随着可再生能源并网发电技术的发展,大功率并网逆变器控制技术成为人们研究的热点方向。本文在分析了传统光伏并网逆变器的控制技术研究现状的基础上,设计了基于LCL滤波器的三相并网逆变器的双闭环控制策略。
本文对LCL型滤波器进行了研究,在滤波电感量相对较小的情况下,其对电流中高频谐波分量的抑制效果明显好于L型和LC型滤波器,这一优势可以提高大功率并网逆变器系统的动态性能,降低系统成本和减少损耗。LCL型滤波器容易发生谐振,会造成系统的不稳定。在电容上串联电阻能提高系统稳定性但会产生功率损耗,而采用虚拟阻抗控制算法复杂,成本较高,难以实现。本文研究设计了并网电感电流作为外环和电容电流作为内环的电流双闭环控制策略,即用电感电流外环直流控制并网电流及其功率因数,通过电容电流内环增加系统的阻尼以抑制系统谐振。实验结果表明该控制策略使系统具有良好的动静态特性,而且易于实现也使系统损耗相对减少。本文还对带LCL型滤波器的三相并网逆变器系统进行了建模及稳定性分析,并利用Matlab仿真进行了理论分析。
本文采用数字信号处理器(Digital Signal Processing)TMS320F...
【英文摘要】
With the development of renewable-energy generating , the control technology of high-power grid-connected inverter has been become a hot research direction. In this paper, a dual-loop control strategy of three-phase grid-connented inverter with LCL filter is designed based on analyzing the traditional control technology of the photovoltaic grid-connected inverter.
In this paper, LCL filter is analyzed that LCL filter has better performance in high-frequency harmonics suppression with less indu...