摘要
在建立无阻尼LCL滤波器的三相电压型PWM变流器数学模型的基础上,系统地研究了电流采样频率和采样点位置对电流环稳定性的影响,并提出了一种稳定控制新策略,即通过调节采样频率控制系统的数字延时来改善系统的频率特性,从而使系统获得稳定;仿真和实验均有效验证了这种控制策略的正确性和可行性。
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.
出处
《电工技术学报》
EI
CSCD
北大核心
2012年第4期110-116,共7页
Transactions of China Electrotechnical Society
基金
教育部新世纪人才资助计划(060512)
国家自然科学基金(50707030)资助项目
