摘要
滞环控制是一种应用较为广泛的电流跟踪控制,在三相光伏并网逆变器系统的设计中,控制策略常采用电流滞环控制。这种控制方式存在的主要问题是开关频率不固定、电流谐波较大。针对该问题提出了一种模糊滞环宽度控制的方法。通过研究开关频率和滞环宽度之间的关系,建立模糊规则,动态地调节滞环比较器的宽度,从而达到稳定开关频率的目的。MATLAB建模仿真表明该方法与传统固定滞环环宽的方法相比,具有跟踪电流谐波含量小,跟踪精度高和响应速度快等优点,同时可有效地降低最大开关频率,保证系统装置运行的可靠性。
Hysteresis control is a control mode of current tracking control, which is widely used in three-phase PV grid-connected inverter system. The main shortcomings are inconstant in the switching frequency and big harmonics of the current. A proposal of a fuzzy hysteresis bandwidth control approach is made for the problems, in which the fuzzy rules are made to regulate the width of the hysteresis dynamically, thus stabilizing the switching frequency by investigating the relationship between switching frequency and hysteresis bandwidth. Modeling and simulation on the MATLAB/Simulink platform show that the method is characterized by small harmonics and high precise in the tracking current and fast response speed contrast to that of the constant bandwidth of hysteresis control, and also maximum switching frequency can be reduced effectively, thus assuring the reliability of the operation of the equipments.
出处
《电测与仪表》
北大核心
2012年第9期38-42,共5页
Electrical Measurement & Instrumentation
基金
广西省自然科学基金资助项目(2010GXNSFA013023)
广西省研究生教育创新计划资助项目(GXU11T32517)
关键词
三相光伏并网逆变器
滞环电流控制
开关频率
模糊控制
three-phase grid-connected inverter, hysteresis current control, switch frequency, fuzzy control
