| 摘要: |
| 对动态电压恢复器中常用的软件锁相环进行了研究， 针对三相不平衡情况下负序分量对锁相环检测精度的影响，提出了基于数学形态滤波器的软件锁相环。通过选取适当的结构元素，结合形态学的基本运算，设计出低通形态滤波器来抑制由负序分量转换而来的2次谐波，提高锁相环的抗干扰能力和检测精度。理论分析和仿真实验都验证了其可行性，结果表明该方法能够大幅衰减负序分量的干扰，形态滤波器运算简单、速度快，能够很好地满足锁相环检测的要求。 |
| 关键词: 动态电压恢复器 锁相环 滤波器 三相不平衡 |
| DOI： |
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| Soft PLL technique of dynamic voltage restorer |
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YANG Xinhua1,2, GUO Zhicheng1
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1.College of Electric and Information Engineering，Lanzhou University of Technology，Lanzhou 730050，China;2.Key Laboratory of Gansu Advanced Control for Industrial Processes，Lanzhou University of Technology，Lanzhou 730050，China
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| Abstract: |
| he soft PLL（Phase Locked Loop） widely used in the dynamic voltage restorer is studied. To avoid the impact of the negative sequence component on the accuracy of PLL under three-phase unbalance condition，a soft PLL based on the mathematical morphology filter is presented，which selects the appropriate morphologic structure elements and combines with the proper morphologic operators to design a low-pass morphological filter for restraining the second harmonic produced by the negative sequence component and improving the detection accuracy and anti-interference ability of PLL. Theoretical analysis and experimental results prove that，the interference is substantially attenuated and the operation of morphological filter is simple and fast，meeting the requirements of PLL detection. |
| Key words: dynamic voltage restorer phase locked loops electric filters three-phase unbalance |
