage feedforward control links are introduced to suppress the influence of grid voltage on the system, so as to enhance the dynamic performance of the system. Theoretical analysis and experimental results show that LCL grid-connected inverter has the advantages of high steady-state accuracy, good dynamic performance and strong anti-jamming ability.
【作者单位】：煤矿电气设备与智能控制山西省重点实验室(太原理工大学);
【基金】：国家自然科学基金项目(U1510112,51577123) 山西省留学归国人员择优资助重点项目(2015)~~
【分类号】：TM464

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