中文摘要：

针对在交流电子负载采用传统L滤波器并网时开关频率附近的高次谐波衰减的不足提出了采用LCL滤波器并网,为减少LCL滤波器对系统稳定性的影响,对LCL滤波器自身存在谐振问题进行分析,深入研究了采用LCL滤波器的并网变换器电流控制策略,在检测网侧电流的电流环中引入滤波电容电流反馈的控制算法代替阻尼电阻的作用,可以改变系统极点分布,有效地抑制谐振,增加系统的稳定性,并研究了系统稳定时控制参数需满足的条件。仿真及实验结果表明,采用LCL滤波器并网时可以有效减少交流电子负载并网输出电流的高次谐波含量,而引入滤波电容电流反馈控制策略是一种简单、可行抑制LCL谐振的方法。

英文摘要：

For better attenuating current harmonics around switching frequency of PWM rectifier injecting to the grid, the simple inductance L-filter is substituted by LCL-filter connected to the grid in the AC electronic load. However, because of the resonance phenomenon of LCL-filter, it may bring stability problems in the current loop. In order to overcome them, a control strategy using the filter-capacitor feedback in the current loop was proposed to achieve the function of damping resistor. First, the frequency responses of the transfer functions models and stability conditions were analyzed. Then the control strategy was studied through simulation and experiment tests. The resuits show that LCL-filter is more effective to reduce the switching frequency pollution emitting in the grid, and the proposed control strategy is feasible to solve the resonance problem of the LCL-filter.