为了增强对不平衡电网的适应能力，提出一种适用于LCL型并网变流器的滑模电流控制策略.建立了电流内环及电压外环的滑模控制方程，采用指数趋近率的设计方法改善滑模动态品质与系统抖振，根据扩展瞬时功率理论计算参考电流指令，在实现三相并网电流呈正弦波形变化的同时，消除了并网有功功率和扩展无功功率的2倍频波动.同时，搭建了基于RT-LAB软件的硬件在环实验控制平台，通过对比实验验证了所提滑模控制算法的正确性，及其在动态响应速度和抗参数扰动方面的优越性.
In order to strengthen the ability in adopting unbalanced grid voltage, a sliding-mode control strategy of current for grid-connected converter with an LCL filter was proposed, and the sliding-mode governing equations of inner current loop and outer voltage loop were established, respectively. Dynamic quality and chattering effect of the designed sliding-mode controller were improved by using exponential rate control method. The referenced current was generated based on extended instantaneous power theory, and the objective of three-phase sinusoidal current was achieved while the second frequency fluctuation in both active and extended reactive power were eliminated. Finally, hardware-in-loop experimental platform based on RT-LAB was built. Results of comparative experiment demonstrated the correctness of proposed algorithm, as well as the excellent properties in dynamic response speed and parameter robustness.
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