单相光伏扬水系统优化控制研究

Research of Optimization Control for Single Phase Photovoltaic Pumping System

太阳能是新能源领域最具潜力的可再生能源,光伏扬水是太阳能最具应用潜力的领域之一。迄今为止,工作效率低、稳定性差是制约其推广的主要瓶颈。提出了一种前馈+反馈的双环路控制器结构和基于变步长扰动观察法+常压法的MPPT算法与调压调速相结合的控制策略。结果表明使用这种结构和控制策略的光伏扬水系统可有效提高系统的工作效率和稳定性。论文详细介绍了系统组成,给出了各主要结构参数设计过程,描述了提高效率及稳定性方法,即在光照和温度剧烈变化时,前馈环路快速检测出光伏电池板功率变化,反馈环路及时消除水泵转速误差,有效抑制系统振荡,双环路复合控制器能快速跟踪系统参数变化,使系统始终工作在最大功率点上。

Solar energy is the most promising renewable energy,and a photovoltaic pumping system is one of the most potential fields of the applications. Up to now,low efficiency and poor stability have been the uppermost ＂bottle neck＂of a serious hindrance to its generalization. An architecture of feed-forward plus feed-back double loop controller and a control strategy of combining an MPPT algorithm of variable step PO plus CVT with speed and voltage regulation are proposed. Tests show that the photovoltaic pumping system based on the controller and control strategy can effectively raise its operation efficiency and stability. In this paper,the composition of the system is presented,the design of the main structure parameters is given,and the means of increasing efficiency and stability of the system is described in detail. That is,when the illumination and temperature change violently,the feed-forward loop quickly detects the power change of PV cell panels,the feedback loop timely eliminates the speed error and effectively suppresses the oscillations,and the double loop compound controller quickly tracks the change of the system parameters so that the system always operates at the maximum power point（ MPP）.