A New Feedback Method for PR Current Control of LCL-Filter-Based Grid-Connected Inverter
A New Feedback Method for PR Current Control of LCL-Filter-Based Grid-Connected Inverter
复制标题
LCL滤波器并网逆变器PR电流控制新反馈方法
DOI：
10.1109/tie.2010.2040552
复制
发表时间：
2010-06-01
影响因子：
7.7
通讯作者：
Xu, Dehong
中科院分区：
文献类型：
--
作者：
Shen, Guoqiao;Zhu, Xuancai;Xu, Dehong
对于带LCL滤波器的并网变换器，比例谐振控制器的谐波补偿器在被补偿频率超出系统控制环带宽时，由于系统不稳定，谐波补偿器通常局限于几个低阶电流谐波。本文提出了一种新的电流反馈控制方法。通过LCL滤波器的两个电感的电流的加权平均值被用作电流PR调节器的反馈。因此，带LCL滤波器的控制系统由三阶函数退化为一阶函数。可以选择较大的比例控制环增益以获得较宽的控制环带宽，并且可以轻松地对系统进行优化，以实现最小的电流谐波畸变和系统稳定性。对采用该控制器的逆变系统进行了研究，并与采用传统控制方法的逆变系统进行了比较。给出了5kw燃料电池逆变器的实验结果，验证了该电流控制策略的有效性。
For a grid-connected converter with an LCL filter, the harmonic compensators of a proportional-resonant (PR) controller are usually limited to several low-order current harmonics due to system instability when the compensated frequency is out of the bandwidth of the system control loop. In this paper, a new current feedback method for PR current control is proposed. The weighted average value of the currents flowing through the two inductors of the LCL filter is used as the feedback to the current PR regulator. Consequently, the control system with the LCL filter is degraded from a third-order function to a first-order one. A large proportional control-loop gain can be chosen to obtain a wide control-loop bandwidth, and the system can be optimized easily for minimum current harmonic distortions, as well as system stability. The inverter system with the proposed controller is investigated and compared with those using traditional control methods. Experimental results on a 5-kW fuel-cell inverter are provided, and the new current control strategy has been verified.