作者:马陈成，於锋，吴晓新，茅靖峰

Authors:MA Chen cheng,YU Feng,WU Xiao xin,MAO Jing feng
摘要:在单相反激光伏微型逆变器中 ,传统断续电流控制策略存在并网电流与电网电压相位延迟大、谐波高等缺点 。针对上述问题 ,提出一种计及时滞的单相反激光伏并网控制策略 。首先 ,建立微型逆变器小信号模型 ,提取并网电流模型中的稳态分量与瞬态分量 ,其中稳态分量用于计算主开关管的稳态占空比 , 同时采用准比例谐振 控制器对系统瞬态分量进行闭环控制 ,获取主开关管的瞬态占空比 ,两态占空比叠加得到主开关管的导通占空比 ; 然后 ,针对微处理器数据采集、数值运算过程中引起的控制信号时间滞后问题 ,设计权重传递函数对其进行补偿 , 使并网电流与电网电压之间相位差达最小 ,保证微型逆变器的稳定性 ;最后 ,搭建 150W 实验样机验证控制策略的可行性。
Abstract:In terms of the single-phase flyback photovoltaic micro-inverters, the traditional discontinuous current mode algorithm takes the disadvantages of large phase delay between the grid-connected current and voltage, and high harmonics of grid-connected current. Therefore, this paper proposes a grid-connected control strategy with a lag-time compensation technique for the single-phase flyback inverter. First, the small signal model of the system is established to obtain the two components in the grid-connected current model, namely, steady-state quantity and transient quantity. Out of them, the steady-state quantity is responsible for calculating the steady-state duty cycle, while the transient quantity is for the transient duty cycle. The final duty cycle applied to the inverter is the superposition of the two duty cycles. Thereafter, in order to compensate the lag-time problem of control signal owing to the data acquisition and numerical calculation, a weighted transfer function is designed to minimize the phase difference between the output grid- connected current and the grid voltage, thus ensuring the high stability of the single-phase flyback micro-inverter. Finally, the tests based on the 150 W experimental prototype verify the effectiveness of the proposed method.

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