Abstract：LCL filter is more and more widely used in PWM converter connected to the grid for its good filter performance. However, it can easily cause the system unstable due to resonances in the underdamping, which make it difficult to maintain the system stable without additional damping. The influence of the AC-side current sampling point and sampling frequency on the stability of current loop is systematically studied based on the mathematical model of the three-phase PWM converter with undamped LCL filter, and then a novel stability control strategy is proposed i.e. amplitude frequency characteristic and phase frequency of control object are improved by regulating sampling frequency to control phase-lag of digital system delay so as to achieve system stability. Simulation and experimental results effectively verify its validity and feasibility.
李军, 李玉玲, 陈国柱. 无阻尼LCL滤波器的并网变流器稳定性控制策略[J]. 电工技术学报, 2012, 27(4): 110-116.
Li Jun, Li Yuling, Chen Guozhu. A Stability Control Strategy for PWM Converter With Undamped LCL-Filter. Transactions of China Electrotechnical Society, 2012, 27(4): 110-116.
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2012, Vol. 27 
