摘要
在分析传统单级单相升压型逆变器固有缺陷的基础上,提出一种单级单相升压型光伏并网逆变系统,并对构成这种系统的附加储能电感旁路开关的电路拓扑、限制储能电感电流的两种开关方式、非线性脉宽调制(pulse width modulation,PWM)单周期控制策略、储能电感电流限定值、一个低频输出周期内的开关状态等效电路和工作模式、主要电路参数设计、系统建模分析等技术进行深入的理论分析,获得了研究结论。附加的旁路开关及其两种开关方式解决了储能电感能量过剩的问题,有效降低了储能电感及其电流;非线性PWM单周期控制策略,是通过采样并反馈逆变桥输出电流实时地调节逆变器的馈能占空比,使逆变桥输出电流在每个开关周期的平均值跟踪基准正弦信号以获得高质量的并网电流波形。设计并研制的1k VA 110V/DC-220V/50Hz样机实验结果证实了所提出拓扑和控制策略的可行性,为单级升压中小容量并网逆变场合提供了一种有效方法。
Based on the analysis of the inherent defects of the traditional single-stage single-phase boost mode inverter, this paper proposed a novel single-stage single-phase boost mode of photovoltaic （PV） grid-connected power generating systems. The technologies such as circuit topologies with an additional energy storage inductance bypass switch, two kinds of switching modes with energy storage inductance current limited, the nonlinear PWM one-cycle control strategy, energy storage inductance current limits, the switch state equivalent circuit and operating modes within one low frequency output period, design of main circuit parameters, system modeling analysis were carried on the thorough theoretical analysis, and the research conclusions were obtained. The additional bypass switch and its two kinds of switching methods solve the problem of too much energy of the energy storage inductor and decrease effectively the value of the energy storage inductor and its current. Through sampling and feeding back the inverting bridge modulation currents in real-time, the nonlinear PWM one-cycle control strategy adjusts the regenerating energy duty ratio of the inverter, which makes the average value of the output current of the inverter bridge in each switching period to track the reference sinusoidal signal in order to obtain high quality grid-connected current waveforms. The experimental results of the designed and developed lkVA 110V/DC-220V/50Hz prototype have conformed the feasibility of the proposed topology and control strategy, which provides an effective method for single-stage boost medium and small capacity grid-connected power generating fields.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2017年第17期5086-5097,共12页
Proceedings of the CSEE
基金
国家自然科学基金重点项目(51537001)~~
关键词
单相并网逆变系统
光伏
升压型
单级
非线性PWM单周期控制
single-phase grid-connected inverter system
photovoltaic （PV）
Boost mode
single stage
nonlinear PWM one-cycle control
